Summary: As a result of the anti‐tumour activity observed in vitro and in vivo with combined anti‐CD20 and anti‐CD74 antibodies, we initiated a phase I/II trial of veltuzumab and milatuzumab in patients with relapsed or refractory B‐cell non‐Hodgkin lymphoma (NHL). Patients received an induction of veltuzumab 200 mg/m² weekly combined with escalating doses of milatuzumab at 8, 16 and 20 mg/kg weekly for 4 weeks. Patients without disease progression could receive an extended induction with treatment on weeks 12, 20, 28 and 36. A total of 35 patients enrolled on the study. Median age was 63 years, median number of prior therapies was 3, and 63% of patients were rituximab refractory. No dose‐limiting toxicities were observed in the phase I study. Related grade 3–4 toxicities included lymphopenia, leucopenia, neutropenia, anaemia, infusion reactions, hyperglycaemia, fatigue and atrial tachycardia. Median weeks of therapy was 12 and 29% of patients completed all 36 weeks of therapy. The overall response rate was 24%, median duration of response was 12 months, and responses were observed at all dose levels and in 50% of patients refractory to rituximab. Combination therapy with veltuzumab and milatuzumab demonstrated activity in a population of heavily pre‐treated patients with relapsed or refractory indolent NHL.

Background: Relapsed or refractory classical Hodgkin lymphoma (cHL) remains a difficult treatment challenge. Although checkpoint inhibitors (CPI) have provided clinical benefit for these patients, responses are generally not durable, and progression eventually occurs. Discovering combination therapies which maximize the immune response of CPI therapy may overcome this limitation. We hypothesized that adding ibrutinib to nivolumab will lead to deeper and more durable responses in cHL by promoting a more favorable immune microenvironment leading to enhanced T-cell-mediated anti-lymphoma responses. Methods: We conducted a single arm, phase II clinical trial testing the efficacy of nivolumab in combination with ibrutinib in patients ≥18 years of age with histologically confirmed cHL who had received at least one prior line of therapy. Prior treatment with CPIs was allowed. Ibrutinib was administered at 560 mg daily until progression in combination with nivolumab 3 mg/kg IV every 3 weeks for up to 16 cycles. The primary objective was complete response rate (CRR) assessed per Lugano criteria. Secondary objectives included overall response rate (ORR), safety, progression free survival (PFS), and duration of response (DoR). Results: A total of 17 patients from two academic centers were enrolled. The median age of all patients was 40 (range 20–84). The median number of prior lines of treatment was five (range 1–8), including 10 patients (58.8%) who had progressed on prior nivolumab therapy. Most treatment related events were mild (<Grade 3) and expected from the individual side effect profiles of ibrutinib and nivolumab. In the intent to treat population (n = 17), the ORR and CRR were 51.9% (9/17) and 29.4% (5/17), which did not meet the prespecified efficacy endpoint of a CRR of 50%. In patients who received prior nivolumab therapy (n = 10), the ORR and CRR were 50.0% (5/10) and 20.0% (2/10), respectively. At a median follow up of 8.9 months, the median PFS was 17.3 months, and the median DOR was 20.2 months. There was no statistically significant difference in median PFS between patients who received previous nivolumab therapy versus patients who were nivolumab naïve (13.2 months vs. 22.0 months, p = 0.164). Conclusions: Combined nivolumab and ibrutinib led to a CRR of 29.4% in R/R cHL. Although this study did not meet its primary efficacy endpoint of a CRR of 50%, likely due to enrollment of heavily pretreated patients including over half of who had progressed on prior nivolumab treatment, responses that were achieved with combination ibrutinib and nivolumab therapy tended to be durable even in the case of prior progression on nivolumab therapy. Larger studies investigating the efficacy of dual BTK inhibitor/immune checkpoint blockade, particularly in patients who had previously progressed on checkpoint blockade therapy, are warranted.

The initial dose of bendamustine, an alkylating agent used in treating indolent lymphoma (iNHL) and mantle cell lymphoma, is variable in clinical practice. 134 patients treated with bendamustine and rituximab were evaluated for starting dosage, patient characteristics, toxicities, and clinical outcome. The starting dosage ranged from 50 to 90 mg/m2. Lower starting dosage (<90 mg/m2) was associated with relapsed disease, increased age and worse performance status (PS), histologic subtype other than follicular lymphoma, baseline renal impairment, and cytopenias. No significant difference was observed in toxicities between patients treated with 90 mg/m2 compared with lower doses. The starting dose of 90 mg/m2 was associated with a higher complete response rate (56% vs. 29%) and longer progression free survival (PFS) (39.5 months vs. 19.7 months). However, in a multivariable model, the higher starting dose was not associated with longer PFS in those with similar age, histology, PS, and number of prior therapies.