Halozyme Therapeutics Inc. is appointing Onyx Pharmaceuticals Inc. veteran Helen Torley as its new chief executive.

Torley was previously chief commercial officer and an executive vice president at San Francisco’s Onyx, a large cancer drug company that was acquired by Los Angeles-area pharma giant Amgen in August for $10.4 billion.

Torley will take the top role Jan. 6.

San Diego-based Halozyme’s current CEO, Gregory Frost, is leaving the CEO position to join Blacksburg, Va.-based Intrexon Corp. as head of its health sector. Frost will continue to lead Halozyme’s scientific advisory board, but will transition to the Blacksburg, Va.-based Intrexon in January.

“Helen’s demonstrated leadership of Onyx’s oncology products will build on Halozyme’s trajectory of value creation, pivoting from partnered to proprietary products,” Kenneth J. Kelley, chairman of the board of directors of Halozyme, said.

Halozyme has a number of enzyme-based therapies in development, such as a drug that it’s working on with in partnership with Swiss pharmaceutical company Roche Holding AG that can subcutaneously deliver a breast cancer treatment.

Shares for the $1.43 billion market cap company dropped 43 cents to $12.65 following the announcement.