Efficacy of checkpoint inhibition after CAR-T failure in aggressive B-cell lymphomas: outcomes from 15 US institutions

Checkpoint inhibitor (CPI) therapy with anti-PD-1 antibodies has been associated with mixed outcomes in small cohorts of patients with relapsed aggressive B-cell lymphomas after CAR-T failure. To define CPI therapy efficacy more definitively in this population, we retrospectively evaluated clinical outcomes in a large cohort of 96 patients with aggressive B-cell lymphomas receiving CPI therapy after CAR-T failure across 15 US academic centers. Most patients (53%) had diffuse large B-cell lymphoma, were treated with axicabtagene ciloleucel (53%), relapsed early (≤180 days) after CAR-T (83%), and received pembrolizumab (49%) or nivolumab (43%). CPI therapy was associated with an overall response rate of 19% and a complete response rate of 10%. Median duration of response was 221 days. Median progression-free survival (PFS) and overall survival (OS) were 54 and 159 days, respectively. Outcomes to CPI therapy were significantly improved in patients with primary mediastinal B-cell lymphoma. PFS (128 vs 51 days) and OS (387 vs 131 days) were significantly longer in patients with late (>180 days) vs early (≤180 days) relapse after CAR-T. Grade ≥3 adverse events occurred in 19% of patients treated with CPI. Most patients (83%) died, commonly because of progressive disease. Only 5% had durable responses to CPI therapy. In the largest cohort of patients with aggressive B-cell lymphoma treated with CPI therapy after CAR-T relapse, our results reveal poor outcomes, particularly among those relapsing early after CAR-T. In conclusion, CPI therapy is not an effective salvage strategy for most patients after CAR-T, where alternative approaches are needed to improve post-CAR-T outcomes

An international analysis evaluating frontline bendamustine with rituximab in extranodal marginal zone lymphoma

: Extranodal marginal zone lymphoma (EMZL) is a heterogeneous non-Hodgkin lymphoma. No consensus exists regarding the standard-of-care in patients with advanced-stage disease. Current recommendations are largely adapted from follicular lymphoma, for which bendamustine with rituximab (BR) is an established approach. We analyzed the safety and efficacy of frontline BR in EMZL using a large international consortium. We included 237 patients with a median age of 63 years (range, 21-85). Most patients presented with Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1 (n = 228; 96.2%), stage III/IV (n = 179; 75.5%), and intermediate (49.8%) or high (33.3%) Mucosa Associated Lymphoid Tissue International Prognosis Index (MALT-IPI). Patients received a median of 6 (range, 1-8) cycles of BR, and 20.3% (n = 48) received rituximab maintenance. Thirteen percent experienced infectious complications during BR therapy; herpes zoster (4%) was the most common. Overall response rate was 93.2% with 81% complete responses. Estimated 5-year progression-free survival (PFS) and overall survival (OS) were 80.5% (95% CI, 73.1% to 86%) and 89.6% (95% CI, 83.1% to 93.6%), respectively. MALT-IPI failed to predict outcomes. In the multivariable model, the presence of B symptoms was associated with shorter PFS. Rituximab maintenance was associated with longer PFS (hazard ratio = 0.16; 95% CI, 0.04-0.71; P = .016) but did not impact OS. BR is a highly effective upfront regimen in EMZL, providing durable remissions and overcoming known adverse prognosis factors. This regimen is associated with occurrence of herpes zoster; thus, prophylactic treatment may be considered

High-Grade B-cell Lymphoma, Not Otherwise Specified: A Multi-Institutional Retrospective Study

In this multi-institutional retrospective study, we examined the characteristics and outcomes of 160 patients with high-grade B-cell lymphoma, not otherwise specified (HGBL-NOS)-a rare category defined by high-grade morphologic features and lack of MYC rearrangements with BCL2 and/or BCL6 rearrangements ( double hit ). Our results show that HGBL-NOS tumors are heterogeneous: 83% of patients had a germinal center B-cell immunophenotype, 37% a dual-expressor immunophenotype (MYC and BCL2 expression), 28% MYC rearrangement, 13% BCL2 rearrangement, and 11% BCL6 rearrangement. Most patients presented with stage IV disease, a high serum lactate dehydrogenase, and other high-risk clinical factors. Most frequent first-line regimens included dose-adjusted cyclophosphamide, doxorubicin, vincristine, and etoposide, with rituximab and prednisone (DA-EPOCH-R; 43%); rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 33%); or other intensive chemotherapy programs. We found no significant differences in the rates of complete response (CR), progression-free survival (PFS), or overall survival (OS) between these chemotherapy regimens. CR was attained by 69% of patients. PFS at 2 years was 55.2% and OS was 68.1%. In a multivariable model, the main prognostic factors for PFS and OS were poor performance status, lactate dehydrogenase \u3e3 × upper limit of normal, and a dual-expressor immunophenotype. Age \u3e60 years or presence of MYC rearrangement were not prognostic, but patients with TP53 alterations had a dismal PFS. Presence of MYC rearrangement was not predictive of better PFS in patients treated with DA-EPOCH-R vs R-CHOP. Improvements in the diagnostic criteria and therapeutic approaches beyond dose-intense chemotherapy are needed to overcome the unfavorable prognosis of patients with HGBL-NOS

