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Background: Cytokines are being explored as a therapeutic strategy to modulate the tumor microenvironment and facilitate immunotherapy benefit in breast cancer. Here, we investigate a locoregional therapeutic approach whereby cytokines (IRX-2) are administered into the subcutaneous peri-areolar tissue (in an anatomic distribution similar to sentinel lymph node mapping) to facilitate immune cell recruitment/activation within the draining lymph nodes and tumor in ESBC. IRX-2 is derived from ex vivo phytohemagglutinin-stimulated lymphocytes and contains multiple cytokines including IL-1β, IL-2, TNF-α, IFN-γ, IL-6, IL-8, and GM-CSF, with stable concentrations from lot to lot. Preclinically, IRX-2 activates T-cells and natural killer (NK) cells, facilitates antigen presentation, and enhances activity of anti-PD-1/L1 in a SCC7 model. In a preceding head/neck squamous cell carcinoma phase I trial, perilymphatic IRX-2 was safe and increased TILs. Here, we report the final clinical results of a phase Ib trial evaluating the feasibility and immunologic activity of IRX-2 in ESBC. Methods: Beginning 21 days prior to surgical resection, enrolled operable patients with stage I-III ESBC (all subtypes) received the pre-operative IRX-2 regimen consisting of a single low-dose cyclophosphamide (300 mg/m2 to facilitate T-regulatory cell depletion), followed by 10 days of subcutaneous peri-areolar IRX-2 injections into the affected breast (1 mL × 2 at tumor axis and at 90°). Endpoints were feasibility (primary endpoint), stromal TIL (sTIL) count (pre-treatment versus post-treatment, blinded average of two pathologist reads using San Antonio H&E sTIL guidelines), PD-L1 expression (Nanostring) and enumeration of peripheral immune cells by flow cytometry. Results: All patients (n=16/16) completed and tolerated the regimen with no surgical delays or treatment-attributed grade III/IV toxicities. Common adverse events (occurring in >15% subjects) attributed to IRX-2 injections were: injection site reaction (grade 1, n=8/16), bruising (grade 1, n=7/16), and pain (grade 1, n=3/16). Common adverse events attributed to low-dose cyclophosphamide were: fatigue (grade 1, n=5/16) and nausea (grade 1/2, n=3/16). Treatment was associated with an increase in sTIL score (Wilcoxon signed-rank p=.04), with 4/10 sTIL-low tumors (0-10% score) re-categorized to sTIL-moderate (11-50% score). Increases in PD-L1 RNA expression were observed (Wilcoxon signed-rank p=.04) in 12/16 tumors (median 57% increase, range: -53% to 185% increase), as well as increases in Nanostring NK and Th1 cell signatures. In blood, increases in CD4 and CD8 effector T-cell activation (ICOS, HLA-DR, and CD38) and T-reg depletion were observed. Conclusions: IRX-2 was well tolerated with preliminary evidence of sTIL increase, PD-L1 upregulation, and peripheral lymphocyte activation. Based upon these data and preclinical evaluations demonstrating synergy with checkpoint inhibition, the IRX-2 regimen is being evaluated for clinical efficacy in conjunction with pembrolizumab and neoadjuvant chemotherapy (doxorubicin, cyclophosphamide, paclitaxel) in patients with stage II-III triple negative breast cancer. Citation Format: Pucilowska J, Egan JE, Berinstein NL, Moxon N, Aliabadi-Wahle S, Imatani JH, Conlin A, Acheson A, Massimino K, Martel M, Campbell M, Wu Y, Sun Z, Redmond W, Shah M, Urba WJ, Page DB. Perilymphatic IRX-2 cytokine therapy to enhance tumor infiltrating lymphocytes (TILs) and PD-L1 expression preceding curative-intent therapy in early stage breast cancer (ESBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-12.

Background Treatment of recurrent/refractory (r/r) DLBCL remains an unmet clinical need, and new effective and well-tolerated treatments are required. DPX-Survivac is a unique T cell activation therapy that targets survivin-expressing tumor cells and has shown anti-tumor activity in clinical trials. This trial is evaluating a novel immunotherapy combination with DPX-Survivac, intermittent low dose CPA and pembrolizumab. Methods ‘SPiReL’ is a Phase 2 non-randomized, open label, efficacy and safety study of a novel immunotherapy combination with DPX-Survivac (a unique T cell activation therapy that targets survivin-expressing tumor cells), intermittent low dose CPA and pembrolizumab, treatment regimen as described in figure 1. Subjects with r/r incurable DLBCL and survivin expression are eligible for participation. This study was approved by the Ontario Cancer Research Ethics Board, approval number 0981.ORR is assessed by modified Cheson criteria. For translational analyses, baseline and on-treatment PBMCs, along with tumor biopsy samples are collected from each subject. Survivin-specific systemic T cell responses are assessed using IFNγ-ELISPOT assay and tumour immune-infiltrate profile by multiplex-IHC. Results Twenty-two subjects have been enrolled to date, 19 are included in the intent to treat (ITT) population and 11 subjects are evaluable in the per protocol (PP) population. In the PP, the ORR is 63.6% including 3 CRs (27.3%), 4 PRs (36.4%) and the DCR is 81.8% (9/11). In the ITT, the ORR is 35% (7/19), and DCR is 52.0% (10/19). Preliminary results show that non-GCB subjects had a higher proportion of clinical response (4/8, 50%), compared to 3/10 (30%) in GCB subjects.DPX-Survivac-induced T cell responses were observed in 8/19 subjects (42.1%) including 6 subjects with clinical response (PR, CR), one SD and one PD. Multiplex-IHC analyses demonstrated baseline tumor PD-L1 expression in 6/7 subjects with a clinical response (85.7%, p Conclusions DPX-Survivac, intermittent low-dose CPA and pembrolizumab is generally well tolerated and can induce clinical responses in subjects with r/r DLBCL (7/11, 63.6% of evaluable subjects), including subjects with both non-GCB and GCB subtypes. Pre-treatment biopsies of clinical responders were characterized by higher baseline tumor PD-L1 expression and CD4 and CD8 infiltration. Extending this exploratory data in a larger cohort may define a r/r DLBCL patient population with a higher likelihood to respond to this novel combination immunotherapy. Trial Registration NCT03349450 Ethics Approval This study was approved by the Ontario Cancer Research Ethics Board, approval number 0981.

Elevated levels of the carcinoembryonic antigen (CEA; CEACAM5) in the serum of colorectal cancer (CRC) patients represent a clinical biomarker that correlates with disease recurrence. However, a mechanistic role for soluble CEA (sCEA) in tumor progression and metastasis remains to be established. In our study, we report that sCEA acts as a paracrine factor, activating human fibroblasts by signaling through both the STAT3 and AKT1-mTORC1 pathways, promoting their transition to a cancer-associated fibroblast (CaF) phenotype. sCEA-activated fibroblasts express and secrete higher levels of fibronectin, including cellular EDA+ -fibronectin (Fn-EDA) that selectively promote the implantation and adherence of CEA-expressing cancer cells. Immunohistochemical analyses of liver tissues derived from CRC patients with elevated levels of sCEA reveal that the expression of cellular Fn-EDA co-registers with CEA-expressing liver metastases. Taken together, these findings indicate a direct role for sCEA as a human fibroblast activation factor, in priming target tissues for the engraftment of CEA-expressing cancer cells, through the differentiation of tissue-resident fibroblasts, resulting in a local change in composition of the extracellular matrix.

