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Supplementary Figure from Clonal Hematopoiesis Is Associated with Increased Risk of Severe Neurotoxicity in Axicabtagene Ciloleucel Therapy of Large B-Cell Lymphoma

To explore the role of clonal hematopoiesis (CH) in chimeric antigen receptor (CAR) T-cell therapy outcomes, we performed targeted deep sequencing on buffy coats collected during the 21 days before lymphodepleting chemotherapy from 114 large B-cell lymphoma patients treated with anti-CD19 CAR T cells. We detected CH in 42 (36.8%) pretreatment samples, most frequently in PPM1D (19/114) and TP53 (13/114) genes. Grade ≥3 immune effector cell-associated neurotoxicity syndrome (ICANS) incidence was higher in CH-positive patients than CH-negative patients (45.2% vs. 25.0%, P = 0.038). Higher toxicities with CH were primarily associated with DNMT3A, TET2, and ASXL1 genes (DTA mutations). Grade ≥3 ICANS (58.9% vs. 25%, P = 0.02) and ≥3 cytokine release syndrome (17.7% vs. 4.2%, P = 0.08) incidences were higher in DTA-positive than in CH-negative patients. The estimated 24-month cumulative incidence of therapy-related myeloid neoplasms after CAR T-cell therapy was higher in CH-positive than CH-negative patients [19% (95% CI, 5.5–38.7) vs. 4.2% (95% CI, 0.3–18.4), P = 0.028].Significance:Our study reveals that CH mutations, especially those associated with inflammation (DNMT3A, TET2, and ASXL1), are associated with severe-grade neurotoxicities in lymphoma patients receiving anti-CD19 CAR T-cell therapy. Further studies to investigate the mechanisms and interventions to improve toxicities in the context of CH are warranted.See related content by Uslu and June, p. 382.This article is highlighted in the In This Issue feature, p. 369

To explore the role of clonal hematopoiesis (CH) in chimeric antigen receptor (CAR) T-cell therapy outcomes, we performed targeted deep sequencing on buffy coats collected during the 21 days before lymphodepleting chemotherapy from 114 large B-cell lymphoma patients treated with anti-CD19 CAR T cells. We detected CH in 42 (36.8%) pretreatment samples, most frequently in PPM1D (19/114) and TP53 (13/114) genes. Grade ≥3 immune effector cell-associated neurotoxicity syndrome (ICANS) incidence was higher in CH-positive patients than CH-negative patients (45.2% vs. 25.0%, P = 0.038). Higher toxicities with CH were primarily associated with DNMT3A, TET2, and ASXL1 genes (DTA mutations). Grade ≥3 ICANS (58.9% vs. 25%, P = 0.02) and ≥3 cytokine release syndrome (17.7% vs. 4.2%, P = 0.08) incidences were higher in DTA-positive than in CH-negative patients. The estimated 24-month cumulative incidence of therapy-related myeloid neoplasms after CAR T-cell therapy was higher in CH-positive than CH-negative patients [19% (95% CI, 5.5–38.7) vs. 4.2% (95% CI, 0.3–18.4), P = 0.028]. Significance: Our study reveals that CH mutations, especially those associated with inflammation (DNMT3A, TET2, and ASXL1), are associated with severe-grade neurotoxicities in lymphoma patients receiving anti-CD19 CAR T-cell therapy. Further studies to investigate the mechanisms and interventions to improve toxicities in the context of CH are warranted. See related content by Uslu and June, p. 382. This article is highlighted in the In This Issue feature, p. 369

Engineering immune cells to target cancer is a rapidly advancing technology. The first commercial products, chimeric-antigen receptor (CAR) T cells, are now approved for hematologic malignancies. However, solid tumors pose a greater challenge for cellular therapy, in part because suitable cancer-specific antigens are more difficult to identify and surrounding healthy tissues are harder to avoid. In addition, impaired trafficking of immune cells to solid tumors, the harsh immune-inhibitory microenvironment, and variable antigen density and presentation help tumors evade immune cells targeting cancer-specific antigens. To overcome these obstacles, T cells are being engineered to express defined T-cell receptors (TCR). Given that TCRs target intracellular peptides expressed on tumor MHC molecules, this provides an expanded pool of potential targetable tumor-specific antigens relative to the cell-surface antigens that are targeted by CAR T cells. The affinity of TCR T cells can be tuned to allow for better tumor recognition, even with varying levels of antigen presentation on the tumor and surrounding healthy tissue. Further enhancements to TCR T cells include improved platforms that enable more robust cell expansion and persistence; coadministration of small molecules that enhance tumor recognition and immune activation; and coexpression of cytokine-producing moieties, activating coreceptors, or mediators that relieve checkpoint blockade. Early-phase clinical trials pose logistical challenges involving production, large-scale manufacturing, and more. The challenges and obstacles to successful TCR T-cell therapy, and ways to overcome these and improve anticancer activity and efficacy, are discussed herein.

Chimeric antigen receptor T-cells (CAR-T) are widely used for the treatment of relapsed/refractory Diffuse large B cell lymphoma (DLBCL). The data for CAR-T cell therapy in patients with extra-nodal(EN) lymphoma is restricted. We included 126 consecutive patients with DLBCL treated with commercially available CAR-T cells (tisagenlecleucel, n=100, 79.4% and axicabtagene ciloleucel, n=26, 20.6%). At lymphodepletion , 72/126(57%) had EN disease, 42/126(33%) patients had nodal disease (ND)-only and 12/126(10%) showed no disease assessed by PET-CT. There were no significant differences in CAR-T related toxicities and in the median PFS between EN patients and ND [10.76(95% CI: 7.8-13.6) vs 14.1 (95% CI:10-18.1) months, p =0.126)]. Similarly, median OS was not significantly different [15.36 (95% CI 12.5-18.2) vs. 18.4 (95% CI 14.8-22.1) months , p =0.100]. Subgroup analysis according to the number of EN involved sites showed that median PFS and OS were significantly higher in patients with ≤ 2 EN sites [12.3 months (95% CI 9-15.5)] vs 4.28 months (95% CI 0.6-7.9), p=0.010] compared to patients with ≥3 EN sites, respectively[16.5 months (95% CI 13.4-19.6) vs 8.7 months (95% CI 4.6-12.8), p=0.05]. In multivariate cox regression analysis, increased number sites of EN disease and high LDH at lymphodepletion negatively impacted PFS (p=0.021 and

Recent compelling evidence showed that innate immune effector cells could recognize allogeneic grafts and prime an adaptive immune response. Signal regulatory protein α (SIRPα) is an immunoglobulin superfamily receptor that is expressed on myeloid cells; the interaction between SIRPα and its ubiquitously expressed ligand CD47 elicits an inhibitory signal that suppresses macrophage phagocytic function. Additional studies showed that donor-recipient mismatch in SIRPα variants might activate monocytic allorecognition, possibly as the result of non-self SIRPα-CD47 interaction. However, the frequency of SIRPα variation and its role in hematopoietic stem cell transplantation (HSCT) remains unexplored. We studied 350 patients with acute myeloid leukemia/myelodysplastic syndrome who underwent HLA-matched related HSCT and found that SIRPα allelic mismatches were present in 39% of transplantation pairs. SIRPα variant mismatch was associated with a significantly higher rate of chronic graft-versus-host disease (GVHD; hazard ratio [HR], 1.5; P = .03), especially de novo chronic GVHD (HR, 2.0; P = .01), after adjusting for other predictors. Those with mismatched SIRPα had a lower relapse rate (HR, 0.6; P = .05) and significantly longer relapse-free survival (RFS; HR, 0.6; P = .04). Notably, the effect of SIRPα variant mismatch on relapse protection was most pronounced early after HSCT and in patients who were not in remission at HSCT (cumulative incidence, 73% vs 54%; HR, 0.5; P = .01). These findings show that SIRPα variant mismatch is associated with HSCT outcomes, possibly owing to innate allorecognition. SIRPα variant matching could provide valuable information for donor selection and risk stratification in HSCT.

