Jazz and Zymeworks Bispecific Antibody Zanidatamab Delivers Practice-Changing Results in Stomach Cancer Study

Jazz Pharmaceuticals and Zymeworks jointly announced positive phase 2 and phase 3 results for their HER2-targeted bispecific antibody zanidatamab in advanced or metastatic gastroesophageal adenocarcinoma (GEA), also known as stomach cancer2345.

In the phase 2 trial, zanidatamab combined with chemotherapy kept 84% of patients with metastatic gastroesophageal cancer alive for at least 18 months2.

Updated data from the phase 2 study demonstrated significant and durable tumor response and increased median progression-free survival (mPFS) and overall survival (OS) when zanidatamab is used as a first-line treatment for HER2-positive mGEA4.

The trial results led to significant stock gains for both Jazz (up 21%) and Zymeworks (up 28%)3.

Zanidatamab has received Orphan Drug designation from the FDA and EMA for gastric and biliary tract cancers and was granted Breakthrough Therapy designation in China4.

A pivotal phase 3 trial (HERIZON-GEA-01, NCT05152147) for zanidatamab in HER2-expressing mGEA is actively enrolling and is expected to read out in Q2 2025, further solidifying its potential as a foundational treatment45.

The results are considered practice-changing, offering a new, durable, and effective regimen for patients with advanced HER2-positive gastric and gastroesophageal cancers245.

Sources:

2. https://www.fiercebiotech.com/biotech/jiving-jazz-after-325m-opt-zymeworks-links-her2-bispecific-84-survival-after-18-months

3. https://firstwordpharma.com/story/6668919

4. https://www.zymeworks.com/zymeworks-presents-updated-phase-2-data-for-zanidatamab-demonstrating-increased-mpfs-in-her2-positive-metastatic-gastroesophageal-adenocarcinoma-at-esmo-2024/

5. https://www.bioworld.com/articles/726235-jazz-zymeworks-unveil-positive-zanidatamab-phase-iii-data