Head and neck squamous cell carcinoma (HNSCC) is an immunosuppressive malignancy characterized by tumor-driven immune-system abnormalities that contribute to disease progression. For patients with surgically resectable HNSCC, treatment is often curative surgery followed by irradiation or chemoradiation in high-risk settings to reduce the risk of recurrence. Poor survival and considerable morbidity of current treatments suggest the need for new therapeutic modalities that can improve outcomes. Defects in antitumor immunity of HNSCC patients include suppressed dendritic cell (DC) maturation, deficient antigen-presenting cell function, compromised natural killer (NK)-cell cytotoxicity, increased apoptosis of activated T lymphocytes, and impaired immune-cell migration to tumor sites. Strategies for relieving immunosuppression and restoring antitumor immune functions could benefit HNSCC patients. IRX-2 is a primary cell-derived biologic consisting of physiologic levels of T-helper type 1 cytokines produced by stimulating peripheral blood mononuclear cells of normal donors with phytohemagglutinin. The primary active components in IRX-2 are IL2, IL1β, IFNγ, and TNFα. In vitro, IRX-2 acts on multiple immune-system cell types, including DCs, T cells, and NK cells, to overcome tumor-mediated immunosuppression. In clinical settings, IRX-2 is administered as part of a 21-day neoadjuvant regimen, which includes additional pharmacologic agents (low-dose cyclophosphamide, indomethacin, and zinc) to promote anticancer immunoresponses. In a Phase IIA trial in 27 patients with surgically resectable, previously untreated HNSCC, neoadjuvant IRX-2 increased infiltration of T cells, B cells, and DCs into tumors and was associated with radiological reductions in tumor size. Event-free survival was 64% at 2 years, and overall 5-year survival was 65%. Follow-up and data analysis are under way in the multicenter, randomized, Phase IIB INSPIRE trial evaluating the IRX-2 regimen as a stand-alone therapy for activating the immune system to recognize and attack tumors.

Five-year overall survival for high-risk Follicular Lymphoma International Prognostic Index follicular lymphoma is only approximately 50% compared with 90% for low risk. To evaluate an approach to improve upon this poor outcome, we completed an exploratory phase II trial of intensified treatment for patients with intermediate and high-risk follicular lymphoma. Front-line treatment with chemo-immunotherapy consisting of rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone was followed by radio- immunotherapy with 90-Yttrium ibritumomab tiuxetan consolidation, and 2 years of rituximab maintenance. The 5-year overall survival for intermediate and high-risk patients was 88% and 83%, respectively. Of 33 enrolled patients, 3 were off study before receiving radio-immunotherapy. Three months post radio-immunotherapy, 28/33 (85%) patients had achieved complete response including 6 patients who had only a partial response to chemo-immunotherapy and converted to complete response after radio-immunotherapy. The 5-year progression-free survival for intermediate and high risk was 79% and 58%, respectively. Nine of 19 patients with molecular markers patients remain in molecular and clinical complete remission with a median follow-up of 48 months (range 3-84 months). Post radio-immunotherapy, hematologic toxicities were mostly grade 1 and 2. However, asymptomatic grade 3 or 4 thrombocytopenia and neutropenia occurred in 11%-36% and 10%-24% of patients, respectively. Myelodysplastic syndrome occurred in 1 patient 4 years post treatment. Whereas many patients had prolonged B-cell reduction and low immunoglobulin levels post treatment, previous immunities to rubella were maintained. More aggressive upfront approaches such as this may benefit higher risk follicular lymphoma, but confirmatory trials are required. http://www.clinicaltrials.gov: NCT01446562.

Background: Recurrent/refractory (r/r) DLBCL presents a major treatment challenge, especially in the setting of patients who are ineligible for, or relapsing after, potentially curative treatments such as autologous stem cell transplant (ASCT) and chimeric antigen receptor T cell (CAR-T) therapy. Efficacious treatment options that are well-tolerated and easily accessible in this population represent a critical unmet medical need. DPX-Survivac is a targeted T cell activation therapy against cancers expressing survivin. Survivin plays an essential role in cancer biology and represents a target of choice to disrupt tumour progression. DPX-Survivac's mechanism of action relies on its ability to generate robust and durable survivin-specific T cells that migrate to, infiltrate and kill tumour cells. DPX-Survivac is administered with intermittent, low dose cyclophosphamide (CPA) used as an immunomodulator. In nonclinical studies, treatment with DPX-Survivac increases PD-L1 and PD-1 expression providing the rationale for combination with pembrolizumab. Methods: "SPiReL" is a Phase 2 non-randomized, open label, efficacy and safety study. Subjects with r/r DLBCL with confirmed survivin expression are eligible for participation. Subjects must also be ineligible for potentially curative therapy. The treatment and testing regimen is shown in the figre below. The primary objective of SPiReL is to document a minimum Objective Response Rate (ORR) of 24% (in 6/25 subjects) using the modified Cheson criteria (2007). Secondary objectives include safety, duration of response and time to next treatment. Exploratory endpoints include T cell response, tumour immune cell infiltration, and biomarker analysis. Results: At data cut-off, 22 subjects have been enrolled in the study. The median age is 75.5 years (50-82). Thirteen of 22 subjects (59.1%) are GCB sub-type, 8 subjects (36.4%) are non-GCB and 1 subject (4.5%) has primary cutaneous DLBCL, leg type. The median number of prior therapies is 2 (1-7), with 4 subjects having previously undergone ASCT and 5 subjects with transformed disease. Of the 22 enrolled subjects, 8 are not evaluable per protocol for clinical efficacy due to early disease progression. Four subjects are active on treatment, 3 of which have not yet reached the first time point for assessment. Clinical outcome was analyzed for the Full Analysis Set (FAS) (n=19) and in the Per Protocol (PP) analysis (n=11). Of 11 subjects in the PP, 7 subjects (63.6%) have achieved an objective response, meeting the study's primary endpoint; 3 subjects (27.3%) with a CR and 4 subjects (36.4%) with a PR. Three subjects (27.3%) achieved SD and thus clinical benefit was demonstrated in 10/11 (90.9%) of evaluable subjects. Two subjects (18.2%) have completed the 1 year treatment period, 8 subjects (72.7%) discontinued treatment due to disease progression, and 1 subject (9.2%) discontinued treatment due to an unrelated Adverse Event (AE). Including the entire FAS, the objective response rate was 7/19 (36.8%). This treatment combination is well-tolerated, only 11% of Treatment Related AEs (TRAEs) were assessed as Grade 3 or higher. The majority of the Grade 1 and 2 TRAEs were Injection Site Reactions (ISRs) related to DPX-Survivac. Ten serious AEs were reported, of which 3 were considered related to study treatment. No subjects have discontinued study treatment due to a TRAE. Analyses of peripheral blood T cell responses to survivin by ELISpot assay shows that 7/7 subjects who achieved an objective response have survivin-specific T cell response. One subject with PD also showed a survivin-specific T cell response, supporting the mechanism of action and the role of DPX-Survivac in anti-tumor activity. Summary: DPX-Survivac and low dose CPA in combination with pembrolizumab, demonstrates promising clinical activity in recurrent/refractory DLBCL with 10/11 (90.9%) of evaluable subjects deriving clinical benefit with minimal toxicity. The primary endpoint of this study has been reached with 7/11 (63.6%) of evaluable subjects achieving an objective response warranting further exploration of DPX-Survivac in this population. Enrollment is continuing to further define the patient population most likely to benefit from this well-tolerated therapy. Figure 1 Disclosures Bence-Bruckler: Merck: Membership on an entity's Board of Directors or advisory committees. Forward:Seattle Genetics: Research Funding; IMV: Research Funding; Merck: Research Funding; Astellas: Research Funding; Servier: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; IMV: Membership on an entity's Board of Directors or advisory committees; Calgene: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; AstraZeneca: Membership on an entity's Board of Directors or advisory committees. Stewart:Roche: Honoraria; Janssen: Honoraria; Abbvie: Honoraria; Gilead: Honoraria; Celgene: Honoraria; Amgen: Honoraria; Sandoz: Honoraria; Novartis: Honoraria; AstraZeneca: Honoraria; Teva: Honoraria. Bramhecha:IMV Inc.: Current Employment. Conlon:IMV Inc.: Current Employment. OffLabel Disclosure: Keytruda (pembrolizumab). Indicated for use in melanoma, nonÃÆ'Ã'¢Ã¢ââ'¬Å¡Ã¢â€šâ'¬ÃƒÂ¢Ã¢â€šâ'¬Ã…“small cell lung cancer (NSCLC), head and neck squamous cell cancer (HNSCC), classical Hodgkin lymphoma (cHL), primary mediastinal B-cell lymphoma (PMBCL), urothelial carcinoma, microsatellite instability-high (MSI-H) or a mismatch repair deficient (dMMR) solid tumor, gastric or gastroesophageal junction (GEJ) adenocarcinoma, squamous cell carcinoma of the esophagus, cervical cancer, hepatocellular carcinoma, Merkel cell carcinoma (MCC), and renal cell carcinoma (RCC).

