Blinatumomab, a bispecific T-cell engaging (BiTE) antibody construct, monotherapy appeared to be effective in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL).1
Because few patients with relapsed/refractory DLBCL achieve prolonged disease-free survival, researchers sought to evaluate the effect of blinatumomab monotherapy on treatment outcomes on this heavily pretreated patient population with a high unmet medical need.
For the phase 2 study, researchers enrolled 25 heavily pretreated patients with DLBCL. Patients were assigned to receive blinatumumab 112 μg daily infused continuously or in a weekly stepwise dose-escalation fashion from 9 to 28 to 112 μg daily, plus dexamethasone prophylaxis. Patients had received a median of 3 prior lines of therapy and it had been a median of 1.5 months since their last regimen.
Results showed that among 21 evaluable patients, the overall response rate after 1 blinatumomab cycle was 43%, including a 19% complete response rate. Researchers found that 3 patients had late complete responses during follow-up without other treatment.
In regard to safety, the most common adverse events with the stepwise dosing schema were tremors, pyrexia, fatigue, and edema. Grade 3 neurologic events in the same group included encephalopathy, aphasia, tremors, speech disorders, dizziness, somnolence, and disorientation.
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The cohort that received 112 μg daily was stopped because of grade 3 neurologic events in the only 2 patients in the group. Five patients in the stepwise-dosing group discontinued treatment due to adverse events; however, most neurologic events resolved.
“Further studies need to define the optimal approach to achieve the target dose without early dropout,” the authors noted.
- Viardot A, Goebeler M-E, Hess G, et al. Phase 2 study of bispecific T-cell engager (BiTE®) antibody blinatumomab in relapsed/refractory diffuse large B cell lymphoma [published online ahead of print January 11, 2016]. Blood. doi: 10.1182/blood-2015-06-651380.