Defining Primary Refractory Large B-cell Lymphoma.

Patients with large B-cell lymphoma (LBCL) that fail to achieve a complete response (CR) or relapse early after anthracycline-containing immunochemotherapy (IC) have a poor prognosis and are commonly considered "primary refractory disease". However, different definitions of primary refractory disease are used in the literature and clinical practice. In this study, we ex-amined variation in the time to relapse used to define refractory status and association with sur-vival outcomes in patients with primary refractory LBCL in a single-center prospective cohort with a validation in an independent multi-center cohort. Newly diagnosed LBCL patients were enrolled in the Molecular Epidemiological Resource cohort (MER; N=949) or the Lymphoma Epidemiology of Outcomes cohort (LEO; N=2,755) from 9/2002 to 5/2021. Primary refractory LBCL was defined as no response (SD) or progressive disease (PD) during or by the end of frontline (1L) IC (primary PD; PPD), partial response at end of treatment (EOT PR), or relapse within 3-12 months after achieving CR at EOT to 1L IC (early relapse). In the MER cohort, pa-tients with PPD had inferior OS (2-year OS rate 15% MER, 31% LEO) when compared to other subgroups considered in defining primary refractory disease, EOT PR (2-year OS rate 38% MER, 50% LEO) and early relapse (2-year OS rate 44% MER, 58% LEO). Among patients re-ceiving frontline IC with curative intent, we identified that patients with PPD are the key sub-group with poor outcomes. We propose a definition of primary refractory LBCL as SD or PD during or by the end of 1L treatment.

International Prognostic Score for Nodular Lymphocyte-Predominant Hodgkin Lymphoma.

PURPOSE: Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare cancer, and large international cooperative efforts are needed to evaluate the significance of clinical risk factors and immunoarchitectural patterns (IAPs) for all stages of pediatric and adult patients with NLPHL. METHODS: Thirty-eight institutions participated in the Global nLPHL One Working Group retrospective study of NLPHL cases from 1992 to 2021. We measured progression-free survival (PFS), overall survival (OS), transformation rate, and lymphoma-specific death rate. We performed uni- and multivariable (MVA) Cox regression stratified by management to select factors for the lymphocyte-predominant international prognostic score (LP-IPS) validated by five-fold cross-validation. RESULTS: We identified 2,243 patients with a median age of 37 years (IQR, 23-51). The median follow-up was 6.3 years (IQR, 3.4-10.8). Most had stage I to II (72.9%) and few B symptoms (9.9%) or splenic involvement (5.4%). IAP was scored for 916 (40.8%). Frontline management included chemotherapy alone (32.4%), combined modality therapy (30.5%), radiotherapy alone (24.0%), observation after excision (4.6%), rituximab alone (4.0%), active surveillance (3.4%), and rituximab and radiotherapy (1.1%). The PFS, OS, transformation, and lymphoma-specific death rates at 10 years were 70.8%, 91.6%, 4.8%, and 3.3%, respectively. On MVA, IAPs were not associated with PFS or OS, but IAP E had higher risk of transformation (hazard ratio [HR], 1.81; P < .05). We developed the LP-IPS with 1 point each for age ≥45 years, stage III-IV, hemoglobin <10.5 g/dL, and splenic involvement. Increasing LP-IPS was significantly associated with worse PFS (HR, 1.52) and OS (HR, 2.31) and increased risk of lymphoma-specific death (HR, 2.63) and transformation (HR, 1.41). CONCLUSION: In this comprehensive study of all ages of patients with NLPHL, we develop the LP-IPS to identify high-risk patients and inform upcoming prospective clinical trials evaluating de-escalation of therapy for patients with low LP-IPS scores (<2).

The Lymphoma Epidemiology of Outcomes cohort study: Design, baseline characteristics, and early outcomes.