Five-year overall survival for high-risk Follicular Lymphoma International Prognostic Index follicular lymphoma is only approximately 50% compared with 90% for low risk. To evaluate an approach to improve upon this poor outcome, we completed an exploratory phase II trial of intensified treatment for patients with intermediate and high-risk follicular lymphoma. Front-line treatment with chemo-immunotherapy consisting of rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone was followed by radio- immunotherapy with 90-Yttrium ibritumomab tiuxetan consolidation, and 2 years of rituximab maintenance. The 5-year overall survival for intermediate and high-risk patients was 88% and 83%, respectively. Of 33 enrolled patients, 3 were off study before receiving radio-immunotherapy. Three months post radio-immunotherapy, 28/33 (85%) patients had achieved complete response including 6 patients who had only a partial response to chemo-immunotherapy and converted to complete response after radio-immunotherapy. The 5-year progression-free survival for intermediate and high risk was 79% and 58%, respectively. Nine of 19 patients with molecular markers patients remain in molecular and clinical complete remission with a median follow-up of 48 months (range 3-84 months). Post radio-immunotherapy, hematologic toxicities were mostly grade 1 and 2. However, asymptomatic grade 3 or 4 thrombocytopenia and neutropenia occurred in 11%-36% and 10%-24% of patients, respectively. Myelodysplastic syndrome occurred in 1 patient 4 years post treatment. Whereas many patients had prolonged B-cell reduction and low immunoglobulin levels post treatment, previous immunities to rubella were maintained. More aggressive upfront approaches such as this may benefit higher risk follicular lymphoma, but confirmatory trials are required. http://www.clinicaltrials.gov: NCT01446562.

Three sequential phase II trials were conducted with different immunotherapy approaches to enhance the outcome of autologous transplant (high-dose therapy and autologous stem cell transplantation (HDT/ASCT)) for recurrent follicular lymphoma. Seventy-three patients were enrolled from 1996 to 2009. Patients received HDT/ASCT combined with (1) interferon-α 3 MU/m(2) subcutaneously (SC) three times per week (TIW) for 2 years post-ASCT, (2) rituximab (R) 375 mg/m(2) for in vivo purging 3-5 days pre-stem cell collection and 2 × 4 weekly R at 2 and 6 months post-ASCT, respectively, or (3) three infusions of R pre-stem cell collection followed by 6× R weekly and interferon-α 3 MU/m(2) SC TIW. Although not statistically significant, progression-free survival (PFS) for patients who received rituximab was 56.4 and 49.1% at 5 and 10 years compared to 36 and 21% in those who did not receive rituximab. Molecular relapse post-HDT/ASCT was the strongest predictor of PFS in a multivariate analysis. Molecular relapse was coincident with or preceded clinical relapses in 84% of patients who relapsed—median of 12 months (range 0-129 months). Adverse events included secondary malignancy, transformation to diffuse large B cell lymphoma, prolonged mostly asymptomatic hypogammaglobulinemia, and pulmonary fibrosis. The long-term toxicity profile must be considered when selecting patients for this treatment.

Background: Dose-modified (dm) CODOX-M/IVAC is commonly used for Burkitt lymphoma (BL) and B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and BL (BCL-U; previously Burkitt-like lymphoma-BLL). Methods: We evaluated the clinical characteristics, outcomes and prognostic markers in patients treated with dmCODOX-M/IVAC+/- rituximab (R) at a single academic center. Results: 31 patients with BL (n = 21) or BCL-U (n = 10) were included. The median age was 45, and 90% were high risk. The 2-year overall survival (OS) and progression-free survival (PFS) were 69% and 62%, respectively, with no differences between BL and BCL-U. By multivariable analysis, rituximab use was significantly associated with improved OS (Hazard Ratio 0.15; 95% CI 0.04 - 0.56) while elevated LDH (Hazard Ratio 2.84, 95% CI 1.52 - 5.29) and rituximab use (Hazard Ratio 0.054, 95% CI 0.01 - 0.32) predicted PFS. Conclusion: DmCODOX-M/IVAC+/- R chemotherapy provides equivalent survival for both BL and BCL-U patients. The addition of rituximab improves overall and progression free survival and is recommended.

Patients with mantle cell lymphoma (MCL) have a particularly poor prognosis when treated with standard chemotherapy, with a median overall survival of only 3 years. These patients have therefore been considered for first-line treatment with more aggressive or experimental strategies, such as high-dose therapy (HDT) with autologous stem cell transplantation (ASCT). While high rates of clinical remission have been achieved with HDT/ASCT, this procedure alone is not believed to be curative and different treatment strategies are being developed to improve outcomes in this group of patients. Single-agent rituximab is active in both newly diagnosed and relapsed MCL and therefore the addition of rituximab to chemotherapy regimens and/or HDT/ASCT may enhance their efficacy. Outside the transplantation setting, rituximab plus chemotherapy has been shown to be highly active in MCL, and preliminary data from randomized trials suggest that the combination may yield superior results compared with chemotherapy alone. The addition of rituximab to transplantation protocols appears to be a very promising strategy for patients with MCL, given as an in vivo purge before HDT/ASCT and/or as posttransplant maintenance therapy. Two phase II clinical trials with rituximab given as an in vivo purge during stem cell mobilization and as posttransplant immunotherapy in patients with previously untreated MCL have generated very promising data. Rituximab is an important addition to cytotoxic therapy and with HDT/ASCT represents a highly active therapy that may be superior to conventional treatment or HDT/ASCT alone in MCL. Randomized prospective studies and longer follow-up are needed to determine whether these regimens can achieve longer survival or possibly cure in this disease.

Introduction: Recurrent/refractory diffuse large B cell lymphoma (DLBCL) remains an area of unmet clinical need. Although autologous stem cell transplant (ASCT), and more recently chimeric antigen receptor (CAR) T cell therapy, have made a significant impact, many patients are ineligible for these treatments due to advanced age, comorbidities, or financial or geographical limitations, or they have relapsed following these treatments. Survivin, a novel target in DLBCL, is overexpressed in approximately 60% of untreated DLBCL with higher rates in relapsed disease. DPX-Survivac, a T cell activating therapy, elicits a strong and prolonged immune response against tumors expressing survivin. DPX-Survivac is combined with pembrolizumab, an anti-PD-1 checkpoint inhibitor, and intermittent low dose cyclophosphamide (CPA), used for an immunomodulatory effect. Pre-clinical studies have demonstrated increased efficacy of this DPX-based drug combination in controlling of tumor growth in murine tumor models, resulting in improved survival (Weir et al. J Immunother Cancer 2016). Methods: "SPiReL" is a Phase 2 non-randomized, open label, efficacy and safety study. Subjects with recurrent/refractory DLBCL with confirmed survivin expression are eligible for participation. Participants must also be ineligible for curative therapy. Study treatment includes administering two doses of 0.5 mL of DPX-Survivac 3 weeks apart followed by up to six 0.1 mL doses every 8 weeks. Intermittent low dose cyclophosphamide is administered orally at 50 mg twice daily for 7 days followed by 7 days off. Pembrolizumab 200 mg is administered every 3 weeks. Study participants continue active therapy for up to one year or until disease progression, whichever occurs first. The primary objective is to document the response rate to this treatment combination using modified Cheson criteria. Secondary objectives include duration of response and safety. Exploratory endpoints include T cell response, tumor immune cell infiltration, and gene expression analysis. Enrollment is ongoing with a goal of up to 25 subjects in this national, multi-center study. Trial design is shown below the text. Results: At the time of data cut-off, 23 subjects have been screened and 12 have been enrolled. The demographics of enrolled subjects include: median age is 75.5 years (50-82), with 3 male subjects participating. The median number of prior therapies is 2.5 (1-6), with 4 subjects having previously undergone ASCT. The median time from diagnosis to screening is 31 months (8-151). Of the 12 enrolled subjects, 3 were not evaluable for clinical efficacy due to early disease progression. One subject has not yet reached the first time point for assessment. In the Per Protocol analysis of 8 evaluable subjects ("PP", N = 8); as compared to a Full Analysis Set ("FAS", N = 11); 7 of 8 subjects (PP = 87.5%) demonstrated clinical benefit, including 6 with tumor regressions (FAS = 63.6%); 2 subjects (PP = 25%) achieved a complete response, 1 of whom has completed the 1 year study period (FAS = 18.2%); 3 subjects (PP = 37.5%) had a partial response (FAS = 27.3%); and 3 (PP = 37.5%) had stable disease remaining on study for 4, 6 and 8 months (FAS = 27.3%). This treatment combination is well-tolerated with mostly grade 1 and 2 adverse events reported; a single grade 3 maculopapular rash and 1 case of grade 4 cytopenia has been observed. Of the 23 screened subjects, survivin expression analysis was performed on 18 subjects. All of the 18 samples analyzed were survivin positive, with a range of 60%-100% of lymphoma cells expressing survivin. Preliminary analysis of peripheral blood T cell responses to survivin by ELISPOT assay shows 2 of 4 subjects had strong survivin-specific T cell responses. Both of these subjects had clinical responses. Summary: DPX-Survivac, in combination with pembrolizumab and low dose cyclophosphamide, demonstrates clinical activity and a favorable safety profile in recurrent/refractory DLBCL with 87.5% of evaluable subjects deriving clinical benefit, including 2 complete responses (25%) and 3 partial responses (37.5%) to date. Enrollment is continuing to further explore the synergistic effect of this combination in this population. Figure Disclosures Berinstein: Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Stewart:Merck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Keytruda (pemroblizumab) is approved for use to treat Melanoma, Metastatic, Non-Small Cell Lung Cancer, Head and Neck Cancer, Hodgkin's Lymphoma, Urothelial Carcinoma, Gastric Cancer, Cervical Cancer, Hepatocellular Carcinoma, Merkel Cell Carcinoma, Renal Cell Carcinoma, and Small Cell Lung Cancer. In this trial, it is being used to treat Diffuse Large B-Cell Lymphoma.

