Innovent Bio Kicks Off First Phase III Trial for Its Debut Triple-Specific Antibody IBI3003

SUZHOU, May 27, 2026 - Innovent Biologics (Suzhou) Co., Ltd. has initiated the first Phase III clinical trial for IBI3003, a novel GPRC5D/BCMA/CD3 triple-specific antibody built on the company's proprietary Sanbody® platform. The pivotal study, registered on China's Drug Clinical Trial Registration and Information Publicity Platform on May 27, targets patients with Relapsed/Refractory Multiple Myeloma(R/R MM).

Figure X. Sourced from the official Drug Clinical Trial Registration & Information Publicity Platform.

Designed as a multicenter, randomized, open-label trial, the study plans to recruit 255 patients across China. It is set to compare the efficacy and safety of IBI3003 with DPd or PVd regimens chosen by investigators, and its primary endpoint is Progression-Free Survival(PFS) evaluated by an Independent Review Committee(IRC). This marks the first Phase III advancement for IBI3003, a core pipeline product of Innovent Bio.

IBI3003's unique molecular design is engineered to overcome the common clinical challenge of single tumor antigen escape. Preclinical research confirms that the candidate delivers stronger in-vivo anti-tumor activity in mouse models than marketed benchmark bispecific antibodies. It also exerts prominent tumor-killing potency against tumors with low BCMA and GPRC5D antigen expression, addressing the limitations of existing therapies for refractory cases.

Innovent Bio first released preliminary Phase I/II clinical data of IBI3003 via an oral report at the 2025 ASH Annual Meeting. The first-in-human trial(NCT06083207), conducted in Australia and mainland China, was designed to assess the safety, tolerability and preliminary efficacy of IBI3003 among R/R MM patients.

The trial enrolled eligible patients who had failed at least two prior lines of treatment. All participants had received at least one proteasome inhibitor(PI), one immunomodulatory drug(IMiD) and one anti-CD38 therapy, and developed relapsed or refractory diseases after their last treatment. Patients with prior BCMA or GPRC5D targeted treatment failure were also included in the study.

A total of 39 patients were enrolled across China and Australia, with administered doses ranging from 0.1 μg/kg to 800 μg/kg. Among all participants, 64.1% were classified as mSMART high-risk patients, and 46.2% had one or more extramedullary disease(EMD) lesions. The cohort had a median of four prior treatment lines. All patients were exposed to three core therapies including PIs, IMiDs and anti-CD38 antibodies, while 51.3% had received at least five types of medications, covering no fewer than two PIs, two IMiDs and one anti-CD38 antibody. In addition, 41% of patients had prior BCMA/GPRC5D targeted treatment experience, and 76.9% were resistant to their latest treatment.

With a median follow-up of 3.25 months and a median treatment duration of 12.14 weeks as of November 7, 2025, the trial yielded impressive clinical outcomes:

In the ≥120 μg/kg dose group(n=24), the overall response rate(ORR) reached 83.3%, including four cases of stringent complete response(sCR), seven cases of very good partial response(VGPR) and nine cases of partial response(PR).

Within the same dose group, the ORR hit 80% among 10 patients with EMD, and achieved 77.8% among 9 patients with prior BCMA/GPRC5D targeted treatment failure.

Notably, 100% of patients who attained complete response(CR) or above in the ≥120 μg/kg dose group tested negative for minimal residual disease(MRD) via central laboratory next-generation sequencing(NGS) detection.

In terms of safety performance, IBI3003 exhibits a controllable safety profile in R/R MM patients. Grade ≥3 treatment-emergent adverse events(TEAEs) were mainly hematological toxicities, which primarily occurred during the dose escalation phase and were reversible and manageable through clinical intervention.

According to Insight database statistics, more than ten GPRC5D/BCMA/CD3 triple antibodies are currently in global clinical development. Innovent Bio's IBI3003 and Johnson & Johnson's Ramantamig lead the global competition, with both candidates advancing into Phase III trials. Other key developers in this track include Mabworks with MBS314, Qilu Pharmaceutical with QLS4131, as well as Simcere and AbbVie's joint candidate SIM0500.