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SAMHD1 is a deoxynucleoside triphosphate triphosphohydrolase (dNTPase) that restricts viral replication in infected cells and limits the sensitivity to cytarabine by hydrolysing its active metabolite, as recently shown in acute myeloid leukemia. Cytarabine is an essential component in the Nordic mantle cell lymphoma protocols (MCL2 and MCL3) for induction and high-dose chemotherapy treatment before autologous stem cell transplantation for younger patients with mantle cell lymphoma (MCL). We here investigated the expression of SAMHD1 in a population-based cohort of MCL (N = 150). SAMHD1 was highly variably expressed in MCL (range, 0.4% to 100% of positive tumor cells). Cases with blastoid/pleomorphic morphology had higher SAMHD1 expression (P = 0.028) and SAMHD1 was also correlated to tumor cell proliferation (P = 0.016). SAMHD1 expression showed moderate correlation to the expression of the transcriptional regulator SOX11 (P = 0.036) but genetic silencing of SOX11 and SAMHD1 by siRNA in MCL cell lines did not suggest mutual regulation. We hypothesized that expression of SAMHD1 could predict short time to progression in patients treated with Cytarabine as part of high-dose chemotherapy. Despite the correlation with known biological adverse prognostic factors, neither low or high SAMHD1 expression correlated to PFS or OS in patients treated according to the Nordic MCL2 or MCL3 protocols (N = 158).

Rituximab monotherapy is widely used for follicular lymphoma. However, there are no established predictors for response or response duration. We analyzed the long-term prognostic relevance of pre-treatment absolute blood counts of lymphocytes with subsets and monocytes in 265 follicular lymphoma patients, uniformly treated with rituximab without chemotherapy, in two Nordic Lymphoma Group trials. There were 265 previously untreated, stage II–IV follicular lymphoma patients with a median follow-up of over 10 years. Absolute B cell counts ≥ median (0.09 × 109/L) were an independent predictor for shorter time to next treatment or death (multivariable analysis P = 0.010). In univariate analysis, absolute monocyte counts ≥ median (0.5 × 109/L) did not correlate with time to next treatment or death, but with inferior overall survival (P = 0.034). Absolute T cell or T cell subset counts were not predictive for outcome. High absolute B cell counts, possibly reflecting circulating lymphoma cells, have an unfavorable impact on time to next treatment or death in patients treated with rituximab without chemotherapy.

Diffuse large B-cell lymphoma (DLBCL) incidence rises with increasing age. Rituximab-anthracycline-based regimens offer a potential cure but also risks of adverse events, especially in the elderly. Using Swedish registers, we conducted a nationwide, population-based study of DLBCL in the very elderly. We obtained information on clinical characteristics, residence, comorbidity, therapy and survival for the 1194 patients aged ≥80 years diagnosed in Sweden 2007-2014. To address selection bias, we also investigated treatment differences between Sweden's Healthcare Regions and whether there were survival differences between the Regions. The 2-year overall and relative survivals were better in patients aged ≥80 years given treatment with curative intent (54%; 64%) than low-intensity (26%; 33%), or palliative treatment (6%; 7%). The fraction of patients treated with curative intent varied between the Healthcare Regions (45-76%). Survival was significantly inferior in Regions with few patients treated with curative intent (multivariable hazard ratio 1.3, 95% confidence interval 1.1-1.6). When treatment intensity and Regions competed, Regions were no longer independent, suggesting that Regional survival differences are due to therapeutic differences. Furthermore, we found that the age-adjusted International Prognostic Index was independently associated with survival. We conclude that patients aged ≥80 years with DLBCL appear to benefit from rituximab-anthracycline-based treatment given with curative intent.

Patients with high-risk aggressive B-cell lymphoma exhibit poor survival after R-CHOP. More intensive regimens yield higher rates of remission but also of complication. We investigated all 401 patients 70 years with high-risk (age-adjusted [aa] international prognostic index [IPI] ≥2, extranodal, or bulky) aggressive B-cell lymphoma hospitalized at Karolinska for urgent start of immunochemotherapy (129 R-Hyper-CVAD; 261 R-CHOP/R-CHOEP). Patients showed IPI 3-5 (70%), WHO PS ≥2 (49%), bulky disease (70%), extranodal (75%) and CNS (8%) involvement. Five-year overall/progression-free survival (OS/PFS) was better in patients who started R-Hyper-CVAD (84%/77%) compared with R-CHOP/R-CHOEP (66%/55%). Differences were independent in multivariable analysis, seen in all patient categories, and accentuated in extreme high-risk disease: R-Hyper-CVAD vs. R-CHOP/R-CHOEP showed 5-year PFS 69% vs.40% in aaIPI 3 and 88% vs. 38% in CNS involvement. For validation, survival was compared between the two Karolinska sites and calendar periods. Survival was superior 2006-2010 at the site that introduced R-Hyper-CVAD/R-MA 2006, identical at both sites 2011-2017 after the other site adopted R-Hyper-CVAD/R-MA 2011, and excellent 2018-2020 when R-Hyper-CVAD/R-MA use increased to 75% of patients. Despite considerable toxicity, also patients aged 61-69 years showed better survival with R-Hyper-CVAD/R-MA. This is the largest single-centre series of patients treated with R-Hyper-CVAD/R-MA, showing favourable outcome in high-risk aggressive B-cell lymphoma.

The SAKK 35/10 phase 2 trial, developed by the Swiss Group for Clinical Cancer Research and the Nordic Lymphoma Group, compared the activity of rituximab vs rituximab plus lenalidomide in untreated follicular lymphoma patients in need of systemic therapy. Patients were randomized to rituximab (375 mg/m2 IV on day 1 of weeks 1-4 and repeated during weeks 12-15 in responding patients) or rituximab (same schedule) in combination with lenalidomide (15 mg orally daily for 18 weeks). Primary end point was complete response (CR)/unconfirmed CR (CRu) rate at 6 months. In total, 77 patients were allocated to rituximab monotherapy and 77 to the combination (47% poor-risk Follicular Lymphoma International Prognostic Index score in each arm). A significantly higher CR/CRu rate at 6 months was documented in the combination arm by the investigators (36%; 95% confidence interval [CI], 26%-48% vs 25%; 95% CI, 16%-36%) and confirmed by an independent response review of computed tomography scans only (61%; 95% CI, 49%-72% vs 36%; 95% CI, 26%-48%). After a median follow-up of 4 years, significantly higher 30-month CR/CRu rates and longer progression-free survival (PFS) and time to next treatment (TTNT) were observed for the combination. Overall survival (OS) rates were similar in both arms (≥90%). Toxicity grade ≥3 was more common in the combination arm (56% vs 22% of patients), mainly represented by neutropenia (23% vs 7%). Addition of lenalidomide to rituximab significantly improved CR/CRu rates, PFS, and TTNT, with expected higher, but manageable toxicity. The excellent OS in both arms suggests that chemotherapy-free strategies should be further explored. This trial was registered at www.clinicaltrials.gov as #NCT01307605.

Background Autologous stem-cell transplantation (ASCT) is a common treatment for lymphoma but it has some mortality. Methods All 433 lymphoma patients who underwent ASCT for lymphoma at Karolinska Huddinge 1994–2016 were investigated, including CD34+ cell amounts, medications, infectious and other complications, intensive care, longitudinal laboratory values, and secondary myeloid neoplasia. Results The 100-day non-relapse and overall mortalities were 5.6% and 7.2%. Stem-cell harvests

Mantle cell lymphoma (MCL), a malignancy of B-lymphocytes, has a poor prognosis. It is thus necessary to improve the understanding of the pathobiology of MCL and identify factors contributing to its aggressiveness. Our studies, based on Affymetrix data from 17 MCL biopsies, real-time quantitative polymerase chain reaction data from 18 sorted primary MCL cells and 108 MCL biopsies compared to non-malignant tissue, reveals that GNAZ expression predicts poor clinical outcome of MCL patients (Cox regression, P = 0·014) and lymphocytosis (Mann-Whitney, P = 0·011). We show that GNAZ translates to Gαz protein - a signalling molecule within the G-protein coupled receptor network. Our findings suggest that GNAZ/Gαz contribute to the MCL pathobiology.

We performed a national population-based study of all patients diagnosed with diffuse large B-cell lymphoma (DLBCL) in Sweden in 2007–2014 to assess treatment intent and risk of relapsed/refractory disease, including central nervous system (CNS) relapse, in the presence of competing risks. Overall, 84% of patients started treatment with curative intent (anthracycline-based) (n = 3550, median age 69 years), whereas 14% did not (n = 594, median age 84 years) (for 2% the intent was uncertain). Patients treated with curative intent had a 5-year OS of 65.3% (95% CI: 63.7–66.9). The median OS among non-curatively treated patients was 2.9 months. The 5-year cumulative incidence of relapsed/refractory disease in curative patients was 23.1% (95% CI: 21.7–24.6, n = 847). The 2-year cumulative incidence of CNS relapse was 3.0% (95% CI: 2.5–3.6, n = 118) overall, and 8.0% (95% CI: 6.0–10.6, n = 48) among patients with high CNS-IPI (4–6), when considering other relapse locations and death as competing events. The incidence of relapsed/refractory DLBCL overall and in the CNS was lower than in previous reports, still one in seven patients was not considered fit enough to start standard immunochemotherapy at diagnosis. These results are important for quantification of groups of DLBCL patients with poor prognosis requiring completely different types of interventions.

Mechanisms for late-onset neutropenia (LON) after rituximab treatment are poorly defined both for non-Hodgkin lymphoma (NHL) and for autoimmune disorders. We performed a case–control analysis of a prospective cohort of 169 evaluable consecutive rituximab-treated NHL patients to assess cytokines involved in neutro- and lymphopoiesis (G-CSF, SDF1, BAFF, APRIL) and inflammation (CRP) as possible LON mechanisms. Fifteen patients (9%) developed LON (peripheral blood /PB/ absolute neutrophil counts /ANC/

Background Chimeric antigen-receptor T-cell and bispecific antibody therapies will likely necessitate a reconsideration of the role of autologous stem-cell transplantation (ASCT) in lymphoma. Patients who are likely to profit from ASCT need to be better identified. Methods Here, we investigated the value of positron emission tomography/computerized tomography (PET/CT) before ASCT. All 521 patients transplanted for lymphoma 1994–2019 at Karolinska (497 conditioned with BEAM) were included. Results Outcome improved over three calendar periods 1994–2004, 2005–2014, 2015–2019 (2-year overall survival [OS]: 66, 73, 83%; P = 0.018). Non-relapse mortality (NRM) at 100 days over the three periods were 9.8, 3.9, 2.9%, respectively. The OS improvement between 1994 and 2004 and 2005–2014 was due to lower NRM (P = 0.027), but the large OS advance from 2015 was not accompanied by a significant reduction in NRM (P = 0.6). The fraction of PET/CT as pre-ASCT assessment also increased over time: 1994–2004, 2%; 2005–2014, 24%; 2015–2019, 60% (P P = 0.0003), also in the subpopulations of aggressive B-cell (P = 0.004) and peripheral T-cell (P = 0.024) lymphomas. Two-year OS and progression-free survival (OS/PFS) for patients in PET/CT-CR were in relapsed/refractory aggressive B-cell lymphoma 87%/75% and peripheral T-cell lymphoma 91%/78%. The corresponding figures in PET/CT-PR were 43%/44 and 33%/33%. Patients with solitary PET/CT-positive lesions showed acceptable outcome with ASCT followed by local irradiation (2-year OS/PFS 80%/60%). CT was less discriminative: 2-year OS/PFS: CT-CR, 76%/66%; CT-PR, 62%/51%. Outcome was inferior after BEAC compared with BEAM conditioning. Conclusions We conclude that the improved outcome reflects better, PET/CT-informed, identification of patients who should proceed to ASCT. The excellent survival of patients in PET/CT-CR indicates that ASCT should remain part of standard therapy for lymphoma.