In the pre-rituximab era, transformation of indolent B-cell lymphoma to diffuse large B-cell lymphoma (DLBCL) was associated with an extremely poor outcome and a median post-transformation survival ranging from 1 to 2 years. We evaluated the impact of rituximab-cyclophosphamide, adriamycin, vincristine, prednisone (R-CHOP) on the survival outcomes of transformed lymphoma compared with de novo DLBCL. Between 2002 and 2010, 317 DLBCL patients who were consecutively diagnosed and treated with R-CHOP were identified at our institution. Patients with transformed lymphoma were included if they had not previously received R-CHOP. Patient characteristics, treatment, and outcome data were retrospectively collected. Sixty patients (19 %) had transformed lymphoma of which 37 (62 %) had transformed from follicular lymphoma, 50 (83 %) were chemotherapy naïve, and 58 (96 %) were rituximab naïve at the time of treatment. With a median follow-up of 31.4 months, 231 patients achieved either complete response or complete response unconfirmed (73 %) with no significant difference between de novo DLBCL (n = 192, 75 %) and the transformed group (n = 39, 65 %) (P = 0.25). Six patients (15 %) relapsed in the transformed group at a median time to relapse of 29.3 months. The 2-year and 5-year overall survivals for all patients were 82 and 72 %, respectively. The overall and progression-free survivals for transformed lymphoma and de novo DLBCL were not statistically different (P = 0.45 and P = 0.38, respectively). With R-CHOP chemotherapy, the prognosis of transformed lymphoma in patients with minimal chemotherapy exposure for indolent disease is similar to that of de novo DLBCL.

Background TRPS-1 is a new GATA transcription factor that is differentially expressed in breast cancer (BC) where it been found recently to regulate epithelial-to-mesenchymal transition (EMT). Patients and methods We carried out a quantitative immunohistochemistry (qIHC) analysis of TRPS-1 expression in 341 primary-stage I–III BC samples in relation to patient clinical characteristics as well as its prognostic value, especially in an estrogen receptor-positive (ER+) subgroup. Results Higher TRPS-1 expression was significantly associated with a number of clinical and pathological characteristics as well as with improved overall survival (OS) and disease-free survival (DFS). Among stage I/II ER+ BC patients who received endocrine therapy alone, those with high TRPS-1 expression had significantly longer OS and DFS. There was also a strong association between TRPS-1 levels and the EMT marker E-cadherin in the ER+ invasive ductal carcinoma cases. Analysis of gene expression data on a panel of BC lines found that TRPS-1 expression was low or absent in BC lines having enriched mesenchymal features. Conclusions Our data indicated that TRPS-1 is an independent prognostic marker in early-stage BC and a new EMT marker that can distinguish patients with ER+ BC who will respond longer to adjuvant endocrine therapy.

Background Future cancer immunotherapies will combine multiple treatments to generate functional immune responses to cancer antigens through synergistic, multi-modal mechanisms. In this study we explored the combination of three distinct immunotherapies: a class I restricted peptide-based cancer vaccine, metronomic cyclophosphamide (mCPA) and anti-PD-1 treatment in a murine tumor model expressing HPV16 E7 (C3). Methods Mice were implanted with C3 tumors subcutaneously. Tumor bearing mice were treated with mCPA (20 mg/kg/day PO) for seven continuous days on alternating weeks, vaccinated with HPV16 E749-57 peptide antigen formulated in the DepoVax (DPX) adjuvanting platform every second week, and administered anti-PD-1 (200 μg/dose IP) after each vaccination. Efficacy was measured by following tumor growth and survival. Immunogenicity was measured by IFN-γ ELISpot of spleen, vaccine draining lymph nodes and tumor draining lymph nodes. Tumor infiltration was measured by flow cytometry for CD8α+ peptide-specific T cells and RT-qPCR for cytotoxic proteins. The clonality of tumor infiltrating T cells was measured by TCRβ sequencing using genomic DNA. Results Untreated C3 tumors had low expression of PD-L1 in vivo and anti-PD-1 therapy alone provided no protection from tumor growth. Treatment with DPX/mCPA could delay tumor growth, and tri-therapy with DPX/mCPA/anti-PD-1 provided long-term control of tumors. We found that treatment with DPX/mCPA/anti-PD-1 enhanced systemic antigen-specific immune responses detected in the spleen as determined by IFN-γ ELISpot compared to those in the DPX/mCPA group, but immune responses in tumor-draining lymph nodes were not increased. Although no increases in antigen-specific CD8α+ TILs could be detected, there was a trend for increased expression of cytotoxic genes within the tumor microenvironment as well as an increase in clonality in mice treated with DPX/mCPA/anti-PD-1 compared to those with anti-PD-1 alone or DPX/mCPA. Using a library of antigen-specific CD8α+ T cell clones, we found that antigen-specific clones were more frequently expanded in the DPX/mCPA/anti-PD-1 treated group. Conclusions These results demonstrate how the efficacy of anti-PD-1 may be improved by combination with a potent and targeted T cell activating immune therapy. Electronic supplementary material The online version of this article (doi:10.1186/s40425-016-0169-2) contains supplementary material, which is available to authorized users.

Central nervous system (CNS) prophylaxis for diffuse large B-cell lymphoma (DLBCL) is controversial with even less evidence in the era of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy. We reviewed the impact of CNS prophylaxis in DLBCL patients treated with R-CHOP at a tertiary care centre over a 7-year period. CNS prophylaxis was recommended for 'higher risk' patients and consisted of intrathecal methotrexate and/or high-dose methotrexate. Of 214 patients 12·6% received CNS prophylaxis. With a median follow-up of 27 months, eight patients (3·7%) developed CNS relapse (75% isolated to the CNS and 62·5% as parenchymal brain disease) at a median time of 17 months. Patients who did not receive CNS prophylaxis had lower events (2·7%) than those who did (11·1%). Half of the CNS relapses occurred in testicular lymphoma patients, 75% of whom had received CNS prophylaxis. In multivariate analysis, testicular involvement was the only significant prognostic factor for CNS relapse (hazard ratio 33·5, P < 0·001). In conclusion, CNS relapse in DLBCL appears to present as a later, more isolated parenchymal event and at a lower rate in the rituximab era compared with historical data. R-CHOP may negate the need for CNS prophylaxis with the exception of testicular lymphoma.

