InSite Vision Incorporated announced the signing of a licensing agreement with Inspire Pharmaceuticals for the United States and Canada.
The agreement provides for the commercialisation by Inspire of AzaSite (1 per cent azithromycin), InSite's topical anti-infective product currently under NDA review by the FDA for the treatment of bacterial conjunctivitis; commonly referred to as "pink eye". The global market opportunity for topical, ocular anti-infective products currently exceeds one billion dollars.
Under the terms of the agreement, InSite grants exclusive rights to Inspire to commercialise AzaSite for ocular infection in the US and Canada. AzaSite contains the drug azithromycin, a broad-spectrum antibiotic formulated with DuraSite, InSite's patented drug-delivery vehicle. If approved, it is anticipated that AzaSite will become the first ocular antibiotic with a once daily dosing regimen after an initial loading dose, which may increase patient compliance and therapeutic efficacy.
The agreement provides that Inspire Pharmaceuticals will pay InSite Vision an upfront license fee of $13 million and an additional $19 million milestone payment contingent on regulatory approval by the FDA. Inspire will also pay a royalty on net sales of AzaSite in the US and Canada, if approved by regulatory authorities. The royalty rate will be 20 per cent on net sales of AzaSite in the first two years of commercialisation and 25 per cent thereafter. InSite Vision will use a portion of the license fee to repay its senior secured notes, with a principal balance of $6.3 million, issued in December 2005 and January 2006.
S Kumar Chandrasekaran, Ph.D., InSite Vision's chief executive officer stated, "The AzaSite license agreement and related collaboration with Inspire represents the first step in realizing the global opportunity provided by our azithromycin/DuraSite drug-delivery platform. This platform will allow us to pursue additional anti-infective products and indications worldwide, supported by our expanded patent portfolio for both the AzaSite and DuraSite technologies.
"Our corporate partnership with Inspire also represents a consistent and mutually focused business strategy, designed to maximize this unique opportunity for the shareholders of both companies. We are truly delighted to be aligned with Inspire Pharmaceuticals in the pursuit of this large and attractive revenue market represented by ocular anti-infective therapies."
Azithromycin is a semi-synthetic antibiotic that is derived from erythromycin and has been available under the trade name Zithromax (Pfizer) since 1992. Azithromycin has been the most commonly prescribed antibiotic in the United States, with an excellent safety and efficacy profile that is most notable for its once-a-day dosing feature. However, the drug had never been formulated as an ophthalmic eye drop for topical dosing because of an unfavourable stability profile.
Over the past few years, InSite Vision has been investigating ocular drug formulations that utilize DuraSite, their patented drug delivery system. DuraSite is a synthetic polymer that stabilizes small molecules like azithromycin in an aqueous matrix. A 1% solution of azithromycin in DuraSite (AzaSite) was developed and has been evaluated in phase 3 multi-centre clinical trials. The data indicates that AzaSite is a broad-spectrum antibiotic with an enhanced killing capacity for pathogens previously resistant to azithromycin, but with a safety profile that maintains many of the same well-known benefits.
Bacterial conjunctivitis is a common ocular surface disease characterized by inflammation of the delicate skin and mucosa on the inside of the eyelids. The bacterial infections are contagious and generally accompanied by irritation, itching, foreign body sensation, watering, mucus discharge and redness (pink eye). The bacterial form of the disease is more common in children than adults. In children, the most common bacterial species associated with acute conjunctivitis are Hemophilus influenzae, Streptococcus pnuemoniae , and Staphylococcus species. Among adults, bacterial conjunctivitis can be an important concern in contact lens wearers. The disease is self-limiting in most cases and usually resolves in 8-10 days. Topical antibiotics are often prescribed to control the public health risk of contagion and to shorten the duration of the disease.
InSite Vision has submitted an electronic NDA filing in a modified Common Technical Document (CTD) format to the FDA for regulatory review. This submission incorporates the positive results from the recently completed Phase 3 clinical trials, pre-clinical studies, chemistry, manufacturing and controls. InSite previously announced the completion of these two Phase 3 studies, including a vehicle controlled study versus AzaSite, and a study comparing 0.3 per cent tobramycin versus AzaSite. The results of these trials showed that AzaSite was safe, well tolerated and efficacious in the treatment of bacterial conjunctivitis.
The NDA submission contains data from the two Phase 3 clinical trials in which 698 patients were treated with AzaSite. Data from these studies demonstrated that when AzaSite was administered twice daily on the first two days, then once daily on days 3-5, it provided clinically and statistically significant improvements in clinical resolution of symptoms, and bacterial eradication compared to placebo, and was equivalent in clinical resolution and bacterial eradication when compared to tobramycin administered four times a day.
InSite Vision has signed a manufacturing supply agreement with Cardinal Health for the manufacture of topical AzaSite (1% azithromycin) commercial units. Cardinal Health manufactured the clinical trial supplies used in InSite Vision's two Phase 3 bacterial conjunctivitis clinical trials, and also the registration batches used for the AzaSite New Drug Application (NDA) filing.