Lazaryan, Aleksandr

Abstract Varlilumab is a monoclonal antibody with agonistic activity on CD27. The efficacy of single-agent PD-1 inhibitors on aggressive B-cell non-Hodkin lymphoma is limited. Preclinical and phase 1 data suggest that Varlilumab is safe and may have synergistic activity with PD-1 inhibitors. In the DIAL study, we explored whether dual immunomodulatory therapy with Varlilumab and Nivolumab in patients with relapsed/refractory aggressive B-NHL was safe and effective. We conducted a randomized phase II clinical trial on adult patients with relapsed/refractory aggressive B-NHL. Patients were randomized to receive Nivolumab monotherapy in the control group and Varlilumab combined with Nivolumab in the experimental group. Crossover to the experimental group was allowed upon progression in the control group. The primary endpoint was the overall response rate based on the Lymphoma Response to Immunomodulatory Therapy Criteria (LYRIC). 54 patients underwent randomization, and 51 received assigned intervention and were included in the intention-to-treat analysis. Objective response was observed in 6 out of 51 patients (ORR 12%). There were 4 responders (ORR 16%) in the Nivolumab group and 2 responders (ORR 7.6%) in the Nivolumab and Varlilumab combination group (p = 0.3). None of the 7 patients that crossed over to the experimental group responded to the addition of Varlilumab. The ORR of patients who were previously exposed to CAR-T cell therapy was 13% (5 out of 39) compared to 8.3% (1 out of 12) in the unexposed patients (p > 0.99). The rate of treatment emergent adverse events was similar between groups, and there was no fatal TEAE in the study. The addition of Varlilumab to Nivolumb did not improve outcomes in patients with aggressive B-NHL. Even though this trial was not designed to evaluate immunotherapy as a rescue therapy after CAR-T failure, most patients (76%) had previously received CAR-T therapy, and their outcomes were equally poor.

Abstract Background: Post-transplant lymphoproliferative disorder (PTLD) occurs in up to 30% of high-risk solid organ transplant recipients and is strongly associated with the intensity and duration of immunosuppression. While Epstein-Barr virus (EBV)-positive monomorphic PTLD and diffuse large B-cell lymphoma (DLBCL) share overlapping morphologic features and expression of canonical B-cell markers, they exhibit distinct EBV transcriptional programs. Immunosuppressive regimens, essential for preventing graft rejection, impair EBV-specific cytotoxic T lymphocyte (CTL) responses, thereby promoting EBV-driven lymphomagenesis. We hypothesized that these differences in viral transcription and immune evasion reflect fundamentally distinct immune microenvironments and host responses in EBV-positive PTLD compared to DLBCL. Methods This prospective, non-interventional study has been conducted at Moffitt Cancer Center since 2019. To characterize tumor-specific T-cell responses in EBV-positive PTLD versus DLBCL, peripheral blood mononuclear cells (PBMCs) from enrolled patients were infected with EBV (ATCC VR-1492) to generate autologous, immortalized lymphoblastoid B-cell lines (LCLs). EBV antigen-specific immune responses were quantified using an IFN-γ ELISpot assay targeting EBNA1, LAMP1, LAMP2A, BARF1, and a CEF peptide pool as a control. To optimize cell viability and functional readout post-thaw, we implemented an overnight resting protocol for PBMCs, which demonstrated superior IFN-γ release compared to the conventional 1-hour rest. Results We present pilot data from 11 consecutive patients (55% male; median age 63.4 years), including 3 with PTLD (2 EBV-positive; 2 monomorphic) and 8 with EBV-negative DLBCL. A total of 12 evaluable PBMC samples were analyzed: 7 pre-treatment, 1 mid-treatment, and 4 post-treatment. Successful generation of autologous LCLs was predominantly achieved using pre-treatment samples, whereas samples collected after B-cell–targeted therapy (Rituximab ± CHOP) showed reduced transformation efficiency. Notably, early pre-treatment samples exhibited a relative enrichment of CD27⁺ memory B cells. Baseline flow cytometric profiling of B cells undergoing LCL transformation revealed low CD19 expression (range <1%–15%). Repeat