China expands approval of SystImmune’s iza-bren into esophageal cancer

Edited by Robert McTiernan··2 min read

China’s National Medical Products Administration has approved izalontamab brengitecan (iza-bren) for adults with recurrent or metastatic esophageal squamous cell carcinoma (ESCC) whose disease progressed after platinum-based chemotherapy and a PD-1/PD-L1 inhibitor, SystImmune announced. The iza-bren approval China marks the second NMPA clearance for the molecule, following an earlier approval in nasopharyngeal carcinoma, and represents a notable expansion for a bispecific antibody-drug conjugate (ADC) developed by Redmond, Washington-based SystImmune and its parent, China-based Sichuan Biokin Pharmaceutical.

The approval rests on the Phase III PANKU-Esophagus01 trial (BL-B01D1-305), which randomized 497 patients with recurrent or metastatic ESCC across 80 Chinese centers to iza-bren or investigator’s choice chemotherapy. The study met both dual primary endpoints: median overall survival was 9.8 months with iza-bren versus 7.2 months with chemotherapy (HR 0.64), and median progression-free survival by blinded independent review was 4.2 months versus 2.0 months (HR 0.50). Treatment discontinuation due to related adverse events was low at 2.0%.

Iza-bren combines dual targeting of EGFR and HER3 with a topoisomerase I inhibitor payload, allowing simultaneous blockade of tumor signaling and targeted delivery of cytotoxic therapy. The platform is being evaluated across multiple epithelial cancers, reflecting growing interest in bispecific ADCs that combine receptor selectivity with bystander killing.

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The approval also strengthens SystImmune’s broader oncology strategy. Positive Phase III results in triple-negative breast cancer have already demonstrated activity beyond ESCC, while Bristol Myers Squibb, which licensed ex-China rights in a USD 8.4 billion collaboration announced in 2023, is advancing the drug in global studies including non-small cell lung cancer and urothelial cancer. SystImmune retains commercialization rights in China.

Clinically, the approval addresses a setting with few established treatment options after both platinum chemotherapy and PD-1/PD-L1 inhibition. As immunotherapy has moved into earlier lines of treatment, patients progressing after checkpoint inhibitors have had limited approved therapies. Iza-bren therefore fills an increasingly important treatment gap while reinforcing China’s emergence as a leading source of next-generation ADC innovation.

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