Principia Biopharma Inc. said one of its directors, Lewis Shuster, has died.

The South San Francisco, Calif.-based company also said it fell out of compliance with the Nasdaq's listing rules as Shuster's death reduced the members of Principia's audit committee to two. The stock market requires listed companies' audit committees to have at least three members.

Principia plans to regain compliance by appointing a new independent director, the company said in a filing.

Principia develops oral therapies for immunology and oncology in the U.S.