Cancer immunotherapy has greatly advanced in recent years, with chimeric antigen receptor (CAR) T cells emerging as an innovative technology that harnesses the immune system to fight malignant diseases. These genetically engineered T-cells have shown encouraging results for B-cell lymphoid malignancies and are now being explored for other cancer types. However, this novel adoptive cell therapy is associated with a new spectrum of immune-mediated adverse events and toxicities. As CAR T cells recognize and engage tumour cells, cytokines are secreted and activate other immune cells, frequently leading to rapid development of cytokine release syndrome, which can result in acute deterioration of the patient's clinical condition. In many patients, cytokine release syndrome is mild and easy to manage, but others experience persistent fevers accompanied by hypotension and hypoxia, which require management with immune-modulatory agents. Another deleterious effect of cytokines released by effector cells is immune effector cell-associated neurotoxicity syndrome. This syndrome, caused by a disruption of the blood-brain barrier as a consequence of the immune process, can result in rapid deterioration in cognitive function. This is often associated with subtle changes in handwriting, often progressing to loss of memory and concentration and reduced ability to name objects or follow commands. In some cases, the neurological state is further compromised by seizures and in rare instances with fulminant life-threatening cerebral oedema. In this review, we discuss these toxicities, as well as other CAR T-cell-related immune phenomenon, and address their clinical manifestations, grading, and management options.

Background & aims After the rise of lymphoma incidence in the 1990's, there is a paucity of epidemiologic studies describing the characteristics of primary gastrointestinal non-Hodgkin's lymphoma (PGIL). This epidemiologic survey aims to identify recent trends in PGIL. Methods A retrospective, population-based study describing adult patients with PGIL in the Israeli Negev region between 1998 and 2013. Results 131 patients were diagnosed with PGIL, representing an annual incidence rate of 22.42/100,000, compared to 35.87/100,000 in the overall Israeli population. Both incidence rates did not significantly change during the study period. The median age was 66 years, and the most common presentation was in the stomach (49.6%) and oral cavity (18.3%). Histologically, diffuse large B cell lymphoma (DLBCL) was predominant (55.0%). Most patients (66.4%) had early stage disease. Only T-cell lymphoma showed a male predominance (14.7% versus 5.4%, P=0.008). Fifty patients (44.2%) had H. pylori testing, and 35 (70.0%) were positive. Of these, 91.4% received eradication treatment, and 57.1% were negative thereafter.Most patients received CHOP or RCHOP protocols (16.0% and 48.1%, respectively). Complete response was achieved in 53.4%. Median follow-up was 48 months, and 62 patients (47.3%) died during the study period. Liver involvement had a worse prognosis, (33.0% 5-year survival) compared to upper and lower GI disease(70.5% and 46.8% respectively, P=0.003 for the comparison between liver and other locations). T-cell lymphoma had worse survival (11 months vs. not reached, P=0.003). Conclusions This study demonstrates the incidence, and clinical characteristics of PGIL in the Negev region. It is important to identify disease characteristics, thus facilitating better disease detection and prognostication.

To explore the role of clonal hematopoiesis (CH) on chimeric antigen receptor (CAR) T-cell therapy outcomes, we performed targeted deep-sequencing on 114 large B-cell lymphoma patients treated with anti-CD19 CAR T-cells. We detected CH in 42 (36.8%) pre-treatment patient samples, most frequently in PPM1D (19/114) and TP53 (13/114) genes. The incidence of grade ≥3 immune-effector cell-associated neurotoxicity syndrome (ICANS) was higher in CH-positive patients compared to CH-negative patients (45.2% vs. 25.0%, p=0.038). Higher toxicities with CH were primarily driven by three CH genes, DNMT3A, TET2 and ASXL1 (DTA mutations). The incidence of grade ≥3 ICANS [58.9% vs. 25%, p=0.02] and grade ≥3 cytokine release syndrome [17.7% vs. 4.2%, p=0.08] were higher in patients with DTA mutations than those without CH. The estimated 24-month cumulative incidence of therapy-related myeloid neoplasms after CAR-T therapy was higher in patients with CH than those without CH (19% [95%CI: 5.5-38.7] vs. 4.2% [95%CI: 0.3-18.4], p=0.028).Statement of SignificanceOur study reveals that clonal hematopoiesis mutations, especially those associated with inflammation (DNMT3A, TET2, ASXL1), are associated with severe grade toxicities in lymphoma patients receiving anti-CD19 chimeric antigen receptor therapy. Further studies to investigate the mechanisms and interventions to improve toxicities in the context of CH are warranted.

Background Major advances in the treatment of patients with hairy cell leukemia (HCL) have been made following the introduction of purine analogues. The major significant short-term toxicity of cladribine therapy are neutropenia and neutropenic fever (NF) which may be life-threatening. Aim In this retrospective study, we compared the incidence and duration of neutropenia and hospitalization in patients with HCL treated with cladribine followed by peg-filgrastim as primary prophylaxis versus daily filgrastim given “on demand” according to absolute neutrophil count (ANC). Methods Medical records of patients with HCL diagnosed and followed in 12 medical centers in Israel during 1985–2015 were examined for details of disease at diagnosis. The efficacy of peg-filgrastim and filgrastim was assessed by evaluating the incidence of neutropenia (ANC 9 ]/L), number and length of hospitalizations, and number of days from the last day of therapy to recovery of ANC to >1.0 × 10 [ 9 ]/L. Results The study population included 202 patients with HCL, 159 of whom (80.7%) were treated with cladribine; 78 patients (49%) required hospitalization for the administration of broad-spectrum antibiotics due to NF. Twenty-eight (19%) patients were treated with peg-filgrastim as primary prophylaxis, while 74 (64%) received filgrastim “on demand” due to neutropenia. Median length of hospitalization, and nadir duration were 8 and 18 days respectively (p = 0.71, p = 0.44). Conclusions Infectious complications post-cladribine treatment remain high. No difference was found in terms of incidence of NF, number of febrile days, and nadir duration in patients receiving primary peg-filgrastim prophylaxis compared to filgrastim given on demand. Both approaches are justifiable, and the choice remains at the physician’s discretion.

The significance of minimal bone marrow (BM) involvement in diffuse large B cell lymphoma (DLBCL), as determined by flow cytometry (FC), is unclear. Patient outcomes were retrospectively analyzed based on their BM biopsy and FC involvement. Eighty-one patients were included, 21 and 51 were positive for biopsy(B+) and FC(FC+) respectively. B+ FC+ patients had a 52.3%CR rate, the B- FC+ group had 76.7%, and the B- FC- had 73.3%. Mean time to progression (TTP) was 67.45, 76.8, and 79.3 months and median Overall survival(OS) was 54.4, 76.6 and 69.5 months for the B+ FC+, B- FC+, and B- FC- groups respectively. A cutoff of 1% pathologic cells was an independent risk factor for TTP. In a multivariable analysis including International Prognostic Index (IPI), sex and HB, FC+ was independently associated with TTP (but not OS) at 5 years (HR 2.64, 95%CI 1.03-6.77) and at 7 years(HR 2.83, 95%CI 1.08-7.39). In summary, FC determined minimal involvement may suggest an intermediate risk group of DLBCL patients.

