Core Insights - Innovent Biologics announced initial data from the first-in-human trial of IBI3003, a novel trispecific antibody targeting GPRC5D, BCMA, and CD3 for relapsed or refractory multiple myeloma, showing favorable tolerability and encouraging efficacy signals, especially in high-risk patients [1][10][11] Group 1: Study Design and Patient Demographics - IBI3003 is designed to target both GPRC5D and BCMA to overcome single antigen escape in multiple myeloma [2] - The Phase 1 study enrolled 39 patients with a median age of 62 years, where 64.1% were classified as high-risk and 46.2% had extramedullary disease [5] - Patients had a median of 4 prior lines of therapy, with 76.9% being refractory to their last treatment [5] Group 2: Treatment Administration and Safety Profile - IBI3003 was administered subcutaneously once weekly, with a switch to every two weeks for patients achieving a partial response after 6 months [4] - The safety profile was manageable, with 97.4% of patients experiencing treatment-emergent adverse events, primarily hematological disorders [8][10] - The incidence of cytokine release syndrome (CRS) was 64.1%, with all cases being Grade 1-2 and resolved with treatment [8] Group 3: Efficacy Results - Among patients treated with 120 g/kg, the overall response rate (ORR) was 83.3%, including stringent complete response in 4 cases and very good partial response in 7 cases [7][9] - The minimal residual disease negativity rate was 100% among patients achieving complete response or better [14] - Encouraging efficacy was particularly noted in high-risk patients, including those with extramedullary disease or prior anti-BCMA and/or anti-GPRC5D therapies [10][11] Group 4: Future Outlook - The company is conducting ongoing dose optimization for IBI3003 in the Phase 1 study, with expectations for deeper anti-tumor responses with continued treatment [10][12] - There is an urgent clinical need for effective treatments in patients with relapsed or refractory multiple myeloma, particularly those with high-risk features [11]