(Reuters) – The U.S. Food and Drug Administration on Thursday granted Mylan NV tentative approval for its generic version of Eli Lilly and Co’s lung cancer drug Alimta.

Shares of Mylan closed up 3.9% at $19.90 on Thursday.

A tentative approval generally signals that the FDA has signed off on the company’s marketing application, but that it cannot sell the medicine until the U.S. patents have expired.

Lilly stands to lose U.S. patent protection on the chemotherapy drug, known generically as pemetrexed, in 2022.

Earlier this month, Lilly won a federal appeals court decision protecting its patent from copycat drugs by Pfizer Inc and India’s Dr Reddy’s Laboratories Ltd.

Alimta is Lilly’s third biggest-selling drug. The Indianapolis-based drugmaker reported second-quarter sales of $577.8 million for the medicine.

(Reporting by Tamara Mathias in Bengaluru; editing by Bill Berkrot)