Innovent: Trispecific Antibody IBI3003 Shows Promising Data in Multiple Myeloma Patients

Innovent Biologics, a biopharmaceutical company, announced updated Phase 1 clinical data for its novel trispecific antibody, IBI3003, targeting GPRC5D, BCMA, and CD3, in patients with relapsed or refractory multiple myeloma (R/R MM). The findings were presented at the 23rd International Myeloma Society (IMS) Annual Meeting.

The Phase 1 dose optimization study determined the recommended Phase 2 dose (RP2D) for IBI3003 to be 360 μg/kg. At this dose, the antibody demonstrated signals of rapid, deep, and durable responses, particularly noted in heavily pretreated patients with high-risk disease and extramedullary involvement.

IBI3003's design aims to overcome tumor escape mechanisms by targeting multiple antigens simultaneously. Preclinical studies indicated superior anti-tumor activity compared to existing bispecific antibodies, especially in cell models with low expression of its target antigens.

The updated data, from a study involving 102 patients in China and Australia, showed an overall response rate (ORR) of 84.6% among 26 patients treated at the RP2D of 360 μg/kg. Among patients achieving complete response (CR) or better, 100% (8 patients) achieved minimal residual disease (MRD) negativity.

The safety profile observed was manageable, with hematologic toxicities being the most common Grade ≥3 treatment-related adverse events. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were generally Grade 1-2 and resolved with treatment. Innovent is continuing clinical trials for IBI3003, both as a monotherapy and in combination regimens.