Hill, Brian T.

SummaryMantle cell lymphoma (MCL) is clinically and biologically heterogeneous. While various prognostic features have been proposed, none currently impact therapy selection, particularly in older patients, for whom treatment is primarily dictated by age and comorbidities. Herein, we undertook a comprehensive comparison of clinicopathological features in a cohort of patients 60 years and older, uniformly treated with bendamustine and rituximab, with a median survival of >8 years. The strongest prognostic indicators in this cohort were a high‐risk call by a simplified MCL international prognostic index (s‐MIPI) (HR: 3.32, 95% CI: 1.65–6.68 compared to low risk), a high‐risk call by MCL35 (HR: 10.34, 95% CI: 2.37–45.20 compared to low risk) and blastoid cytology (HR: 4.21, 95% CR: 1.92–9.22 compared to classic). Patients called high risk by both the s‐MIPI and MCL35 had the most dismal prognosis (HR: 11.58, 95% CI: 4.10–32.72), while those with high risk by either had a moderate but clinically relevant prognosis (HR: 2.95, 95% CI: 1.49–5.82). A robust assay to assess proliferation, such as MCL35, along with stringent guidelines for cytological evaluation of MCL, in combination with MIPI, may be a strong path to risk‐stratify older MCL patients in future clinical trials.

Abstract Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma; data indicate that blastoid and pleomorphic variants have a poor prognosis. We report characteristics and outcomes of patients with blastoid/pleomorphic variants of MCL. We retrospectively studied adults with newly diagnosed MCL treated from 2000 to 2015. Primary objectives were to describe progression-free survival (PFS) and overall survival (OS). Secondary objectives included characterization of patient characteristics and treatments. Of the 1029 patients with MCL studied, a total of 207 neoplasms were blastoid or pleomorphic variants. Median follow-up period was 82 months (range, 0.1-174 months); median PFS was 38 months (95% confidence interval [CI], 28-66) and OS was 68 months (95% CI, 45-96). Factors associated with PFS were receipt of consolidative autologous hematopoietic transplantation (auto-HCT; hazard ratio [HR], 0.52; 95% CI, 0.31-0.80; P < .05), MCL International Prognostic Index (MIPI) intermediate (HR, 2.3; 95% CI, 1.2-4.3; P < .02) and high (HR, 3.8; 95% CI, 2.0-7.4; P < .01) scores, and complete response to induction (HR, 0.29 (95% CI, 0.17-0.51). Receipt of auto-HCT was not associated with OS (HR, 0.69; 95% CI, 0.41-1.16; P = .16) but was associated with MIPI intermediate (HR, 5.7; 95% CI, 2.5-13.2; P < .01) and high (HR, 10.8; 95% CI, 4.7-24.9; P < .01) scores. We report outcomes in a large cohort of patients with blastoid/pleomorphic variant MCL. For eligible patients, receipt of auto-HCT after induction was associated with improved PFS but not OS. Higher MIPI score and auto-HCT ineligibility were associated with worse survival.