Bruton tyrosine kinase (BTK) inhibition is an effective treatment approach for patients with Waldenström macroglobulinemia (WM). The phase 3 ASPEN study compared the efficacy and safety of ibrutinib, a first-generation BTK inhibitor, with zanubrutinib, a novel highly selective BTK inhibitor, in patients with WM. Patients with MYD88L265P disease were randomly assigned 1:1 to treatment with ibrutinib or zanubrutinib. The primary end point was the proportion of patients achieving a complete response (CR) or a very good partial response (VGPR) by independent review. Key secondary end points included major response rate (MRR), progression-free survival (PFS), duration of response (DOR), disease burden, and safety. A total of 201 patients were randomized, and 199 received ≥1 dose of study treatment. No patient achieved a CR. Twenty-nine (28%) zanubrutinib patients and 19 (19%) ibrutinib patients achieved a VGPR, a nonstatistically significant difference (P = .09). MRRs were 77% and 78%, respectively. Median DOR and PFS were not reached; 84% and 85% of ibrutinib and zanubrutinib patients were progression free at 18 months. Atrial fibrillation, contusion, diarrhea, peripheral edema, hemorrhage, muscle spasms, and pneumonia, as well as adverse events leading to treatment discontinuation, were less common among zanubrutinib recipients. Incidence of neutropenia was higher with zanubrutinib, although grade ≥3 infection rates were similar in both arms (1.2 and 1.1 events per 100 person-months). These results demonstrate that zanubrutinib and ibrutinib are highly effective in the treatment of WM, but zanubrutinib treatment was associated with a trend toward better response quality and less toxicity, particularly cardiovascular toxicity.

Plerixafor + granulocyte-colony stimulating factor (G-CSF) is administered to patients with lymphoma who are poor mobilizers of hematopoietic stem cells (HSCs) in Europe. This international, multicenter, non-interventional registry study (NCT01362972) evaluated long-term follow-up of patients with lymphoma who received plerixafor for HSC mobilization versus other mobilization methods. Propensity score matching was conducted to balance baseline characteristics between comparison groups. The following mobilization regimens were compared: G-CSF + plerixafor (G + P) versus G-CSF alone; G + P versus G-CSF + chemotherapy (G + C); and G-CSF + plerixafor + chemotherapy (G + P + C) versus G + C. The primary outcomes were progression-free survival (PFS), overall survival (OS), and cumulative incidence of relapse (CIR). Overall, 313/3749 (8.3%) eligible patients were mobilized with plerixafor-containing regimens. After propensity score matching, 70 versus 36 patients were matched in the G + P versus G-CSF alone cohort, 124 versus 124 in the G + P versus G + C cohort, and 130 versus 130 in the G + P + C versus G + C cohort. For both PFS and OS, the upper bound of confidence interval for the hazard ratio was >1.3 for all comparisons, implying that non-inferiority was not demonstrated. No major differences in PFS, OS, and CIR were observed between the plerixafor and comparison groups.

Follicular lymphoma (FL) is a heterogeneous disease; therefore, reliable prognostic tools are needed to plan treatment strategies. The FL International Prognostic Index (FLIPI) was developed before the rituximab era, while the PRIMA-PI was built on rituximab chemotherapy. Our objective was to evaluate these two prognostic tools in a cohort of 291 patients with FL treated in two prospective randomised Nordic Lymphoma Group trials with rituximab +/- interferon. All patients had symptomatic/progressive disease and were previously untreated. The PRIMA-PI was prognostic for both time to treatment failure (TTF) and overall survival (OS) (log-rank P = 0 center dot 003 and P < 0 center dot 001, respectively). The PRIMA-PI high-risk identified a small group of patients with a very short TTF and OS compared to the low-risk group, with a hazard ratio (HR) of 1 center dot 90 (95% confidence interval [CI] 1 center dot 30-2 center dot 78, P = 0 center dot 001) and HR of 3 center dot 19 (95% CI 1 center dot 75-5 center dot 83, P < 0 center dot 001), respectively. The FLIPI risk groups were prognostic only for OS (log-rank P = 0 center dot 018). The simplified PRIMA-PI was valid in our FL cohort with first-line rituximab-containing chemo-free therapy and shows an improved risk stratification compared to the FLIPI, especially in patients aged >60 years. Patients in the PRIMA-PI high-risk group should be considered for alternative therapies.

Purpose: To evaluate the safety, efficacy, and immunobiological correlates of allogeneic NK-cell–based therapy in primary chemotherapy-refractory or relapsed high-risk myelodysplastic syndrome (MDS), secondary AML (MDS/AML), and de novo AML patients. Experimental Design: Sixteen patients received fludarabine/cyclophosphamide conditioning combined with total lymphoid irradiation followed by adoptive immunotherapy with IL2–activated haploidentical NK cells. Results: NK-cell infusions were well-tolerated, with only transient adverse events observed in the 16 patients. Six patients achieved objective responses with complete remission (CR), marrow CR, or partial remission (PR). Five patients proceeded to allogeneic hematopoietic stem cell transplantation (HSCT). Three patients are still free from disease >3 years after treatment. All evaluable patients with objective responses (5/5 evaluable) had detectable donor NK cells at days 7/14 following infusion and displayed reduction of tumor cell clones, some of which carried poor prognosis mutations. Residual lin−CD34+CD123+CD45RA+ blast cells in responders had increased total HLA class I and HLA-E expression. Responding patients displayed less pronounced activation of CD8+ T cells and lower levels of inflammatory cytokines following NK-cell infusion. Intriguingly, despite omission of systemic IL2, all patients displayed increased frequencies of activated Ki-67+CD127−FoxP3+CD25hiCD4+ Treg cells of recipient origin following NK-cell therapy. Conclusions: Overall, this study suggests that high-risk MDS is responsive to NK-cell therapy and supports the use of haploidentical NK-cell infusions as a bridge to HSCT in refractory patients. Objective clinical responses and reduction of high-risk clones were associated with detectable donor-derived NK cells, immunoediting of residual blast cells, and less pronounced host immune activation. Clin Cancer Res; 24(8); 1834–44. ©2018 AACR.

INTRODUCTION Patients with high-risk aggressive B-cell lymphoma exhibit poor survival after R-CHOP-like immunochemotherapy. More intensive regimens yield higher rates of remission but also of complication, which have hindered their use, particularly in older patients. At Karolinska, the standard intensive regimen has been R-Hyper-CVAD/R-MA for patients with high-risk characteristics, such as high age-adjusted international prognostic index (aaIPI) and extranodal disease. METHODS In this analysis, high-risk disease was defined as aaIPI ≥ 2 or any extranodal involvement. We examined Karolinska's 136 patients who received at least one cycle of R-Hyper-CVAD/R-MA in first-line therapy for high-risk disease, excluding Burkitt, transformed, and primary CNS lymphoma. Patients were diagnosed between 2006 and 2020; 89 were diffuse large B-cell lymphoma, 23 high-grade B-cell lymphoma, 17 primary mediastinal B-cell lymphoma, 4 T cell/histiocyte-rich B-cell lymphoma, 2 aggressive B-cell lymphoma unspecified, 1 lymphomatoid granulomatosis grade 3. For outcome, we investigated progression-free survival (PFS). RESULTS In this cohort of 136 patients with high-risk disease treated with at least one cycle of R-Hyper-CVAD/R-MA, the median age was 52 years (range, 19-69); 36 patients (26%) were 61-69 years old. Lactate dehydrogenase was elevated in 92%, stage III-IV disease was seen in 93%, WHO performance status ≥2 in 49%, aaIPI = 3 in 38%, extranodal disease in 30%, CNS involvement in 17%, and Charlson comorbidity index ≥2 in 11%. At 5 years, the PFS in all patients was 72% and in the 50 patients with aaIPI = 3, 66% (Figure 1). In patients ≤60 years old, 5-year PFS was 76% (aaIPI = 3, 69%). In patients 61-69 years, the 5-year PFS was 58% (aaIPI = 3, 59%). Six out of 136 patients (4%) died from toxicity during induction therapy (3/6 were 61-69 years old). CONCLUSIONS This is to our knowledge the largest published single-center series of patients treated with R-Hyper-CVAD/R-MA for high-risk aggressive B-cell lymphoma. Outcome in these patients aged 19-69 years was excellent, with 5-year PFS 72%. Particularly patients with aaIPI = 3 showed rather good outcome with 5-year PFS 66%. For comparison, in Sweden the 5-year overall survival of R-CHOP-treated patients ≤60 years with aaIPI = 3 is 40% (Melén CM et al. Brit J Haematol. 614-622. 2016). We will continue to explore R-Hyper-CVAD/R-MA as primary therapy for high-risk aggressive B-cell lymphoma. Figure 1 Figure 1. Disclosures Wahlin: Gilead Sciences: Research Funding; Roche: Consultancy, Research Funding.

Background: Patients (pts) with relapsed or refractory (R/R) follicular lymphoma (FL) develop increasingly aggressive disease and are at increased risk for histologic transformation, death, or both. The combination of rituximab and lenalidomide (R 2) is a highly effective therapy for pts with R/R FL, but most pts eventually relapse, and better treatment options are needed. Epcoritamab (DuoBody ®-CD3×CD20) is a subcutaneously administered bispecific antibody that binds to CD3 on T cells and CD20 on B cells and induces conditional T-cell-mediated killing of malignant B cells. Single-agent epcoritamab demonstrated manageable safety and substantial antitumor activity in pts with heavily pretreated B-cell non-Hodgkin lymphoma (NHL) in the phase 1/2 EPCORE NHL-1 trial (NCT03625037). Among heavily pretreated pts with R/R FL (median, 5 prior lines of therapy) treated with epcoritamab (dose, 0.76-48 mg), the overall response rate was 90% (9/10), with 50% (5/10) achieving complete response (Hutchings, Lancet, in press). Treatment with R 2 has immunomodulatory properties that may potentiate the activity of epcoritamab, suggesting that combining R 2 with epcoritamab may be beneficial. The encouraging data from the EPCORE NHL-1 trial supported initiation of the EPCORE NHL-2 trial (NCT04663347), a phase 1/2 trial evaluating epcoritamab in combination with various standard of care therapies in pts with B-cell NHL. Herein, we present preliminary results from arm 2 of this trial, which is evaluating epcoritamab in combination with R 2 in pts with R/R FL. Methods: Adults with histologically confirmed R/R CD20+ FL received epcoritamab in a dose-escalation phase followed by an expansion phase at the recommended phase 2 dose in combination with R 2 for 12 cycles (28 days/cycle). Step-up dosing and corticosteroids during cycle 1 were used to mitigate cytokine release syndrome (CRS). Responses were evaluated by position emission tomography-computed tomography per the 2014 Lugano classification criteria. Results: As of June 29, 2021, 16 pts were treated with the combination of epcoritamab + R 2 (3 pts treated with epcoritamab 24 mg and 13 with 48 mg). Five pts completed at least 6 weeks of therapy and were evaluable for efficacy. A median of 3 cycles per pt have been administered. Fourteen (88%) pts remain on treatment. Median age was 68 years (range, 52-81), 10 (63%) pts were female, and 11 (69%) had 1 prior line of therapy (range in all 16 pts, 1-3 prior lines). All pts received prior immunochemotherapy, and 6 (38%) had disease progression ≤2 years after initial treatment (POD24). CRS occurred in 31% of pts (5/16) and all cases were of grade 1/2. The median time to onset of CRS was 15 days (study day 16; range, 5-16) and median time to resolution was 2 days; no pt required tocilizumab. Other adverse events (AEs) reported in >15% of pts were injection-site reaction (25%; 4/16), constipation (19%; 3/16), cough (19%; 3/16), diarrhea (19%; 3/16), and stomatitis (19%; 3/16), all grade 1/2. No immune effector cell-associated neurotoxicity syndrome events or fatal AEs were observed. Five (31%) pts required hospitalization due to 6 serious AEs (grade 1 CRS related to epcoritamab in 3 pts; unrelated grade 2 mania in 1 pt; unrelated grade 3 pneumonia in 1 pt; and unrelated grade 3 atrial flutter). All 5 response-evaluable pts achieved an objective response by week 7, with 4 achieving complete metabolic response. All 5 responders had stage IV disease at baseline, 3 had an FL International Prognostic Index of 4/5, 3 had received >2 prior lines of therapy, and 2 had POD24 with first-line therapy. Conclusions: These data from a small population of pts suggest that epcoritamab can be safely combined with R 2 with a manageable toxicity profile, with no new safety signals or unexpected AEs. The novel chemotherapy-free combination showed encouraging preliminary activity with early responses in all evaluable pts by week 7, including a majority of pts with high-risk features. Enrollment is ongoing. Additional data will be presented. Disclosures Linton: Blood Cancer UK: Research Funding; Genmab: Consultancy, Research Funding; Roche: Consultancy, Honoraria, Research Funding, Speakers Bureau; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Research Funding; Beigene: Research Funding; Aptitude Health: Honoraria, Speakers Bureau; Hartley Taylor: Honoraria, Speakers Bureau; Kite: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Roy Castle Lung Cancer Foundation: Research Funding; Janssen: Other: Travel support. Wahlin: Roche: Consultancy, Research Funding; Gilead Sciences: Research Funding. Leepä: MSD: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; CHO Pharma USA: Consultancy; Orion: Consultancy; Genmab: Research Funding; University of Helsinki and Helsinki University Hospital: Current Employment; Takeda: Research Funding; Bayer: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Nordic Nanovector: Research Funding; Finnish Cancer Organizations: Membership on an entity's Board of Directors or advisory committees. Morschhauser: Chugai: Honoraria; Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech, Inc.: Consultancy; Celgene: Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Incyte: Membership on an entity's Board of Directors or advisory committees; AstraZenenca: Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genmab: Membership on an entity's Board of Directors or advisory committees; Roche: Consultancy, Speakers Bureau; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Servier: Consultancy; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Elliot: Genmab: Current Employment, Patents & Royalties: P158-US-PSP3 . Liu: Genmab: Current Employment. Cota Stirner: AbbVie: Current Employment. Abbas: Genmab: Current Employment. Falchi: Abbvie: Consultancy, Research Funding; Genetech: Research Funding; Roche: Research Funding; Genmab: Consultancy, Research Funding.

