June 9 (Reuters) - Acadia Pharmaceuticals ACAD.O said on Monday that the U.S. Court of Appeals has confirmed the validity of its patent for Nuplazid, its drug for hallucinations and delusions associated with Parkinson's disease.

The decision supports a December 2023 ruling from the U.S. District Court of Delaware, ensuring the patent remains protected in Acadia's legal battle against India-based drugmaker MSN Laboratories.

The appeals court followed a precedent that says an earlier patent claim cannot be invalidated by a later one if they share the same priority date.

"We are gratified that the U.S. Federal Appeals Court has affirmed the lower court's ruling in favor of our composition of matter patent for Nuplazid, securing protection into 2030 for this patent, and beyond based on the recent favorable ruling for our formulation patent providing patent protection for Nuplazid 34 mg capsule formulation into 2038," said CEO Catherine Owen Adams.

This decision comes after another favorable ruling for Acadia regarding its formulation patent for Nuplazid. The court supported Acadia's claims of infringement and validity in its legal case against Aurobindo Pharma ARBN.NS and other companies.

The U.S. FDA approved Nuplazid for the treatment of hallucinations and delusions associated with Parkinson's disease psychosis in 2016.

(Reporting by Siddhi Mahatole in Bengaluru; Editing by Alan Barona)

((siddhi.mahatole@thomsonreuters.com))