FILE PHOTO: The company's logo is seen at the new cell and gene therapy factory of Swiss drugmaker Novartis in Stein, Switzerland, November 28, 2019. REUTERS/Arnd Wiegmann

ZURICH (Reuters) - Swiss drugmaker Novartis on Monday said it is jettisoning what it had hoped would be a billion-dollar-selling asthma drug, fevipiprant, from its development program after the medicine failed another set of key trials.

The drug’s star fell in October when the Basel-based company announced it had failed a pair of trials in moderate asthmatic patients.

Now, fevipiprant has flopped in two additional studies in moderate-to-severe patients, spelling the end to its development for asthma.

Novartis chief drug developer John Tsai had continued to hold out hope that the trial failures in moderate patients were a fluke and that the drug would be more effective in patients hit harder by the respiratory disorder.

Instead, fevipiprant failed to reduce exacerbations -- an acute episode of symptoms growing worse -- compared to a placebo over a 52-week treatment period for either the 150 mg or 450 mg dose of the drug.

“The totality of these results do not support further development of fevipiprant in asthma,” said Novartis, which had hoped the medicine would become an alternative for patients for whom existing therapies like inhaled corticosteroids did not bring sufficient improvement.

Despite the failure, Novartis continues to hold out hope that it has about two dozen potential blockbuster medicines -- those that will exceed $1 billion in annual sales -- in its pipeline.