Background: Marginal zone lymphoma (MZL) is the third most common lymphoma in Western countries, accounting for 8-12% of non-Hodgkin lymphoma (Delinger NM. Cancer Manag Res. 2018;10:315-24). MZL is categorized into nodal, extranodal, and splenic subtypes. While the relative 5-year survival rate for patients (pts) with MZL is 84.4% (Olszewski AJ, Castillo JJ. Cancer. 2013;119:629-38), pts often experience relapse or refractory (R/R) disease. Parsaclisib is a potent, highly selective, next-generation inhibitor of phosphatidylinositol 3-kinase (PI3K)δ. Here we report results of the primary analysis of the cohort of Bruton's tyrosine kinase (BTK) inhibitor (BTKi)-naive pts with R/R MZL treated with parsaclisib monotherapy in the open-label, phase 2 study CITADEL-204 (NCT03144674, EudraCT 2017-000970-12). Methods: Pts ≥18 years of age, with histologically confirmed MZL, prior receipt of ≥1 line of systemic therapy including anti-CD20 treatment, and either disease progression or inadequate response to most recent regimen were eligible. Pts had an Eastern Cooperative Oncology Group performance status (ECOG PS) ≤2, radiologically measurable lymphadenopathy, lymphoid malignancy (extranodal), or histologically confirmed bone marrow infiltration (splenic). The study enrolled 2 cohorts: pts who received prior treatment with ibrutinib (cohort 1, N=10) or pts naive to BTKi therapy (cohort 2, N=100). Only data from cohort 2 are presented in this abstract. Pts were allocated to receive parsaclisib 20 mg once daily (QD) for 8 weeks followed by either 20 mg once weekly (weekly-dosing group [WG]) or 2.5 mg QD (daily-dosing group [DG]). Pts received prophylaxis for Pneumocystis jirovecii pneumonia during the study. The primary endpoint was objective response rate (ORR) as assessed by an independent review committee (IRC); secondary endpoints were duration of response (DOR), complete response rate (CRR), progression-free survival (PFS), overall survival (OS), and safety and tolerability. All radiology-based endpoints were evaluated by an IRC. Results: At data cutoff for the primary analysis (Jan 15, 2021), 100 pts with MZL enrolled in cohort 2 (nodal 31.0%, extranodal 34.0%, and splenic 35.0%) had been treated (WG, N=28; DG, N=72). Median (range) age was 71.0 (35-95) years, 53.0% were male, and 95.0% had ECOG PS ≤1. 49.0% of pts had received 1 line, 31.0% received 2 lines, and 20.0% received ≥3 lines of prior systemic therapy (median [range], 2.0 [1-8]); 46.0% of pts had relapsed disease and 49.0% were refractory to their most recent prior therapy. 65.0% of pts had discontinued treatment, primarily due to adverse events (29.0%) or progressive disease (28.0%). The median (range) duration of treatment and follow-up from first dose to data cutoff were 13.4 (0.4-30.9) and 22.8 (11.9-37.0) months for all pts (N=100), and 11.6 (0.4-30.9) and 21.0 (11.9-37.0) months for the DG (N=72), respectively. The ORR (95% CI) was 58.0% (47.7-67.8) for all pts and 58.3% (46.1-69.8) for the DG (Table 1); CRR (95% CI) was 6.0% (2.2-12.6) for all pts and 4.2% (0.9-11.7) for the DG. Among all treated pts who achieved complete or partial response, 65.5% of responses occurred at the first disease assessment (median time to response, 8.1 weeks); median DOR (95% CI) was 12.2 (8.1-17.5) months for all pts and the DG. Median PFS (95% CI) was 16.5 (13.5-19.6) and 16.5 (11.5-20.6) months for all pts and the DG, respectively. Median OS was not reached. Among 100 pts treated in cohort 2, treatment-emergent adverse events (TEAEs) occurred in 96.0% of pts (grade ≥3 in 63.0%). The most common TEAEs were diarrhea (47.0%) and cough (23.0%), and the most common grade ≥3 TEAEs included diarrhea (12.0%), neutropenia and pneumonia (9.0% each), and colitis (7.0%). TEAEs leading to dose interruption or dose reduction occurred in 56.0% and 16.0% of pts, respectively. TEAEs led to treatment discontinuation in 29.0% of pts, the most common were diarrhea (9.0%) and colitis (5.0%). Serious TEAEs were experienced by 47.0% of pts overall, the most common was pneumonia (9.0%). 6.0% of pts experienced fatal TEAEs including febrile neutropenia and sepsis (1 pt each) that were considered treatment-related. Conclusion: Pts with R/R MZL demonstrated a rapid and durable clinical response to parsaclisib monotherapy. Treatment was generally well tolerated, and the safety profile was manageable. Results suggest parsaclisib may be a potential treatment option for R/R MZL. Figure 1 Figure 1. Disclosures Phillips: AstraZeneca: Consultancy; ADCT, BeiGene, Bristol Myers Squibb, Cardinal Health, Incyte, Karyopharm, Morphosys, Pharmacyclics, Seattle Genetics: Consultancy; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; BMS: Consultancy, Research Funding; Bayer: Consultancy, Research Funding; AbbVie: Consultancy, Research Funding; Incyte: Consultancy, Other: received travel expenses from Incyte, Research Funding. Avigdor: Pfizer: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; BMS: Research Funding; Janssen: Research Funding; Takeda: Consultancy, Honoraria. Gurion: JC Health CARE; Roche: Honoraria; Medison; Gilead Sciences; Takeda Pharmaceuticals: Consultancy. Corradini: KiowaKirin; Incyte; Daiichi Sankyo; Janssen; F. Hoffman-La Roche; Kite; Servier: Consultancy; AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Honoraria; Amgen; Takeda; AbbVie: Consultancy, Honoraria, Other: Travel and accommodations; Novartis; Gilead; Celgene: Consultancy, Other: Travel and accommodations; BMS: Other: Travel and accommodation; Sanofi: Consultancy, Honoraria; Incyte: Consultancy; AbbVie, ADC Theraputics, Amgen, Celgene, Daiichi Sankyo, Gilead/Kite, GSK, Incyte, Janssen, KyowaKirin, Nerviano Medical Science, Novartis, Roche, Sanofi, Takeda: Consultancy; Novartis, Janssen, Celgene, BMS, Takeda, Gilead/Kite, Amgen, AbbVie: Other: travel and accomodations. Mehta: Seattle Genetics; Incyte; TG Therapeutics: Consultancy; Seattle Genetics; Incyte; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Affirmed; Kite/Gilead; Roche-Genetech; Celgene/BMS; Oncotartis; Innate Pharmaceuticals; Seattle Genetics; Incyte; Takeda; Fortyseven Inc/Gilead; TG Therapeutics; Merck; Juno Pharmaceuticals/Bristol Myers Squibb: Research Funding. Lossos: NIH grants: Research Funding; Verastem: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Lymphoma Research Foundation: Membership on an entity's Board of Directors or advisory committees; University of Miami: Current Employment; NCI: Research Funding; Stanford University: Patents & Royalties; Seattle Genetics: Consultancy. Zinzani: Janssen-Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; EUSA Pharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ImmuneDesign: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Verastem: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; TG Therapeutics Inc: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Servier: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Portola: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BeiGene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck Sharp & Dohme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; ADC Therapeutics: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Kyowa Kirin: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Thieblemont: Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Hospira: Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses , Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses ; Bayer: Honoraria; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses . Jurczak: AbbVie, AstraZeneca, Bayer, BeiGene, Celtrion, Celgene, Debbiopharm, Epizyme, Incyte, Janssen, Loxo Oncology, Merck, Mei Pharma, Morphosys, Novo Nordisk, Roche, Sandoz, Takeda, TG Therapeutics, Pharmacyclics, Affirmed, Gilead Sciences, Nordic Nanovecto: Research Funding; AstraZeneca, BeiGene, Janssen, Loxo Oncology, Sandoz, Roche: Membership on an entity's Board of Directors or advisory committees; Maria Sklodowska-Curie National Research Institute of Oncology: Current Employment; Jagiellonian University: Ended employment in the past 24 months; European Medicines Agency, Sandoz-Novartis, Janssen China R&D, BeiGene, Epizyme, Acerta, AstraZeneca: Consultancy. Zheng: Incyte Corporation: Current Employment, Current equity holder in publicly-traded company. Rappold: Incyte: Current Employment, Current equity holder in publicly-traded company. Zhao: Incyte: Current Employment, Current equity holder in publicly-traded company. Johnson: Epizyme: Consultancy, Research Funding; Boehringer Ingelheim: Consultancy; Bristol-Myers: Honoraria; Celgene: Honoraria; Genmab: Honoraria; Incyte: Honoraria; Kite Pharma: Honoraria; Kymera: Honoraria; Morphosys: Honoraria; Novartis: Honoraria; Takeda: Honoraria; Oncimmune: Consultancy; Janssen: Consultancy. OffLabel Disclosure: Investigational PI3Kdelta inhibitor (parsaclisib) for patients with MZL

