BeiGene (Suzhou) Co. Ltd.

Zymeworks and Jazz Pharmaceuticals said that the addition of their HER2 bispecific Ziihera helped stave off disease progression in certain patients with gastroesophageal adenocarcinoma — a type of cancer that occurs in the stomach, esophagus and the area where the two meet. And in a subset that got Ziihera plus BeOne Medicines’ Tevimbra, the patients lived for longer than those who got standard treatments. The overall survival benefit for those patients was statistically significant. Both progression-free survival and overall survival were primary endpoints in the study. It’s the first Phase 3 trial readout for Ziihera, and it appears to be a resounding success. Jazz plans to file for approval based on the study in the first half of 2026. The 914-patient study, known as HERIZON-GEA-01, looked at two Ziihera combinations as first-line options in patients with advanced HER2-positive gastroesophageal cancer. One of the combinations tested was Ziihera plus chemotherapy, while the other included those two treatments plus Tevimbra. A third comparator arm included the current standard treatment of trastuzumab (sold under the brand name Herceptin, among others) plus chemotherapy. The companies said the Ziihera and chemotherapy arm also showed a “strong trend toward statistical significance” for overall survival, and the study is continuing with another survival readout for the Ziihera-chemotherapy arm expected in mid-2026. Jazz first won FDA approval last year for the HER2 bispecific in biliary tract cancer. The drug was first developed at Zymeworks and is being commercialized by Jazz in the US, Europe and Japan, among other markets, and by BeOne, formerly Beigene, in Asia/Pacific countries (except Japan). Zymeworks’ stock $ZYME jumped 30% Monday, and Jazz’s $JAZZ rose 20%. BeOne’s shares increased by 3%.