Dec 19 (Reuters) - Novartis AG said on Friday the U.S. health regulator declined to approve inclisiran, the Swiss drugmaker's potential treatment for elevated low-density cholesterol in adults, citing unresolved facility inspection issues.

The European Commission last week approved the drug, branded Leqvio, which Novartis bought last year in a deal worth nearly $10 billion and expects to be a top seller.

The purchase was a part of the drugmaker's $9.7 billion takeover of The Medicines Co last November in a bid to challenge cardiovascular medicines from Amgen Inc, Sanofi and Regeneron Pharmaceuticals.

"Novartis is confident in the quality of the regulatory submission for inclisiran....We look forward to meeting with the FDA (Food and Drug Administration) and our third-party manufacturing partner to discuss the feedback received and next steps," Novartis Chief Medical Officer John Tsai said in a company statement.

No onsite inspection was conducted by the FDA, the company said, adding that the regulator would schedule a facility inspection if it was deemed necessary once safe travel resumes.

In an emailed response to a query, Novartis identified the supplier as Corden Pharma Caponago, based in Italy, which is responsible for drug product manufacturing. (Reporting by Manojna Maddipatla in Bengaluru, Additional reporting by Michael Shields in Zurich; Editing by Anil D'Silva, Devika Syamnath and Christina Fincher)