To address the current and long-term unmet health needs of the growing population of non-Hodgkin lymphoma (NHL) patients, we established the Lymphoma Epidemiology of Outcomes (LEO) cohort study (NCT02736357; https://leocohort.org/). A total of 7735 newly diagnosed patients aged 18 years and older with NHL were prospectively enrolled from 7/1/2015 to 5/31/2020 at 8 academic centers in the United States. The median age at diagnosis was 62 years (range, 18-99). Participants came from 49 US states and included 538 Black/African-Americans (AA), 822 Hispanics (regardless of race), 3386 women, 716 age <40 years, and 1513 rural residents. At study baseline, we abstracted clinical, pathology, and treatment data; banked serum/plasma (N = 5883, 76.0%) and germline DNA (N = 5465, 70.7%); constructed tissue microarrays for four major NHL subtypes (N = 1189); and collected quality of life (N = 5281, 68.3%) and epidemiologic risk factor (N = 4489, 58.0%) data. Through August 2022, there were 1492 deaths. Compared to population-based SEER data (2015-2019), LEO participants had a similar distribution of gender, AA race, Hispanic ethnicity, and NHL subtype, while LEO was underrepresented for patients who were Asian and aged 80 years and above. Observed overall survival rates for LEO at 1 and 2 years were similar to population-based SEER rates for indolent B-cell (follicular and marginal zone) and T-cell lymphomas, but were 10%-15% higher than SEER rates for aggressive B-cell subtypes (diffuse large B-cell and mantle cell). The LEO cohort is a robust and comprehensive national resource to address the role of clinical, tumor, host genetic, epidemiologic, and other biologic factors in NHL prognosis and survivorship.

Three-year follow-up analysis of axicabtagene ciloleucel in relapsed/refractory indolent non-Hodgkin lymphoma (ZUMA-5).

ABSTRACT: Axicabtagene ciloleucel (axi-cel) is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory (R/R) follicular lymphoma (FL). Approval was supported by the phase 2, multicenter, single-arm ZUMA-5 study of axi-cel for patients with R/R indolent non-Hodgkin lymphoma (iNHL; N = 104), including FL and marginal zone lymphoma (MZL). In the primary analysis (median follow-up, 17.5 months), the overall response rate (ORR) was 92% (complete response rate, 74%). Here, we report long-term outcomes from ZUMA-5. Eligible patients with R/R iNHL after ≥2 lines of therapy underwent leukapheresis, followed by lymphodepleting chemotherapy and axi-cel infusion (2 × 106 CAR T cells per kg). The primary end point was ORR, assessed in this analysis by investigators in all enrolled patients (intent-to-treat). After median follow-up of 41.7 months in FL (n = 127) and 31.8 months in MZL (n = 31), ORR was comparable with that of the primary analysis (FL, 94%; MZL, 77%). Median progression-free survival was 40.2 months in FL and not reached in MZL. Medians of overall survival were not reached in either disease type. Grade ≥3 adverse events of interest that occurred after the prior analyses were largely in recently treated patients. Clinical and pharmacokinetic outcomes correlated negatively with recent exposure to bendamustine and high metabolic tumor volume. After 3 years of follow-up in ZUMA-5, axi-cel demonstrated continued durable responses, with very few relapses beyond 2 years, and manageable safety in patients with R/R iNHL. The ZUMA-5 study was registered at www.clinicaltrials.gov as #NCT03105336.

Matching-adjusted indirect comparison from the Lymphoma Epidemiology of Outcomes Consortium for Real World Evidence (LEO CReWE) study to a clinical trial of mosunetuzumab in relapsed or refractory follicular lymphoma.

Mosunetuzumab is a novel bispecific antibody targeting epitopes on CD3 on T cells and CD20 on B cells with the goal of inducing T-cell mediated elimination of malignant B cells. A recent pivotal phase I/II clinical trial (GO29781) demonstrated that mosunetuzumab induced an overall response rate of 80%, complete response rate of 60%, and a median progression-free survival of 17.9 months in patients with relapsed/refractory (r/r) follicular lymphoma (FL) following at least two prior lines of systemic therapy, including alkylator and anti-CD20 antibody-based therapy. Historical data from cohorts receiving therapy for r/r FL can provide some context for interpretation of single-arm trials. We compared the results from the mosunetuzumab trial to outcomes from a cohort of patients with r/r FL from the LEO Consortium for Real World Evidence (LEO CReWE). We applied clinical trial eligibility criteria to the LEO CReWE cohort and utilized matching-adjusted indirect comparison weighting to balance the clinical characteristics of the LEO CReWE cohort with those from the mosunetuzumab trial. Overall response rates (73%, 95% CI:65-80%) and complete response rates (53%, 95% CI:45-61%) observed in the weighted LEO CReWE cohort were lower than those reported on the mosunetuzumab trial (ORR=80%, 95% CI:70-88%; CR=60%, 95% CI:49-70% respectively). Progression-free survival at 12 months was similar in the weighted LEO CReWE (60%, 95% CI:51-69%) and the mosunetuzumab trial (PFS 58%, 95% CI:47-68%). Sensitivity analyses examining the impact of matching variables, selection of line of therapy, and application of eligibility criteria, provide context for best practices in this setting.

