Innovent Biologics announced on October 23 that arcotatug tavatecan, its CLDN18.2-targeted antibody-drug conjugate licensed to Takeda outside Greater China, met both dual primary endpoints in the international Phase 3 G-HOPE-001 study in previously treated, CLDN18.2-positive advanced gastric or gastroesophageal junction cancer. Median overall survival was 10.2 months on arcotatug tavatecan against 6.9 months on treatment of physician’s choice (irinotecan, paclitaxel or trifluridine and tipiracil), a hazard ratio of 0.57 (95 percent confidence interval 0.45 to 0.73, p below 0.0001), which is a 43 percent reduction in the risk of death. The results were presented orally as a late-breaking abstract at the ESMO Congress in Madrid.
Progression-free survival showed the same direction at larger magnitude. By independent review, median progression-free survival was 7.1 months against 3.1 months (hazard ratio 0.45, 95 percent confidence interval 0.35 to 0.58), and the confirmed objective response rate was 37.4 percent against 7.7 percent. The study enrolled 464 participants in China and Japan who had progressed on two to four prior systemic regimens, with CLDN18.2 positivity defined as staining of at least 2+ intensity in at least 75 percent of tumor cells. These are the trial’s prespecified primary analyses, not subgroup or post-hoc cuts, and both endpoints cleared their statistical criteria at prespecified interim analyses.
Safety is the differentiator the sponsor is selling. Grade 3 or higher treatment-related adverse events occurred in 47.4 percent of arcotatug patients against 55.9 percent on physician’s choice, and severe gastrointestinal events, the historical weakness of CLDN18.2 targeting, were uncommon: grade 3 or higher nausea in 0.9 percent, vomiting in 2.6 percent and diarrhea in 1.3 percent. Anemia (20.4 percent) and lowered blood counts were the most common severe events. Treatment-related discontinuations were 1.7 percent.
The regulatory position is already moving. After the first interim analysis, Innovent submitted a new drug application to China’s NMPA, where the drug is under priority review; Innovent calls it the first CLDN18.2 ADC to have an application accepted for regulatory review globally. Takeda, which holds rights outside Greater China under the companies’ license and collaboration agreement (the drug carries Takeda code TAK-921), plans global Phase 3 trials in gastric and pancreatic cancer. A separate Phase 3 in CLDN18.2-positive pancreatic cancer is running in China, and the drug holds FDA Fast Track designation in pancreatic cancer.
The honest limits are geographic and evidentiary. G-HOPE-001 ran only in China and Japan, the two highest-incidence gastric cancer markets, which is why Takeda’s planned global trials, not this readout alone, decide the ex-China filing path. And every figure here is the sponsor’s presentation of its own trial; the full dataset has not yet appeared in a peer-reviewed journal.