immunophenotyping at 3 weeks identified residual T cells within cultures, suggesting ongoing B-cell clearance. In matched flow cytometry and ELISpot assays from 7 evaluable patients with pre-treatment samples, EBV-positive PTLD cases demonstrated pronounced overexpression of PD-1 and TIM-3, but not LAG-3, alongside markedly diminished T-cell responses to EBV antigens. This distinct immunophenotypic and functional signature suggests T-cell exhaustion or dysfunction, likely driven by prior immunosuppression, which may impair immune surveillance and facilitate EBV-driven lymphomagenesis. Conclusions Our findings reveal distinct immunologic profiles in EBV-positive monomorphic PTLD compared to EBV-negative DLBCL, characterized by immune exhaustion and impaired T-cell functionality. Specifically, overexpression of PD-1 and TIM-3—but not LAG-3—in EBV-positive PTLD correlated with diminished antigen-specific T-cell responses, as measured by ELISpot, underscoring the role of prior immunosuppression in shaping ineffective tumor-specific immunity. Successful generation of autologous LCLs was predominantly achieved from pre-treatment PBMCs, highlighting the impact of B-cell–depleting therapies (Rituximab ± CHOP) on downstream immune profiling feasibility. The persistence of residual T cells in long-term LCL cultures suggests ongoing B-cell clearance and may reflect previously unrecognized immune dynamics in PTLD. Collectively, these data provide novel insights into the immune landscape of EBV-driven PTLD and support the rationale for therapeutic strategies aimed at reversing T-cell exhaustion—such as immune checkpoint blockade or adoptive T-cell therapies—to restore anti-EBV immunity in transplant recipients.

LBA7564 Background: Patients with r/r B-NHL have a dismal prognosis. DIAL (Dual Immunomodulation in Aggressive Lymphoma) was a multi-center randomized phase II study testing the efficacy of nivolumab (PD-1 inhibitor) plus varlilumab (CD27 agonist) in this population. Methods: Patients were randomized (1:1) to nivolumab (240 mg IV every 2 weeks for 4 months, 480 mg IV monthly thereafter; group 1) alone or combined with varlilumab (3 mg/kg IV monthly; group 2). Cross-over (group 1 to 2) was allowed for progression. Primary endpoint was overall response (ORR) per LYRIC criteria. A sample size of 48 patients per arm would provide 80% power to detect increase in ORR from 25% to 45% using a one-sided test (p = 0.15). Pre-specified interim analysis occurred after half of the patients completed first radiologic assessment. Secondary endpoints included overall survival (OS), progression-free survival (PFS), and adverse events (AEs). Exploratory endpoints included tumor genomic assessment and immune profiling of blood and tumor. Results: 53 patients were enrolled (27 in group 1; 26 in group 2). Interim analysis included 24 patients from each arm. Mean age was 65.2 years, 34 (70.8%) were male, and 36 (75%) received prior CAR-T cell therapy. Baseline characteristics were balanced between arms. Grade ≥ 3 AEs were observed in 8 (33.3%) and 7 (30.4%) of patients in groups 1 and 2, respectively. Common AEs (> 5%) of any grade included fatigue, lymphopenia, diarrhea, rash. There were no treatment-associated deaths. Toxicity profile was similar between arms. Table summarizes efficacy outcomes. ORR was achieved in 6 patients (12.5%), not statistically different between arms; 4 responses were complete. Seven patients crossed over (1 responded after crossing). Median OS (8.6 vs 7.3 months; p = 0.39) and PFS (2.7 vs 1.4 months; p = 0.06) were similar between arms. Subgroup analysis of patients with prior CAR-T cell therapy showed similar ORR (5/36; 14%), not statistically different between arms. Correlative analysis results will be presented at conference. The trial met futility criterion on interim analysis and enrollment ceased based on pre-specified stopping rule. Conclusions: Dual immunomodulatory therapy did not enhance anti-tumor activity in patients with aggressive B-NHL compared to nivolumab alone. Response rates were low and consistent with previous data using PD-1 inhibitors in this population. Prior therapy with CAR-T cell does not seem to sensitize patients to PD-1 blockade. Toxicity profile was acceptable and dual therapy did not increase the rate of AEs. Clinical trial information: NCT03038672. [Table: see text]

