Multicenter phase 1 trial of the anti-SIRPα antibody LM-101 for relapsed/refractory lymphoma and advanced head and neck cancer

LM-101 is an antibody that blocks the CD47-SIRPα interaction. A multicenter phase 1 trial in China evaluated LM-101 as monotherapy and in combination with rituximab or toripalimab in relapsed or refractory (R/R) lymphoma and advanced head and neck cancer (HNC). In the dose-escalation phase the recommended phase 2 dose (RP2D) was established at 40 mg/kg every three weeks. Seventeen-six patients received LM-101 monotherapy, 10 lymphoma patients received LM-101 plus rituximab, and 9 HNC patients received LM-101 plus toripalimab. No dose-limiting toxicities were observed. Grade ≥ 3 hematologic treatment-related adverse events included lymphopenia (5.9% with monotherapy; 40% with LM-101 with LM-101 plus rituximab), neutropenia (5.9% and 20%, respectively) and leukopenia (5.9% and 20%, respectively). Non-hematologic TRAEs were infrequent and predominantly grade 1-2. Objective response rates were 17.6% with monotherapy and 50.0% with LM-101 plus rituximab. Disease control rates were 75.0% for LM-101 plus rituximab and 42.9% for LM-101 plus toripalimab. The authors conclude that LM-101 was well tolerated. The preliminary efficacy signal supports further evaluation of LM-101 plus rituximab in R/R lymphoma.