In early clinical testing for esophageal squamous cell carcinoma, the bispecific ADC izalontamab brengitecan reported a confirmed objective response rate of 29.3% across 82 post-treated patients, rising to 39.6% at the 2.5 mg/kg dose, with a 79.2% disease control rate. The main adverse events were anemia and thrombocytopenia. Those signals have propelled multiple Phase 3 trials, positioning the program among the most advanced in the class.
The broader news is a new analysis from Kuick Research projecting the first commercial launch of a bispecific antibody-drug conjugate by 2029. The report maps an expanding pipeline of more than 100 BsADCs in clinical development, with China outpacing other regions and accounting for over 60 candidates. Recent milestones underscore the acceleration: Avenzo/DualityBio’s AVZO-1418 (EGFR/HER3) cleared FDA IND in May and began Phase 1/2 in July using DualityBio’s DIBAC platform; Junshi’s EGFR/HER3 BsADC JS212 received an IND from China’s NMPA in May with BioDlink providing end-to-end CDMO support; and Biohaven and Merus initiated co-development of three BsADCs leveraging Biclonics with proprietary conjugation and payload technologies.
Strategically, the projection toward a 2029 debut reflects a convergence of platform maturity, capital, and manufacturing readiness rather than a sudden breakthrough in biology. Bispecific designs promise improved tumor selectivity and resistance management in solid tumors, but they add CMC and clinical complexity on top of an already exacting ADC modality. Sponsors are spreading risk through cross-border licensing and CDMO partnerships to stitch together bispecific engineering, linker-payload optimization, and scalable GMP supply. The center of gravity in China is not just volume; it is speed of IND clearance, onsite CDMO capacity, and a dense tumor-oncology trial ecosystem that can generate data quickly, though global registrational credibility will still hinge on randomized designs and multi-region execution.
For operational stakeholders, this wave brings both opportunity and pressure. Sites should anticipate tighter screening, anchored in dual-antigen expression, with mandatory fresh biopsies during dose escalation, and increased monitoring for PK, immunogenicity, ocular, and hepatic effects, alongside standard myelosuppression management. CROs will need deeper bioanalytical and immunological benches, as well as nimble safety management, to navigate hematologic toxicity while preserving dose intensity. CDMOs face an elevated bar for quality attributes—such as DAR distribution, site-specific conjugation fidelity, and impurity control—where bispecific architectures can magnify variability. Regulators will likely expect robust companion diagnostic strategies and subgroup attribution to mitigate off-target toxicity risks. They may scrutinize cross-region data bridging, particularly for China-origin assets targeting U.S. or EU labels.
The near-term watchlist centers on whether the leading programs can sustain response and tolerability through randomized cohorts in tumor types with entrenched standards. Izalontamab’s Phase 3 trials will test the class’s viability; EGFR/HER3 programs like AVZO-1418 and JS212 must demonstrate that bispecific binding translates into consistent activity beyond early enrichment. Manufacturing scale-up remains a latent gatekeeper, as does the global supply of cytotoxic payloads under tightening export controls. Expect more platform-for-asset swaps, CDMO tie-ups, and mid-stage co-development deals as sponsors hedge CMC and regulatory risk. If a 2029 approval materializes, it will likely be supported by programs that establish a clear companion diagnostic, control hematologic toxicity without dose erosion, and demonstrate operational reliability across multi-region trials and commercial-scale CMC. This high bar will separate technology demonstrations from durable franchises.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