7500 Background: The Bruton’s tyrosine kinase inhibitor (BTKi) ibrutinib +/- anti-CD20 antibody obinutuzumab (IO) is a standard frontline regimen for older adults with CLL. BTKi alone do not often lead to complete response (CR) or undetectable minimal residual disease (uMRD), thus are given indefinitely. Smaller trials showed that IO plus venetoclax (IVO) can induce uMRD CRs which may allow successful discontinuation. Methods: Alliance for Clinical Trials in Oncology A041702 is a multicenter trial designed to evaluate if IVO with response-guided discontinuation of I improves progression free survival (PFS) versus IO with indefinite I in treatment-naïve, older CLL pts. IO is given in standard fashion, and in the IVO arm V is added at C3D1 and continued until C14D28. After 14 cycles, pts undergo response evaluation including CT scans and bone marrow biopsy with central MRD assessment by flow cytometry. Pts in IVO arm with uMRD CR discontinue I; all others continue I until progression or unacceptable toxicity. Eligible pts were age ≥70 years (amended to ≥65). Pts had CrCl ≥ 40 mL/min, bilirubin ≤ 1.5 x ULN, and no other life-limiting intercurrent illness. Pts were stratified based on Rai stage and +/- del17p13.1 by FISH, and randomized 1:1 to IO:IVO. With 431 evaluable pts, the trial had 90% power to detect significant improvement in PFS using a one-sided log-rank test with one-sided type 1 error rate of 2.5%. The Alliance DSMB approved release of data on Nov 4, 2022 after meeting the protocol defined futility threshold at the second planned event-driven interim analysis. Data were locked on December 15, 2022. Results: Between January 4, 2019 and July 15, 2022, 465 pts were registered (IO:232, IVO:233). Median age was 74; 67% of pts were men. Rai stage 3-4 was seen in 55% and del17p in 13%. With median follow-up of 14 months, PFS of IO was 87.5% compared to 85% on IVO. Events were observed in 29 pts on IO (4 progressions, 23 deaths, 2 pts started other therapy) and 35 on IVO (7 progressions, 28 deaths). The predefined futility boundary was crossed, with a hazard ratio (HR) of 1.20 (95% CI: 0.73-1.97) in favor of IO. COVID-19 was the leading cause of death in both arms, (11 COVID-19 deaths on IO, 19 on IVO), with 13 and 11 additional deaths from other causes, respectively. Censoring pts with COVID-19 related deaths, PFS HR is 0.82 (95% CI: 0.44-1.53) in favor of IVO. Grade 3+ toxicity and discontinuation in year 1 of therapy were similar between arms. Conclusions: This study demonstrates that PFS for IVO is not superior to IO for treatment-naive older CLL pts in the setting of the COVID-19 pandemic. Study treatment is ongoing, and long-term follow-up will determine if there are advantages to IVO, with special attention to MRD and therapy discontinuation. Support: U10CA180821, U10CA180882, U24 CA196171; https://acknowledgments.alliancefound.org . Clinical trial information: NCT03737981 .

AbstractCheckpoint 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.

In phase 2 of ZUMA-1, a single-arm, multicenter, registrational trial, axicabtagene ciloleucel (axi-cel) autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy demonstrated durable responses at 2 years in patients with refractory large B-cell lymphoma (LBCL). Here, we aimed to assess survival and safety in ZUMA-1 after 5 years of follow-up. Eligible adults with refractory LBCL (diffuse large B-cell lymphoma, primary mediastinal B-cell lymphoma, and transformed follicular lymphoma) received lymphodepleting chemotherapy followed by axi-cel infusion targeted at 2×106 cells/kg. Investigator-assessed response, updated survival, safety, and pharmacokinetic outcomes were assessed in treated patients. The objective response rate in the 101 treated patients was 83% (58% complete response rate), and with a median follow-up of 63.1 months, responses were ongoing at data cutoff in 31%. Median overall survival (OS) was 25.8 months and the estimated 5-year OS rate was 42.6%. Disease-specific survival (excluding deaths unrelated to disease progression) estimated at 5 years was 51.0%. No new serious adverse events or deaths related to axi-cel were observed after additional follow-up. Peripheral blood B cells were detectable in all evaluable patients at 3 years with polyclonal B-cell recovery in 91%. Ongoing responses at 60 months were associated with early CAR T-cell expansion. In conclusion, this 5-year follow-up analysis of ZUMA-1 demonstrates sustained overall and disease-specific survival, with no new safety signals in patients with refractory LBCL. Protracted B-cell aplasia was not required for durable responses. These findings support the curative potential of axi-cel in a subset of patients with aggressive B-cell lymphomas. ClinicalTrials.gov, number NCT02348216

