Puma falls on neratinib side effects
Puma Biotechnology Inc. (NYSE:PBYI) lost $9.01 (11%) to $72.22 on Thursday after data from two Phase II trials showed neratinib (PB272) led to high rates of severe diarrhea in patients with HER2-positive metastatic breast cancer, even after some patients received prophylaxis with antidiarrheal agent loperamide.
In the Phase II FB-7 trial, patients received either Herceptin trastuzumab, neratinib alone, or a combination of the two. Patients in the neratinib and combo groups received either no prophylaxis, two weeks of loperamide or four weeks of loperamide. Rates of grade 3 diarrhea ranged from 15% for those receiving neratinib alone plus four weeks of loperamide to 42% for neratinib alone and no prophylaxis. Among those receiving the combination therapy, grade 3 diarrhea rates were 35% in the two-week loperamide group and 23% in the four-week group. ...