JAZZ Hits 52-Week High on Encouraging Gastric Cancer Study Data

Core Insights - Jazz Pharmaceuticals (JAZZ) shares increased nearly 21% following the announcement of positive results from the HERIZON-GEA-01 study, which evaluated Ziihera (zanidatamab) as a first-line treatment for HER2+ locally advanced or metastatic gastroesophageal adenocarcinoma (GEA) [1][8] Study Results - The HERIZON-GEA-01 study compared two regimens: Ziihera plus chemotherapy and Ziihera combined with BeOne Medicines' PD-1 inhibitor Tevimbra plus chemotherapy, against the standard of care treatment, trastuzumab plus chemotherapy [2] - Both regimens demonstrated statistically significant and clinically meaningful improvements in progression-free survival (PFS), achieving one of the study's dual primary endpoints [3] - For overall survival (OS), the three-drug regimen showed significant improvements, while the two-drug regimen indicated a strong trend toward statistical significance [4] Future Plans - Jazz intends to present detailed data from the HERIZON-GEA-01 study at a medical meeting in the first quarter of 2026 [5] - The company plans to seek label expansion for Ziihera in the GEA indication in the first half of 2026 based on the study results [6] Stock Performance - Following the positive study results, Jazz shares reached a 52-week high, with the findings suggesting Ziihera's potential to become the new standard of care for first-line HER2+ GEA, an area with significant commercial potential [7] - Year-to-date, JAZZ stock has risen 38%, outperforming the industry growth of 15% [7] Development Pipeline - The HERIZON-GEA-01 study marks the first late-stage results for Ziihera, which is also being developed in late-stage studies for first-line biliary tract cancer (BTC) and metastatic breast cancer [10] - Additionally, Ziihera is under evaluation in two mid-stage studies for HER2-positive solid tumors and HER2+ neoadjuvant and adjuvant breast cancer [11] Licensing Agreement - Ziihera was acquired through a licensing agreement with Zymeworks, granting Jazz exclusive rights to develop and market the drug outside of Asia/Pacific [12]