The study was conducted by Napo Pharmaceuticals in collaboration with Puma Biotechnology. Mytesi is currently indicated for the symptomatic relief of noninfectious diarrhea in HIV/AIDS patients . Nerlynx, of Puma, a pan HER TKI indicated for extended treatment of patients with early stage HER2 & for metastatic HER2 breast cancer. A 28-day preclinical pharmacological study in healthy female dogs demonstrated that crofelemer caused an approximate 30% reduction in the incidence and severity of diarrhea associated with daily oral administration of neratinib, which was statistically significant. Crofelemer also demonstrated significant improvement in the proportion of responder dogs, and there was a trend for fewer neratinib dose reductions in both crofelemer treatment groups when compared to the control group. Crofelemer is undergoing development for potential additional indications of symptomatic relief of cancer therapy-related diarrhea (CTD) and of CTD.