MacroGenics Inc. (NASDAQ: MGNX) Announces Phase 2/3 MAHOGANY and MGC018 Clinical Study Data

MacroGenics Inc. (NASDAQ: MGNX) has announced results from its Cohort A first part of the Phase 2/3 MAHOGANY margetuximab clinical study. 

Margetuximab being developed for HER2+ gastric cancer 

Margetuximab-cmkb (MARGENZA) is an approved HER2+ metastatic breast cancer treatment the company is studying as a possible first-line HER2+ gastric cancer or gastroesophageal junction cancer treatment in conjunction with checkpoint inhibitor without or with chemotherapy.

CEO Scott Koenig said, “We are excited to share our results from the interim analysis of Part 1 of the MAHOGANY Cohort A study at ESMO. This study is designed to support potential registration of margetuximab in combination with other agents for patients with gastric or gastroesophageal junction cancer as part of our strategy to advance margetuximab in HER2+ cancer. The findings suggest the combination of margetuximab and retifanlimab may potentially provide a chemotherapy-free option as a first-line treatment for patients whose tumors are positive for both HER2 and PD-L1. We are pleased these data support the protocol’s prespecified advancement into Part 2 of MAHOGANY Cohort A.”

MacroGenics releases data in MGC018 study 

The company has also announced interim anti-tumor activity and safety data from the dose-expansion cohorts of the ongoing phase 1 MGC018 clinical study. The company designed the experimental antibody-drug conjugate to offer a DNA-alkylating duocarmycin payload to both non-dividing and dividing cells in a B7-H3-reliant manner. 

Koenig said, “We are highly encouraged by the growing data from our ongoing Phase 1 study of MGC018. Consistent with previously presented data, we observed PSA reductions of 50% or greater in 54% of patients with metastatic castration-resistant prostate cancer. And now, we are particularly pleased to see partial responses emerge – both confirmed and unconfirmed – in mCRPC and NSCLC patients, with encouraging anti-tumor activity observed in the majority of patients for both tumor types. Also, we are very pleased with the evolving safety profile of MGC018, which showed neutropenia as the only Grade 3 or higher TRAE that exceeded a rate of 10% in this trial.”