Phase 1 Study of Mosunetuzumab Alone or with Venetoclax for Treating Relapsed or Refractory Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma

What this Trial Is About

Researchers are evaluating the safety, tolerability, pharmacokinetics, and preliminary efficacy of mosunetuzumab Lunsumio alone or combined with venetoclax in adults with relapsed or refractory chronic lymphocytic leukemia CLL or small lymphocytic lymphoma SLL. The study includes participants who have had prior treatments including BTKi andor venetoclax, and some participants progressing on BTKi may continue that therapy during initial mosunetuzumab treatment. This is a phase 1B, open-label study involving multiple treatment groups, including an additional arm for non-US participants receiving combination therapy or standard-of-care regimens. Participants will receive mosunetuzumab by subcutaneous injection, either alone or combined with venetoclax or with ongoing BTKi therapy for the first three cycles. The study includes dose escalation and dose expansion phases, with one arm also receiving the standard rituximab plus venetoclax regimen for comparison. Tocilizumab may be administered intravenously as needed to manage cytokine release syndrome. Treatments are tailored based on prior therapies and disease progression, with some arms limited to non-US participants. Throughout the study, participants will be closely monitored with regular assessments for safety and treatment response, including measuring dose-limiting toxicities, objective response rates, progression-free survival, overall survival, and adverse events. Pharmacokinetic parameters of mosunetuzumab, BTKi, and venetoclax will be evaluated. Participants may undergo laboratory tests, imaging, and clinical evaluations over periods of up to 12 months or 24 months depending on the study arm. The total duration includes screening and treatment phases with ongoing safety follow-up.

A Study Evaluating the Safety, Efficacy, and Pharmacokinetics of Mosunetuzumab and a Combined Regimen of Mosunetuzumab and Venetoclax in Participants With Relapsed or Refractory Chronic Lymphocytic Leukemia