Pfizer asked U.S. regulators Tuesday to authorize its experimental pill for COVID-19, setting the stage for a likely launch this winter of a promising treatment that can be taken at home. … Pfizer’s pill has been shown to significantly cut the rate of hospitalizations and deaths among people with coronavirus infections. The FDA is already reviewing a competing pill from Merck and several smaller drugmakers are also expected to seek authorization for their own antiviral pills in the coming months.