High-dose methotrexate-based chemotherapy is the mainstay of treatment of primary central nervous system lymphoma (PCNSL), but relapses remain frequent. High-dose chemotherapy (HDC) with autologous stem-cell transplant (ASCT) may provide an alternative to address chemoresistance and overcome the blood-brain barrier. In this single-center phase-2 study, newly diagnosed PCNSL patients received 5 to 7 cycles of chemotherapy with rituximab, methotrexate (3.5 g/m²), procarbazine, and vincristine (R-MPV). Those with a complete or partial response proceeded with consolidation HDC with thiotepa, cyclophosphamide, and busulfan, followed by ASCT and no radiotherapy. Primary end point was 1-year progression-free survival (PFS), N = 32. Median age was 57, and median Karnofsky performance status 80. Following R-MPV, objective response rate was 97%, and 26 (81%) patients proceeded with HDC-ASCT. Among all patients, median PFS and overall survival (OS) were not reached (median follow-up: 45 months). Two-year PFS was 79% (95% confidence interval [CI], 58-90), with no events observed beyond 2 years. Two-year OS was 81% (95% CI, 63-91). In transplanted patients, 2-year PFS and OS were 81%. There were 3 treatment-related deaths. Prospective neuropsychological evaluations suggested relatively stable cognitive functions posttransplant. In conclusion, this treatment was associated with excellent disease control and survival, an acceptable toxicity profile, and no evidence of neurotoxicity thus far. This trial was registered at www.clinicaltrials.gov as NCT00596154. Key Points We conducted a phase-2 study in newly diagnosed PCNSL utilizing R-MPV and HDC with ASCT. Excellent disease control and OS (2-year PFS: 79%) were observed, with an acceptable toxicity profile and minimal neurotoxicity.

PURPOSE: Mosunetuzumab is a bispecific antibody targeting CD20 and CD3 that redirects T cells to engage and eliminate malignant B cells and is being developed for relapsed or refractory (R/R) B-cell non-Hodgkin lymphomas (B-NHLs). METHODS: This first-in-human trial (ClinicalTrials.gov identifier: NCT02500407 ) evaluated the safety and tolerability and efficacy of mosunetuzumab in patients with R/R B-NHL and established the recommended phase II dose. Data from dose escalation are presented. Single-agent mosunetuzumab was administered intravenously in 3-week cycles, at full dose in cycle 1 day 1 (group A) or with ascending (step-up) doses during cycle 1 on days 1, 8, and 15 (group B), for eight or 17 cycles on the basis of tumor response. RESULTS: Two hundred thirty patients were enrolled. Doses up to 2.8 mg and 60 mg were assessed in groups A and B, respectively; maximum tolerated dose was not exceeded. In group B (n = 197), common adverse events (≥ 20% of patients) were neutropenia (28.4%), cytokine release syndrome (27.4%), hypophosphatemia (23.4%), fatigue (22.8%), and diarrhea (21.8%). Cytokine release syndrome was mostly low-grade (grade ≥ 3: 1.0%) and mainly confined to cycle 1. Across the doses investigated (group B), best overall response rates were 34.9% and 66.2% in patients with aggressive and indolent B-NHL, respectively, and complete response rates were 19.4% and 48.5%. Among patients with a complete response, the median duration of response was 22.8 months (95% CI, 7.6 to not estimable) and 20.4 (95% CI, 16 to not estimable) in patients with aggressive and indolent B-NHL, respectively. CONCLUSION: Mosunetuzumab, administered with step-up dosing, has a manageable safety profile and induces durable complete responses in R/R B-NHL. The expansion stage of the study is ongoing at the dose level of 1/2/60/60/30 mg selected for further study.

PURPOSE: We conducted a phase II study evaluating pembrolizumab plus gemcitabine, vinorelbine, and liposomal doxorubicin (pembro-GVD) as second-line therapy for relapsed or refractory (rel/ref) classical Hodgkin lymphoma (cHL) (ClinicalTrials.gov identifier: NCT03618550 ). METHODS: Transplant eligible patients with rel/ref cHL following first-line therapy were treated with two to four cycles of pembrolizumab (200 mg intravenous [IV], day 1), gemcitabine (1,000 mg/m² IV, days 1 and 8), vinorelbine (20 mg/m² IV, days 1 and 8), and liposomal doxorubicin (15 mg/m², days 1 and 8), given on 21-day cycles. The primary end point was complete response (CR) following up to four cycles of pembro-GVD. Patients who achieved CR by labeled fluorodeoxyglucose-positron emission tomography (Deauville ≤ 3) after two or four cycles proceeded to high-dose therapy and autologous hematopoietic cell transplantation (HDT/AHCT). HDT/AHCT was carried out according to institutional standards, and brentuximab vedotin maintenance was allowed following HDT/AHCT. RESULTS: Of 39 patients enrolled, 41% had primary ref disease and 38% relapsed within 1 year of frontline treatment. 31 patients received two cycles of pembro-GVD, and eight received four cycles. Most adverse events were grade 1 or two, whereas few were grade 3 and included transaminitis (n = 4), neutropenia (n = 4), mucositis (n = 2), thyroiditis (n = 1), and rash (n = 1). Of 38 evaluable patients, overall and CR rates after pembro-GVD were 100% and 95%, respectively. Thirty-six (95%) patients proceeded to HDT/AHCT, two received pre-HDT/AHCT involved site radiation, and 13 (33%) received post-HDT/AHCT brentuximab vedotin maintenance. All 36 transplanted patients are in remission at a median post-transplant follow-up of 13.5 months (range: 2.66-27.06 months). CONCLUSION: Second-line therapy with pembro-GVD is a highly effective and well-tolerated regimen that can efficiently bridge patients with rel/ref cHL to HDT/AHCT.

Purpose: Limited data exist regarding the activity of bendamustine in Hodgkin lymphoma (HL). This phase II study evaluated the efficacy of bendamustine in relapsed and refractory HL. Patients and Methods: Patients with relapsed and refractory HL who were ineligible for autologous stem-cell transplantation (ASCT), or for whom this treatment failed, received bendamustine 120 mg/m² as a 30-minute infusion on days 1 and 2 every 28 days with growth factor support. The primary end point was overall response rate (ORR). A secondary end point was referral rate to allogeneic stem-cell transplantation (alloSCT) for patients deemed eligible for alloSCT at the time of enrollment. Results: Of the 36 patients enrolled, 34 were evaluable for response. Patients had received a median of four prior treatments, and 75% had relapsed after ASCT. The ORR by intent-to-treat analysis was 53%, including 12 complete responses (33%) and seven partial responses (19%). The response rate among evaluable patients was 56%. Responses were seen in patients with prior refractory disease, prior ASCT, and prior alloSCT; however, no responses were seen in patients who relapsed within 3 months of ASCT. The median response duration was 5 months. Five patients (20% of those eligible) proceeded to alloSCT after treatment with bendamustine. Grade ≥ 3 adverse events were infrequent and most commonly included thrombocytopenia (20%), anemia (14%), and infection (14%). Conclusion: This study confirms the efficacy of bendamustine in heavily pretreated patients with HL. These results support current and future studies evaluating bendamustine combinations in relapsed and refractory HL.