Personalised therapy in follicular lymphoma - is the dial turning?

Follicular lymphoma is the most common indolent lymphoma accounting for approximately 20%-25% of all new non-Hodgkin lymphoma diagnoses in western countries. Whilst outcomes are mostly favorable, the spectrum of clinical phenotypes includes high-risk groups with significantly inferior outcomes. This review discusses recent updates in risk stratification and treatment approaches from upfront treatment for limited and advanced stage follicular lymphoma to the growing options for relapsed, refractory disease with perspectives on how to approach this from a personalized lens. Notable gaps remain on how one can precisely and prospectively select optimal treatment for patients based on varying risks, with an anticipation that an increased understanding of the biology of these different phenotypes and increasing refinement of imaging- and biomarker-based tools will, in time, allow these gaps to be closed.

Healthcare Utilization Disparities of Adolescent and Young Adults Compared to the Older Lymphoma Population.

BACKGROUND: Adolescent and Young Adults (AYAs) are an underserved, high-risk population. Identifying health care utilization patterns, and particularly acute care visits, is important as these are high-intensity, expensive services. We investigated whether differences exist in health care utilization between the AYA lymphoma population compared to their older adult counterparts. MATERIALS AND METHODS: Two correlated outcomes were used to measure health care utilization: 4 or more acute visits (emergency department or urgent care) and number of nonacute visits (office or telephone visits). We studied 442 patients with aggressive lymphoma patients 15 years or older at time of diagnosis managed at our cancer center within 2 years of their diagnosis. A multivariate generalized linear mixed model simultaneously estimated the effect of baseline predictors on 4 or more acute care visit with robust Poisson regression and nonacute visit counts with negative binomial regression allowing for a within-subject random effect. RESULTS: AYAs had increased risk of having ≥4 acute visits (RR = 1.96; P = .047) compared to their older counterparts. Obesity (RR = 2.04, P = .015) and living less than 50 miles from the cancer center (RR = 3.48, P = .015) were independently associated with higher risk of acute care usage. Acute care visits for psychiatric or substance use related reasons were significantly higher (P = .0001) among AYA (10/114, 8.8%) vs. non-AYA (3/328, 0.9%). CONCLUSION: Disease-targeted interventions to address high acute health care utilization is needed amongst AYAs. Additionally, early multidisciplinary involvement after cancer diagnosis particularly with psychiatric expertise amongst AYAs and palliative care involvement in both groups is needed.

Arrhythmogenic Cardiotoxicity Associated With Contemporary Treatments of Lymphoproliferative Disorders.

Background There are limited data on risk of arrhythmias among patients with lymphoproliferative disorders. We designed this study to determine the risk of atrial and ventricular arrhythmia during treatment of lymphoma in a real-world setting. Methods and Results The study population comprised 2064 patients included in the University of Rochester Medical Center Lymphoma Database from January 2013 to August 2019. Cardiac arrhythmias-atrial fibrillation/flutter, supraventricular tachycardia, ventricular arrhythmia, and bradyarrhythmia-were identified using International Classification of Diseases, Tenth Revision (ICD-10) codes. Multivariate Cox regression analysis was used to assess the risk of arrhythmic events with treatments categorized as Bruton tyrosine kinase inhibitor (BTKi), mainly ibrutinib/non-BTKi treatment versus no treatment. Median age was 64 (54-72) years, and 42% were women. The overall rate of any arrhythmia at 5 years following the initiation of BTKi was (61%) compared with (18%) without treatment. Atrial fibrillation/flutter was the most common type of arrhythmia accounting for 41%. Multivariate analysis showed that BTKi treatment was associated with a 4.3-fold (P<0.001) increased risk for arrhythmic event (P<0.001) compared with no treatment, whereas non-BTKi treatment was associated with a 2-fold (P<0.001) risk increase. Among subgroups, patients without a history of prior arrhythmia exhibited a pronounced increase in the risk for the development of arrhythmogenic cardiotoxicity (3.2-fold; P<0.001). Conclusions Our study identifies a high burden of arrhythmic events after initiation of treatment, which is most pronounced among patients treated with the BTKi ibrutinib. Patients undergoing treatments for lymphoma may benefit from prospective focused cardiovascular monitoring prior, during, and after treatment regardless of arrhythmia history.