Twenty-seven subjects with squamous cell cancer of the head and neck received the neoadjuvant IRX-2 immunotherapy regimen prior to surgery in a Phase 2 trial. Pretreatment tumor biopsies were compared with the primary tumor surgical specimens for lymphocyte infiltration, necrosis and fibrosis, using hematoxylin and eosin stain and immunohistochemistry in 25 subjects. Sections were examined by three pathologists. Relative to pretreatment biopsies, increases in lymphocyte infiltration (LI) were seen using H and E or immunohistochemistry. CD3+ CD4+ T cells and CD20+ B cells were primarily found in the peritumoral stroma and CD3+ CD8+ T cells and CD68+ macrophages were mainly intratumoral. LI in the surgical specimens were associated with reductions in the primary tumor size. Improved survival at 5 years was correlated with high overall LI in the tumor specimens. Neoadjuvant IRX-2 immunotherapy regimen may restore immune responsiveness presumably by mobilizing tumor infiltrating effector lymphocytes and macrophages into the tumor.

New therapies are urgently required for the treatment of patients with melanoma. Here we describe the generation and preclinical evaluation of 3 new recombinant ALVAC(2) poxviruses vCP2264, vCP2291, and vCP2292 for their ability to induce the desired cellular immune responses against the encoded melanoma-associated antigens. This was done either in HLA-A2/K transgenic mice or using in vitro antigen-presentation studies. These studies demonstrated that the vaccine was able to induce HLA-A*0201-restricted T-cell responses against gp100 and NY-ESO-1, detectable directly ex vivo, in HLA-A2/K-transgenic mice. The in vitro antigen presentation studies, in the absence of appropriate animal models, demonstrated that target cells infected with the vaccine construct were lysed by MAGE-1, MAGE-3 or MART-1 peptide-specific T cells. These data indicate that ALVAC(2)-encoded melanoma-associated antigens can be properly processed and presented to induce antigen-specific cytotoxic T-cell responses. To enhance the immunogenicity of the melanoma antigens, a TRIad of COstimulatory Molecules (TRICOM) were also cloned into all 3 vectors. Increased in vitro proliferation and IFN-γ production was observed with all ALVAC(2) poxviruses encoding TRICOM, confirming the immune-enhancing effect of the ALVAC-encoded TRICOM. These studies demonstrated that all components of the vaccine were functionally active and provide a rationale for moving this candidate vaccine to the clinic.

7 Background: The IRX-2 biologic is an injectable immunotherapy containing cytokines derived from stimulated lymphocytes. In preclinical models, IRX-2 activates T-cells, natural killer (NK) cells, macrophages, and dendritic cells, and facilitates maturation of antigen-presenting cells. Stromal tumor-infiltrating lymphocytes (sTILs) are associated with improved outcomes in early stage breast cancer (ESBC), and neoadjuvant IRX-2 increased TILs in a head/neck squamous cell carcinoma trial. We conducted a phase Ib trial to evaluate the feasibility/activity of IRX-2 in ESBC. Methods: Beginning 21 days prior to surgical resection, enrolled operable patients with stage I-III ESBC received the pre-operative IRX-2 regimen consisting of a single low dose of cyclophosphamide (300 mg/m2 to facilitate T-regulatory cell depletion), followed by 10 days of subcutaneous peri-areolar injections of IRX-2 into the affected breast (1 mL × 2 at tumor axis and at 90°). Endpoints were feasibility (primary), sTIL count (secondary), and immune monitoring by flow cytometry and immune transcriptome analysis (Nanostring PanCancer Immune Panel). Results: As of October 2017, 12 patients are enrolled and evaluable. All patients received all planned injections with no treatment-related surgical delays, complications, or grade III/IV toxicities. Treatment was associated with a mean 52% relative increase in sTILs (range –25% to +166%, p = 0.02). RNA expression profiling revealed the greatest increases in Th1 cell signature (mean +28.5%, range -5.3% to +283%), but also increases in CD8+, NK, and DC signatures. PDL1 RNA expression increased in 10/12 patients (mean +131.5%, range –83% to +1112%). In blood, increases in T-cell activation markers (ICOS, HLADR, and CD38) and T-reg depletion were observed at 1-month follow-up. Conclusions: Peri-lymphatic IRX-2 was well tolerated with preliminary evidence of sTIL recruitment, PDL1 upregulation, and peripheral lymphocyte activation. Study enrollment is ongoing, including patients for a pre-neoadjuvant-chemotherapy triple-negative ESBC cohort. Clinical trial information: NCT02950259.

Although there has been initial success with some types of immunotherapy, such as adoptive cellular therapy and monoclonal antibody therapy for cancer, the experience with therapeutic cancer vaccines has been much less encouraging. Almost all randomized phase III trials testing therapeutic cancer vaccines have failed to meet their end points. There are several potential explanations for this, ranging from factors related to the clinical trial design and the vaccine itself. Perhaps the most important are host-related factors. Specifically, progression and metastases of many cancers are associated with induction of multiple cancer-specific immune-inhibitory pathways. These inhibitory pathways include induction of T-cell anergy through dendritic cell dysfunction, release of immunosuppressive cytokines, T-cell exhaustion through inhibitory T-cell signaling and T regulatory cell-mediated tumor-specific immune suppression. All of these pathways have been shown to be operational in patients with melanoma. To enhance the activity of therapeutic cancer vaccines, these immunosupressive pathways need to be addressed and reversed. A number of new immunomodulatory reagents that are able to interfere with some of these pathways are now being assessed in the clinic. Sanofi Pasteur designed a clinical trial in patients with advanced or metastatic melanoma that is intended to both induce tumor-specific T-cell responses and modulate or reverse some of the immune suppression pathways that the melanoma has induced. To accomplish this, the recently optimized ALVAC melanoma multi-antigen vaccine is administered with high doses of IFN-alpha. Clinical trial parameters have also been optimized to enhance the likelihood of inducing and documenting antitumor activity. Success with other therapeutic cancer vaccine approaches will likely require similar approaches in which promising immunogenic vaccines are integrated with biologically and clinically active immunomodulatory reagents.

Immunotherapy employs cytokines for modifying local inflammatory reactions. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to activate dendritic cells, macrophages, and granulocytes leading to clinical trials using GM-CSF-based cancer vaccine approaches. Interleukin-2 (IL-2) is an important T cell stimulatory cytokine approved as exogenous antitumor agent. The ALVAC viral vector system uses a recombinant canarypox virus for local gene expression. We report a phase I clinical trial using intratumoral administration of ALVAC GM-CSF or ALVAC IL-2 in skin metastases of melanoma or leiomyosarcoma. ALVAC GM-CSF and ALVAC IL-2 were injected at 107.12 and 106.92, 50% cell culture infectious dose in eight metastases with acceptable tolerability. Local and systemic inflammatory reactions were observed. The transgene determined the local infiltrate: GM-CSF induced monocyte and macrophage enrichment of the peritumoral inflammatory infiltrate, whereas IL-2 increased local T lymphocytes. Stable disease of injected lesions was seen after ALVAC GM-CSF application, whereas ALVAC IL-2 treatment led to partial regression in three out of eight injected tumors, accompanied by decreased expression of melanocytic antigens. Local GM-CSF expression could be induced. In summary, ALVAC GM-CSF and ALVAC IL-2 injections are safe and can mediate local biologic and immunologic effects.

Harnessing the immune system to control cancer has been a challenge for cancer immunotherapists for many years. However, while specific immune responses to tumour-associated antigenic targets have been successfully induced in some patients, these responses have not always been sufficient to reproducibly and consistently mediate useful anti-tumour clinical activity. Many checks and balances have been incorporated into the immune response by nature to prevent or reduce the likelihood of autoimmunity or exaggerated protective inflammatory responses. Tolerance to self-antigens expressed on tumours is a major limitation in generating functional anti-tumour responses. In recent years, many of the pathways that mediate this tolerance have been identified, and reagents that can be used to manipulate these pathways have been clinically evaluated. These include: (a) pathways to activate professional antigen presenting cells, such as through Toll-like receptors, growth factors, such as GM-CSF, and the CD40 pathway; (b) use of cytokines, such as IL-2, IL-12, and Interferon α to enhance immune activation; and (c) pathways that inhibit T cell inhibitory signals, or Tregs. This article reviews clinical trials that have evaluated these approaches, and highlights promising combination vaccine/immunomodulator combination treatments based upon published clinical trial results.