Background: CD20 antibody plus alkylator and/or anthracycline based immunochemotherapy (IC) is a standard frontline therapy for patients with follicular lymphoma (FL) with 10-year event-free survival (EFS) and overall survival (OS) rates of approximately 50% and 80% respectively in long-term follow-up of clinical trials. Currently available clinical prognostic indices for FL have been designed using PFS and OS endpoints. Early events, commonly defined as progression of disease within 24 months (POD24) or early transformation to a more aggressive histology, are associated with inferior outcomes and increased risk of death due to refractory FL. Timely identification of the minority of patients with elevated mortality risk might enhance clinical management and research strategies. The FLIPI24 Consortium was created to develop a clinical prognostic index using early events as the primary endpoint. We report the outcomes for the pooled cohort and investigate the implications of therapy patterns on potential model development. Methods: Individual patient data were pooled and harmonized from 11 prospective observational cohorts from Europe, North America, and Australia. Patients who were diagnosed with grades 1-3A FL and initiated frontline IC were eligible. EFS was defined as time from start of IC to progression, relapse, retreatment (2nd line), histologic transformation, or death due to any cause. Early events were defined using status at 24 months from start of IC. OS was defined as time from start of IC to death due to any cause. Kaplan Meier curves and Cox proportional hazards models were used to evaluate outcomes by clinical features and therapy types. Results: 9006 patients were abstracted and harmonized, 6111 patients initiated frontline IC between 2002 and 2018 and were included in this analysis. Median age at diagnosis was 61 years (IQR 52-69) and 50% were male. Complete FLIPI data were available in 5637 patients (92%) and 46%, 32%, and 22% were low, intermediate, and high risk, respectively. IC type was 3079 R-CHOP or like (50%) , 1529 R-CVP or like (25%), 918 R-bendamustine (B-R) or like (15%), and 585 fludarabine or other alkylator based IC (10%); 3187 received CD20 antibody maintenance (52%). Patients receiving R-CHOP were younger, more frequently grade 3A, and more frequently had elevated LDH; differences in other characteristics by IC type were not clinically meaningful. At median follow-up of 42 months (IQR 17-72), 2647 patients (43%) had an event (any) and 1494 patients (25%) died. Median survival after an early (non-death) event was 49 months (95% CI: 41-58); 5-year OS was 46% (95% CI: 43-49) compared to 89% (95% CI: 88-90) in patients without POD24. Across all IC types, EFS estimates at 2 and 10 years from start of IC were 80% (95% CI:79-81) and 49% (95% CI:48-51) and OS estimates were 92% (95% CI: 91-92) and 70% (95% CI: 69-72), respectively. FLIPI was highly associated with both EFS (c-statistic=0.61) and OS (c-statistic=0.65) from the initiation of IC (both p Treatment patterns changed significantly over the study timeframe. Use of B-R and/or maintenance increased to 30% and 70% respectively in N=2937 patients treated in 2010-2018 (Era2) compared to Conclusion: EFS and OS from this large pooled analysis of observational cohorts is similar to long-term follow-up of randomized clinical trials in the IC era and support the use of these data for model development. Modeling efforts for early events should adjust for initial IC selection and use of maintenance therapy. Utilization of bendamustine and/or maintenance therapy increased over the study timeframe from 2002-2018, and Era2 was associated with improved EFS but not OS. This cohort provides comprehensive and robust observational data to define clinical predictors in IC treated patients. Figure 1 Figure 1. Disclosures Maurer: Genentech: Research Funding; Morphosys: Membership on an entity's Board of Directors or advisory committees, Research Funding; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees; Nanostring: Research Funding. Flowers: Janssen: Research Funding; Takeda: Research Funding; National Cancer Institute: Research Funding; Biopharma: Consultancy; BeiGene: Consultancy; Amgen: Research Funding; Celgene: Consultancy, Research Funding; Xencor: Research Funding; Acerta: Research Funding; Bayer: Consultancy, Research Funding; Sanofi: Research Funding; 4D: Research Funding; Adaptimmune: Research Funding; Allogene: Research Funding; EMD: Research Funding; TG Therapeutics: Research Funding; Burroughs Wellcome Fund: Research Funding; Kite: Research Funding; AbbVie: Consultancy, Research Funding; Cellectis: Research Funding; Denovo: Consultancy; Cancer Prevention and Research Institute of Texas: CPRIT Scholar in Cancer Research: Research Funding; Karyopharm: Consultancy; Gilead: Consultancy, Research Funding; Genmab: Consultancy; Epizyme, Inc.: Consultancy; Novartis: Research Funding; Nektar: Research Funding; Morphosys: Research Funding; Iovance: Research Funding; Spectrum: Consultancy; Pfizer: Research Funding; Ziopharm: Research Funding; Guardant: Research Funding; Eastern Cooperative Oncology Group: Research Funding; SeaGen: Consultancy; Pharmacyclics/Janssen: Consultancy; Genentech/Roche: Consultancy, Research Funding; Pharmacyclics: Research Funding. Villa: Janssen: Honoraria; Gilead: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria; Seattle Genetics: Honoraria; Celgene: Honoraria; Lundbeck: Honoraria; Roche: Honoraria; NanoString Technologies: Honoraria. Weibull: Jansen-Cilag: Other: part of a research collaboration between Karolinska Institutet and Janssen Pharmaceutica NV for which Karolinska Institutet has received grant support. Ghesquieres: Janssen: Honoraria; Mundipharma: Consultancy, Honoraria; Roche: Consultancy; Celgene: Consultancy, Honoraria; Gilead Science: Consultancy, Honoraria. Kridel: Gilead Sciences: Research Funding. Gandhi: Janssen: Research Funding; Novartis: Honoraria. Cheah: Celgene: Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: advisory; Loxo/Lilly: Consultancy, Honoraria, Other: advisory; AstraZeneca: Consultancy, Honoraria, Other: advisory; AbbVie: Research Funding; Beigene: Consultancy, Honoraria, Other: advisory; Ascentage pharma: Consultancy, Honoraria, Other: advisory; Gilead: Consultancy, Honoraria, Other: advisory; MSD: Consultancy, Honoraria, Other: advisory, Research Funding; Janssen: Consultancy, Honoraria, Other: advisory; Roche: Consultancy, Honoraria, Other: advisory and travel expenses, Research Funding. Hawkes: Gilead: Membership on an entity's Board of Directors or advisory committees; Merck Sharpe Dohme: Membership on an entity's Board of Directors or advisory committees; Antigene: Membership on an entity's Board of Directors or advisory committees; Regeneron: Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squib/Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck KgA: Research Funding; Specialised Therapeutics: Consultancy; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Roche: Membership on an entity's Board of Directors or advisory committees, Other: Travel and accommodation expenses, Research Funding, Speakers Bureau; Janssen: Speakers Bureau. Seymour: Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sunesis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Mei Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees; Morphosys: Honoraria, Membership on an entity's Board of Directors or advisory committees; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Research Funding, Speakers Bureau. Freeman: Amgen: Honoraria; Celgene: Honoraria; Sanofi: Honoraria, Speakers Bureau; Incyte: Honoraria; Abbvie: Honoraria; Teva: Research Funding; Roche: Research Funding; Janssen: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria; Bristol Myers Squibb: Honoraria, Speakers Bureau. Clausen: Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel expences ASH 2019; Gilead: Consultancy, Other: Travel expences 15th ICML ; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Wahlin: Gilead Sciences: Research Funding; Roche: Consultancy, Research Funding. Link: Novartis, Jannsen: Research Funding; Genentech/Roche: Consultancy, Research Funding; MEI: Consultancy. Ekstroem Smedby: Janssen Cilag: Research Funding; Takeda: Consultancy. Sehn: Genmab: Consultancy; Novartis: Consultancy; Debiopharm: Consultancy. Trněný: Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Portola: Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; 1st Faculty of Medicine, Charles University, General Hospital in Prague: Current Employment; Celgene: Consultancy; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; Amgen: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses; MorphoSys: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria; Gilead Sciences: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Incyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. El-Galaly: ROCHE Ltd: Ended employment in the past 24 months; Abbvie: Other: Speakers fee. Cerhan: Celgene/BMS: Other: Connect Lymphoma Scientific Steering Committee, Research Funding; Regeneron Genetics Center: Other: Research Collaboration; Genentech: Research Funding; NanoString: Research Funding.

Mobilized PBSC are the main source for allogeneic HSCT. We aimed to evaluate factors that affect CD34+ cell yield including the donor's age, gender, BSA, processed blood volume and the method of G-CSF dose calculation. Data from 170 healthy donors were analyzed. The concentration of CD34+ cells in the peripheral blood (PB) and the processed volume of blood were significantly correlated to CD34+ cells yield (P

Purpose: Follicular lymphoma (FL) is generally regarded as an indolent malignancy, yet the clinical outcome is highly variable. In recent years, POD24 (progression of disease within 24 months) has emerged as a potential prognostic marker for overall survival (OS) in FL and other non-Hodgkin lymphomas. The association with survival, however, has mostly been studied in selected clinical trial cohorts and among patients treated with R-CHOP. We aimed to investigate OS by timing of progression and type of primary treatment in a population-based setting in Sweden. Methods: We identified all patients diagnosed with FL in stages II-IV and grade 1-3a between 2007 and 2014, using the population-based Swedish lymphoma register. Data were complemented with information on progression, transformation and second-line treatment through medical charts review up to December 31st, 2017. The analysis covered 4 out of 6 health care regions (75% of all patients diagnosed nationally). The patients were categorized according to type of first-line treatment: R-chemo of any type, R-Benda, R-CHOP (including R-CHOEP), or other (including immunotherapy only). Among patients where it was decided to start first-line treatment within 6 months of diagnosis (and where treatment was started within nine months), POD was defined as either lack of response to first-line therapy (stable [SD] or progressive disease [PD]), or initial response and subsequent relapse/progression/transformation as indication for second-line therapy. To quantify the impact of timing of POD on survival, the five-year OS conditional on either being progression-free (PF) or having experienced POD at different time points during follow-up, was estimated using a flexible parametric illness-death model. Results: Among a total of 970 FL patients, median age at diagnosis was 66 years and patients were followed for a median of 6.4 years (range 0-12 years). The 5-year OS was 75% and progression-free survival was 59%. Six hundred (62%) patients had a first-line treatment within nine months of diagnosis and were hence analyzed further, whereas the remaining 370 (38%) patients were classified as wait-and-watch and were not analyzed further. Among the 600 treated patients, 337 (56%) had R-chemo (R-CHOP or alike (n=210), R-Benda (n=97), other (n=30)), and 263 (44%) received non-R-chemo treatment (mainly R-monotherapy, radiotherapy only, or R-lenalidomide). Patients who received R-Benda were on average older than the other groups. Among patients treated with R-chemo, those who stayed progression-free had a 5-year conditional OS above 75% regardless of PF time point. For patients who progressed, the 5-year conditional OS improved as time point of POD was prolonged (Fig 1a, left panel). Early POD (within 12-24 months) was associated with a particularly poor prognosis (5-year conditional OS below 55%). The OS improvement over time of POD was especially pronounced among R-Benda treated patients (Fig 1b, right panel). Among patients receiving non-R-chemo treatments, early POD was associated with a slightly worse 5-year OS but differences between POD and PF patients were less marked (Fig 1a, right panel). Conclusion: This population-based study of Swedish stage II-IV FL patients shows that among immunochemotherapy-treated patients, progression of disease was always associated with worse survival in comparison to progression-free patients regardless of timing of progression. This reduction in survival was more pronounced the earlier the progression (as described by others). Interestingly, among patients selected for milder non-immunochemotherapy-based treatments, progression of disease did not have a strong effect on survival. Disclosures Weibull: Janssen Cilag: Research Funding. Wahlin:Gilead Sciences: Research Funding; Roche: Consultancy, Research Funding. Smedby:Takeda: Research Funding; Janssen: Research Funding; Celgene: Consultancy.