HLA-DPB1 mismatches between donor and recipient are commonly seen in allogeneic hematopoietic stem cell transplantation from an unrelated donor. HLA-DPB1 mismatch, conventionally determined by the similarity of the T-cell epitope (TCE), is associated with an increased risk of acute graft-versus-host disease (GVHD) and a decreased risk of disease relapse. We investigated the clinical impact of HLA-DPB1 molecular mismatch quantified by mismatched eplets (ME) and the Predicted Indirectly Recognizable HLA Epitopes Score (PS) in a cohort of 1,514 patients receiving hematopoietic stem cell transplants from unrelated donors matched at HLA-A, -B, -C, -DRB1/3/4/5, and - DQB1 loci. HLA-DPB1 alloimmunity in the graft-versus-host direction, determined by high graft-versus-host ME/PS, was associated with a reduced risk of relapse (hazard ratio [HR]=0.83, P=0.05 for ME) and increased risk of grade 2-4 acute GVHD (HR=1.44, P

BackgroundCOVID-19 Convalescent plasma (CCP) is safe and effective, particularly if given at an early stage of the disease. Our study aimed to identify an association between survival and specific antibodies found in CCP.Patients and MethodsPatients ≥18 years of age who were hospitalized with moderate to severe COVID-19 infection and received CCP at the MD Anderson Cancer Center between 4/30/2020 and 8/20/2020 were included in the study. We quantified the levels of anti-SARS-CoV-2 antibodies, as well as antibodies against antigens of other coronavirus strains, in the CCP units and compared antibody levels with patient outcomes. For each antibody, a Bayesian exponential survival time regression model including prognostic variables was fit, and the posterior probability of a beneficial effect (PBE) of higher antibody level on survival time was computed.ResultsCCP was administered to 44 cancer patients. The median age was 60 years (range 37-84) and 19 (43%) were female. Twelve patients (27%) died of COVID-19-related complications. Higher levels of two non-SARS-CoV-2-specific antibodies, anti-HCoV-OC43 spike IgG and anti-HCoV-HKU1 spike IgG, had PBE = 1.00, and 4 SARS-CoV-2-specific antibodies had PBEs between 0.90 and 0.95. Other factors associated with better survival were shorter time to CCP administration, younger age, and female sex.ConclusionsCommon cold coronavirus spike IgG antibodies anti-HCoV-OC43 and anti-HCoV-HKU1 may target a common domain for SARS-CoV-2 and other coronaviruses. They provide a promising therapeutic target for monoclonal antibody production.

We reviewed pre-diagnosis clinical data of 420 patients with pathologically confirmed myelodysplastic syndromes (MDSs) presenting with anemia. In 232 patients with yearly pre-diagnosis complete blood counts (CBCs), we also analyzed CBC kinetics in respects to a standardized timepoint in which all patients had similar levels of hemoglobin (Hgb). At the standardized timepoint (last documented 12 > Hgb ≥ 11 g/dL), occurring months-years before diagnosis, median CBC values were Hgb 11.4 g/dL, absolute neutrophil count (ANC) 2.7 × 103 (k)/mcl, and platelets (PLTs) 181 k/mcl. Gradual changes in CBC could be observed years prior to this timepoint, for the most part while within normal/near-normal limits. During this time, most patients had a coexisting alternative etiology for anemia. Patients with high-risk cytogenetic/blast features had a rapid and steeper decrease in counts in the last year before developing a concerning anemia (decrease in: Hgb 0.75 g/dL vs 0.55 g/dL; PLT 29.5 vs 4.5 k/mcl; ANC 0.86 vs 0.4 k/mcl, P = .03). Low-risk patients had a high rate of longstanding mild anemia (31% vs 16%, P = .05). Rate of development of cytopenia and number of involved hematopoietic lines were prognostic. In 65% of patients, with near normal CBC at the standardized timepoint, but in whom there was a decrease in multiple hematopoietic lines over the preceding year, the 5-year overall survival (5yOS) was 53% compared to 71% in patients with isolated slowly progressing anemia (20% of patients). In 15% of patients with mild cytopenia developing after both a rapid decrease and multiple involved lines, prognosis was dismal (5yOS 34%). In conclusion, kinetics of pre-MDS CBC values correlate with disease risk and survival.

In recent years, considerable progress has been made in frontline therapy for elderly/physically unfit patients with CLL. The combination of obinutuzumab and chlorambucil (O-Clb) has been shown to prolong progression free survival (PFS, median PFS-31.5 months) and overall survival (OS) compared to chlorambucil alone. More recently, obinutuzumab given in combination with either ibrutinib or venetoclax improved PFS but not OS when compared to O-Clb. In this retrospective multinational, multicenter co-operative study, we evaluated the efficacy and safety of frontline treatment with O ± Clb in unfit patients with CLL, in a “real-world” setting. Patients with documented del (17p13.1)/TP53 mutation were excluded. A total of 437 patients (median age, 75.9 years; median CIRS score, 8; median creatinine clearance, 61.1 mL/min) were included. The clinical overall response rate was 80.3% (clinical complete and partial responses in 38.7% and 41.6% of patients, respectively). Median observation time was 14.1 months and estimated median PFS was 27.6 months (95% CI, 24.2-31.0). In a multivariate analysis, high-risk disease [del (11q22.3) and/or IGHV-unmutated], lymph nodes of diameter > 5 cm, obinutuzumab monotherapy and reduced cumulative dose of obinutuzumab, were all independently associated with shorter PFS. The median OS has not yet been reached and estimated 2-year OS is 88%. In conclusion, in a “real-world” setting, frontline treatment with O-Clb achieves PFS comparable to that reported in clinical trials. Inferior outcomes were noted in patients with del (11q22.3) and/or unmutated IGHV and those treated with obinutuzumab-monotherapy. Thus, O-Clb can be still considered as legitimate frontline therapy for unfit CLL patients with low-risk disease.

Objectives To ascertain the relevance of bone marrow cellularity (BMC) to the interpretation of blast percentage (blast%) in MDS prognostication. Methods We compared survival prediction based on blast% adjusted to different levels of cellularity, compared to the survival based on the original IPSS-R blast% grouping. Results We analyzed 355 consecutive MDS patients. Cellularity, in and of itself or its interaction with blast%, was not associated with overall survival (OS). In a small subset of patients with a hypercellular marrow (15%; n = 26), dismal prognosis was observed at lower levels of blast%. For these cases OS was similar to higher IPSS-R blast groups. For example, within the Intermediate group (blast% 5%-10%), those with a hypercellular marrow and >6% blasts had an OS of 10 m similar to 16 m in the High (blast% 10%-19%) blast group. These changes did not translate into a significant improvement in overall prognostic power of a cellularity-adjusted IPSS-R (C index 0.71 vs. 0.70). Conclusion Adjusting blast% to cellularity did not improve prognostication. However, within IPSS-R-defined blast groups, a small subset of patients with relatively higher blast% and hypercellularity may have a worse prognosis than expected.

