By Mary Welch
Inspire Pharmaceuticals Inc. entered into a $6.25 million partnership with Santen Pharmaceutical Co. Ltd. to develop INS365 for the treatment of dry-eye disease, less than three months after inking a $17.5 million deal with Kissei Pharmaceutical Co. Ltd. to develop the drug for respiratory uses.
"It's the same product, different formulation," said Christy Shaffer, vice president of development for Durham, N.C.-based Inspire.
Under the partnership deal, Inspire will receive up to $6.25 million, consisting of the sale of equity and milestone payments, plus royalties on net sales from the Osaka, Japan-based company. Santen, whose sales volume of prescription eye-care products ranks first in Japan and third in the world, will receive exclusive rights to develop and market the product in Japan and nine other Asian countries.
Inspire is in talks with possible developmental partners in the U.S. and Europe, but intends to wait until Phase I results of INS365 are compiled before pursuing a deal. The company expects to go public in 2000.
Inspire intends to begin Phase I safety studies in the U.K. in the first half of 1999, which is the same time frame in which the company plans to file an investigational new drug (IND) application in the U.S. Additional Phase I studies will also take place in the U.S., Shaffer said.
Inspire, which has focused on respiratory conditions, has centered its products around the members of the P2Y receptor family. "The decision to look at the P2Y receptor and INS365 for dry eye just popped into my head," said Ben Yerxa, director of preclinical programs.
The idea, Yerxa said, "emerged out of discussions to apply the technology to applications other than respiratory ones. INS365 stimulates the secretion of fluids — mucin, water, ions and other proteins — all of which make up the natural tear component."
Shaffer said the project "shows that P2Y2 receptor agonists are applicable to the treatment of diseases of mucosal surfaces beyond the respiratory tract. We intend to look at other areas of the body where mucosal hydration is impaired or deficient."
Six Million Suffer From Dry Eye In The U.S.
In preclinical studies on animals, INS365 was found to enhance the ability of ocular surface tissues to produce tears of normal composition.
Lack of tearing results from a glandular problem or improper balance of the tear fluid mechanism, which can be brought on by eye strain; tired eyes are a mild form of the disease. A severe dry-eye case is "like having sand in your eye 24 hours a day," said Yerxa.
About 6 million people in the U.S. and 16 million in the major global pharmaceutical markets suffer from dry eye disease. Greg Mossinghoff, senior director of operations and strategic planning for Inspire, said the current global market for dry-eye products is estimated to be $350 million and "consists primarily of tear-replacement therapy. However, the market is expected to increase dramatically as new products with pharmacological activity, such as INS365, are launched."
Unlike current eye drops that add moisture to the eye, INS365 stimulates the secretion of natural tears and may normalize conjunctival function.
In September, Inspire and Kissei, of Matsumoto City, Japan, signed a deal that will allow Kissei to develop INS365 for the treatment of chronic obstructive pulmonary diseases, including chronic bronchitis. The inhaled drug stimulates mucociliary clearance by activating the P2Y2 receptor. The receptor is located on the apical surface of specialized cells within the respiratory tract. (See BioWorld Today, Sept. 15, 1998, p. 1.) *