Langerhans cells (LCs) are the antigen-presenting cells of the epithelial layer and are responsible for initiating immune responses against skin and mucosa-invading viruses. Human papillomavirus (HPV)-mediated suppression of LC function is a crucial mechanism of HPV immune evasion, which can lead to persistent infection and development of several human cancers, including cervical, anal, and head and neck cancers. The cell-derived cytokine-based biologic, IRX-2, consists of multiple well-defined cytokines and is broadly active on various immune cell subsets. In this study, we investigated primary human LC activation after exposure to HPV16, followed by treatment with IRX-2 in vitro, and evaluated their subsequent ability to induce HPV16-specific T cells. In contrast to its activity on dendritic cells, HPV16 alone is not sufficient to induce phenotypic and functional activation of LCs. However, IRX-2 induces a significant upregulation of antigen presentation and costimulatory molecules, T helper 1 (Th1)-associated cytokine release, and chemokine-directed migration of LCs pre-exposed to HPV16. Furthermore, LCs treated with IRX-2 after HPV16 exposure induced CD8(+) T-cell responses against specific HLA-A*0201-binding HPV16 T-cell epitopes. The present study suggests that IRX-2 is an attractive immunomodulator for assisting the immune response in eradication of HPV-infected cells, thereby potentially preventing HPV-induced cancers.

A comprehensive differential gene expression screen on a panel of 54 breast tumors and >200 normal tissue samples using DNA microarrays revealed 15 genes specifically overexpressed in breast cancer. One of the most prevalent genes found was trichorhinophalangeal syndrome type 1 (TRPS-1), a gene previously shown to be associated with three rare autosomal dominant genetic disorders known as the trichorhinophalangeal syndromes. A number of corroborating methodologies, includingin situhybridization, e-Northern analysis using ORF EST (ORESTES) and Unigene EST abundance analysis, immunoblot and immunofluorescence analysis of breast tumor cell lines, and immunohistochemistry, confirmed the microarray findings. Immunohistochemistry analysis found TRPS-1 protein expressed in >90% of early- and late-stage breast cancer, including ductal carcinomain situand invasive ductal, lobular, and papillary carcinomas. The TRPS-1 gene is also immunogenic with processed and presented peptides activating T cells found after vaccination of HLA-A2.1 transgenic mouse. Human T cell lines from HLA-A*0201+female donors exhibiting TRPS-1-specific cytotoxic T lymphocyte activity could also be generated.

Follicular lymphoma (FL) is a unique disease characterised by a long natural history and responsiveness to many different therapies. We have reviewed the prognostic significance of the quality of both clinical and molecular responses for patients with FL. We have found that, as might be expected, patients who achieve a complete clinical response to treatment have a better prognosis than patients who achieve an incomplete or a partial response. However, unlike aggressive lymphomas, treatments that produce a higher frequency of complete responses do not result in better survival outcomes than treatments that produce lower complete response rates. Recent improvements in technologies have enabled quantitative monitoring of responses at the molecular level and at much higher degrees of sensitivity than can be obtained at the clinical level. Although these data are very heterogeneous and have many limitations, data are emerging that demonstrate that achieving molecular remissions after standard dose chemotherapy, high dose chemotherapy or various immunotherapies may have prognostic significance for patients with FL. With sensitive, quantitative, standardised and reproducible tools for molecular monitoring and with the combination of novel targeted biological therapies, we are approaching an era, where the potential to cure patients with FL is being turned into a reality.

Recently, immunotherapy has been widely investigated for the treatment of cancer. While much of the success in this area lies with passive immunotherapy, the focus of this review is active vaccination strategies, which are showing promise. Cancer cells express a wide profile of different proteins, some of which are related to oncogenic transformation and are specific to cancer cells only. However, in cancer, most protein targets presented to the immune system from tumor cells are self-antigens. The immune system is highly tolerant of, and therefore does not react to, these self-antigens. Active immunotherapy aims to reverse this immune tolerance so the immune system can respond appropriately to self-antigens. To generate a successful antitumor response, several features should be considered: a target antigen on tumor cells to direct the immune response, a platform to present the vaccine-derived antigen to the immune system, an adjuvant to enhance immune stimulation, and appropriate monitoring techniques. New tools are becoming available for monitoring, although the clinical relevance for these assays needs to be established. Optimism for cancer vaccine approaches are increasing. Recent studies have shown that it is possible to break immune tolerance to self-antigens. Promising therapeutic clinical activity has been demonstrated, and other studies have shown that cancer vaccines are most beneficial for minimal residual disease states. Further optimization of cancer vaccines and larger clinical studies are required.

High-dose therapy with stem-cell transplantation is a potentially curative therapy for younger patients with relapsed aggressive non-Hodgkin's lymphoma (NHL) and is also under investigation in relapsed indolent NHL. There are, however, risks associated with this treatment strategy. Autologous stem-cell transplantation (ASCT) continues to be associated with a high risk of relapse, while graft-versus-host disease is a major limiting factor with allogeneic stem-cell transplantation. The presence of minimal residual disease (MRD) in the harvested, re-infused stem cells, or remaining in the patient following chemotherapy, is associated with relapse after ASCT. As a result, monitoring and eradicating MRD has become a major focus of many studies in NHL. Rearrangement and overexpression of the bcl-1 and bcl-2 genes are the hallmarks of mantle-cell and follicular lymphoma, respectively, and evidence suggests that they are promising surrogate markers of MRD. Polymerase chain reaction analysis is a sensitive methodology used to monitor the status of occult lymphoma cells bearing these genetic aberrations, and results from trials of ASCT have shown that clearance of bcl-1/JH- and bcl-2/JH-positive cells following treatment is associated with a significant improvement in outcome. Rituximab, the anti-CD20 monoclonal antibody, is increasingly used for in vivo purging and can effectively eradicate bcl-1/JH- and bcl-2-positive cells. If the encouraging preliminary results with rituximab are maintained with a longer follow-up, this agent could play a pivotal role in improving outcome after stem-cell transplantation in NHL.

In clinical trials, metronomic cyclophosphamide (CPA) is increasingly being combined with vaccines to reduce tumor-induced immune suppression. Previous strategies to modulate the immune system during vaccination have involved continuous administration of low dose chemotherapy, studies that have posed unique considerations for clinical trial design. Here, we evaluated metronomic CPA in combination with a peptide vaccine targeting HPV16E7 in an HPV16-induced tumor model, focusing on the cytotoxic T-cell response and timing of low dose metronomic CPA (mCPA) treatment relative to vaccination. Mice bearing C3 tumors were given metronomic CPA on alternating weeks in combination with immunization with a DepoVax vaccine containing HPV16E749–57 peptide antigen every 3 weeks. Only the combination therapy provided significant long-term control of tumor growth. The efficacy of the vaccine was uncompromised if given at the beginning or end of a cycle of metronomic CPA. Metronomic CPA had a pronounced lymphodepletive effect on the vaccine draining lymph node, yet did not reduce the development of antigen-specific CD8+ T cells induced by vaccination. This enrichment correlated with increased cytotoxic activity in the spleen and increased expression of cytotoxic gene signatures in the tumor. Immunity could be passively transferred through CD8+ T cells isolated from tumor-bearing mice treated with the combinatorial treatment regimen. A comprehensive survey of splenocytes indicated that metronomic CPA, in the absence of vaccination, induced transient lymphodepletion marked by a selective expansion of myeloid-derived suppressor cells. These results provide important insights into the multiple mechanisms of metronomic CPA induced immune modulation in the context of a peptide cancer vaccine that may be translated into more effective clinical trial designs.