OBJECTIVE To evaluate disease characteristics and long-term outcomes in patients requiring second-line treatment following fludarabine, cyclophosphamide, and rituximab (FCR), for relapsed/refractory disease (R/R), or following discontinuation due to toxicities. METHOD A retrospective analysis of 126 chronic lymphocytic leukemia patients treated with frontline FCR: 63 received second-line treatment (41 relapsed, nine refractory [SD/PD], 13 prior toxicity). Time to next treatment (TTNT) was calculated from beginning FCR to initiation of second-line therapy. Overall and event-free survival was calculated from initiation of salvage treatment (OS2/EFS2). RESULTS Median follow-up for the entire cohort was 67 and 37 months from second-line therapy. TTNT

A non-invasive myelodysplastic syndromes (MDS) diagnostic model would allow for care while avoiding invasive bone marrow examinations (BME). BME-established MDS patients were compared to non-MDS (BME-excluded) patients. Variables (gender, age, hemoglobin (Hb), mean red blood cell corpuscular volume (MCV), platelet (PLT), and white blood cell (WBC)) were combined with multivariate logistic regression; a probability score (Y) was calculated. MDS (n = 48) and non-MDS (n = 63) patients were used to establish the model. The ROC was drawn, giving an AUC of 0.748 (95% CI: 0.656-0.84). Two cutoff values were used for Y. Y ≥ 0.633: high likelihood (positive predictive value (PPV) = 85%); Y ≤ 0.288: low likelihood (negative predictive value (NPV) = 81%) of MDS. The first group is defined as probable MDS (pMDS); the second, probably not MDS (pnMDS). The model was validated with 40 additional patients (20 with and 20 without MDS). Using clinical and lab data, we could diagnose or exclude MDS in about half of the patients, avoiding BME. Future work will use larger cohorts of patients to improve and further validate the model.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapy for patients with hematologic malignancies. It is conventionally believed that alloreactivity is initiated by T-cells recognizing the non-self HLA molecules on the graft. Cells from the innate immune system, such as macrophages and monocytes, are induced by nonspecific "danger" molecules released from damaged tissue. Recent studies revealed that the innate immune system could distinguish the non-self graft and subsequently prime the adaptive immune system to advance the allorecognition process. Signal regulatory protein α (SIRPα) is an immunoglobulin superfamily receptor that is expressed on macrophages and myeloid cells. The interaction between SIRPα and its ubiquitously expressed ligand, CD47, suppresses the macrophages phagocytic function. It has been demonstrated that recipient's monocytes detect polymorphism in SIRPα, and mismatches of SIRPα between donor and recipient can regulate the allorecognition response in the murine model. Our group has recently investigated the role of SIRPα variant mismatch in recipients of allo-HSCT from an HLA-matched related donor for treatment of acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS). We found that donor/recipient SIRPα mismatch was commonly detected in 39% of transplant pairs, and the presence of the mismatch was significantly associated with an increase rate of chronic graft-versus-host disease (cGvHD) and a lower rate of early relapse. We hypothesized that comparable effects could be occurring in recipients of allo-HSCT for treatment of lymphoid malignancies. We tested our hypothesis in a cohort of patients who received an allo-HSCT from an HLA matched-related donor at our institution between January 2008 and December 2018 for the treatment of lymphoid malignancies. Only patients who received a peripheral blood stem cell graft and tacrolimus/methotrexate for GvHD prophylaxis were eligible for the study. A total of 313 patients met the eligibility criteria including 310 (99%) who engrafted and 3 (1%) who died early before engraftment. The risk of early death was not associated with SIRPα mismatch variant. Only patients who engrafted (N=310) were included in subsequent analyses. Among these, 42% (N=130) of donor/recipient pairs were SIRPα mismatched. The majority of patients were treated for acute lymphoblastic leukemia (N=115, 37%) or non-Hodgkin's lymphoma (NHL) (N=114, 37%), followed by chronic lymphoblastic leukemia (N=59, 19%), and Hodgkin's lymphoma (N=22, 7%). Most (N=259, 84%) of patients had chemo-sensitive disease. The median age at transplant was 51 (range: 18-72) years, and 64% of patients were female. The median age of donors was 50 (range: 18-79) years and 53% were male. Conditioning regimens were myeloablative in 52% of cases. Outcomes were evaluated accounting for competing risks. The median follow-up in surviving patients was 74 (range: 3-124) months. A total of 99, 84, 108, and 51 patients experienced grade 2-4 acute GvHD, cGvHD requiring systemic immunosuppressive therapy, disease progression, and non-relapse mortality (NRM), respectively. Multivariate analyses showed that SIRPα mismatch was associated with a significantly higher rate (hazard ratio [HR]=1.9, P=.005) of cGvHD requiring systemic immunosuppressive therapy, and a lower rate (HR=.5, P=.004) of disease progression. Notably, the increased rate of cGVHD was consistent across the 4 lymphoid malignancies evaluated, yet the lower rate of relapse was observed in all diagnoses except NHL. There was no significant impact of SIRPα mismatch on grade 2-4 acute GvHD (HR=1.2, P=.3) or on NRM (HR=0.7, P=.3). Consistent with our preceding study in the AML/MDS cohort, the mismatch in SIRPα, a regulatory protein in innate immunity, is associated with a higher rate of cGvHD and relapse protection in patients who underwent allo-HSCT for lymphoid malignancies. The results of this study could be clinically important in donor selection and provide insight into the underlying role of innate immunity in allo-HSCT. Disclosures Shpall: Adaptimmune: Consultancy; Takeda: Patents & Royalties; Novartis: Consultancy; Magenta: Honoraria; Navan: Consultancy; Bayer HealthCare Pharmaceuticals: Honoraria; Magenta: Consultancy; Axio: Consultancy; Affimed: Patents & Royalties; Novartis: Honoraria.

Decreased absolute lymphocyte counts (ALCs) following frontline therapy for chronic lymphocytic leukemia may be associated with disease control, even in patients without evidence of minimal residual disease. We studied the prognostic significance of ALCs during the first year following treatment with fludarabine, cyclophosphamide, and rituximab (FCR). We evaluated 99 patients who achieved a partial response without lymphocytosis ( 1.8 vs not reached for ALC ≤ 0.7 at 9 months, P