Around half of patients with Hodgkin Lymphoma (HL) who progress or relapse through first line therapy can be cured with salvage chemotherapy followed by autologous stem cell transplant (ASCT). However, this leaves approximately 50% of patients that will relapse after ASCT. The pivotal phase II SG035-00303 trial demonstrated that these patients can be successfully treated with Brentuximab Vedotin (BV), and a proportion of them can be long term free of disease without any further intervention. The objective of the current study was to investigate whether these findings were borne out in the real world via interrogation of the EBMT registry. We retrospectively analysed data for 101 patients with HL who had BV as their first treatment for relapse after ASCT from 2012 to 2019. The median age at ASCT was 34 years (range: 19-65), 60% being male and with 62% being in complete response (CR) at the time of ASCT. Carmustine, Etoposide, Cytarabine and Melphalan (BEAM) was the most common conditioning regimen, having been employed in 72% of the cases. The median time from ASCT to relapse was 10.1 months (interquartile range (IQR): 6.1-25.1). The median time on BV was 3.4 months (IQR: 2.1-5.24). BV treatment resulted in a best overall response rate (ORR) of 59% with a CR rate of 37%. At last follow-up only 2 patients remain on treatment with BV. The main reason for discontinuation of BV was progression which occurred in 37% of the patients. In 32 cases (33%) the treatment was stopped electively to proceed to a second transplant, and overall nearly a quarter (22%) completed the full treatment course. Only 5% of patients stopped due to toxicity (peripheral neuropathy 2 and neutropenia, infusion reaction and other, 1 each). Further therapy was given after BV in over half of evaluable patients (58%), with check point inhibitors (CPIs) being the most common agents used (24% of these). Nearly two thirds (64/101) of the patients received a second transplant, which were nearly all allogeneic stem cell transplant (alloSCT, 59/64), and most of these (49/59) with reduced intensity conditioning (RIC). 26% of the alloSCT recipients experienced grade II-IV acute graft versus host disease (GvHD) and 25% developed chronic GvHD. At last follow up, 62% of all patients were alive with a median follow-up of 25 months after starting BV. Of these, 27 had received a second transplant, who were mostly in CR at last follow up (26/27) and a further 22 had relapsed. There were 11 patients of the 63 still alive who continued to be responding to BV without further therapy with a median duration of response of 30 months. In conclusion BV use for relapse after ASCT was well tolerated generally, with only a minority of patients stopping treatment due to toxicity. However, although almost two thirds of the patients achieved a response, further treatment was often needed after BV, notably with CPIs and most patients were consolidated with a RIC alloSCT. These results confirm that only a minority of patients can achieve a durable remission with BV alone. Disclosures Brice: Takeda France: Consultancy, Honoraria; Millennium Takeda: Research Funding; BMS: Honoraria. Blaise:Molmed: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria; Sanofi: Honoraria; Pierre Fabre medicaments: Honoraria. Stamatoullas:Celgene: Honoraria; Takeda: Consultancy. Robak:Takeda: Consultancy, Research Funding; UCB: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel grant, Research Funding; Amgen: Consultancy, Other: Travel grant; Roche: Consultancy, Other: Travel grant, Research Funding; Abbvie: Consultancy, Honoraria, Other: Travel grant, Research Funding; Gilead: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Acerta: Research Funding; Morphosys AG: Research Funding. Wahlin:Roche and Gilead: Consultancy.

The clinical course of follicular lymphoma (FL) is highly variable. Recently the m7-FL international prognostic index (FLIPI) integrating performance status, FLIPI score and the mutational status of seven genes, was shown to stratify patients into "low-risk" and "high-risk" with respect to 5-year failure-free survival after first-line immunochemotherapy. Our aim was to evaluate the model after rituximab without chemotherapy. The Nordic Lymphoma Group performed two randomized clinical trials on indolent lymphoma patients receiving single rituximab and rituximab with interferon-α2a. In total, 95 FL patients had sufficient fresh-frozen diagnostic material for sequencing. A targeted panel for the genes EZH2, ARID1A, MEF2B, EP300, FOXO1, CREBBP and CARD11 was utilized for m7-FLIPI score calculation. With a median follow-up of 10·6 years, 76% of patients were alive. No difference in time to treatment failure (TTF), defined as the interval between start of trial therapy and initiation of new therapy or death, nor overall survival (OS) was found between the m7-FLIPI risk groups (log-rank P = 0·94 and 0·99, respectively). EZH2 mutations were associated with longer TTF (log-rank P = 0·04) and in EP300 mutations were associated with shorter TTF (log-rank P = 0·01). We conclude that the prognostic value of the m7-FLIPI clinicogenetic model seems dependent on therapeutic regimen.

TPS7568 Background: Most patients with the indolent non-Hodgkin lymphoma (NHL) subtypes FL or MZL respond to first-line treatment but relapse is common, and there is no single standard treatment for patients with R/R FL or MZL. Tafasitamab is an Fc-engineered humanized monoclonal antibody (mAb) against CD19 which is broadly expressed in FL and MZL, and regulates B-cell proliferation via B-cell receptor signaling. In preclinical studies, tafasitamab has shown activity against NHL cell lines in combination with rituximab (anti-CD20 mAb) and lenalidomide (LEN). Tafasitamab monotherapy has shown promising clinical activity in a phase 2a study in patients with R/R NHL (NCT01685008), with an ORR of 29% (n/N = 10/34) in patients with FL and 33% (n/N = 3/9) in patients with MZL. In an ongoing phase 2, single-arm study (L-MIND, NCT02399085), tafasitamab plus LEN followed by tafasitamab alone demonstrated an ORR of 57.5% (n/N = 46/80) in patients with R/R diffuse large B-cell lymphoma (FDA approved indication). These preclinical and clinical observations from phase 2 trials suggest a potential clinical benefit of tafasitamab plus LEN and rituximab for patients with R/R FL or MZL. Methods: This phase 3 double-blind, placebo-controlled, randomized study is designed to investigate whether tafasitamab plus LEN and rituximab provides improved clinical benefit compared with LEN and rituximab in patients with R/R FL or R/R MZL. Patients will be randomized 1:1 to receive tafasitamab (12 mg/kg IV on days 1, 8, 15, and 22 of a 28-day cycle [cycles 1–3], then days 1 and 15 [cycles 4–12]) plus LEN (20 mg PO QD, days 1–21/ cycle for 12 cycles) and rituximab (375 mg/m2 IV on days 1, 8, 15, and 22 of cycle 1, then day 1 of cycles 2–5), or placebo (0.9% saline solution IV) plus LEN and rituximab. The primary study endpoint is PFS (investigator assessed [INV] by Lugano 2014 criteria) for patients with FL. Key secondary endpoints are PFS (INV) in overall population (FL and MZL), PET-CR rate (INV) at end of treatment (4–8 weeks after last treatment) and OS in patients with FL. Inclusion criteria include age ≥18 y, histologically confirmed FL (grade 1, 2, or 3a) or MZL (nodal, splenic, or extranodal), documented R/R disease, ≥1 prior systemic anti-CD20 therapy (including anti-CD20 refractory disease), ECOG PS ≤2, adequate systemic organ function, and high tumor burden (per GELF criteria). Exclusion criteria include prior rituximab plus LEN treatment, history of radiotherapy for other diseases (≥25% of bone marrow), nonhematologic malignancy, congestive heart failure (LVEF < 50%), active systemic infection, known CNS lymphoma, or severe immunocompromised state. inMIND (NCT04680052, EudraCT2020-004407-13) is currently enrolling patients; planned enrollment is 528 patients with R/R FL and 60–90 patients with R/R MZL. Clinical trial information: NCT04680052.

8007 Background: Bruton tyrosine kinase (BTK) inhibition is an emerging standard of care for WM. ASPEN is a randomized phase 3 study comparing zanubrutinib (ZANU), a potent and selective BTK inhibitor, versus ibrutinib (IBR), a first generation BTK inhibitor, in WM patients. Methods: Patients with WM and MYD88 mutation were randomly assigned 1:1 to receive ZANU (160 mg twice daily) or IBR (420 mg once daily). Patients without MYD88 mutations were assigned to a separate cohort, received ZANU, and are reported separately. Randomization was stratified by CXCR4 mutational status and the number of lines of prior therapy (0 vs 1-3 vs >3). The primary end point was the proportion of patients achieving a complete response or very good partial response (CR+VGPR). Sample size was calculated to provide 81% power to detect a difference in CR+VGPR rate of 35% vs 15% in the subset of patients with relapsed or refractory (R/R) WM. Primary analysis was planned to occur at ~12 months after last patient enrolled. Results: In total, 201 patients were randomized from Jan 2017 to Jul 2018. The treatment groups were well balanced for important baseline factors, except in the ZANU arm there were more elderly patients (aged >75 years, 33.3% vs 22.2%) and more anemia (hemoglobin ≤110 g/L, 65.7% vs 53.5%). At a median follow-up of 19.4 months, the rate of CR+VGPR was 28.4% vs 19.2% with ZANU vs IBR, respectively (2-sided P=0.09). Rates of atrial fibrillation, contusion, diarrhea, edema peripheral, hemorrhage, muscle spasms, pneumonia, and adverse events (AEs) leading to discontinuation or death were lower with ZANU. The rate of neutropenia was higher with ZANU (Table); however, grade ≥ 3 infection rates were similar (17.8% vs 19.4%). Conclusions: ASPEN is the largest phase 3 trial of BTK inhibitors in WM and the first head-to-head comparison of BTK inhibitors in any disease. Although not statistically significant, ZANU was associated with a higher CR+VGPR response rate, and demonstrated clinically meaningful advantages in safety and tolerability compared to IBR. Clinical trial information: NCT03053440 . [Table: see text]

Purpose For indolent lymphoma, the optimal timing, sequence, and choice of therapeutic regimens remain a matter of debate. In two Nordic Lymphoma Group randomized trials, symptomatic or clearly progressing patients were treated first line with a rituximab-containing regimen without chemotherapy. The purpose of this study was to assess long-term survival, risk of transformation, and need of new therapies. Methods Data were collected at cross-sectional follow-up for 321 patients with indolent lymphoma (84% with follicular lymphomas [FL]) included in one of two Nordic Lymphoma Group trials (accrual 1998 to 1999 and 2002 to 2008). All patients received first-line therapy with one or two cycles of four weekly infusions of rituximab 375 mg/m2, and 148 were randomly allocated to the addition of interferon alfa-2a. Follow-up data were retrieved from initial trial databases and medical records on repeated clinical evaluations. Results At the end of follow-up, 73% of patients were alive, with a median follow-up after random assignment of 10.6 years. Among all, 36% (38% with FL) had never needed chemotherapy. For patients with FL who required new therapy within 24 months because of early disease progression, the 10-year survival rate was 59% versus 81% for those with longer remission. Interferon was not shown to improve long-term outcome. Transformation was diagnosed in 20% of all patients (2.4% per person-year) and in 18% with FL. An additional malignancy was found in 12%. Conclusion Approximately one third of patients with symptomatic indolent lymphoma (30% with FL, 23% without FL) did not need new therapy in the long term after first-line rituximab without chemotherapy. In the entire cohort, 10-year survival was excellent with no major safety issues, which suggests that chemotherapy can be delayed safely in the majority of patients.

Survival has improved among patients with diffuse large B-cell lymphoma (DLBCL) with the addition of anti-CD20 antibody therapy. We aimed to quantify trends and remaining loss in expectation of life (LEL) due to DLBCL at a national population-based level. Patients diagnosed with DLBCL 2000-2013 (N = 7114) were identified through the Swedish Lymphoma Registry and classified according to the age-adjusted International Prognostic Index (aaIPI). The novel measure LEL is the difference between remaining life years among patients and the general population and was predicted using flexible parametric models from diagnosis and among 2-year survivors, by age and sex. Median age at DLBCL-diagnosis was 70 (18-105) years and 54.8% presented with stage III-IV disease. On average, LEL due to DLBCL decreased from 8.0 (95% CI: 7.7-8.3) to 4.6 (95% CI: 4.5-4.6) years over the study period. By risk group, LEL was most reduced among patients with aaIPI ≥2 aged 50-60 years. However, these patients were still estimated to lose >8 years in 2013 (eg, LELmales50years 8.6 years (95% CI: 5.0-12.3)). Among 2-year survivors, LEL was reduced from 6.1 years (95% CI: 5.6-6.5) (aaIPI ≥ 2) and 3.8 years (95% CI: 3.6-4.1) (aaIPI < 2) to 1.1 (95% CI: 1.1-1.2) and 1.0 year (95% CI: 0.8-1.1), respectively. The reduction was observed across all ages. Results for females were similar. By using LEL we illustrate the improvement of DLBCL survival over time. Despite adequate immunochemotherapy, substantial LEL among patients with IPI ≥ 2 points to remaining unmet medical needs. We speculate that observed reduced losses among 2-year survivors indicate a reduction of late relapses.

