MacroGenics stock up 110% after announcing positive Phase 3 trial results
Shares of biotech MacroGenics Inc. shot up 110% in premarket trade Wednesday after the company announced that the Phase 3 trial of potential breast cancer treatment margetuximab met its primary endpoint. Margetuximab is the company's monoclonal antibody aimed at treating later-stage breast cancer patients who test positive for a protein called human epidermal growth factor receptor 2, or HER-2. A gene mutation that makes an excess of the HER-2 protein is present in about 15% of primary invasive breast cancers, according to UpToDate, an evidence-based medical resource used by clinicians. This particular trial showed longer progression-free survival in patients treated with a combination of margetuximab and chemotherapy compared to those on trastuzumab (brand name Herceptin) and chemotherapy, a standard-of-care treatment. The company also said approximately 85% of patients in the study were carriers of the CD16A 158F allele, a gene variation has been associated with a reduced clinical response to Herceptin and other antibodies. MacroGenics said it plans to submit a biologics license application to the U.S. Food and Drug Administration in the second half of 2019. Shares of MacroGenics have fallen 13% in the year to date, while the S&P 500 has gained 9.2%. Market Pulse Stories are Rapid-fire, short news bursts on stocks and markets as they move. Visit MarketWatch.com for more information on this news.