Integrative Analysis of Clinicopathological Features Defines Novel Prognostic Models for Mantle Cell Lymphoma in the Immunochemotherapy Era: A Report from The North American Mantle Cell Lymphoma Consortium

BACKGROUND: Patients with mantle cell lymphoma (MCL) exhibit a wide variation in clinical presentation and outcome. However, the commonly used prognostic models are outdated and inadequate to address the needs of the current multidisciplinary management of this disease. This study aims to investigate the clinical and pathological features of MCL in the immunochemotherapy era and improve the prognostic models for a more accurate prediction of patient outcomes. METHODS: The North American Mantle Cell Lymphoma Project is a multi-institutional collaboration of 23 institutions across North America to evaluate and refine prognosticators for front-line therapy. A total of 586 MCL cases diagnosed between 2000 and 2012 are included in this study. A comprehensive retrospective analysis was performed on the clinicopathological features, treatment approaches, and outcomes of these cases. The establishment of novel prognostic models was based on in-depth examination of baseline parameters, and subsequent validation in an independent cohort of MCL cases. RESULTS: In front-line strategies, the use of hematopoietic stem cell transplantation was the most significant parameter affecting outcomes, for both overall survival (OS, p \u3c 0.0001) and progression-free survival (PFS, p \u3c 0.0001). P53 positive expression was the most significant pathological parameter correlating with inferior outcomes (p \u3c 0.0001 for OS and p = 0.0021 for PFS). Based on the baseline risk factor profile, we developed a set of prognostic models incorporating clinical, laboratory, and pathological parameters that are specifically tailored for various applications. These models, when tested in the validation cohort, exhibited strong predictive power for survival and showed a stratification resembling the training cohort. CONCLUSIONS: The outcome of patients with MCL has markedly improved over the past two decades, and further enhancement is anticipated with the evolution of clinical management. The innovative prognostic models developed in this study would serve as a valuable tool to guide the selection of more suitable treatment strategies for patients with MCL

Integrative Analysis of Clinicopathological Features Defines Novel Prognostic Models for Mantle Cell Lymphoma in the Immunochemotherapy Era: a Report From the North American Mantle Cell Lymphoma Consortium

BACKGROUND: Patients with mantle cell lymphoma (MCL) exhibit a wide variation in clinical presentation and outcome. However, the commonly used prognostic models are outdated and inadequate to address the needs of the current multidisciplinary management of this disease. This study aims to investigate the clinical and pathological features of MCL in the immunochemotherapy era and improve the prognostic models for a more accurate prediction of patient outcomes. METHODS: The North American Mantle Cell Lymphoma Project is a multi-institutional collaboration of 23 institutions across North America to evaluate and refine prognosticators for front-line therapy. A total of 586 MCL cases diagnosed between 2000 and 2012 are included in this study. A comprehensive retrospective analysis was performed on the clinicopathological features, treatment approaches, and outcomes of these cases. The establishment of novel prognostic models was based on in-depth examination of baseline parameters, and subsequent validation in an independent cohort of MCL cases. RESULTS: In front-line strategies, the use of hematopoietic stem cell transplantation was the most significant parameter affecting outcomes, for both overall survival (OS, p \u3c 0.0001) and progression-free survival (PFS, p \u3c 0.0001). P53 positive expression was the most significant pathological parameter correlating with inferior outcomes (p \u3c 0.0001 for OS and p = 0.0021 for PFS). Based on the baseline risk factor profile, we developed a set of prognostic models incorporating clinical, laboratory, and pathological parameters that are specifically tailored for various applications. These models, when tested in the validation cohort, exhibited strong predictive power for survival and showed a stratification resembling the training cohort. CONCLUSIONS: The outcome of patients with MCL has markedly improved over the past two decades, and further enhancement is anticipated with the evolution of clinical management. The innovative prognostic models developed in this study would serve as a valuable tool to guide the selection of more suitable treatment strategies for patients with MCL

Effect of cumulative dose of brentuximab vedotin maintenance in relapsed/refractory classical Hodgkin lymphoma after autologous stem cell transplant: an analysis of real-world outcomes

