Zai Lab Announces First Patient Dosed in Greater China in the Global Phase 2/3 MAHOGANY Study of Margetuximab in Gastric and Gastroesophageal Junction Cancer

SHANGHAI and SAN FRANCISCO, Oct. 06, 2020 (GLOBE NEWSWIRE) -- Zai Lab Limited (NASDAQ: ZLAB; HKEX: 9688), an innovative commercial stage biopharmaceutical company, announced dosing of the first patient in Greater China in the global MAHOGANY study evaluating margetuximab, an investigational, Fc-optimized monoclonal antibody targeting HER2, in combination with a checkpoint inhibitor, with or without chemotherapy, as a potential first-line treatment for patients with HER2-positive gastric cancer (GC) or gastroesophageal junction (GEJ) cancer.

“Gastroesophageal adenocarcinoma is the fifth and second most common tumor type worldwide and in China, respectively. The unmet need is significant considering it is often diagnosed at an advanced stage and patients with disease therefore have very poor prognosis,” said Dr. Samantha Du, Founder, Chairwoman and Chief Executive Officer of Zai Lab. “Given margetuximab has shown promise in multiple combination regimens as a first-line treatment for patients whose tumors are positive for HER2, we look forward to working with our partner, MacroGenics, in the MAHOGANY study.”

MAHOGANY is a Phase 2/3 clinical trial in two modules designed to evaluate margetuximab in combination with a checkpoint inhibitor, with or without chemotherapy, as a potential first-line treatment for patients with advanced or metastatic HER2-positive GC/GEJ.

Module A is designed as a single arm study to evaluate margetuximab plus retifanlimab, an investigational anti PD-1 monoclonal antibody, in patients with HER2-positive and PD-L1-positive tumors. The primary outcome measure for efficacy is objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors (RECIST).

Module B is designed as a randomized trial to evaluate margetuximab plus a checkpoint inhibitor in combination with chemotherapy compared to standard of care therapy of trastuzumab with chemotherapy in patients with HER2-positive tumors irrespective of PD-L1 expression. Patients randomized to one of two experimental arms containing a checkpoint inhibitor will receive either retifanlimab or tebotelimab, an investigational DART molecule targeting PD-1 and LAG-3. The primary outcome measure for efficacy is overall survival (OS).