Introduction. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) are common adverse effects of chimeric antigen receptor (CAR) T-cell therapy. Elevated biomarkers, such as ferritin and LDH, have been shown to correlate with more severe toxicity. The endothelial activation and stress index (EASIX) is a surrogate of endothelial activation, and correlates to other biomarkers of endothelial dysfunction. In allogeneic hematopoietic cell transplantation (HCT), it is predictive of toxicity such as fluid overload, which is correlative with endothelial dysfunction, as well as sinusoidal obstruction syndrome, non relapse mortality and overall survival (Luft et al, BMT 2019, Varma et al, BBMT, 2020, Jiang et al, Haematologica, 2020). In this study we describe the correlation of EASIX to CAR T cell related CRS and ICANS. Methods. Retrospective data from consecutive patients treated with standard of care axi-cel for non-Hodgkin's lymphoma at MD Anderson Cancer Center between January 2018 and April 2020 were included in the study. CRS and ICANS were graded according to CARTOX criteria (Neelapu et al, Nat Rev Clin Oncol, 2018), and after 5/2019, according to the ASTCT criteria (Lee et al, BBMT, 2019). EASIX parameters were recorded prior to lymphodepletion (the latest value on days -12 to -6) and were available for all 171 patients. The score was defined as lactate dehydrogenase (U/L) × creatinine (mg/dL)/ thrombocytes (10^9 cells per L), with LDH adjusted to the upper limit of normal. Predictors of toxicity were evaluated using Fine and Grey regression analysis considering death before grade 2-4 toxicity as a competing risk. Results. 171 consecutive patients treated with commercial axi-cel for diffuse large B cell lymphoma (n=133), transformed follicular lymphoma (n=28) and primary mediastinal lymphoma (n=10) were included in the study. Median age was 59 years (range, 18-85), and 120 (70%) were male. 151 patients had an ECOG performance status ≤1, 45 patients (26%) had a previous autologous HCT, and 3 (1.8%) had a previous allogeneic HCT. Prior to lymphodepletion, 96 (56%) patients had a high IPI score (≥3) and 134 (78%) were refractory to the previous line of treatment. With a median follow-up of 259 days (range: 25-800) since infusion, ICANS of any grade was noted in 109 (64%) patients, with 84 (49%) having grades 2-4. CRS of any grade was observed in 160 (93%) patients, with 81 (47%) having grades 2-4 CRS. A total of 56 (33%) patients were diagnosed with grade 2-4 ICANS and CRS. The median EASIX score for the entire cohort was 2.1 (range: 0.3-283; inter-quartiles: 1.1 and 4.6). On univariate analysis, EASIX levels above the median were associated with higher cumulative incidence (CI) of grade 2-4 ICANS (% CI: 61 vs 31%; HR=2.4, p Multivariate analysis showed EASIX score to be an independent predictor of grade 2-4 ICANS (HR=2.3, p=0.001) or CRS (HR=2.3, p=0.001); female gender of ICANS (HR=1.7, p=0.03) and lack of prior autologous transplant of CRS (HR=1.9, p=0.02). The impact of IPI did not reach statistical significance for either ICANS (HR=1.3, p=0.3) or CRS (HR=1.2, p=0.4). Further multivariate analysis for other biomarkers and their incorporation into a revised biomarker score will be presented at the meeting. Conclusions. Our results suggest that the EASIX score prior to lymphodepletion predicts higher grade CRS and ICANS in patients receiving axi-cel. These results of routinely available clinical variables require further prospective studies for validation, however our study shows that this score may better stratify patient risk of toxicity, and possibly inform clinical decisions and prevention strategies for patients at higher risk. Disclosures Nieto: Secura Bio: Other: Grant Support; Novartis: Other: Grant Support; Astra Zeneca: Other: Grant Support; Affimed: Consultancy, Other: Grant Support. Hosing:NKARTA Inc.: Consultancy. Westin:47: Research Funding; Amgen: Consultancy; Morphosys: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Kite: Consultancy, Research Funding; Curis: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding; Genentech: Consultancy, Research Funding. Lee:Celgene: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Guidepoint Blogal: Consultancy; Aptitude Health: Speakers Bureau; Oncternal Therapeutics: Research Funding; Seattle Genetics: Research Funding; Takeda: Research Funding. Nastoupil:Celgene: Honoraria, Research Funding; Karus Therapeutics: Research Funding; Bayer: Honoraria; Genentech, Inc.: Honoraria, Research Funding; Gamida Cell: Honoraria; Gilead/KITE: Honoraria; Novartis: Honoraria, Research Funding; Merck: Research Funding; TG Therapeutics: Honoraria, Research Funding; LAM Therapeutics: Research Funding; Janssen: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding. Parmar:Cellenkos Inc.: Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Wang:Guidepoint Global: Consultancy; Dava Oncology: Honoraria; Verastem: Research Funding; Molecular Templates: Research Funding; Celgene: Consultancy, Other: Travel, accommodation, expenses, Research Funding; OMI: Honoraria, Other: Travel, accommodation, expenses; Nobel Insights: Consultancy; Lu Daopei Medical Group: Honoraria; Beijing Medical Award Foundation: Honoraria; Pharmacyclics: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; MoreHealth: Consultancy; AstraZeneca: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Janssen: Consultancy, Honoraria, Other: Travel, accommodation, expenses, Research Funding; Oncternal: Consultancy, Research Funding; OncLive: Honoraria; InnoCare: Consultancy; Targeted Oncology: Honoraria; Loxo Oncology: Consultancy, Research Funding; Pulse Biosciences: Consultancy; Kite Pharma: Consultancy, Other: Travel, accommodation, expenses, Research Funding; Juno: Consultancy, Research Funding; BioInvent: Research Funding; VelosBio: Research Funding; Acerta Pharma: Research Funding. Flowers:AbbVie: Consultancy, Research Funding; Kite: Research Funding; Leukemia and Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; V Foundation: Research Funding; Cancer Prevention and Research Institute of Texas: Research Funding; Bayer: Consultancy; National Cancer Institute: Research Funding; Eastern Cooperative Oncology Group: Research Funding; Burroughs Wellcome Fund: Research Funding; TG Therapeutics: Research Funding; Millennium/Takeda: Consultancy, Research Funding; Acerta: Research Funding; Spectrum: Consultancy; Pharmacyclics/Janssen: Consultancy; Karyopharm: Consultancy; OptumRx: Consultancy; Gilead: Consultancy, Research Funding; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Denovo Biopharma: Consultancy; Celgene: Consultancy, Research Funding; BeiGene: Consultancy. Hawkins:Kite: Membership on an entity's Board of Directors or advisory committees. Rezvani:GemoAb: Membership on an entity's Board of Directors or advisory committees; Affimed: Other: Educational grant; Adicet Bio: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics: Other: Educational grant; Virogen: Membership on an entity's Board of Directors or advisory committees; Takeda: Other: Licensing agreement; Formula Pharma: Membership on an entity's Board of Directors or advisory committees. Champlin:Takeda: Patents & Royalties; DKMS America: Membership on an entity's Board of Directors or advisory committees; Genzyme: Speakers Bureau; Actinium: Consultancy; Johnson and Johnson: Consultancy; Omeros: Consultancy; Cytonus: Consultancy. Shpall:Magenta: Membership on an entity's Board of Directors or advisory committees; Takeda: Other: Licensing Agreement; Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Zelluna: Membership on an entity's Board of Directors or advisory committees; Adaptimmune: Membership on an entity's Board of Directors or advisory committees. Neelapu:Novartis: Other: personal fees; Bristol-Myers Squibb: Other: personal fees, Research Funding; Merck: Other: personal fees, Research Funding; Kite, a Gilead Company: Other: personal fees, Research Funding; Celgene: Other: personal fees, Research Funding; Pfizer: Other: personal fees; Allogene Therapeutics: Other: personal fees, Research Funding; Cell Medica/Kuur: Other: personal fees; Incyte: Other: personal fees; Precision Biosciences: Other: personal fees, Research Funding; Legend Biotech: Other; Adicet Bio: Other; Calibr: Other; Unum Therapeutics: Other, Research Funding; Poseida: Research Funding; Cellectis: Research Funding; Karus Therapeutics: Research Funding; Acerta: Research Funding; Takeda Pharmaceuticals: Patents & Royalties; N/A: Other. Kebriaei:Jazz: Consultancy; Novartis: Other: Served on advisory board; Kite: Other: Served on advisory board; Ziopharm: Other: Research Support; Pfizer: Other: Served on advisory board; Amgen: Other: Research Support.