Pembrolizumab Added to Ifosfamide, Carboplatin, and Etoposide Chemotherapy for Relapsed or Refractory Classic Hodgkin Lymphoma: A Multi-institutional Phase 2 Investigator-Initiated Nonrandomized Clinical Trial.

Importance: To our knowledge, this is the first clinical trial designed to investigate concurrent treatment with a checkpoint inhibitor and conventional chemotherapy in relapsed or refractory classic Hodgkin lymphoma in patients destined for an autologous stem cell transplant. Objective: To evaluate the complete response rate as assessed by 18F-fluorodeoxyglucose-positron emission tomography with computed tomography (FDG-PET/CT) after salvage therapy for patients with relapsed or refractory classic Hodgkin lymphoma. Design, Setting, and Participants: A single-group, phase 2, multi-institutional nonrandomized clinical trial to evaluate the addition of pembrolizumab to ifosfamide, carboplatin, and etoposide (ICE) chemotherapy was conducted from April 20, 2017, to October 29, 2020, at 5 US sites. The 42 patients were aged 18 years or older, with an Eastern Cooperative Oncology Group Performance Status Scale score of 0 or 1 and biopsy-proven relapsed or refractory classic Hodgkin lymphoma after 1 or 2 prior lines of chemotherapy. Patients were required to be appropriate candidates for transplant, with measurable lesions detected by FDG-PET/CT. Interventions: Two cycles of pembrolizumab (200 mg intravenously on day 1) with ICE chemotherapy every 21 days, followed by stem cell mobilization and collection, and then 1 cycle of pembrolizumab monotherapy followed by FDG-PET/CT response assessment. Main Outcomes and Measures: The primary end point was complete response rate detected by FDG-PET/CT, defined as a Deauville score of 3 or lower. Patients with a complete response proceeded to an autologous stem cell transplant. Secondary end points included progression-free survival, overall survival, stem cell mobilization, and neutrophil and platelet engraftment. Adverse events were monitored to assess safety. Results: Forty-two patients were enrolled, with 37 evaluable for the primary end point. The median age was 34 years (range, 19-70 years), 25 patients were female (68%), 6 were African American (16%), and 26 were White (70%). The complete response rate for the 37 patients assessed by FDG-PET/CT imaging was 86.5% (95% CI, 71.2%-95.5%); the overall response rate was 97.3% (36 patients), with 10.8% partial responses (4 patients). New areas of FDG-PET positivity in 2 patients were biopsied, showing noncaseating granuloma in 1 case and a reactive lymph node in a second. Progression-free survival and overall survival 2-year estimates were 87.2% (32 patients; 95% CI, 77.3%-98.3%) and 95.1% (95% CI, 88.8%-100%), respectively. The addition of pembrolizumab to ICE chemotherapy did not negatively affect stem cell mobilization or collection or engraftment, similar to prior experience in this patient population and setting. Conclusions and Relevance: Results suggest that the addition of pembrolizumab to ICE chemotherapy was well tolerated and highly effective in comparison with prior reports of chemotherapy-only regimens, supporting further investigation in patients with relapsed or refractory classic Hodgkin lymphoma eligible for an autologous stem cell transplant. Trial Registration: ClinicalTrials.gov Identifier: NCT03077828.

Acalabrutinib and high-frequency low-dose subcutaneous rituximab for initial therapy of chronic lymphocytic leukemia.

Bruton tyrosine kinase inhibitors are an effective therapeutic agent for previously untreated patients with chronic lymphocytic leukemia but require indefinite treatment that can result in cumulative toxicities. Novel combinations of agents that provide deep remissions could allow for fixed duration therapy. Acalabrutinib, unlike ibrutinib, does not inhibit anti-CD20 monoclonal antibody-dependent cellular phagocytosis, making it a suitable partner drug to rituximab. Using standard dosing (375 mg/m2) of rituximab causes loss of target membrane CD20 cells and exhaustion of the finite cytotoxic capacity of the innate immune system. Alternatively, using high-frequency, low-dose (HFLD), subcutaneous rituximab limits loss of CD20 and allows for self-administration at home. The combination of HFLD rituximab 50 mg administered twice a week for 6 cycles of 28 days with the addition of acalabrutinib starting in week 2 was evaluated in a phase II study of 38 patients with treatment naive chronic lymphocytic leukemia. Patients achieving a complete response with undetectable minimal residual disease after 12 or 24 cycles of acalabrutinib could stop therapy. All patient responded, including one with a complete response with undetectable minimal residual disease in the peripheral blood and bone marrow at 12 months who stopped therapy. At a median follow-up of 2.3 years 2 patients with high-risk features have progressed while on acalabrutinib monotherapy. We conclude that HFLD rituximab in combination with acalabrutinib is an effective and tolerable self-administered home combination that provides a platform to build upon regimens that may more reliably allow for fixed-duration therapy. This trial was registered at www.clinicaltrials.gov #NCT03788291.