PURPOSE Brexucabtagene autoleucel (brexu-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory mantle cell lymphoma (MCL). This therapy was approved on the basis of the single-arm phase II ZUMA-2 trial, which showed best overall and complete response rates of 91% and 68%, respectively. We report clinical outcomes with brexu-cel in the standard-of-care setting for the approved indication. PATIENTS AND METHODS Patients who underwent leukapheresis between August 1, 2020 and December 31, 2021, at 16 US institutions, with an intent to manufacture commercial brexu-cel for relapsed/refractory MCL, were included. Patient data were collected for analyses of responses, outcomes, and toxicities as per standard guidelines. RESULTS Of 189 patients who underwent leukapheresis, 168 (89%) received brexu-cel infusion. Of leukapheresed patients, 79% would not have met ZUMA-2 eligibility criteria. Best overall and complete response rates were 90% and 82%, respectively. At a median follow-up of 14.3 months after infusion, the estimates for 6- and 12-month progression-free survival (PFS) were 69% (95% CI, 61 to 75) and 59% (95% CI, 51 to 66), respectively. The nonrelapse mortality was 9.1% at 1 year, primarily because of infections. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 8% and 32%, respectively. In univariable analysis, high-risk simplified MCL international prognostic index, high Ki-67, TP53 aberration, complex karyotype, and blastoid/pleomorphic variant were associated with shorter PFS after brexu-cel infusion. Patients with recent bendamustine exposure (within 24 months before leukapheresis) had shorter PFS and overall survival after leukapheresis in intention-to-treat univariable analysis. CONCLUSION In the standard-of-care setting, the efficacy and toxicity of brexu-cel were consistent with those reported in the ZUMA-2 trial. Tumor-intrinsic features of MCL, and possibly recent bendamustine exposure, may be associated with inferior efficacy outcomes.

AbstractPlasmablastic lymphoma (PBL) is a rare entity, commonly associated with immunosuppressed states such as human immunodeficiency virus (HIV) infection or solid organ transplant. The clinical course is characterized by high relapse rates and a poor prognosis, leading some clinicians to recommend aggressive frontline therapy. However, a specific review of limited stage (LS) PBL patients is not available to evaluate outcomes and justify treatment recommendations. We performed a retrospective review of LS PBL cases to provide insight into this rare disease. Our cohort consisted of 80 stage I or II PBL patients from 13 US academic centers. With a median follow up of 34 months (1–196), the 3‐year progression‐free survival (PFS) and overall survival (OS) of the entire cohort were 72% (95% CI 62, 83) and 79% (95% CI 70, 89), respectively. The 3‐year PFS and OS of patients treated with frontline chemotherapy alone was 65% (95% CI 50, 84) and 71% (95% CI 56, 89), respectively, compared to 85% (95% CI 72, 100) and 96% (95% CI 89, 100), respectively, in patients treated with combined frontline chemotherapy with radiation consolidation. Our data demonstrate favorable outcomes in LS PBL with no improvements in outcome from aggressive frontline treatment including Hyper‐CVAD or auto‐SCT consolidation. Multivariate regression analysis (MRA) demonstrated improved PFS for patients receiving EPOCH based frontline therapy versus CHOP (HR: 0.23; p = 0.029). Frontline chemotherapy followed by radiation consolidation versus chemotherapy alone appeared to be associated with improved relapse and survival outcomes but did not show statistical significance in MRA.

Abstract The prognostic relevance of diagnosis to treatment interval (DTI) in patients with newly diagnosed mantle cell lymphoma (MCL) is unknown. Hence, we sought to evaluate the impact of DTI on outcomes in MCL using 3 large datasets (1) the University of Iowa/Mayo Clinic Specialized Program of Research Excellence Molecular Epidemiology Resource, (2) patients enrolled in the ALL Age Asthma Cohort/CALGB 50403, and (3) a multisitecohort of patients with MCL. Patients were a priori divided into 2 groups, 0 to 14 days (short DTI) and 15 to 60 days (long DTI). The patients in whom observation was deemed appropriate were excluded. One thousand ninety-seven patients newly diagnosed with MCL and available DTI were included in the study. The majority (73%) had long DTI (n=797). Patients with short DTI had worse eastern cooperative oncology group performance status (ECOG PS ≥2), higher lactate dehydrogenase, bone marrow involvement, more frequent B symptoms, higher MCL International Prognostic Index (MIPI ≥6.2), and were less likely to receive intensive induction therapy than long DTI group. The median progression-free survival (2.5 years vs 4.8 years, p<0.0001) and overall survival (7.8 years vs. 11.8 years, p<0.0001) were significantly inferior in the short DTI group than the long DTI cohort and remained significant for progression-free survival and overall survival in multivariable analysis. We show that the DTI is an important prognostic factor in patients newly diagnosed with MCL and is strongly associated with adverse clinical factors and poor outcomes. DTI should be reported in all the patients newly diagnosed with MCL who are enrolling in clinical trials and steps must be taken to ensure selection bias is avoided.