Diquafosol receives approvable letter from FDA

DURHAM, N.C. — A drug in development for the treatment of dry eye received a second “approvable” letter from the Food and Drug Administration, according to a press release.

The FDA said in its letter that clinical trials of diquafosol tetrasodium ophthalmic solution failed “to demonstrate adequate replication of results for the efficacy endpoints and therefore are insufficient to establish efficacy,” according to a press release from Inspire Pharmaceuticals, the drug’s developer.

Inspire had submitted an amended new drug application for diquafosol earlier this year after the drug failed to meet the primary endpoint in an earlier phase 3 trial.

The FDA letter said that “consistent findings of corneal clearing” must be demonstrated to support the claim of efficacy for the drug, according to Inspire.

The company said that diquafosol “functions as an agonist at the P2Y2 receptor, stimulating the release of natural tear components targeting all three mechanisms of action involved in tear secretion – mucin, lipids and fluid.”

The FDA “strongly encouraged” Inspire to discuss with the FDA how best to move forward with its application for the drug, said Christy L. Shaffer, PhD, Inspire’s president and chief executive officer.

An Allergan official said that company is committed to supporting Inspire’s effort to secure approval of the drug.

“Though the development of pharmaceuticals to treat dry eye disease is challenging, we still believe that diquafosol could potentially provide a valuable addition to the spectrum of treatments available to patients suffering from dry eye,” said Scott Whitcup, MD, executive vice president of research and development at Allergan.

Allergan is jointly developing diquafosol with Inspire. Inspire currently promotes two Allergan ophthalmic drugs: Elestat (epinastine) 0.05%, for allergic conjunctivitis; and Restasis (cyclosporine) for dry eye.