The U.S. Food and Drug Administration has approved two regimens containing Jazz Pharmaceuticals’ Ziihera for adults with unresectable locally advanced or metastatic HER2-positive gastroesophageal adenocarcinoma, the company said on Monday.
The approval is based on the Phase 3 HERIZON-GEA-01 trial, published in the New England Journal of Medicine, which evaluated Ziihera in combination with chemotherapy and, in one arm, with Tevimbra (tislelizumab-jsgr). In the trial, both Ziihera-containing regimens reduced the risk of disease progression or death by 35% compared with trastuzumab plus chemotherapy. Median progression-free survival reached 12.4 months versus 8.1 months in the control arm.
The combination of Ziihera, tislelizumab-jsgr and chemotherapy also lowered the risk of death by 28%, achieving a median overall survival of 26.4 months compared with 19.2 months for the trastuzumab-based regimen. Gastroesophageal adenocarcinoma is the fifth most common cancer globally, with roughly 20% of cases classified as HER2-positive.
Ziihera’s prescribing information includes boxed warnings for diarrhea and embryo-fetal toxicity. Diarrhea occurred in 85% of patients receiving Ziihera with chemotherapy and tislelizumab-jsgr, with Grade 3 or 4 events in 26% of cases and fatal outcomes reported in 1.5% of patients. Jazz plans to host an investor webcast on August 25 at 4:30 p.m. ET to discuss the approval and next steps.