Introduction: Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy has improved survival outcomes in patients with relapsed/refractory (r/r) large B-cell lymphoma (LBCL). However, many patients experience systemic toxicities such as cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) and about 60% relapse. Recent studies indicate that the gut microbiome can modulate tumor response and also influence toxicities associated with immune checkpoint inhibitor therapy. However, the influence of gut microbiome has not been well-studied in patients receiving CAR T-cell therapy. Here, we analyzed the association between gut microbiome composition and diversity metrics with survival outcomes and toxicities in r/r LBCL patients treated with anti-CD19 CAR T-cell therapy. Methods: Baseline stool samples were collected from r/r LBCL patients within 3 days of CAR T-cell infusion (days -3 to +3). Taxonomic profiling was performed on all samples using targeted ribosomal 16S RNA gene sequencing of the V4 region. The anti-tumor response was assessed as per Lugano 2014 criteria. Bacterial community alpha diversity was calculated using the inverse Simpson Index (ISI). Results were correlated with toxicity outcomes, including CRS and ICANS, as well as efficacy outcomes, including response, progression-free (PFS), and overall survival (OS). Results: We analyzed baseline stool samples from 33 r/r LBCL patients (24 DLBCL, 7 transformed follicular lymphoma, and 2 double-hit lymphomas) treated with standard of care axicabtagene ciloleucel (n =30) or tisagenlecleucel (n=3). The median age of the cohort (23 males, 10 females) was 54 (range 28 - 84) years. The number of patients with ECOG performance status (PS) 0-1, Ann-Arbor stage ≥3, and International Prognostic Index (IPI) of ≥3 at the time of apheresis were 29 (88%), 33 (100%), and 15 (46%), respectively. The median number of prior lines of therapy was 3 (range 2-6). The median follow-up from CAR-T infusion was 7.3 (range 0.8 -13.6) months. The best overall and complete response (CR) rates were 82% (27/33) and 58% (19/33), respectively. All patients were evaluable for toxicity assessment and 29 were evaluable for response assessment at 3 months (3 patients died of toxicity before 3 months and 1 was lost to follow-up). Since ongoing response at 3 months was previously shown to be associated with long-term durability (Locke et al, Lancet Oncol 2019), we analyzed differences in baseline gut microbiome markers in patients with or without ongoing CR at 3 months post-CAR-T infusion. ISI was significantly higher in patients with ongoing CR at 3 months (N=13) compared to those without ongoing CR (NoCR) group (N=16) (Fig.1A, p=0.045). However, beta diversity using weighted UniFrac distances by principal coordinate analysis was not significantly different. ISI did not correlate with age, sex, IPI score, ECOG PS, serum LDH, number of lines of therapy or disease status (primary refractory vs. relapsed). We found an increased relative abundance of several bacterial families in patients with ongoing CR vs. NoCR group. We also analyzed the impact of gut microbial diversity on PFS and OS by stratifying the patients according to the tertile of ISI. The PFS of patients in the highest tertile of ISI values (n=11, median PFS not reached) was significantly higher compared to those with intermediate (n=11, median PFS = 2.82 months, HR 12.7, 95% CI 3.61 to 44.77, log-rank, p=0.001) or low (n=11, median PFS = 2.43 months, HR 12.9, 95% CI 3.68 to 45.75, log-rank, p=0.001) ISI values (Fig. 1B). High ISI values also correlated positively and significantly with OS (Fig. 1C). We did not observe any significant association between microbial diversity, either alpha or beta, and toxicities including CRS [(grade 0-1 (N=22) vs ≥2 (N=11)] and ICANS [(grade 0-2 (N=23) vs ≥3 (N=10)]. Additional details including impact of microbial composition will be presented at the meeting. Conclusion: Our results suggest that the baseline gut bacterial diversity may serve as a predictive biomarker for efficacy of anti-CD19 CAR T-cell therapy in r/r LBCL patients, with high diversity favoring improved outcomes. If confirmed in larger studies, future investigations should explore if the microbiome could be a modulator of CAR T-cell response in order to determine whether developing therapeutic interventional strategies to favorably alter the microbiome are warranted. Disclosures Nastoupil: TG Therapeutics: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Merck: Research Funding; Celgene: Honoraria, Research Funding; Gamida Cell: Honoraria; Gilead/KITE: Honoraria; Bayer: Honoraria; Pfizer: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Genentech, Inc.: Honoraria, Research Funding; LAM Therapeutics: Research Funding; Karus Therapeutics: Research Funding. Westin:Janssen: Consultancy, Research Funding; Amgen: Consultancy; Kite: Consultancy, Research Funding; Curis: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Genentech: Consultancy, Research Funding; BMS: Consultancy, Research Funding; 47: Research Funding; Morphosys: Consultancy, Research Funding; Astra Zeneca: Consultancy, Research Funding. Lee:Guidepoint Blogal: Consultancy; Celgene: Research Funding; Seattle Genetics: Research Funding; Oncternal Therapeutics: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Aptitude Health: Speakers Bureau; Takeda: Research Funding. Kebriaei:Kite: Other: Served on advisory board; Novartis: Other: Served on advisory board; Ziopharm: Other: Research Support; Amgen: Other: Research Support; Pfizer: Other: Served on advisory board; Jazz: Consultancy. Shpall:Takeda: Other: Licensing Agreement; Adaptimmune: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Zelluna: Membership on an entity's Board of Directors or advisory committees; Magenta: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees. Jain:Cellectis: Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Precision Bioscienes: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Verastem: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; BeiGene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics: Research Funding; Aprea Therapeutics: Research Funding; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: 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, Research Funding; BMS: Research Funding; Pfizer: Research Funding; ADC Therapeutics: Research Funding; Incyte: Research Funding; TG Therapeutics: Honoraria, Membership on an entity's Board of Directors or advisory committees. Green:KDAc Therapeutics: Current equity holder in private company. Flowers:Kite: Research Funding; Pharmacyclics/Janssen: Consultancy; Spectrum: Consultancy; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Eastern Cooperative Oncology Group: Research Funding; AbbVie: Consultancy, Research Funding; Leukemia and Lymphoma Society: Membership on an entity's Board of Directors or advisory committees; Acerta: Research Funding; Karyopharm: Consultancy; V Foundation: Research Funding; National Cancer Institute: Research Funding; Bayer: Consultancy; Denovo Biopharma: Consultancy; Cancer Prevention and Research Institute of Texas: Research Funding; Millennium/Takeda: Consultancy, Research Funding; BeiGene: Consultancy; OptumRx: Consultancy; Genentech, Inc./F. Hoffmann-La Roche Ltd: Consultancy, Research Funding; Burroughs Wellcome Fund: Research Funding; TG Therapeutics: Research Funding. Champlin:Genzyme: Speakers Bureau; DKMS America: Membership on an entity's Board of Directors or advisory committees; Cytonus: Consultancy; Omeros: Consultancy; Johnson and Johnson: Consultancy; Actinium: Consultancy; Takeda: Patents & Royalties. Wargo:Imedex, Dava Oncology, Omniprex, Illumina, gilead, PeerView, PET, MedImmune and Bristol-Myers Squibb: Honoraria, Speakers Bureau; Merck: Consultancy; Microbiome DX: Consultancy; GlaxoSmithKline: Consultancy, Research Funding; Roche/Genentech: Consultancy, Research Funding; Novartis: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Astrazeneca: Consultancy; Biothera Pharmaceuticals: Consultancy. Neelapu:Celgene: Other: personal fees, Research Funding; Pfizer: Other: personal fees; Allogene Therapeutics: Other: personal fees, Research Funding; Cell Medica/Kuur: Other: personal fees; Novartis: Other: personal fees; N/A: Other; Precision Biosciences: Other: personal fees, Research Funding; Incyte: Other: personal fees; Bristol-Myers Squibb: Other: personal fees, Research Funding; Acerta: Research Funding; Takeda Pharmaceuticals: Patents & Royalties; Poseida: Research Funding; Cellectis: Research Funding; Karus Therapeutics: Research Funding; Calibr: Other; Legend Biotech: Other; Adicet Bio: Other; Merck: Other: personal fees, Research Funding; Kite, a Gilead Company: Other: personal fees, Research Funding; Unum Therapeutics: Other, Research Funding.