Background: Autologous stem-cell transplantation (ASCT) is established lymphoma therapy, but the procedure has a substantial treatment-related mortality. Methods All 433 lymphoma patients who underwent ASCT at Karolinska Huddinge 1994-2016 were investigated, including long- and short-term mortality, causes of death, longitudinal laboratory values and anti-lymphoma treatments, harvested and transplanted CD34 cell amounts, infectious and other complications, microbiology findings, intensive care, drugs administered, chemotherapy-induced nausea, hospital stay, and secondary myeloid neoplasia. Findings: BEAM was the conditioning for 93%. The 100-day overall and non-lymphoma mortality were 7·2% and 5·6%. Stem cell harvests

IF 5.128; International audience; The role of autologous stem cell transplantation (ASCT) in patients with marginal zone lymphoma (MZL) is debatable. This study investigated the outcome and prognostic factors affecting the outcome of patients undergoing ASCT for MZL. Eligible patients had non‐transformed nodal, extra‐nodal (MALT) or splenic MZL (SMZL), aged ≥18 years, who underwent a first ASCT between1994 and 2013 and were reported to the European Society for Blood and Marrow Transplantation, Fondazione Italiana Linfomi or Gruppo Italiano Trapianto Di Midollo Osseo registries. The study included 199 patients, [111 MALT lymphoma, 55 nodal MZL (NMZL) and 33 SMZL]. Median age at transplantation was 56 years. The median number of prior therapies was 2 (range 1–8), including rituximab in 71%. 95% had chemosensitive disease. 89% received a chemotherapy‐based high‐dose regimen. There were no significant differences in patient and transplant characteristics between the 3 histological subtypes except for a lower percentage of patients previously treated with rituximab in the MALT sub‐group and more transplants performed in recent years in the other sub‐groups. After a median follow‐up of 5 years, 5‐year cumulative incidence of relapse/progression and non‐relapse mortality were 38% and 9%, respectively. Five‐year event‐free survival (EFS) and overall survival (OS) were 53% and 73%, respectively. Five‐year cumulative incidence of second malignancies was 6%. Multivariate analysis revealed age ≥65 years was associated with a shorter EFS and OS. In addition, patients with SMZL had a shorter OS than those with MALT. ASCT may provide clinical benefit in MZL patients who have failed multiple lines of chemoimmunotherapy.

Six cycles of R-CHOP-21 are not inferior to eight cycles for treatment of diffuse large B-cell lymphoma : a Nordic Lymphoma Group Population-based Study

Introduction In the absence of a known affected family member, frequent symptoms of Gaucher disease (GD), a rare lysosomal storage disorder, such as thrombocytopenia or splenomegaly, often lead to hematological diagnostic workup. Objectives The aim of the study was to compare the clinical utility of aspiration biopsy of the bone marrow (ASP) with trephine biopsy (TB) for the diagnosis of GD type 1 (GD1). Patients and methods Six non-Jewish patients with sporadic GD1 were initially examined with ASP and TB to establish the cause of cytopenia and splenomegaly. In the current study, samples from each patient consisted of 2 bone marrow slides. On each slide, 500 nucleated cells were counted and then averaged. The composition of bone marrow TBs was assessed using digital images analyzed on a computer. Results Of 6 patients, 5 carried at least 1 N370S allele with a c.1226A>G mutation in the GBA1 gene. The median number of Gaucher cells identified during cytological assessment of bone marrow smears was 4 (range, 1-18), and the median percentage of Gaucher cells was 0.4% (range, 0.1%-1.8%). The absolute proportion of Gaucher cells in histological samples ranged from 22% to 36% (median value, 28%), and the ratio of Gaucher cell infiltrate to hematopoietic tissue ranged from 34% to 54% (median value, 47%). The median value of the ratio of Gaucher cells to hematopoietic tissue was strikingly lower when using ASP compared with TB (P = 0.028). Conclusions Our results indicate that ASP is not a reliable diagnostic tool for the detection of GD1. Thus, patients with unclear long-lasting splenomegaly and/or thrombocytopenia, in whom bone marrow aspirate cytology is negative for Gaucher cells, should be routinely referred for an enzymatic assay for GD.

Background Diffuse large B cell lymphoma (DLBCL) is an aggressive but often curable disease. However a proportion of the patients are primary refractory or relapse (R/R DLBCL) following standard immuno-chemotherapy, which is associated with a much worse prognosis especially if the CNS is involved. Current knowledge around the incidence of R/R DLBCL is mostly derived from randomized controlled trials or specialized center cohorts presenting selected patient materials. With new available treatment options for these patients it is of great importance to accurately estimate the incidence in absolute terms. Here we investigated the incidence of R/R DLBCL overall and in the CNS in a nationwide population-based cohort accounting for the presence of competing risks. Methods Patients with a primary diagnosis of DLBCL in 2007-2014 were identified using the Swedish Lymphoma Register and followed until October 31st 2017. Primary CNS lymphomas, primary mediastinal B-cell lymphomas and transformed lymphomas were excluded. The register contains information about clinical characteristics, primary treatment, treatment response and relapse. Information regarding treatment response and progression/relapse as well as site of relapse was validated through medical chart review in all patients. Primary treatment with curative intent was defined as having started treatment with anthracycline-based chemotherapy (mostly R-CHOP). Overall (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method in the full cohort. Cumulative incidence of R/R DLBCL was estimated in the subset of patients who were treated with curative intent accounting for the competing risk of death. The net probability of CNS progression/relapse by CNS IPI was estimated in curatively treated patients who did not have CNS involvement at diagnosis. The cumulative incidence of CNS relapse was estimated non-parametrically with death and non-CNS progression/relapse as competing risks among all curatively treated patients and restricted to patients with high CNS IPI (4-6) separately. Results In the study population of 4205 patients, median age at diagnosis was 71 years (range 18 to 105). Sixteen percent of patients (n=677, median age 83 years) were not able to start treatment with curative intent, with the median OS in this group of only 2.7 months. Two-year OS for patients treated with curative intent was 88% (95% CI: 87-89) and 2-year progression free survival (PFS) was 70% (95% CI: 69-72) (fig 1a). The 5-year cumulative incidence of relapsed/refractory disease in patients treated with curative intent was 23% (95% CI: 22-24, total N=713) (fig 1b) and the majority relapsed within two years (n=646, 77%). Five percent of the patients starting primary treatment with curative intent, only received 1 or 2 treatment cycles and were not evaluated for response. The 2-year cumulative incidence of CNS relapse in curatively treated patients was 2.8% (95% CI: 2.7-3.4, total N=126) (fig 1b). For patients with high CNS IPI (4-6) the 2-year rate of CNS relapse was 12% (95% CI: 8-16) when estimated using the Kaplan-Meier method (fig 1c), but only 8% (95% CI: 6-11) in the cumulative incidence model (fig 1d) accounting for other relapses and death as competing events. Conclusion The 5-year cumulative incidence of relapsed/refractory disease in patients with DLBCL treated with curative intent is 23% in this population-based study, which is lower than in previously published reports. Overall, 16% of patients were not able to start primary curative intent treatment, representing an older group of patients with a dismal OS. An additional 5% of patients were not able to tolerate more than 1-2 cycles, defining another group of patients with unmet medical needs. The 2-year cumulative incidence of CNS relapse is Figure 1 A): Overall survival (OS) and progression-free survival (PFS) among 4205 patients with diffuse large B-cell lymphoma (DLBCL) diagnosed in Sweden 2007-2014 treated with curative (n=3528 ) or palliative intent (n=677). B): Cumulative incidence of CNS relapse in the presence of competing risks of death and non-CNS relapse. C): Net probability of CNS relapse by CNS IPI (N=3499). D): Cumulative incidence of CNS relapse restricted to 414 patients with high CNS IPI (4-6). Disclosures Harrysson: Janssen pharmaceuticals: Other: This project was partly funded through a private-public collaboration between KI and Janssen pharmaceuticals.; Swedish Cancer Society: Other: This project was partly funded by the Swedish Cancer Society.. Eloranta:Karolinska Institutet: Other: coordinator for a public-private real world evidence; Janssen Pharmaceuticals.: Other: project coordinator for a public-private real world evidence. Ekberg:Janssen Pharmaceuticals: Other: This project was partly funded through a private-public collaboration between KI and Janssen pharmaceuticals.; Swedish Cancer Society: Other: This project was partly funded by the Swedish Cancer Society. Enblad:Kite/Gilead: Membership on an entity's Board of Directors or advisory committees. Jerkeman:Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Roche: Honoraria, Research Funding. Wahlin:Roche and Gilead: Consultancy. Andersson:Gilead, Janssen and Roche: Consultancy; Gilead: Research Funding; Abbvie and Janssen: Membership on an entity's Board of Directors or advisory committees. Smedby:Janssen Pharmaceuticals: Other: This project was partly funded through a private-public collaboration between KI and Janssen pharmaceuticals.; Takeda: Research Funding; Celgene: Honoraria.

A common treatment for follicular lymphoma is rituximab monotherapy. To identify patients for whom this regimen is adequate as first-line therapy, we applied the World Health Organization (WHO) classification for grading follicular lymphoma in a prospective central pathology review of the biopsies of previously untreated patients in two randomized trials of rituximab without chemotherapy. In the first trial (n₁ = 53), higher WHO grades correlated with longer time to next treatment, independently of clinical prognostic factors (p = 0.030); the finding was replicated in the second trial (n₂ = 221; p = 0.019). Higher grades were associated with better treatment responses (p = 0.018). Furthermore, also grades externally confirmed by independent local pathologists correlated with time to next treatment (p = 0.048). Flow cytometry in a separate patient series showed that the intensity of CD20 increased with the malignant cell size (p0.00005). In conclusion, WHO grade 1 follicular lymphoma correlates with inferior outcome after rituximab monotherapy. WHO grading might provide a clinically useful tool for personalized therapy.

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is an indolent CD20+ lymphoma. Its scarcity has made clinical trials difficult and there is no consensus on first-line treatment. We conducted a population-based study of all patients diagnosed with NLPHL in Sweden between 2000 and 2014 (N = 158; 41 women and 117 men), focusing on clinical features, therapy and overall survival. The median female and male age was 59 and 44 years, respectively (P = 0·002). In early-stage disease, there was little mortality and no survival differences between therapies. In patients with advanced-stage disease, mortality was relatively high in patients who did not receive first-line rituximab but absent in those who did (10-year survival, 55% vs. 100%; P = 0·033); there were no imbalances of prognostic factors between those two groups. In advanced stages, first-line rituximab use increased markedly between 2000-2004 and 2005-2014 (7% vs. 67%; P < 0·00005), as did 10-year survival, 53% vs. 72% (multivariate P = 0·027). Although all patients were diagnosed in the 2000s, this is the longest-followed (and largest) population-based cohort. We report a hitherto unreported 15-year median age difference between sexes, increasing rituximab use and improved survival.

The tumour microenvironment influences outcome in patients with follicular lymphoma (FL), but its impact on transformation is less studied. We investigated the prognostic significance of the tumour microenvironment on transformation and survival in FL patients treated in the rituximab era. We examined diagnostic and transformed biopsies from 52 FL patients using antibodies against CD3, CD4, CD8, CD21 (CR2), CD57 (B3GAT1), CD68, FOXP3, TIA1, PD-1 (PDCD1), PD-L1 (CD274) and PAX5. Results were compared with a second cohort of 40 FL patients without signs of transformation during a minimum of five years observation time. Cell numbers and localization were semi-quantitatively assessed. Better developed CD21+ follicular dendritic cell (FDC) meshworks at diagnosis was a negative prognostic factor for overall survival (OS), progression-free survival (PFS) and time to transformation (TTT) in patients with subsequently transformed FL. Remnants of FDC meshworks at transformation were associated with shorter OS and PFS from transformation. High degrees of intrafollicular CD68+ and PD-L1+ macrophage infiltration, high total area scores and an extrafollicular/diffuse pattern of FOXP3+ T cells and high intrafollicular scores of CD4+ T cells at diagnosis were associated with shorter TTT. Scores of several T-cell subset markers from the combined patient cohorts were predictive for transformation, especially CD4 and CD57.