Sixteen cycles of Brentuximab vedotin (BV) after autologous stem cell transplant (ASCT) in high-risk relapsed/refractory classical Hodgkin lymphoma demonstrated an improved 2-year progression-free survival (PFS) over placebo. However, most patients are unable to complete all 16 cycles at full dose due to toxicity. This retrospective, multicenter study investigated the effect of cumulative maintenance BV dose on 2-year PFS. Data were collected from patients who received at least one cycle of BV maintenance after ASCT with one of the following high-risk features: primary refractory disease (PRD), extra-nodal disease (END), or relapse 75% of the planned total cumulative dose, cohort 2 with 51-75% of dose, and cohort 3 with ≤50% of dose. The primary outcome was 2-year PFS. A total of 118 patients were included. Fifty percent had PRD, 29% had RL<12, and 39% had END. Forty-four percent of patients had prior exposure to BV and 65% were in complete remission before ASCT. Only 14% of patients received the full planned BV dose. Sixty-one percent of patients discontinued maintenance early and majority of those (72%) were due to toxicity. The 2-year PFS for the entire population was 80.7%. The 2-year PFS was 89.2% for cohort 1 (n=39), 86.2% for cohort 2 (n=33), and 77.9% for cohort 3 (n=46) (P=0.70). These data are reassuring for patients who require dose reductions or discontinuation to manage toxicity

Promising tolerability and efficacy results from dose-escalation in an ongoing phase Ib/II study of mosunetuzumab (M) with polatuzumab vedotin (Pola) in patients (pts) with relapsed/refractory (R/R) B-cell non-Hodgkin’s lymphoma (B-NHL)

7520 Background: Mosunetuzumab (M), a full-length, humanized, IgG1 bispecific antibody targeting CD20 and CD3, has shown promising efficacy and safety as monotherapy for R/R B-NHL (NCT02500407; Assouline, et al. ASH 2020). The combination of M with the anti-CD79b antibody-drug conjugate, Pola, showed synergistic anti-lymphoma activity in a mouse xenograft model. These data supported a Phase Ib/II, open-label, multicenter trial of M-Pola for R/R B-NHL (GO40516, NCT03671018). Here we present early clinical data from the Phase Ib cohort. Methods: Pts with R/R follicular lymphoma (FL, grade [Gr] 1–3a) or aggressive NHL (aNHL), including de novo diffuse large B-cell lymphoma (DLBCL), transformed FL (trFL) and FL Gr 3b (FL3b), received Cycle (C) 1 step-up doses of M on Day (D) 1 (1mg) and D8 (2mg), the target dose on C1D15, then continued at the target dose on C2D1 onwards. M was given every 21 days for eight cycles (or 17 cycles if stable disease or a partial response after C8). Pola (1.8mg/kg) was given with M on D1 of each cycle for six cycles. Results: As of November 17, 2020, 22 pts had received M-Pola (M target doses: 9mg, n=7; 20mg, n=3; 40mg, n=6; 60mg [with D1 dose of 30mg from C3 onwards], n=6). Pts had DLBCL (n=12), FL (n=3), FL3b (n=3) and trFL (n=4). Pt characteristics include: median age of 70 (38–81) years; median of 3 (1–10) prior lines of therapy; 7 (32%) pts had prior CAR-T therapy; 17 (77%) and 19 (86%) pts had disease refractory to last prior therapy and prior anti-CD20 therapy, respectively. Median follow-up duration was 9.6 (0.7–23.7) months. The most frequent treatment-related adverse events (AEs) were neutropenia (45.4%), fatigue, nausea and diarrhea (all 36.4%). Cytokine release syndrome (CRS) was observed in 2 pts (9.1%; both Gr 1 by ASTCT 2019 criteria). One dose-limiting toxicity (Gr 3 new onset atrial fibrillation) was observed in the 40mg cohort. The maximum tolerated dose was not exceeded. The most common Gr ≥3 and serious AEs were both neutropenia, observed in 8 (36.4%) and 3 (13.6%) pts, respectively. Two (9.3%) Gr 5 AEs occurred: sudden cardiac death (n=1) and respiratory failure (n=1); neither was deemed treatment related. No immune effector cell-associated neurotoxicity was observed. The Table shows preliminary efficacy data. Preliminary efficacy in the dose-escalation cohort. Conclusions: These data indicate that M-Pola has an acceptable safety profile, with no Gr ≥2 CRS observed, and promising efficacy in pts with R/R NHL with predominantly aggressive disease. The Phase II expansion cohort in R/R DLBCL is ongoing, with no mandatory hospitalization required. Clinical trial information: NCT03671018. [Table: see text

Mosunetuzumab Plus Polatuzumab Vedotin Demonstrates a Favorable Safety Profile and Efficacy in Patients (Pts) with Relapsed or Refractory (R/R) Large B-Cell Lymphoma (LBCL): Primary Analysis of a Phase Ib/II Study

