The seamless trial design then moved to dose expansion, using the two single doses established in the dose-finding phase of the study. Ultimately, Dr. Abramson said, the third and pivotal diffuse large B-cell lymphoma (DLBCL) cohort received the higher single dose, since a dose-response relationship was seen in the earlier cohorts. No increase in cytokine release syndrome or neurotoxicity has been seen with the higher dose in patients evaluated to date.
Patients (median age, 61 years) were eligible to participate in the trial if they had relapsed or refractory DLBCL, primary mediastinal B-cell lymphoma, grade 3B follicular lymphoma, or mantle cell lymphoma. Patients with a failed prior allogeneic stem cell transplant or secondary central nervous system involvement were eligible, but all patients had to have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2.
As the trial moved to the core pivotal phase, eligibility requirements shifted slightly to include patients with ECOG status 0 or 1, and lymphoma diagnoses narrowed to include only DLBCL not otherwise specified (NOS), transformed follicular lymphoma, and high-grade B-cell lymphoma with double- and triple-hit cytogenetics. The core group was nearing completion of accrual at the time of the presentation, which presented preliminary results from this phase of the trial.
Among the 88 evaluable patients in the initial population with DLBCL receiving any of three dose levels, the best overall response rate (ORR) was 74% (95% confidence interval, 63%-83%); 52% of these patients achieved complete response (CR; 95% CI, 41%-63%).