Antares Pharma has exclusively licensed its oxybutynin gel 3% to Daewoong Pharmaceutical, for marketing in South Korea. Antares will receive undisclosed upfront payments, regulatory milestones and sales-based milestones, as well as royalties on net sales for the product.
Antares' FDA-approved oxybutynin product is a clear, odourless, translucent hydroalcoholic topical gel containing oxybutynin, an antispasmodic, antimuscarinic agent. It is available in a metered-dose pump that has been shown to be an effective and safe treatment for overactive bladder (OAB). As the active ingredient is delivered transdermally, it is not metabolised by the liver in the same way as orally administered oxybutynin. This results in a low level of side-effects, such as dry mouth and constipation. Applied once daily to the thigh, abdomen, upper arm or shoulder, an 84mg (approximately 3mL) dose delivers a consistent dose of oxybutynin through the skin over a 24-hour period, providing significant efficacy without sacrificing tolerability.
FDA approval of the product was based on a 12-week, multicentre, placebo-controlled, Phase III study conducted by Antares. Patients treated with 84mg oxybutynin gel daily achieved steady state drug concentrations within three days and experienced a statistically significant decrease in OAB symptoms versus placebo, including the number of urinary incontinence episodes per week. Statistically significant improvements in daily urinary frequency and urinary void volume were also seen with the 84mg dose.