SAN FRANCISCO — A pharmaceutical company may have chosen an imperfect methodology to present its clinical trial results, but that alone is not enough to plead a violation of securities laws, the U.S. Court of Appeals for the Ninth Circuit ruled Thursday.

The decision in In re Rigel Pharmaceutical Securities Litigation appeared to create a strong level of protection for pharmaceutical companies against claims that they didn’t present results of clinical trials in the fairest possible light. Neither the U.S. Supreme Court nor the Ninth Circuit had addressed the issue previously, according to Ninth Circuit Senior Judge Procter Hug Jr.’s opinion.