Inspire Pharmaceuticals Inc. expects to generate between $30 million and $45 million next year in sales of its newly approved and newly acquired eye drop, AzaSite (azithromycin ophthalmic solution) 1%, and that's just the start for a product expected to boost the company's growing ophthalmology franchise.
The FDA cleared AzaSite late Friday as a treatment for bacterial conjunctivitis caused by susceptible isolates of CDC coryneform group G, Haemophilus influenzae, Staphylococcus aureus, Streptococcus mitis group, Streptococcus pneumoniae. Inspire, of Durham, N.C., plans to launch it late next quarter as a complement to two ocular products its sales staff already has a hand in marketing, Elestat (epinastine HCl ophthalmic solution) 0.05% for allergic conjunctivitis and Restasis (cyclosporine ophthalmic emulsion) 0.05% for dry eye. Both are sold to specialty physicians such as allergists, ophthalmologists and optometrists through co-promotion arrangements with Allergan Inc., of Irvine, Calif., but limits preclude Inspire's 64 existing reps from booking sales and doing primary marketing.
With AzaSite, the company plans to do much more.
"It enables us to build a proper and appropriate commercial infrastructure that not only enables us to launch Azasite," President and CEO Christy Shaffer told BioWorld Today, "but allows us to be in a position to continue to launch products that come out of our portfolio."
So in addition to providing an opportunity to grow the company's sales staff - 34 more reps are being hired to broaden into select pediatric and primary care practices - the new approval also lays the groundwork for a more dynamic marketing group at Inspire, which is being built as an integrated business. Its pipeline includes ocular products in development for dry eye and glaucoma, as well as respiratory products for cystic fibrosis and allergic rhinitis.
AzaSite, which has patent coverage until 2019, should provide patients a reduced dosing regimen compared to other available products for bacterial conjunctivitis, potentially leading to better compliance and outcomes. Its FDA label recommends one drop twice-a-day for two days, followed by one drop once a day for the next five days, for a total of nine drops in the affected eye. In comparison, Vigamox (moxifloxacin, Alcon Inc.) requires 21 drops, and 36 drops of Zymar (gatifloxacin, Allergan) are needed.
AzaSite's "much more convenient" dosing regimen should prove especially helpful in treating pediatric patients, Shaffer said. The product is approved for adults and children as young as 1 year, and Joseph Schachle, Inspire's executive vice president and chief of commercial operations, said that physicians' general confidence in AzaSite's active ingredient, the popular antibiotic azithromycin, should make it an attractive option in addition to its relative convenience.
It's entering an annual U.S. market of about $360 million for ocular antibiotics, about 90 percent of which comes from branded drugs. Vigamox and Zymar, both of which were approved in 2003, generated $200 million and $100 million last year, respectively.
"There's a lot of value in the market," Schachle told BioWorld Today, noting the dominant sales numbers of branded drugs among the 15 million annual U.S. prescriptions. He added that he expects the product to eventually grab a significant double-digit share of the market.
The FDA based its decision largely on data from two Phase III studies in which AzaSite met its primary endpoint by resolving patients' bacterial conjunctivitis. More specifically, the results demonstrated that it provided clinically and statistically significant improvements in clinical resolution of symptoms and bacterial eradication compared to placebo, and it was equivalent in clinical resolution and bacterial eradication compared to the antibiotic tobramycin administered four times a day for five days.
Inspire acquired the product's exclusive U.S. and Canadian rights for ocular infections earlier this year from InSite Vision Inc., which is receiving a $19 million milestone payment for the approval. The azithromycin ophthalmic solution is formulated with DuraSite, InSite's ocular drug delivery system that enhances the antibiotic's retention time on the surface of the eye.
"Because we'd already built a sales force and had internal R&D expertise in ophthalmology, we wanted to [further] build the ophthalmic portfolio," Shaffer said of the in-licensing arrangement. InSite has yet to file for Canadian approval.
That company, of Alameda, Calif., received a $13 million up-front payment when the deal was struck. Terms of the agreement also call for Inspire to pay InSite sales royalties of 20 percent in the first two years of commercialization and 25 percent in subsequent years. InSite's management has said the company, which has a commercially available glaucoma genetic test called OcuGene, plans to pursue additional commercial partnerships this year to expand AzaSite's market opportunities beyond the U.S. and Canada. (See BioWorld Today, Feb. 20, 2007.)
Inspire's late-stage pipeline includes a product for cystic fibrosis, denufosol tetrasodium, which is in a Phase III trial scheduled to complete enrollment in the fourth quarter. In addition, the company and the FDA are discussing regulatory requirements for an oral antihistamine called bilastine, which has completed Phase III work in Europe under the management of FAES Farma SA, of Madrid, Spain. The company also expects Phase II results on a nasal spray formulation of epinastine for allergic rhinitis in the middle of this year.
Lastly, discussions with the FDA on a path forward for Prolacria (diquafosol tetrasodium) for dry eye remain ongoing. The subject of two approvable letters, the Allergan-partnered product might need additional clinical work, but that's yet to be determined.
On Monday, Inspire's stock (NASDAQ:ISPH) gained 27 cents to close at $7.65, after trading as high as $8.70, while shares in InSite (AMEX:ISV) lost 14 cents to close at $1.63.