Multinational phase 1-2 study of glofitamab for relapsed or refractory mantle cell lymphoma

Patients with relapsed or refractory mantle cell lymphoma (R/R MCL) have a poor prognosis. A multinational phase 1-2 trial evaluated the T-cell engaging CD20 x CD3 bispecific antibody (fixed-duration; 12 cycles) for R/R MCL. Seven days before the first glofitamab dose patients received obinutuzumab to mitigate the risk of cytokine release syndrome (CRS) with glofitamab. Among 61 enrolled patients, 60 were evaluable for safety and efficacy. Patients had received a median of two previous therapies (range 1-5). Complete response rate to glofitamab was 78.3% (95% CI 65.8-87.9) and overall response rate was 85.0% (73.4-92.9); among patients who had received previous BTK inhibitor, the CRR was 71.0% (52.0-85.8) and the ORR was 74.2% (55.4-81.1). Four adverse events led to glofitamab withdrawal (all infections). The authors conclude that fixed-duration glofitamab induced high CR rates in heavily pretreated patients with R/R MCL. The safety profile was manageable with appropriate support.