Abstract Standard initial therapy of chronic graft vs. host disease (cGVHD) with glucocorticoids results in suboptimal response. Safety and feasibility of therapy with ofatumumab (1000 mg IV on days 0 and 14) and prednisone (1 mg/kg/day) was previously established in our phase I trial (n = 12). We now report the mature results of the phase II expansion of the trial (n = 38). The overall NIH severity of cGVHD was moderate (63%) or severe (37%) with 74% of all patients affected by the overlap subtype of cGVHD and 82% by prior acute cGVHD. The observed 6 month clinician-reported and 2014 NIH-defined overall response rates (ORR = complete + partial response [CR/PR]) of 62.5% (1-sided lower 90% confidence interval=51.5%) were not superior to pre-specified historic benchmark of 60%. Post-hoc comparison of 6 month NIH response suggested benefit compared to more contemporaneous NIH-based benchmark of 48.6% with frontline sirolimus/prednisone (CTN 0801 trial). Baseline cGVHD features (organ involvement, severity, initial immune suppression agents) were not significantly associated with 6-month ORR. The median time to initiation of second-line therapy was 5.4 months (range 0.9-15.1 months). Failure-free survival (FFS) was 64.2% (95% CI 46.5-77.4%) at 6 months and 53.1% (95% CI 35.8-67.7%) at 12 months, whereas FFS with CR/PR at 12 months of 33.5% exceeded a benchmark of 15% in post-hoc analysis, and was associated with greater success in steroid discontinuation by 24 months (odds ratio 8 (95% CI 1.21-52.7). This single-arm phase II trial demonstrated acceptable safety and potential efficacy of the upfront use of ofatumumab in combination with prednisone in cGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01680965.

Abstract Introduction: Amphiregulin (AREG) is an epidermal growth factor receptor (EGFR) ligand that can restore integrity to damaged intestinal mucosa in murine models of acute graft-versus-host disease (aGVHD). We previously described AREG as a circulating biomarker of late-onset aGVHD, but its relevance combined with clinical risk factors has not yet been tested in a large cohort of patients with aGVHD occurring prior to day 100 post-transplant. We therefore tested samples from two aGVHD first-line treatment trials, Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0302 and 0802, and identified a clinically relevant threshold level of circulating AREG at aGVHD onset. We then investigated whether incorporating AREG into the refined Minnesota Risk Score could further risk-stratify patients. Patients and Methods: Blood samples were obtained at the onset of systemic aGVHD treatment within BMT CTN 0302 (serum) and BMT CTN 0802 (plasma). All patients with response data and samples for analysis from both trials were included (N=251). We determined the association of AREG with clinical outcomes, including risk stratification by the refined Minnesota criteria, day 28 complete/partial response (CR/PR) to first-line therapy, 2-year overall survival (OS) and 6-month and 2-year non-relapse mortality (NRM). We investigated the effect of AREG on clinical endpoints per a doubling in the value of AREG, defined a clinically relevant threshold level in the AREG values using two-fold cross-validation, and confirmed the clinical relevance of this cut-point in independent samples (N=92) from pooled from drawn from the Chronic GVHD Consortium and the Mount Sinai Acute GVHD International Consortium (MAGIC). Results: In patients enrolled in BMT CTN 0302/0802, AREG levels were 1.7-fold higher in patients with Minnesota high-risk (HR) compared to standard-risk (SR) aGVHD (HR median 53.4 vs SR 31 pg/ml, p<0.01). Every 2-fold increase in AREG was associated with a 33% decrease in the likelihood of day 28 CR/PR (odds ratio [OR] 0.67, p<0.01, table). Clinical factors alone, as determined by the refined Minnesota Risk Score, were associated with day 28 CR/PR (p=0.02, table). Adding AREG to the Minnesota Risk Score could further risk-stratify patients. Minnesota SR patients with elevated AREG ≥ 33 pg/mL showed a 59% lower odds of day 28 CR/PR than SR patients with low AREG (OR 0.41, p=0.02). Patients