Newly formed Seragon Pharmaceuticals Inc. has appointed N. Anthony Coles, the former CEO and board chairman of Onyx Pharmaceuticals Inc., to its board of directors.

San Diego-based Seragon develops breast cancer therapies. Bay Area-based Onyx was bought out by Los Angeles’ Amgen Inc. for $10.4 billion last October.

Seragon was spun off last August from Aragon Pharmaceuticals Inc., which was bought by Johnson & Johnson (NYSE: JNJ) in a deal worth up to $1 billion. Seragon raised $30 million in Series A financing in October, largely from the same investor group that founded Aragon.

Aragon developed a treatment for prostate cancer, and Onyx also developed cancer treatments.

Coles’ experience in leading a successful company focused on cancer treatments will make him “an invaluable member” of the board, Seragon CEO Richard Heyman said.