The prognostic value of grading follicular lymphoma has been debated since the 1980s. There is consensus that World Health Organization (WHO) grades 1 and 2 are indolent, but not whether grades 3A or 3B are aggressive. We retrospectively reviewed the follicular lymphoma diagnoses according to the 2008 WHO classification in all diagnostic specimens from a population-based cohort of 505 patients with a median follow-up time of 10·0years (range, 4·6-16·0). After excluding 43 patients with concomitant diffuse large B-cell lymphoma, 345 remained with grade 1-2, 94 with grade 3A, and 23 with grade 3B follicular lymphoma. Grades 1-2 and 3A seemed equally indolent, with indistinguishable clinical courses, even in patients receiving anthracyclines. Compared with grades 1-3A and independently of clinical factors, grade 3B correlated with higher mortality (P=0·008), but outcome was improved after upfront anthracycline-containing therapy (P=0·015). In contrast to grade 1-3A patients, grade 3B patients experienced no relapses or deaths beyond 5years of follow-up. Furthermore, patients with grade 3B were predominantly male and seldom presented with bone-marrow involvement. We conclude that follicular lymphoma grade 1-3A is indolent and incurable with conventional therapy. Grade 3B appears to be an aggressive but curable disease.

P-glycoprotein (PGP) over-expression on malignant cells is associated with poor prognosis and treatment outcome due to the development of a multidrug resistance phenotype. In this study, we analyzed the correlation between expression of PGP and lymphoid antigens (Ly) on leukemic myeloblasts versus response to therapy and survival in acute myeloid leukemia (AML). Fifty-one consecutive patients, aged 16-75 (median age 44.6 years), diagnosed with de novo AML between 1997 and 2000, and who received at least one induction chemotherapy course, were enrolled in the study. Expression of PGP on ≥ 10% of the myeloblasts (PGP(+)AML) at the time of diagnosis was observed in 21 patients (41%). The complete remission rate did not differ between PGP(+) (13/21) and PGP(-) (20/30) patients (62 vs. 67%). Twelve of the 51 patients (24%) were still alive after a median follow-up time of 11.5 years (range 10.7-13.1). The Ly(+)AML patients showed significantly better overall survival compared with Ly(-)AML patients (8/18 vs. 4/33 patients alive at the last follow-up, P = 0.003). The subgroup of patients with co-expression of PGP and Ly also showed better overall survival compared with PGP(+)AML patients without Ly expression (4/8 vs. 0/13 patients alive at the last follow-up; P = 0.04). Our results suggest that expression of lymphoid antigens on PGP(+) myeloblasts in AML can positively affect survival in AML patients, mainly due to a decreased relapse risk and better survival. Although the small number of patient may be perceived as a limitation of the study, the long follow-up period strengthens its value. Further prospective trials are needed to obtain more information concerning the association between PGP and lymphoid antigens in AML, which would put our results in their ultimate proper context.

Purpose: T cells influence outcome in follicular lymphoma, but their contributions seem to be modified by therapy. Their impact in patients receiving rituximab without chemotherapy is unknown. Experimental Design: Using flow cytometry, we evaluated the T cells in tumors and/or blood in a total of 250 follicular lymphoma patients included in two Nordic Lymphoma Group randomized trials that compared single rituximab with IFN-α2a–rituximab combinations. Results: In univariate analysis, higher levels of CD3+, CD4+, and CD8+ T cells in both tumors and blood correlated with superior treatment responses, and in multivariate analysis, tumor-CD3+ (P = 0.011) and blood-CD4+ (P = 0.029) cells were independent. CD4+ cells were favorable regardless of treatment arm, but CD8+ cells were favorable only in patients treated with single rituximab, because IFN-α2a improved responses especially in patients with low CD8+ cell levels. Higher levels of blood-CD3+ (P = 0.003) and blood-CD4+ (P = 0.046) cells predicted longer overall survival, and higher levels of blood-CD8+ cells longer times to next treatment (P = 0.046). Conclusions: We conclude that therapeutic effects of rituximab are augmented by tumor-associated T cells for rapid responses and by systemic T cells for sustained responses. CD4+ and CD8+ cells are both favorable in patients treated with rituximab. IFN-α2a abrogates the negative impact of few CD8+ cells. Clin Cancer Res; 17(12); 4136–44. ©2011 AACR.

Background Our knowledge around the incidence of relapse and primary refractory disease in patients with diffuse large B-cell lymphoma (DLBCL) in the rituximab era is mostly derived from randomized controlled trials or specialized center cohorts presenting selected patient materials. With new therapies being evaluated and launched at diagnosis as well as in the relapsed/refractory setting there is a need for a better understanding of the response and outcome with current treatment strategies. Here we investigated the incidence of primary refractory DLBCL and first relapse as well as survival among patients with relapsed/refractory DLBCL in a population-based cohort. Methods Patients with a primary diagnosis of DLBCL in 2007-2014 were identified using the Swedish Lymphoma Register in 5 of 6 health care regions, and followed until October 31st 2017. Primary CNS lymphomas and primary mediastinal B-cell lymphomas were excluded. The register contains information about clinical characteristics, primary treatment, treatment response and relapse. Information regarding treatment response and progression/relapse was validated through medical chart review in all patients. Primary treatment with curative intent was defined as having started treatment with anthracycline-based chemotherapy (mostly R-CHOP). Early relapse was defined as having primary refractory disease (stable or progressive disease (SD/PD) at response evaluation) or relapse within a year from diagnosis. Overall and progression-free survival probabilities were estimated with the Kaplan-Meier method in the entire cohort and among relapsed/refractory patients by early/late relapse and by age +/- 70 years. Additionally, cumulative incidence of relapsed/refractory disease by follow-up time was shown graphically accounting for the presence of competing risks. Results In the study population of 3165 patients, median age at diagnosis was 71 years (range 18 to 97). In this unselected cohort, 80% of the patients started treatment with curative intent. Five-year overall survival (OS) for patients treated with curative intent was 78% (95% CI: 76-80) and 5-year progression free survival (PFS) was 60% (95% CI: 58-62). Patients who received non-curative intent or palliative therapy (20%) had a median OS of 4.7 months (95% CI: 3.4-5.7). The 10-year cumulative incidence of relapsed/refractory disease in patients treated with curative intent was 22% (95% CI: 20-24) and the majority relapsed within two years (n=315, 60%). Five percent of the patients starting primary treatment with curative intent, only received 1 or 2 treatment cycles and were not evaluated for response. Patients with relapsed/refractory disease had a poor prognosis. For patients with early relapse, median survival from the date of relapse was 4.6 months (95% CI: 4.1-5.7) and 5-year OS was 11% (95% CI; 8-15) whereas patients with late relapse had a median survival of 18.0 months (95% CI: 13.0-24.5) and a 5-year OS of 26% (95% CI: 20-33). Survival in younger patients (≤70 years) by early and late relapse was higher although still low; 5-year OS in early relapse was 17% (95% CI: 12-23) and in late relapse 37% (95% CI: 27-48). Among older patients (>70 years) with early relapse, 5-year OS was only 4% (95% CI: 2-9) and in patients with late relapse it was 16% (95% CI: 9-24). More information regarding treatment intensity among relapsed/refractory patients will be presented. Conclusion The 10-year cumulative incidence of relapsed/refractory disease in patients with DLBCL treated with curative intent is 22% in this population-based study, which is lower compared to previous reports. Outcome for patients with relapsed/refractory disease continues to be poor especially for patients with early progression/relapse, even among younger patients going on to intensive second-line chemotherapy aiming for autologous stem cell transplantation. These results underscore both the urgency of new therapies for relapsed/refractory DLBCL as well as the need for identification of high-risk patients already at diagnosis. Figure 1. Overall survival (OS) and progression-free survival (PFS) among 3165 patients with diffuse large B-cell lymphoma (DLBCL) diagnosed in Sweden 2007-2014 treated with curative or palliative intent, and cumulative incidence of relapsed/refractory disease and survival among 529 relapsed/refractory patients by timing of relapse (early/late) and age (+/-70 years). Figure. Figure. Disclosures Harrysson: Janssen Pharmaceuticals: Other: The Department have recieved partial funding from Janssen Pharmaceuticals. Eloranta:Janssen Pharmaceuticals: Other: S Eloranta is currently employed as a project coordinator and her salary is funded via a public-private real world evidence collaboration between Karolinska Institutet and Janssen Pharmaceuticals. Ekberg:Janssen Pharmaceuticals: Other: The department has received partial funding from Janssen Pharmaceuticals. Wahlin:Gilead: Consultancy, Honoraria, Research Funding; Roche: Research Funding. Smedby:Janssen Pharmaceuticals: Other: The Department have recieved partial funding from Janssen Pharmaceuticals.

Background In patients with follicular lymphoma (FL) the clinical international prognostic index FLIPI is well established, but recently the impact of a number of gene mutations was evaluated. The m7-FLIPI prognostic model, derived from the FLIPI score combined with ECOG and the mutational status of seven specific genes, was shown to stratify FL patients into "low-risk" and "high-risk" with respect to 5-year failure-free survival after first-line immunochemotherapy (R-CHOP or R-CVP) (Pastore, Lancet Oncol 2015). The Nordic Lymphoma Group (NLG) performed two trials (accrual 1998-1999 and 2002-2008, respectively) including a total of 439 patients with symptomatic/progressing indolent B-cell lymphoma (79% FL) randomized 1:1 to treatment with single rituximab or rituximab plus interferon-α2a (Kimby, Leuk Lymphoma 2008, 2015). A follow-up study after 10 years found 36% still chemotherapy-free (Lockmer, JCO 2018). Aim: As part of a long-term follow-up of we aimed to investigate whether the m7-FLIPI prognostic model could be validated in a FL patient cohort treated with first-line-immunotherapy only. Methods Fresh-frozen diagnostic lymph node biopsies with sufficient material for gene sequencing were available from 88 patients with verified FL grades 1-3a and 7 patients with indolent B-cell lymphoma not otherwise specified. A targeted Lymphochip panel including the seven genes of the m7-FLIPI, EZH2, ARID1A, MEF2B, EP300, FOXO1, CREBBP and CARD11, was used. Clinical data were retrieved from the databases of the two trials and from follow-up medical records. Variables assessed included all post-trial therapies, the last dates of follow-up and causes of death. The m7-FLIPI score was calculated according to the published sum of predictor algorithm with respect to high-risk FLIPI, ECOG >1 and occurrence of non-silent mutations. Time to treatment failure (TTF), the primary endpoint, was defined as the interval between start of trial therapy and either initiation of new lymphoma therapy due to relapse or intolerance, or death from any cause. TTF was chosen rather than the date of stable or progressive disease described in the Pastore report, as the date of new therapy is less affected by assessment frequency and quality. The Pastore cut-off score of ≥ 0.84 for discrimination between the m7-FLIPI high- vs low-risk group was applied. TTF and overall survival (OS) were estimated with the Kaplan-Meier method and the log-rank test applied for comparison between risk groups. Results Mutational status was obtained from 95 patients, four of them with two biopsies each. In two of the doublets mutations differed between samples in which case the earliest dated samples was chosen for risk analyses. Three patients (two FL) could not be risk-stratified according to the m7-FLIPI score due to missing clinical information. Patient characteristics and gene mutations are shown in Table 1. The mutation frequency distribution was broadly similar to the Pastore report cohorts, mutations in the epigenetic modifier CREBBP by far the most common. With a median follow-up after randomization of 10.6 (range 0.6-18.3) years, 72 (76%) patients were alive. Of all, 28% had never required any new therapy, and 39% had not required any chemotherapy. For 13 out of 23 patients the cause of death was lymphoma-related i.e. due to progression of disease or complications of therapy. No difference in TTF nor OS was found between the m7-FLIPI high- vs low-risk group (fig 1a-b), but in the high-risk FLIPI group OS was shorter (fig 1d). Mutation in the EZH2 gene, coding for the catalytic subunit of a histone methyltransferase, was associated with longer TTF (p=0.04) also within FLIPI risk groups but not with OS (p=0.63). Conclusion The m7-FLIPI prognostic clinicogenetic model was not valid in our cohort with FL patients treated with only immunotherapy. Mutation in the gene EZH2 was associated with longer TTF and high-risk FLIPI with shorter OS. Disclosures Wahlin: Gilead: Consultancy, Honoraria, Research Funding; Roche: Research Funding. Kimby:AbbVie: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria; Roche: Honoraria.