Background: Mosunetuzumab (Mosun) is a CD20xCD3 T-cell engaging bispecific antibody that engages and redirects T cells to eliminate malignant B cells. The ongoing Phase Ib/II GO40516 study (NCT03671018) investigates Mosun in combination with polatuzumab vedotin (Pola; M-Pola) in pts with B-cell non-Hodgkin lymphoma (B-NHL). The Phase II expansion phase of the M-Pola regimen (with conventional Mosun and Pola dose and dose schedule), showed an acceptable safety profile and promising anti-tumor activity in pts with R/R B-NHL at interim analysis (Budde et al. ASH 2021). With enrollment complete, we present full dose-expansion cohort results. Methods: Eligible pts had confirmed R/R LBCL (including diffuse LBCL not otherwise specified, high-grade B-cell lymphoma [HGBCL], transformed follicular lymphoma [tFL], and follicular lymphoma [FL] grade [Gr] 3b) and had received ≥1 prior line of therapy (including an anti-CD20 antibody). Treatment cycles were 21 days. Pola (1.8mg/kg; intravenous [IV]) was administered on Day (D) 1 of Cycles (C) 1-6. Mosun IV was administered with C1 step-up dosing to mitigate cytokine release syndrome (CRS), with the following dose and dose schedule: 1mg on C1D1, 2mg on C1D8, 60mg on C1D15 and C2D1, and 30mg on D1 of C3+. Pts with a complete response (CR) completed Mosun after C8, and pts with stable disease or partial response at the end of C8 continued Mosun for a total of 17 cycles. Primary endpoint was best overall response rate (ORR) by independent review committee (IRC) using Lugano 2014 criteria (Cheson et al. J Clin Oncol 2014). CRS events were reported using ASTCT criteria (Lee et al. Biol Blood Marrow Transplant 2019). Results: As of April 7, 2023, 98 pts received M-Pola in the dose-expansion cohort. Median age was 68.0 years (range: 20-88), 71.4% were male, 87.8% had de novo DLBCL, 8.2% had tFL, 4.1% had Gr 3b FL, 18.4% had HGBCL (including double/triple-hit lymphoma), 7.1% had bulky disease (≥10 cm), 51.0% had an International Prognostic Index score 3-5, and 85.7% had Ann Arbor stage III/IV disease. The median number of prior lines of therapy was 2 (range: 1-8), 35.7% had prior CAR-T therapy, and 11.2% had prior ASCT. Most pts (80.6%) were refractory to prior anti-CD20 therapy, 58.2% were primary refractory, 77.6% were refractory to their previous therapy, and 26.5% were refractory to CAR-T therapy. The median number of cycles received was 8 for Mosun (range: 1-17) and 6 for Pola (range: 1-6). Adverse events (AEs) occurring in ≥15% of pts were fatigue (42.9%), neutropenia (28.6%), nausea (26.5%), diarrhea (23.5%), pyrexia (23.5%), headache (21.4%), CRS (18.4%), chills (17.3%), and peripheral sensory neuropathy (16.3%). Gr 3/4 AEs that occurred in ≥5% pts were neutropenia (20.4%) and fatigue (7.1%). Gr 5 AEs occurred in 3 (3.1%) pts, of which 2 were due to COVID-19 pneumonia and 1 was due to pneumonia. None were considered related to treatment. CRS events were observed in 18.4% of pts: Gr 1 n=11, Gr 2 n=4, Gr 3 n=3. All CRS events were resolved by data cut-off. Three pts received tocilizumab, 2 pts had a vasopressor, 2 pts received high flow oxygen, and 2 pts required ICU admission for CRS. Mosun-related neurologic AEs potentially consistent with immune effector cell-associated neurotoxicity syndrome occurred in 5 pts (5.1%); all were Gr 1/2 except 1 Gr 4 encephalopathy event. Treatment-related neuropathy occurred in 25.5% of pts (all Gr 1/2). Eleven pts (11.2%) discontinued treatment due to AEs, of which 5 (5.1%) were treatment-related: 1 (1.0%) due to encephalopathy (Mosun-related) and 4 (4.1%) due to peripheral neuropathy (Pola-related). Investigator-assessed ORR and CR rate were 62.2% and 50.0%, respectively ( Table). Median duration of response was not reached (NR; 95% confidence interval [CI]: 11.6-NR); median duration of CR was NR (95% CI: 20.5-NR). Median progression-free survival was 9.6 months (95% CI: 5.6-18.6) and overall survival was 23.3 months (95% CI: 15.2-NR), with a median follow-up of 18.6 months (95% CI: 17.7-23.7). In pts with prior CAR-T therapy (n=35), the ORR and CR rates were 60.0% and 45.7%, respectively. In primary refractory pts (n=57), the ORR and CR rates were 56.1% and 40.4%, respectively. Conclusions: M-Pola continues to show a favorable safety profile and compelling efficacy in highly refractory pts, including those with prior CAR-T therapy and/or primary refractory disease. Primary analysis data, including IRC responses and biomarker analyses, will be presented