Mersana dips after $75M IPO

Antibody-drug conjugate (ADC) developer Mersana Therapeutics Inc. (NASDAQ:MRSN) slipped $1 to $14 in its first day of trading Wednesday after raising $75 million through the sale of 5 million shares at $15 in an IPO underwritten by JPMorgan, Cowen, Leerink and Wedbush PacGrow. The price was at the midpoint of Mersana's proposed range, and valued the company at $339.7 million.

Mersana's lead program, XMT-1522, is an ADC targeting HER2. The company expects safety data by YE17 from a Phase I trial, primarily in breast cancer patients. Mersana also hopes to test the therapy in patients with non-small cell lung cancer (NSCLC) and gastric cancer...