Background: Follicular lymphoma (FL) is a heterogenous disease. The optimal timing, sequence and choice of therapy remain matters of debate and there is no optimal prognostic tool. The FLIPI (Follicular Lymphoma International Prognostic Index) is based on five bio-clinical parameters and is widely used, but not as guide for choice of treatment. Recently a new prognostic score (PRIMA-PI), based solely on two parameters, bone marrow involvement and serum beta2 microglobulin (ß2m) was proposed for patients treated with immunochemotherapy (Bachy E., Blood 2018). The Nordic Lymphoma Group (NLG) performed two randomized trials including patients with symptomatic/progressive indolent CD20+ lymphoma, with rituximab monotherapy or rituximab in combination with interferon (IFN)-α2a as primary treatment, without maintenance (Kimby E., 2008, 2015). The 10 years follow-up of these patients showed a good survival with no major safety issues and no need for later chemotherapy in 38% of FL patients (Lockmer S, JCO 2018). Aim/Purpose: To evaluate two different prognostic systems (the new PRIMA-PI and the FLIPI), for overall survival (OS) and time to treatment failure (TTF) in a cohort of symptomatic/progressive FL patients treated with a rituximab-containing first-line regimen without chemotherapy. Methods: Previously untreated patients with a confirmed FL diagnosis (n=269) or indolent lymphoma not otherwise specified (n=22, most FLs with insufficient material for grading), treated in the NLG randomized trials with two cycles rituximab (375 mg/m2 x 4 weeks), with or without IFN-α2a, were classified into the three PRIMA-PI categories: high-risk: ß2m> 3mg / L, intermediate-risk: ß2m ≤ 3 mg / L with bone marrow involvement and low-risk: ß2m ≤ 3 mg / without bone marrow involvement. The FLIPI scores were also assessed. TTF, defined as the interval between randomization and either initiation of new lymphoma therapy due to relapse or intolerance, or death from any cause, as well as OS were estimated using the Kaplan Meier method. The log-rank test was used for comparison between risk groups. Results: Out of 291 patients, 252 had complete data on PRIMA-PI and FLIPI (at the time of randomization in the original trials) and were available for analyses of TTF and OS. Patient characteristics are shown in Table 1. PRIMA-PI seemed to identify a true high-risk group of 47 patients, 32 of them being high risk also according to FLIPI, while a larger patient group (n=117) was classified as FLIPI high-risk. After a long follow-up time, median 9.9 years (0.4 -18.8) from randomization, median 10.6 years for the 214 patients (74%) still alive, 76 patients (26%) were failure-free and 108 (37%) without need of any chemotherapy, Patients with PRIMA-PI high showed a shorter TTF compared to PRIMA-PI intermediate and low (Fig 1a), whereas the FLIPI risk-groups were not significantly separated (Fig 1b). Evidence of transformation to aggressive disease was seen in 55 patients, with no significant difference in frequency between the PRIMA-PI groups, nor between FLIPI groups. Both PRIMA-PI and FLIPI were of significant value for predicting OS, most evident after a long follow-up time (Fig 1c and d). In 41 patients the cause of death was progressive disease or therapy complications, regarded as lymphoma-related death, whereas 21 died of other causes. The lymphoma-specific survival was related to the PRIMA-PI (log-rank p=0.03), but not to the FLIPI (n.s). Prognosis was worse for the PRIMA-PI high-risk group than the for the low-risk, also when adjusted for sex, high age (>60 years), diagnosis, stage, ECOG and FLIPI risk-group; TTF HR 1.82 (95% CI 1.16-2.85, p=0.01) and OS HR 2.3 (95% CI 1.00-5.38, p=0.05). Conclusion: FL patients included in two NLG trials with complete clinical data and a median follow-up of >10 years after randomization have been assessed for validation of different prognostic indices. In these patients, all with chemo-free first-line therapy, the PRIMA-PI was shown a valid predictor of both TTF and OS and seemed more useful than the FLIPI. The PRIMA-PI high risk identified a group of patients (19% of all) with true poor prognosis. Disclosures Kimby: Roche: Honoraria; Roche: Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees; Gilead: Honoraria; AbbVie: Membership on an entity's Board of Directors or advisory committees. Holte:Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees; Roche, Norway: Research Funding. Wahlin:Roche: Research Funding; Gilead: Consultancy, Honoraria, Research Funding. Hagberg:Roche: Honoraria.

Purpose: Follicular lymphoma is a heterogeneous disease with variable prognosis and clinical course. We hypothesized that the presence of nonmalignant T cells in the microenvironment of the tumor may affect the outcome.Experimental Design: Using flow cytometry, we evaluated the T-cell subsets in the lymph node microenvironment of follicular lymphoma. All patients in South Stockholm County with indolent follicular lymphoma and with flow cytometry done on a diagnostic lymph node between 1994 and 2004 were included (N = 139). Diagnosis and grade (1, 2, and 3a) were confirmed by re-review. Flow cytometry results were reanalyzed. Lymphocyte subsets, the Follicular Lymphoma International Prognostic Index, grade, and clinical characteristics were evaluated in univariable and multivariable Cox analysis with respect to overall survival (OS) and disease-specific survival (DSS).Results: Higher CD8+ T-cell levels correlated with longer OS and DSS, independently of the Follicular Lymphoma International Prognostic Index (OS, P = 0.017; DSS, P = 0.020) and independently of all other prognostic factors (OS, P = 0.001; DSS, P = 0.004). Median OS was not reached for patients in the upper quarter of CD8+ T-cell levels (>8.6%), 10.4 years for patients in the middle half (4.2-8.6%), and 6.0 years for patients in the lower quarter (Conclusions: Higher levels of CD8+ T cells predict a better prognosis, and these data support an important role for nonmalignant immune cells in the biology of follicular lymphoma. Evaluating the CD8+ T cells by flow cytometry at diagnosis may provide prognostic information.

Patients with advanced CD20 + indolent lymphoma, requiring therapy, were randomized to rituximab (four weekly infusions of 375 mg/m(2)) or to rituximab combined with 5 weeks of interferon-α2a (IFN-α2a) (3-4.5 MIU daily) as priming. Responding patients were eligible for a second cycle with the same allocated treatment. In total, 156 patients were randomized to rituximab and 157 to rituximab + IFN-α2a. In the intention-to treat (ITT) population, 244 patients (78%) responded to cycle 1. After a second cycle the complete remission/complete remission unconfirmed (CR/CRu) rate was 41% with the combination versus 24% with monotherapy (p = 0.005). The median time to treatment failure (primary endpoint) in ITT patients was 28 vs. 21.5 months, respectively (p = 0.302). After a long median follow-up (61 months), 33% (42% of patients responding to cycle 1) were still failure-free with an overall survival rate of 88% and with no difference between the treatment groups. The trial was registered at ClinicalTrials.gov Identifier: NCT01609010.

Treatment for follicular lymphoma (FL) improved with rituximab. In Sweden, first-line rituximab was gradually introduced between 2003 and 2007, with regional differences. The first national guidelines for FL were published in November 2007, recommending rituximab in first-line therapy. Using the population-based Swedish Lymphoma Registry, 2641 patients diagnosed with FL from 2000 to 2010 were identified and characterized by year and region of diagnosis, age (median, 65 years), gender (50% men), first-line therapy and clinical risk factors. Overall and relative survivals were estimated by calendar periods (2000-2002, 2003-2007 and 2008-2010) and region of diagnosis. With each period, first-line rituximab use and survival increased. Survival was superior in regions where rituximab was quickly adopted and inferior where slowly adopted. These differences were independent in multivariable analyses. Ten-year relative survival for patients diagnosed 2003-2010 was 92%, 83%, 78% and 64% in the age groups 18-49, 50-59, 60-69 and ⩾70, respectively. With increasing rituximab use, male sex emerged as an adverse factor. Survival improved in all patient categories, particularly in elderly women. The introduction and the establishment of rituximab have led to a nationwide improvement in FL survival. However, rituximab might be inadequately dosed in younger women and men of all ages.

Background: The randomized phase-2 trial SAKK 35/10 was conducted by the Swiss Group for Clinical Cancer Research (SAKK) and the Nordic Lymphoma Group (NLG) to compare the activity of single-agent rituximab versus rituximab plus lenalidomide in the first-line treatment of symptomatic follicular lymphoma (FL). The results of primary endpoint (complete remission [CR/CRu] at week 23) assessment were previously reported, showing that addition of lenalidomide to rituximab results in a significantly higher CR/CRu rate at the expected cost of increased but manageable toxicity (Kimby et al. Blood 2014.124 (21):799; Zucca et al. Hematol Oncol 2015. 33(s1): 105). Here we report the first analysis of secondary endpoints, progression-free survival (PFS), time to next anti-lymphoma treatment (TTNT), CR duration, as well as CR/CRu rate at 30 months (CR30). Methods: 154 patients (pts) with grade 1 to 3a FL, untreated and in need of systemic therapy, were randomized to receive either rituximab (375mg/m2 at week 1, 2, 3, 4, 12, 13, 14 and 15) or rituximab (same schedule) plus lenalidomide (15 mg daily, from 14 days before the first until 14 days after the last rituximab administration). The sample size was calculated to allow the detection of a 20% increase of the CR/Cru rate with 90% power and type I error 0.10; a one-sided Z-test for proportions was used to compare the two arms. Treatment was discontinued in pts who did not achieve at least a 25% reduction in the sum of products of tumor diameters at week 10. Primary and secondary endpoints were defined according to the NCI international standardized criteria (Cheson et al 1999). Results: 77 pts (median age 63 years, 52% with stage IV and 47% with poor-risk FLIPI score) were allocated in the single-agent rituximab arm and 77 (median age 61 years, 48% with stage IV and 47% with poor-risk FLIPI score) in the combination arm. A higher CR/CRu rate in the combination arm was documented both by the investigator assessment (36% vs 25%) and by the independent response reviewers of CT scans (61% vs. 36%). Adverse events of grade ≥3 were more common (56% vs 22% of pts) in the combination arm, including neutropenia (23% vs 7%). At a median follow up of 3.1 years, a longer CR duration was seen for the pts in the combination arm (median not reached vs 2.3 years) as well as a longer PFS (median not reached vs. 2.3 years), these differences were not statistically significant. The CR30, recently identified as a reliable surrogate of PFS (Sargent et al. Hematol Oncol 2015. 33(s1): 166), was significantly improved by the addition of lenalidomide to rituximab (42% vs 19%, p=0.001). Moreover, TTNT was significantly longer with the combination (median not reached vs 2.1 years, p=0.02) [Figure1]. Overall survival rates at 3 years were 93% and 92%, respectively. Conclusions: The SAKK 35/10 randomized trial confirmed that lenalidomide plus rituximab is an active and feasible initial treatment for FL pts in need of therapy. Addition of lenalidomide significantly increased the CR/CRu rate at week 23 (primary endpoint) and was maintained throughout 30 months. Although the trial was not powered to detect survival differences (secondary endpoints), a significantly better TTNT and a trend towards prolonged PFS and CR duration was seen in the combination arm. The excellent overall survival in both arms suggests that chemotherapy-free strategies should be further explored. Figure 1. Time to next anti-lymphoma therapy by treatment arm Figure 1. Time to next anti-lymphoma therapy by treatment arm Disclosures Kimby: Jansen: Membership on an entity's Board of Directors or advisory committees, Other: Honoraria for lecture at educational session; Celgene: Other: Honoraria for lecture. educational meeting; Pfizer: Other: Research grant; Roche: Other: Honoraria for lecture in educational meetings; Gilead: Honoraria, Other: honoraria for educational lecture in meeting sponsored by Gilead. Mey:roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Research Funding. Wahlin:Roche: Consultancy. Hernberg:Roche: Consultancy, Honoraria. de Nully Brown:Roche: Research Funding. Ferreri:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Zander:Bristol Myers, Celgene, Amgen, Mundipharma, Janssen-Cilag, Takeda Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees.