Revolution Medicines Inc. priced its initial public offering at $17 a share Wednesday evening, and will collect about $238 million. The clinical-stage oncology company said it would sell 14 million shares at that price, after increasing the size and target price of its offering Tuesday. Underwriters -- led by JPMorgan, Cowen, SVB Leerink and Guggenheim -- have access to an additional 2.1 million shares that could push the total higher.