Shares of McKesson Corp. /zigman2/quotes/206975466/composite MCK -1.06% hiked up 1.1% in premarket trading Wednesday, after the health care supply and retail pharmacy company raised its full-year profit outlook and announced a $4 billion boost to its share repurchase program. The company now expects fiscal 2022 adjusted earnings per share of $22.35 to $22.95, up from previous guidance of $21.95 to $22.55, to reflect an additional 40 cents per share related to the U.S. government's COVID-19 vaccine distribution program. That compares with the current FactSet EPS consensus for fiscal 2022 of $22.32. The company also announced a new $4.0 billion increase to its stock buyback program. The increase alone represents nearly 12% of the company's market capitalization of $34.29 billion as of Tuesday's close. The stock has rallied 8.9% over the past three months, while the SPDR Health Care Select Sector ETF /zigman2/quotes/205918244/composite XLV -0.29% has slipped 2.4% and the S&P 500 /zigman2/quotes/210599714/realtime SPX -1.04% has tacked on 3.8%.