Databases were searched to identify studies published over the past 10 years that addressed the utility of patient-reported outcomes (PROs) in patients receiving chimeric antigen receptor (CAR) T cell therapy in patients with hematological malignancies. Among 280 records, three articles covering 206 patients were eligible. The data were prospectively collected at multiple time points. The compliance rates were 70% to 94%. There was an inverse relationship between fatigue and social function among adults. The quality of life (QoL) improvement and ability to complete PROs were linked to disease status. About 40% of adults reported at least some cognitive difficulties, with a detrimental impact on mental and physical health status. In adults, the most commonly reported cognitive impairment was memory difficulties. Depression was associated with cognitive difficulties. Younger adults were at higher risk of long-term poor mental health, anxiety, and depression. For pediatric and adolescent patients, emotional dysfunction improves over time. QoL status improved over time; yet, severe cytokine release syndrome and neurotoxicity caused delayed improvement. Information regarding whether the PROs were integrated into medical records and clinical guidelines is lacking. Utilizing PROs in patients on CAR T cell therapy seems feasible and informative. Studies utilizing larger sample sizes and using validated PRO tools at different time points remain unmet needs.

Context Relapse after allogeneic hematopoietic cell transplantation (allo-HCT1) leads to poor survival in patients with acute myeloid leukemia (AML). A second allo-HCT can achieve durable remission in a subset of patients. Objective To assess outcomes of patients who underwent allo-HCT2 for relapsed AML and identify risk factors associated with survival. Design We reviewed consecutive medical records of 91 adult patients (age >18 years) with AML who underwent allo-HCT2 for relapsed disease at our institution from January 2000 until August 2019. Results At allo-HCT2, median age was 43 (range, 18–67), donor types were HLA-identical sibling 41%, HLA-matched-unrelated 35%, haploidentical 21%, and cord-blood 1%. Donors were different at allo-HCT2 in 53% patients. The majority of patients received reduced intensity conditioning (78%) and were in remission (58%) at allo-HCT2. The median remission duration after allo-HCT1 was 8.4 months (range, 1–70); median time between transplants 13.6 months (range, 2.6–73). The median follow-up of surviving patients after allo-HCT2 was 25 months (range, 4–70), with 32% alive at time of analysis; the most common cause of death was disease recurrence (87%). At 2-years, progression-free-survival, overall survival, and cumulative incidence of relapse were 30% (95% CI, 18–37%), 36% (95% CI, 26–47%) and 42% (95% CI, 32–54%), respectively. The cumulative incidence of grades II–IV acute and chronic GVHD were 35% and 18%, respectively. In multivariate analysis, persistent disease at time of allo-HCT1 and allo-HCT2, along with high leukemia burden at allo-HCT2 (defined as BM blast >10%) [HR,2.4; p=0.006], development of cGVHD after allo-HCT1 [HR,3.1; p 2) [HR, 2.1; p=0.01] were associated with inferior PFS after allo-HCT2. These factors also predicted for OS. A total of 19, 55, and 17 patients had neither, one, or more than one adverse factors, respectively. Two-year OS was 60%, 40%, and 0%, and PFS was 47%, 28%, and 0% in these 3 respective groups. Conclusions Long-term survival benefit is possible after allo-HCT2 in patients with AML who relapsed after allo-HCT1. This can be achieved in patients without cGVHD after allo-HCT1 who are fit and in remission at time of allo-HCT1, along with

Background/aim In this retrospective study, we summarized the national Israeli experience with hairy cell leukemia (HCL) in a large cohort of patients with a long follow-up. Patients and methods Demographic data, and relevant laboratory and clinical parameters were analyzed, emphasizing the outcome after first-line treatment with cladribine. Results Data on 203 patients was collected from 12 medical centers during 1985-2015. Mean and median follow-up were 7.5 years and 5.18 years (interquartile range=0.1-40 years), and 5- and 10-year survival were 96% and 90.62%, respectively. The median age of diagnosis was 55.5 years for Jews and 49 years for Arabs (p=0.021), and most patients were males (81.77%); 52.2% were Ashkenazi Jews, 36.1% Sephardic Jews and 11.7% were Arab, Druze or other ethnicity. Cladribine was given to 159 patients (80.7%%) and most (62%) received intravenous (i.v.) and 38% received subcutaneous (s.c.) therapy. Overall survival and time to next treatment were not significantly different between the two schedules (i.v., s.c.). In univariate analysis of a variety of factors, only age >65 years had a negative impact on outcome, with shorter overall survival. It is of interest that Arab patients with HCL were diagnosed at an earlier age, but had a similar clinical course and outcome to both Ashkenazi and Sephardic Jews.

