On December 14, 2018, the Company completed review of preliminary topline results for its Phase 2b clinical trial of oral Prurisol in moderate-to-severe chronic plaque psoriasis. Prurisol did not meet the primary endpoint in either treatment arm (300mg and 400mg) assessed as a measure of efficacy (active versus control) using the Psoriasis Area and Severity Index (PASI) scale—specifically, the proportion of subjects achieving at least a 75 percent reduction from baseline in PASI score (PASI75) at Week 12. While additional analysis of the Prurisol data is planned, based on these trial results, the Company will discontinue the Prurisol psoriasis program, focusing development efforts on advancing its other clinical assets, Kevetrin and Brilacidin, both of which have shown therapeutic potential in treating multiple indications.
Acting through immune modulation and PRINS reduction, Prurisol is a novel dermatology drug candidate in development as an orally-delivered psoriasis treatment utilizing the advantages of the FDA's 505(b)(2) development approach. This regulatory approach helps expedite a drug’s potential approval as it allows the FDA to rely, in part, on existing long-term safety data of an already approved drug, in this instance, Ziagen—thereby shortening development time and reducing costs. Prurisol is protected by a composition of matter patent.
Innovation has successfully completed a Phase 2 clinical trial of Prurisol in patients with mild-to-moderate Chronic Plaque Psoriasis. Overall analyses showed (pdf) the drug to appear safe, well-tolerated and efficacious in the highest dosing arm across 12 weeks of treatment. Patients with more moderate forms of psoriasis saw the greatest clinical improvements. Pharmacokinetic data further revealed an early and dose-dependent response that improved as treatment duration increased.
“A NEW ORAL PSORIASIS DRUG THAT DELIVERS
SUBSTANTIAL EFFICACY WOULD BENEFIT PATIENTS AND COMMAND CONSIDERABLE MARKET VALUE.”
— Dr. Arthur Bertolino
Due to its mechanism of action, Prurisol may also have applicability in treating other autoimmune-based diseases, such as Psoriatic Arthritis and Rheumatoid Arthritis.