San Francisco – September 29, 2026 -- Innovent Biologics reported an 84.6% overall response rate for its trispecific antibody IBI3003 at the recommended Phase 2 dose in heavily pretreated multiple myeloma patients, data presented in an oral session at the 23rd International Myeloma Society Annual Meeting 2026.
Trial identifies 360 μg/kg as the optimal dose after testing three dose levels
Among 26 patients treated at 360 μg/kg with a median follow-up of 7.57 months, median progression-free survival has not yet been reached. The cohort produced 11 stringent complete responses, 4 very good partial responses, and 7 partial responses. Response rates climbed to 94.7% among 19 patients who had received only 2 to 4 prior lines of therapy, and 92.3% among 13 patients without extramedullary disease.
Responses arrived within weeks, with deep remissions confirmed by MRD testing
Median time to first response was 0.99 months, while median time to a complete response or better was 2.79 months. Among patients who reached complete response, minimal residual disease negativity by next-generation sequencing reached 100% (n=8), with three patients achieving MRD-negative status after a single treatment cycle.
Broader Phase 1 cohort of 102 patients shows heavy prior treatment burden
The full dose-optimization population, enrolled across China and Australia at doses from 0.1 to 800 μg/kg, had a median age of 62 and a median of 4 prior therapy lines (range 2-12). All patients had failed a proteasome inhibitor, an immunomodulatory drug, and an anti-CD38 antibody; 33.3% had prior BCMA or GPRC5D-targeted therapy, and 88.2% were refractory to their last regimen. As of the June 30, 2026 data cutoff, median follow-up stood at 6.65 months.
Safety profile remains manageable despite high infection and CRS rates
Cytokine release syndrome occurred in 52% of patients and neurotoxicity in 3.9%, with all events limited to Grade 1-2 and resolved with treatment. Infections were reported in 42.2% of patients, with Grade 3 or higher infections in 26.5%. No Grade 3 or higher oral toxicities linked to GPRC5D targeting were observed, and only two patients experienced Grade 3 rash.
Biomarker data confirm sustained tumor suppression at the recommended dose
Serum soluble BCMA levels fell by a median of 98.38% from baseline after three treatment cycles in the 360 μg/kg group, indicating deep and durable target engagement.
Professor Peng Liu of Zhongshan Hospital Affiliated to Fudan University noted that relapsed or refractory multiple myeloma patients who fail proteasome inhibitors, immunomodulatory drugs, and anti-CD38 therapies typically see an ORR of only 29.8%, median progression-free survival of 4.6 months, and median overall survival of 12.4 months, underscoring the unmet need the trial data addresses.
Company advances IBI3003 into pivotal Phase 3 testing in China
Innovent is running the Phase 3 TriadicMM-1 study (NCT07623798), a randomized, open-label trial comparing IBI3003 against investigator's choice of therapy in patients with 1 to 4 prior treatment lines, with progression-free survival as the primary endpoint. Phase 1/2 studies continue in China, Australia, and the United States under NCT06083207 and NCT07336472, alongside a separate Phase 2 study combining IBI3003 with a CD38 monoclonal antibody for frontline myeloma patients (NCT07764861).