SAN RAFAEL, Calif. (AP) — BioMarin Pharmaceutical Inc. said Monday that it bought privately held biotechnology firm Zacharon Pharmaceuticals for $10 million.

The deal will expand BioMarin’s expertise and drug development efforts.

Zacharon, based in San Diego, is focused on research to help develop drugs to treat metabolic disorders, nervous system and neurological diseases.

BioMarin for all of Zacharon’s share capital up front and may make further payments in the future for clinical, regulatory and commercial milestones.

Shares of the San Rafael, Calif.-based pharmaceutical company fell 40 cents to close at $52.14. The stock has traded in a 52-week range of $31.91 to $53.45.