Risk Factors for and Outcomes of Follicular Lymphoma Histological Transformation at First Progression in the GALLIUM Study.

BACKGROUND: Although advanced­stage follicular lymphoma (FL) is considered incurable, survival has improved with the introduction of the anti-CD20 antibodies, rituximab (R) and obinutuzumab (G). However, FL can undergo histological transformation (HT) to a more aggressive disease, and a validated model for predicting HT risk is not yet available. PATIENTS AND METHODS: We assessed HT incidence, risk factors and outcomes in the phase III, GALLIUM study evaluating R- or G-chemotherapy in patients with previously untreated, advanced-stage FL (ClinicalTrials.gov NCT01332968). HT rates were assessed by repeat tumour biopsy at disease progression or relapse, at the investigator's discretion. RESULTS: Of 1202 patients enrolled, 315 (26.2%) experienced progressive disease; 46 (14.6%) had a biopsy at first progression, 40 of whom had biopsy-confirmed HT. HT risk factors were male sex (subdistribution hazard ratio [sHR], 2.21; 95% confidence interval [CI], 1.16-4.20), elevated baseline serum lactate dehydrogenase (sHR, 3.97; 95% CI, 2.03-7.76), and elevated baseline serum ß2-microglobulin (sHR, 1.96; 95% CI, 1.02-3.79). Patients with HT at first progression had poorer post-progression survival than those with relapsed FL (2-year rate: 55.9% vs. 83.1%). Relapse with HT occurred earlier than FL relapse (median time from randomisation: 0.8 vs. 2.3 years). CONCLUSION: HT was a low-frequency event associated with poor survival outcomes in the GALLIUM study. Male sex and elevated baseline levels of serum LDH and B2M were significant risk factors for HT. Further research is required to develop validated prognostic indices for HT risk and guide treatment decisions.

Durvalumab as monotherapy and in combination therapy in patients with lymphoma or chronic lymphocytic leukemia: The FUSION NHL 001 trial.

BACKGROUND: Studies suggest that immune checkpoint inhibitors may represent a promising strategy for boosting immune responses and improving the antitumor activity of standard therapies in patients with relapsed/refractory hematologic malignancies. AIMS: Phase 1/2 FUSION NHL 001 was designed to determine the safety and efficacy of durvalumab, an anti-programmed death ligand 1 (PD-L1) antibody, combined with standard-of-care therapies for lymphoma or chronic lymphocytic leukemia (CLL). METHODS AND RESULTS: The primary endpoints were to determine the recommended phase 2 dose of the drugs used in combination with durvalumab (durvalumab was administered at the previously recommended dose of 1500 mg every 4 weeks) and to assess safety and tolerability. Patients were enrolled into one of four arms: durvalumab monotherapy (Arm D) or durvalumab in combination with lenalidomide ± rituximab (Arm A), ibrutinib (Arm B), or rituximab ± bendamustine (Arm C). A total of 106 patients with relapsed/refractory lymphoma were enrolled. All but two patients experienced at least one treatment-emergent adverse event (TEAE); those not experiencing a TEAE were in Arm C (diffuse large B-cell lymphoma [DLBCL]) and Arm D (DLBCL during the durvalumab monotherapy treatment period). No new safety signals were identified, and TEAEs were consistent with the respective safety profiles for each study treatment. Across the study, patients with follicular lymphoma (FL; n = 23) had an overall response rate (ORR) of 59%; ORR among DLBCL patients (n = 37) was 18%. Exploratory biomarker analysis showed that response to durvalumab monotherapy or combination therapy was associated with higher interferon-γ signature scores in patients with FL (p = .02). CONCLUSION: Durvalumab as monotherapy or in combination is tolerable but requires close monitoring. The high rate of TEAEs during this study may reflect on the difficulty in combining durvalumab with full doses of other agents. Durvalumab alone or in combination appeared to add limited benefit to therapy.

