After meeting with the FDA, Inspire Pharmaceuticals Inc. agreed to conduct an additional pivotal trial for its dry-eye candidate, diquafosol tetrasodium, a move that is expected to delay FDA action by more than a year.
However, Wall Street responded kindly to the news, adding 45 cents to the company's stock (NASDAQ:ISPH), pushing it to its Friday close of $13.
Perhaps that's because the investment community levied its punishment for diquafosol in December when the FDA issued an approvable letter, but requested more data. Inspire's stock dropped $3.21, or 19.6 percent, on that news, closing at $13.14. (See BioWorld Today, Dec. 23, 2003.)
Also on Friday, the Durham, N.C.-based company said it finished hiring its specialty ophthalmology sales force, now totaling 64, for the launch of Elestat, a topical allergic conjunctivitis treatment developed by partner Allergan Inc., of Irvine, Calif. (Allergan also is Inspire's diquafosol partner.)
So the atmosphere on Friday at Inspire wasn't one of despair, Mary Bennett, the company's senior vice president, operations and communications, told BioWorld Today.
"We're very positive, because for one, we're launching Elestat," she said. "This is our first product that is going to bring significant revenue to the company, so that's exciting. Our sales force is hitting the streets right now. We also have clarity on exactly what we need to do [for diquafosol], and I think that's important."
Inspire and the FDA agreed in their meeting Jan. 29 to a Phase III study with an undisclosed endpoint. "What it really comes down to is powering the study properly and ensuring that we have an optimal time point," Bennett said. "We are reviewing [current] data to determine what kind of study to run and what kind of patients respond best."
Bennett expects Inspire to start the study early in the second quarter. If enrollment is completed by early 2005, Bennett said the firm would file an amendment to the new drug application immediately thereafter, with possible FDA action toward the middle or end of 2005.
When Inspire received its approvable letter in December, the firm hoped its pending Phase III trial would supply sufficient data to win approval. But that trial, study 03-108, a "chamber" trial of 200 people, missed its primary endpoint of reducing exacerbation of dry eye after exposure to the chamber. ("Chamber" refers to a controlled environment used for testing.)
Even though 03-108 hit secondary endpoints regarding dry eye before exposure to the chamber, the FDA requested the additional trial, Bennett said.
Diquafosol tetrasodium, an eye drop in 2 percent preservation-free solution, is designed to stimulate P2Y2 receptors located on the ocular surface and inner lining of the eyelid.
Inspire's NDA, filed in June, contained data from one Phase II and two Phase III studies, involving more than 1,200 dry-eye patients. Two of the trials - one Phase III and the Phase II trial - demonstrated a statistically significant improvement in cornea staining, while the second Phase III study missed its endpoint.
Allergan plans to file for European approval this year.
Beyond diquafosol, Inspire is developing a small molecule called INS-37217 as a potential treatment for cystic fibrosis and retinal disease. The molecule is in Phase II programs for each indication.
Inspire's other dry-eye product, Restasis, was launched last April by Allergan. The companies have a co-promotion agreement whereby Allergan employs the primary sales team for Restasis.