MacroGenics has reported positive data from the Phase III clinical trial (SOPHIA) of its investigational drug margetuximab for the treatment of patients with HER2-positive metastatic breast cancer.
Margetuximab is designed as an immune-enhancing monoclonal antibody using the company’s Fc Optimisation technology platform.
It targets the human epidermal growth factor receptor 2 oncoprotein, which is expressed by tumour cells in breast, gastroesophageal and other solid tumours.
The drug blocks the oncoprotein, and its Fc domain stimulates the immune system.
The SOPHIA trial met the primary endpoint of prolongation of progression-free survival (PFS) in the margetuximab and chemotherapy combination arm, compared to trastuzumab plus chemotherapy.
Participants treated with the investigational combination achieved a 24% risk reduction in PFS.
In the case of 85% patients with CD16A (FcγRIIIa) 158F allele, margetuximab plus chemotherapy led to 32% PFS risk reduction compared to the trastuzumab arm.
MacroGenics president and CEO Scott Koenig said: “Our Fc-engineered, immune-enhanced molecule has demonstrated a superior outcome in a head-to-head study against HERCEPTIN.
“We look forward to additional opportunities to develop margetuximab in other HER2-positive breast and gastric cancer populations.”
Conducted at around 200 sites in North America, Europe and Asia, the Phase III trial enrolled 536 patients and administered margetuximab or trastuzumab in combination with one of four chemotherapy agents.
Results showed acceptable safety and tolerability with the investigational combination, comparable overall to that of trastuzumab plus chemotherapy.
MacroGenics is currently performing follow-up to assess the impact of therapy on the sequential primary endpoint of overall survival (OS).
The company expects to submit a biologics license application (BLA) to the US Food and Drug Administration (FDA) in the second half of this year.