Chronic lymphocytic leukemia (CLL) occurs in older individuals with a median age at diagnosis of 72 years. In recent years, there has been considerable progress in the frontline therapy of elderly/physically unfit patients with CLL. The German CLL11 trial showed that addition of obinutuzumab to chlorambucil (G-Clb) prolongs progression free survival (PFS) and overall survival (OS) compared to chlorambucil alone or in combination with rituximab. More recently, obinutuzumab together with ibrutinib or venetoclax were shown to be superior to G-Clb with regard to PFS, but there was no advantage in terms of OS. In this retrospective, multinational and multicenter co-operative study the European Research Initiative on CLL (ERIC) and the Israeli CLL Study Group (ICLLSG) evaluated the efficacy of frontline treatment with G-Clb in patients with CLL, in a "real-world" setting. Our analysis excluded CLL patients with documented del(17p) or TP53 mutations since they are no longer treated with chemotherapy. Results: A total of 437 treatment-naïve patients with CLL from 51 medical centers located in 13 countries were included. The median age of this patient population was 75.9 years; 59.7% were men, median CIRS total score was 8 and estimated creatinine clearance 61.1 mL/min. Seventy four patients had Binet stage A (17.2%), 167 (38.8%) stage B and 190 (44.1%) stage C. Results of FISH and IGHV mutational status were available for 332 and 115 patients, respectively. High-risk cytogenetics, del(11q) was documented in 18.7% patients and IGHV-unmutated gene in 64.4%. The vast majority of patients were treated with G-Clb (N=408) and the rest with obinutuzumab monotherapy (G-monotherapy, N=29). The clinical overall response was 86.5%, including clinical complete and partial responses in 41.6% and 45.8% of cases, respectively. The median observation time was 14.1 months (m) and the median PFS of the entire cohort was 27.6m (95% CI, 24.2-31.0). The PFS for G-Clb was significantly better than G-monotherapy (P=0.001; HR=0.38, 95% CI: 0.22-0.67), being the 2-year PFS estimates 61.8% and 52.8%, respectively. The median PFS was significantly shorter for patients with del(11q) (19.2m) compared to those with normal FISH (not reached, P5cm, G-monotherapy, reduced cumulative dose of obinutuzumab and status less than CR, were independently associated with shorter PFS. Seventy patients (16%) received a second-line treatment. The median OS for the entire cohort has not been reached yet and 2-year OS estimate is 88%. In conclusion, in a "real-world" setting, frontline treatment with G-Clb achieves PFS comparable to that reported in clinical trials. Inferior outcomes were observed in patients with high-risk disease [del(11q) and/or IGHV-unmutated] and those treated with G-monotherapy. Thus, even today in the era of novel drugs, G-Clb can be considered a legitimate frontline treatment in unfit CLL patients with low-risk disease [non-del(11q) and IGHV-mutated]. Disclosures Herishanu: Roche: Honoraria; AbbVie: Honoraria; Janssen: Honoraria. Simkovic:Roche: Honoraria; University Hospital Hradec Kralove: Employment; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Acerta: Consultancy, Honoraria. Mauro:Gilead: Consultancy, Research Funding; Shire: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding; Jannsen: Consultancy, Research Funding; Roche: Consultancy, Research Funding. Coscia:Abbvie: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm Therapeutics: Research Funding. Scarfo:AstraZeneca: Honoraria; Janssen: Honoraria; AbbVie: Honoraria. Tedeschi:AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen spa: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead: Consultancy; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; SUNESIS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BeiGene: Honoraria. Gimeno Vázquez:JANSSEN: Consultancy, Speakers Bureau; Abbvie: Speakers Bureau. Assouline:F. Hoffmann-La Roche Ltd: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau. Levato:Novartis: Honoraria; Pfizer: Honoraria; Incyte: Honoraria; BMS: Honoraria. Rigolin:Gilead: Speakers Bureau; Gilead: Research Funding; AbbVie: Speakers Bureau. Loscertales:Janssen: Honoraria; Roche: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria; Gilead: Honoraria. Ghia:Dynamo: Consultancy, Honoraria; AbbVie: Consultancy, Honoraria, Research Funding; Acerta/AstraZeneca: Consultancy, Honoraria; ArQule: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Juno/Celgene: Consultancy, Honoraria; Sunesis: Consultancy, Honoraria, Research Funding; Novartis: Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy; Gilead: Consultancy, Honoraria, Research Funding.

Background: The majority of the patients with low risk myelodysplastic syndrome (MDS) become RBC-transfusion-dependent and thus symptoms resulting from iron overload and oxidative stress may develop. Yet, iron-chelation has not been part of the standard treatment for these patients. The purpose of this study was to assess the effect of deferiprone (L1), an iron chelator, on oxidative stress parameters in iron overloaded and blood dependent patients with low risk MDS. Methods: This work was supported by a grant from Apopharma. Nineteen low risk MDS patients were enrolled. Patients were classified as very low-, low- and intermediate-risk disease, according to the Revised International Prognostic Scoring System (IPSS-R). Inclusion criteria were a cumulative transfusion burden of >20 red blood cells (RBC) units and evidence of iron overload (serum ferritin >1,000 ng/mL). Deferiprone at a dose of up to a maximum dose of 100 mg/kg was administrated for 4 months. Blood samples were taken at baseline, at each monthly visit, and at the end of the study. The samples were tested for oxidative stress parameters: reactive oxygen species (ROS), phosphatidylserine (PS), glutathione (GSH) and membrane lipid peroxidation (LP); iron parameters: serum ferritin and cellular labile iron pool (LIP), and CBC. The primary efficacy variable as a measurement of oxidative stress was ROS. Student's t-test was applied for statistical analyses. Results: Patients (n=19) were treated with deferiprone in a daily dose of 25-100 mg/kg, median of 50 mg/kg/day. Eight patients received treatment for 120 days and completed the study. One of them had mild neutropenia that resolved after short discontinuation of the study drug and finished the study with no more complications. Eleven patients did not finish the study: eight patients due to gastrointestinal (GI) adverse effects, two patients withdrew their consent (one of them after mild neutropenia that resolved) and one patient was killed in a car accident. We thus had measurements of at least two time points for 16 of the patients. The median number of RBC transfusions during study period was 11 (2-20). The primary efficacy variable ROS, as a measurement of oxidative stress, was significantly decreased, in all three lineages: platelet, RBC and neutrophils (decrease of 32%, 33% and 32% respectively, each at P=0.001). Deferiprone administration was also associated with a reduction in other cellular markers of oxidative stress in RBC: PS, GSH, LP and LIP (decrease of 54%, 98%, 300%, and 42% respectively, each at P=0.001). No significant changes were observed in serum ferritin levels, likely due to the short treatment period in patients on repeated transfusion requirements. Conclusions: This is the first prospective study on chelation with Deferiprone in MDS patients. Our data provide preliminary evidence that administration of Deferiprone in a median daily dose of at 50 mg/kg can decrease iron-induced oxidative stress in iron-overloaded MDS patients. Of note, no events of agranulocytosis were observed. The future remains challenge is to prove that reduction in iron toxicity will eventually translate into a clinically meaningful improvement. Prof. Rachmilewitz who unfortunately passed away last year, had a significant contribution to the conception and design of this study. Disclosures No relevant conflicts of interest to declare.

BackgroundAntiretroviral therapy is frequently associated with adverse metabolic effects and lipodystrophy, but the role of HIV protease inhibitors and the mechanisms involved are poorly understood. The HIV protease inhibitor nelfinavir (NFV) impairs insulin signal propagation by inducing similar signalling defects to those induced by exposure to oxidative stress.AimWe set out to determine if oxidative stress is involved in NFV-induced insulin resistance in 3T3-L1 adipocytes, and whether antioxidant agents with unique modes of action can prevent this effect.ResultsCells exposed to NFV exhibited the following markers of increased oxidative stress: a decrease in both total and low molecular weight reduced thiols, a 20-fold increase in haem oxygenase 1 (HO-1) mRNA, an increase in intracellular reactive oxygen species production (determined by 2′,7′-dichlorofluorescein fluorescence), and increased markers of apoptosis. Enhancing cellular thiols with N-acetylcystein prevented the NFV-induced drop in reduced thiols and partially protected against the induction in HO-1, but failed to prevent insulin resistance or cleavage of poly ADP ribose polymerase (PARP), a process indicative of activation of pro-apoptotic caspases. Conversely, the superoxide dismutase-mimetic antioxidant MnTBAP had no effect on cellular thiols in response to NFV, but protected against HO-1 induction and against the impairment in insulin-stimulated Akt/protein kinase B activation and PARP cleavage.ConclusionsInduction of oxidative stress plays a role in adipocyte insulin resistance and apoptosis induced by NFV through a radical-dependent but thiol-independent mechanism(s). The results may suggest a new mechanism for the adverse effects of NFV on fat cells, and offer potential new intervention approaches.