Purpose Idiotypes (Ids), the unique portions of tumor immunoglobulins, can serve as targets for passive and active immunotherapies for lymphoma. We performed a multicenter, randomized trial comparing a specific vaccine (MyVax), comprising Id chemically coupled to keyhole limpet hemocyanin (KLH) plus granulocyte macrophage colony-stimulating factor (GM-CSF) to a control immunotherapy with KLH plus GM-CSF. Patients and Methods Patients with previously untreated advanced-stage follicular lymphoma (FL) received eight cycles of chemotherapy with cyclophosphamide, vincristine, and prednisone. Those achieving sustained partial or complete remission (n = 287 [44%]) were randomly assigned at a ratio of 2:1 to receive one injection per month for 7 months of MyVax or control immunotherapy. Anti-Id antibody responses (humoral immune responses [IRs]) were measured before each immunization. The primary end point was progression-free survival (PFS). Secondary end points included IR and time to subsequent antilymphoma therapy. Results At a median follow-up of 58 months, no significant difference was observed in either PFS or time to next therapy between the two arms. In the MyVax group (n = 195), anti-Id IRs were observed in 41% of patients, with a median PFS of 40 months, significantly exceeding the median PFS observed in patients without such Id-induced IRs and in those receiving control immunotherapy. Conclusion This trial failed to demonstrate clinical benefit of specific immunotherapy. The subset of vaccinated patients mounting specific anti-Id responses had superior outcomes. Whether this reflects a therapeutic benefit or is a marker for more favorable underlying prognosis requires further study.

A20 is an aggressive BALB/c B cell lymphoma that, despite its expression of B7-2, rapidly forms tumors in syngeneic mice. We have generated A20 transfectants expressing elevated levels of B7-2 (A20/B7-2high) or 4-1BBL (A20/4-1BBL(low,mod,high)) and found that mice which were able to reject the A20/B7-2 or A20/4-1BBL transfectants were also resistant to subsequent systemic challenge with the parental cell line. To assess whether the effectiveness of 4-1BBL in enhancing anti-tumor immunogenicity was dependent on additional signals from B7-CD28 interaction, we injected the A20 variants into BALB/c CD28(-/-) mice. We found that CD28(-/-) mice were able to reject the A20/4-1BBL variants while A20/B7-2 cells formed tumors. However, when the A20/4-1BBL resistant CD28(-/-) mice were systemically challenged with the A20 parental line, tumors formed rapidly. Upon restimulation in vitro, splenocytes from A20/4-1BBL immunized CD28(+/+) mice were able to kill parental tumors whereas splenocytes from CD28(-/-) mice showed a reduction in CTL activity against A20 or A20/4-1BBL targets. Examination of cytokine production by the immunized animals indicated that the CD28(-/-) splenocytes secreted substantially less IL-2 as well as reduced levels of IFN-gamma compared with their CD28(+/+) counterparts. Thus, 4-1BBL expressing tumors are capable of priming CTL responses against 4-1BBL transfected as well as parental tumors in the absence of CD28. However, in the absence of CD28 signaling, the production of cytokines and particularly IL-2 was lower, resulting in a weaker CTL recall response and reduced ability to survive challenge with parental tumor.

Our overall strategy is to develop multivalent recombinant vaccines capable of eliciting broad immune responses in patients with malignant melanoma or colorectal cancer. We report herein results from initial studies conducted in cancer patients to evaluate the effect of intratumoral administration of recombinant canarypox viruses carrying cytokine genes. Our current focus is on the induction of tumor-specific T-cell responses using a prime/boost immunization schedule with a unique vector system derived from the canary pox virus called ALVAC, in which we incorporate genes encoding Tumor Associated Antigens (TAAs) of interest. Clinical studies in colorectal cancer evaluating an ALVAC CEA candidate vaccine have shown that this approach is safe and can induce tumor-specific T cell responses. Additional clinical studies evaluating candidate vaccines against melanoma and colorectal cancer, targeting either the gp100, Mage 1, Mage 3 or p53 molecules are ongoing.

Treatment outcomes were documented for 204 adult patients with clinical Stage I-II Hodgkin's disease who were treated with risk-adapted ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine) and radiotherapy (RT) at the Toronto-Sunnybrook Regional Cancer Centre between 1984 and 1994. Forty-nine patients with clinical Stage I disease (excluding bulky mediastinal presentations) and 50 patients with a combination of clinical Stage IIA disease, age 50 years or less, and favourable pathology (lymphocyte predominant or nodular sclerosing histology) were identified as low risk and treated with RT alone to 35 Gy. One hundred and five high-risk patients were treated with chemotherapy (86 with ABVD) followed by RT to 25 Gy. The 7-year cause-specific, overall and disease-free survivals were 95%, 90% and 75% respectively for the low-risk cohort, and 91%, 90% and 88% respectively for the high-risk cohort. In-field relapses accounted for 50% of the failures in both groups. Sixteen of 24 (67%) patients with RT failure and 6/14 (43%) with combined modality therapy (CMT) failure were salvaged. Twenty-eight per cent of the patients treated with RT and 21% of those treated with CMT developed hypothyroidism by 7 years. Fatal complications were recorded in 6% of the low-risk patients managed with RT and 8% of high-risk patients managed with CMT. Septic death and second malignancy accounted for the majority of treatment-related fatalities. Risk-adapted therapy emphasizing RT alone for selected patients with favourable prognostic factors and CMT based on ABVD provides excellent long-term disease control. Further treatment refinements, including the wider application of CMT with lower doses of chemotherapy and RT, will be required to reduce the rate of fatal complications to more acceptable levels.

Affinity-purified polyclonal antibodies against the hBRAG (human B cell RAG-associated gene) protein were generated to characterize hBRAG at the biochemical level. Immunoblotting and immunoprecipitation experiments with these antibody reagents demonstrate that this protein can be expressed in B cells as a membrane-integrated glycoprotein disulfide-linked dimer. However, both glycosylated and unglycosylated isoforms of hBRAG are detectable with these reagents. Additionally, their use in cell surface biotinylation and flow cytometry reveals subcellular hBRAG pools both at cell surface and intracellular locations. Co-immunoprecipitation experiments with hBRAG antisera detected the association of hBRAG with phosphorylated proteins in resting B cells, including the protein tyrosine kinase Hck, which is subsequently dephosphorylated upon B cell receptor (BCR) ligation. Consistent with its cell surface expression and possible link to BCR signaling, experiments in which alpha-hBRAG antibodies were used to generate early activation signals suggest a modest but specific element of tyrosine phosphorylation occurring through a putative hBRAG receptor. Additional experiments also suggest that hBRAG may be involved in positively enhancing BCR ligation-mediated early activation events. Collectively, these results are consistent with a function for hBRAG as a B cell surface signaling receptor molecule. Coupled with the earlier observation that hBRAG expression correlates with early and late B cell-specific RAG expression, we submit that hBRAG may mediate regulatory signals key to B cell development and/or regulation of B cell-specific RAG expression.

Determining the activity of viral and cellular regulatory elements in B or T lymphoid cell lines would facilitate appropriate utilization of the regulatory sequences for gene transfer- and expression-dependent applications. We have compared the activity of the CMV, RSV and SV40 viral promoter/enhancers as well as the Vlambda1 cellular promoter, in three B cell lines (REH, SMS-SB, C3P), three T cell lines (CEM, Jurkat, ST-F10), and two non-lymphoid cell lines (K-562, HeLa) using the luciferase reporter gene. In B cell lines, the activity of the CMV promoter/enhancer construct was the highest ranging from 10- to 113-fold greater than that of SV40. In contrast, in T cell lines the RSV promoter/enhancer activity was 11-65-fold higher than that of SV40. The Vlambda1 promoter activity was close to that of SV40 promoter/enhancer in most of the cell lines tested. We conclude that CMV and RSV promoter/enhancers contain stronger regulatory elements than do the SV40 and Vlambda1 for expression of genes in lymphoid cell lines.

A20 is a B cell lymphoma that constitutively expresses the costimulatory molecule B7-2 yet grows readily as a tumor in syngeneic BALB/c mice. We have compared the tumorigenicity of A20 variants expressing either B7-1 (A20/B7-1) or B7-2 (A20/B7-2) with an A20 variant expressing B7-1 and B7-2 with 4-1BBL (A20/4-1BBL), a costimulatory member of the TNF family. Mice injected with tumors expressing the vector backbone (A20/CMV) or B7-1 developed tumors within 25 days of s.c. injection. In contrast, mice injected with A20/4-1BBL were tumor free for the 150-day follow-up period, while 25% of mice injected with A20/B7-2 developed tumors. Tumorigenicity experiments using nude mice indicated the requirement for T cells for variant rejection. Almost all mice that resisted the initial tumor challenge were resistant to further challenge with the parental tumor. Splenocytes from these mice showed high CTL lytic activity against the parental tumor, A20, as well as the syngeneic BALB/c lymphoma K46J, but showed background levels of lytic activity against the congenic SCID thymoma line ST-D2 or the allogeneic EL4 thymoma. In vitro blocking experiments with anti-B7-1 plus anti-B7-2 and/or soluble 4-1BB receptor showed B7-1, B7-2, and 4-1BBL all contributed to the CTL activity. Thus, the data show that neither B7-1 or B7-2 alone can confer full immunogenicity to the A20 lymphoma but that the addition of 4-1BBL results in a tumor that is highly immunogenic and can confer long-lasting protection against challenge with parental tumor in vivo.

