FDA Approves Two First-Line Regimens for Advanced Gastric Cancer for Jazz Pharmaceuticals

On Tuesday, the U.S. Food and Drug Administration approved two combination regimens containing Ziihera from Jazz Pharmaceuticals plc as first-line treatments for adults with unresectable locally advanced or metastatic HER2-positive gastroesophageal adenocarcinoma.

Zanidatamab is being developed across multiple clinical trials as a targeted treatment option for patients with HER2-expressing solid tumors. Zanidatamab is being co-developed by Jazz and BeOne Medicines Ltd under a license agreement with Zymeworks Inc., the original developer of the molecule.

FDA Approval Details and Trial Results

The regulatory decision covers Ziihera in combination with fluoropyrimidine- and platinum-containing chemotherapy, with or without BeOne Medicines' Tevimbra.

Gastroesophageal adenocarcinoma includes gastric cancer, gastroesophageal junction cancer, and esophageal cancer, and is the fifth most common cancer globally. Approximately 20% of patients test positive for HER2, with more than 31,000 new gastric cancer diagnoses annually in the United States.

Survival Improvement Results

In clinical evaluations, both Ziihera combination regimens significantly improved progression-free survival in the overall HER2-positive patient population.

These regimens reduced the risk of disease progression or death by 35%, extending median progression-free survival to 12.4 months, compared to 8.1 months for patients receiving trastuzumab plus chemotherapy.

Additionally, the triple regimen of Ziihera, tislelizumab-jsgr, and chemotherapy achieved a statistically significant overall survival benefit compared to the trastuzumab control arm. The risk of death was reduced by 28%.

Patients achieved a median overall survival of 26.4 months, compared to 19.2 months in the control arm. This extension of more than 7 months represents the longest median overall survival recorded in a Phase III trial for advanced HER2-positive gastroesophageal cancer.

These survival benefits were consistent across key prespecified patient subgroups, including geographic regions and PD-L1 status.

JAZZ/ZYME Stock Performance: As of Tuesday's publication, Jazz Pharmaceuticals shares rose 3.82% to $264.19, while Zymeworks shares fell 8.98% to $26.18.