with Minnesota HR aGVHD with AREG ≥ 33 pg/mL had the worst outcomes, with an 82% lower odds of day 28 CR/PR in comparison to HR with low AREG (OR 0.18, p<0.01). High AREG was associated with worse OS and NRM in both Minnesota SR (hazard ratios 2-year OS 2.3, p<0.01 and 6 month NRM 2.95, p=0.01, respectively) and HR patients (hazard ratios 2-year OS 3.35, p<0.01 and 6-month NRM 9.38, p<0.01 respectively, figure). Finally, in independent samples from the Chronic GVHD Consortium/MAGIC we confirmed that high AREG was associated with worse day 28 CR/PR (55.2% vs. 79.4%, p=0.02) and significantly worse 6-month survival after the onset of aGVHD (57.1% vs. 82.5%, p=0.01). Conclusion: AREG is elevated in patients with poor aGVHD outcomes and adds to the accuracy of risk stratification when combined with the refined Minnesota Risk Score. AREG ≥33 pg/mL at aGVHD onset is associated with lower day 28 CR/PR and higher mortality in samples from 4 multicenter cohorts. The mechanism of elevated circulating AREG in severe aGVHD is not yet known, although we hypothesize the degree of AREG elevation reflects the intensity of immune-mediated tissue injury resulting in AREG release. With accumulating evidence of altered EGFR ligands in aGVHD, further investigation into epithelial repair pathways involving AREG may lead to new adjunctive therapies to overcome poor steroid response in high-risk aGVHD. Disclosures Holtan: Incyte: Other: One-time advisory board member. Khera: Novartis: Consultancy. Lee: Mallinckrodt: Honoraria; Amgen: Other: One-time advisory board member; Bristol-Myers-Squibb: Other: One-time advisory board member; Kadmon: Other: One-time advisory board member. Chen: Immudex: Research Funding. Arora: Takeda Oncology: Consultancy. Flowers: Pharmacyclics: Consultancy. Cutler: Pfizer: Consultancy; Kite: Consultancy; Incyte: Consultancy; Bristol-Myers Squibb: Consultancy; Pharmacyclics: Consultancy; Astellas: Consultancy. Jagasia: Janssen: Consultancy, Research Funding; Therakos: Consultancy, Research Funding; Mallinckrodt: Consultancy. Hexner: Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding. Levine: Novartis Pharmaceuticals Corporation: Membership on an entity's Board of Directors or advisory committees. MacMillan: Magenta Therapeutics: Research Funding.

Background Although rituximab‐based high‐dose therapy is frequently used in diffuse large B cell lymphoma (DLBCL) patients undergoing autologous hematopoietic cell transplantation (auto‐HCT), data supporting the benefits are not available. Herein, we report the impact of rituximab‐based conditioning on auto‐HCT outcomes in patients who have DLBCL. Methods Using the Center for International Blood and Marrow Transplant Research (CIBMTR) registry, 862 adult DLBCL patients undergoing auto‐HCT between 2003 and 2017 using BEAM (BCNU, etoposide, cytarabine, melphalan) conditioning regimen were included. All patients received frontline rituximab‐containing chemoimmunotherapy and had chemosensitive disease pre‐HCT. Early chemoimmunotherapy failure was defined as not achieving complete remission (CR) after frontline chemoimmunotherapy or relapse within 1 year of initial diagnosis. The primary outcome was overall survival (OS). Results The study cohort was divided into 2 groups: BEAM (n = 667) and R‐BEAM (n = 195). On multivariate analysis, no significant difference was seen in OS ( P = .83) or progression‐free survival (PFS) ( P = .61) across the 2 cohorts. No significant association between the use of rituximab and risk of relapse ( P = .15) or nonrelapse mortality ( P = .12) was observed. Variables independently associated with lower OS included older age at auto‐HCT ( P < .001), absence of CR at auto‐HCT ( P < .001) and early chemoimmunotherapy failure ( P < .001). Older age ( P < .0002) and non‐CR pre‐HCT ( P < .0001) were also associated with inferior PFS. There was no significant difference in early infectious complications between the 2 cohorts. Conclusion In this large registry analysis of DLBCL patients undergoing auto‐HCT, the addition of rituximab to the BEAM conditioning regimen had no impact on transplantation outcomes. Older age, absence of CR pre auto‐HCT, and early chemoimmunotherapy failure were associated with inferior survival.