This study was designed to evaluate the efficacy and toxicity of dose intensifying DHAP (dexamethasone, cytarabine and cisplatin) salvage chemotherapy by adding mitoxantrone with GM-GSF support in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL). From March 1992 to January 1995, 22 patients with intermediate and high grade (aggressive) NHL refractory or relapsed after adriamycin containing chemotherapy regimens were treated with M-DHAP+GM-CSF, (dexamethasone 40 mg i.v. days 1-4, cisplatin 100 mg/m2 i.v. by continuous infusion over 24 hours on day 1, cytarabine 2 gm/m2, i.v. every 12 hours for 2 doses on day 2, mitoxantrone 10 mg/m2 i.v. on days 3 and 4 and GM-CSF 250-500 microg/m2 s.c. daily beginning day 5 until absolute neutrophil count recovery. Most patients had poor prognostic factors including primary refractory disease (18/22), bulky disease (12/22), elevated LDH (9/22), or bone marrow involvement (8/22). All 22 patients were evaluable. The overall response rate was 41% (CR 23% and PR 18%). There were three toxic deaths, all related to sepsis. Median progression free survival (PFS) and overall survival (OS) rates were 5.2 months and 11.8 months respectively. At the same time of the analysis two patients were alive after high-dose therapy and bone marrow transplant at 34 and 36 months follow-up and two were alive with disease. The maximal acceptable dosage of mitoxantrone was 10 mg/m2 x 2 due to serious hematologic toxicity. Treatment delays and dose reductions compromised delivering the optimal dose intensity of M-DHAP. A poor prognostic group of patients with refractory or recurrent aggressive lymphoma, many of whom were not eligible for high-dose therapy and stem cell transplantation were treated with repeated cycles of dose intensified DHAP with growth factor support. Although M-DHAP had therapeutic activity even in patients considered to have primary refractory disease, myelosuppression was dose limiting and frequently limited the number of cycles. Therefore, if M-DHAP is to be further evaluated, therapeutic results may be improved further by incorporating strategies to reduce myelotoxicity such as the use of growth factors to reduce platelet transfusion requirements or the use of autologous stem cell support after each cycle.

Because of evidence that failure to deliver full dose CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) may compromise the outcome of elderly patients with aggressive non-Hodgkin's lymphoma (NHL), we attempted to deliver full dose CHOP to these patients. The objective of this review was to assess the relative received dose intensity (ARRDI), toxicity and outcome of elderly patients treated with curative intent with CHOP at our centre. Charts were reviewed of all patientsor = 65 years with newly diagnosed aggressive NHL referred to the Toronto-Sunnybrook Regional Cancer Centre (TSRCC) for initial management from 1990-1995 before routine use of G-CSF. Sixty eligible patients were identified. 31 received CHOP +/- radiation (XRT), 9 other curative treatment and 20, palliative treatment. The mean ARRDI calculated on 29/31 patients receiving CHOP was .86; 41%=1.0, 24%=.90-.99, 14%=.75-.89 and 21%=.75. During 141 cycles of CHOP. 17 (12%) episodes of febrile neutropenia (FN) occurred in 14 (45%) patients and other grade 3/4 toxicity occurred in10% of patients. There were 3 (10%) toxic deaths. Sixteen (52%) patients required a total of 29 admissions to hospital for FN (59%) or other causes. Of the 31 patients, 16 (52%) achieved a complete remission (CR), 7 (23%) a partial remission-1 (PR-1), 2 (6%) a partial remission-2 (PR-2), 1 (3%) had no response (NR), 2 (6%) had progressive disease and 3 (10%) were not evaluable (NE). The median progression free survival (PFS) and overall survival (OS) were (16+) months and (24.5) months respectively. We found that physician biases resulted in the selection of; younger patients (median 71 vs. 80 years), patients with a better ECOG performance status (or =2, 13% vs. 50%) and patients with less co-morbid illness (42% vs. 90%) for attempt at curative treatment with CHOP chemotherapy. Age was never the sole reason for offering palliative treatment. In conclusion, a subset of patients over the age of 65 with aggressive NHL, who have a good performance status and minimal co-morbid illness can tolerate full dose CHOP chemotherapy without G-CSF support. Future strategies should emphasize full dose treatment with curative intent with minimization of both hematologic and non-hematologic toxicity. Clinical studies are required to determine whether routine G-CSF support will reduce toxicity or improve outcome in this group of patients.

The different display reverse transcription-PCR (DD RT-PCR) technique was used to identify novel cDNA detecting mRNA transcripts co-expressed with human recombination activating gene-1 (RAG1). A 5.0-kb transcript detected by the differential display amplicon 3G1 was found to correlate strongly with RAG1 mRNA expression in various human cell lines. Subsequent screenings of a pre-B cDNA library with 3G1 led to the identification of a complete cDNA we have termed hBRAG (human B-cell RAG-Associated Gene). The hBRAG cDNA encodes a 503-amino acid (aa) protein with no known homology to any nucleotide or protein sequence. The predicted molecular mass of 55 kDa was confirmed by in vitro translation. Based on sequence analysis, the predicted open reading frame encodes for a type II transmembrane spanning glycoprotein with the N-terminal 81 -aa in the cytoplasm, a 17-aa transmembrane domain, and a C-terminal 405-aa extracellular domain with four potential N-glycosylation sites. Northern blot analysis indicated a close association of the 5.0-kb hBRAG mRNA transcript with RAG1 in numerous human pro-B, pre-B and mature B cell lines assessed, but not in human T cell lines. In human tissues, hBRAG is expressed at highest levels in B cell-enriched tissues, but is not expressed in fetal or adult thymus. Southern blotting analysis revealed that this gene is conserved across eukaryotes, is expressed as a single copy in the human genome, and is likely not a multigene family member. The hBRAG gene was localized to the long arm of chromosome 10 (10q26). Transfection of the full-length hBRAG cDNA increased levels of human RAG1 transcripts in the B cell line OCI LY8-C3P, but not in the non-lymphoid line K562, suggesting a B cell-specific role for the hBRAG product in regulating RAG expression.

Summary Background Monoclonal antibodies are being utilized for treatment of patients with low-grade non-Hodgkin’s lymphoma as well as other cancers. Results from phase I and II clinical studies has shown that the chimeric monoclonal antibody Rituximab has minimal toxicity and significant therapeutic activity in low grade non-Hodgkin’s lymphoma. Patients and methods We have recently reported on a multicentre pivotal phase III clinical trial involving 166 patients with recurrent low-grade lymphoma who were treated with four infusions of Rituximab. Eighty patients (48%) achieved objective responses including 10 patients (6%) with complete responses. Overall, 126 patients (76%) had a ≥ 20% reduction in overall tumor size. The median response duration and time to progression are 11.6 and 13.2 months, respectively. The infusional and long term toxicities were limited. Results In this report we describe the pharmacokinetic data obtained on these patients. Measurable concentrations of Rituximab were detected in all patients after the first infusion and increased throughout the treatment course. The half-life of the monoclonal antibody increased from 76.3 hours after the first infusion to 205.8 hours after the fourth infusion and was concomitant with a four-fold decrease in the antibody clearance. At three months and six months post-treatment, the median Rituximab serum levels were 20.3 μg/ml (range 0.0 to 96.8 μg/ml in 104 patients) and 1.3 μg/ml (range 0.0–28.7 μg/ml in 13 patients), respectively. A statistically significant correlation was found between the median antibody concentration and response for multiple time points during the treatment and followup. The mean serum antibody concentration was also inversely correlated with measurements of tumor bulk and with the number of circulating B cells at baseline. Conclusions We conclude that Rituximab is therapeutically effective against B-cell lymphoma. Pharmacokinetic data suggests that certain subsets of patients may possibly benefit from increased dosing and studies to address this are currently underway.