Bendamustine in combination with ofatumumab as first line treatment for elderly patients with mantle cell lymphoma: a phase II risk-adapted design.

This study evaluated ofatumumab (Ofa), an anti-CD20 monoclonal antibody, alone or with bendamustine (Benda), in transplant-ineligible patients with mantle cell lymphoma. Low-risk patients received Ofa monotherapy. Non-responders received subsequent treatment with Benda-Ofa. Six patients received Ofa monotherapy and 3 patients crossed over to Bend-Ofa. Twenty-four high-risk patients were initially treated with Benda-Ofa. The overall response rate for patients treated with Ofa monotherapy was 1/6 (17%) and 23/25 (92%) for patients treated with Benda-Ofa. With a median follow-up of 8.6 years, all Ofa patients progressed with a median progression-free survival (PFS) of 0.6 years (95% CI 0.31-NR) and remain alive. With a median follow-up of 6.3 years, Bend-Ofa treated patients had median PFS 2.5 years (95% CI 1.8-NR) and a median overall survival of 7.4 years (95% CI 5.8-NR). Benda-Ofa had a favorable adverse event profile and efficacy similar, but not clearly superior, to those reported for Benda-Rituximab.

Treatment patterns and outcomes of patients with relapsed or refractory follicular lymphoma receiving three or more lines of systemic therapy (LEO CReWE): a multicentre cohort study.

BACKGROUND: Novel therapies for relapsed or refractory follicular lymphoma are commonly evaluated in single-arm studies without formal comparison with other treatments or historical controls. Consequently, rigorously defined treatment outcomes informing expectations for novel therapeutic strategies in this population are sparse. To inform outcome expectations, we aimed to describe treatment patterns, survival outcomes, and duration of response in patients with relapsed or refractory follicular lymphoma receiving three or more lines of systemic therapy. METHODS: In this multicentre cohort study, we developed a database of patients with relapsed or refractory follicular lymphoma from eight academic centres in the USA using data collected in the LEO Cohort study (NCT02736357) and the LEO Consortium. For this analysis, eligible patients were aged at least 18 years, had non-transformed grade 1-3a follicular lymphoma, and were receiving systemic therapy in the third line or later after previous therapy with an anti-CD20 antibody and an alkylating agent. Clinical data and patient outcomes were abstracted from medical records by use of a standard protocol. The index therapy for the primary analysis was defined as the first line of systemic therapy after the patient had received at least two previous systemic therapies that included an alkylating agent and an anti-CD20 therapy. The main endpoints of interest were overall response rate, progression-free survival, and overall survival. Outcomes were also evaluated in subsets of clinical interest (index therapy characteristics, patient and disease characteristics, treatment history, and best response assessment). FINDINGS: We screened 933 patients with follicular lymphoma, of whom 441 were included and diagnosed between March 6, 2002, and July 20, 2018. Index therapies included immunochemotherapy (n=133), anti-CD20 antibody monotherapy (n=53), lenalidomide with or without anti-CD20 (n=37), and phosphoinositide 3-kinase inhibitors with or without anti-CD20 (n=25). 57 (13%) of 441 patients received haematopoietic stem-cell transplantation and 98 (23%) of 421 patients with complete data received therapy on clinical trials. After a median follow-up of 71 months (IQR 64-79) from index therapy, 5-year overall survival was 75% (95% CI 70-79), median progression-free survival was 17 months (15-19), and the overall response rate was 70% (65-74; 280 of 400 patients evaluable for response). Patients who were refractory to therapy with an alkylating agent had a lower overall response rate (170 [68%] of 251 patients vs 107 [77%] of 139 patients) and a significantly lower 5-year overall survival (72%, 95% CI 66-78 vs 81%, 73-89; hazard ratio 1·60, 95% CI 1·04-2·46) than patients who were not refractory to therapy with an alkylating agent. INTERPRETATION: Patients with relapsed or refractory follicular lymphoma receive heterogeneous treatments in the third-line setting or later. We observed high response rates to contemporary therapies that were of short duration. These data identify unmet needs among patients with follicular lymphoma, especially those who are refractory to alkylating agents, and might provide evidence by which clinical trials evaluating novel treatments could be assessed. FUNDING: Genentech and the National Cancer Institute.