US-based Strategic Science and Technologies (SST) has completed a Phase 1 clinical trial of its first-in-class topical sildenafil product candidate SST-6006, to treat men with erectile dysfunction (ED).
The trial was designed to evaluate the safety, tolerability and pharmacokinetics of SST-6006 in healthy men when applied topically directly to the entire penis.
A group of subjects also received a single oral dose of sildenafil to allow for a comparison between SST-6006 and oral sildenafil.
Strategic Science and Technologies scientific founder and chief executive officer Eric Fossel said these promising results provide additional clinical validation of the company's KNOSIS platform and its ability to successfully deliver therapeutic doses of highly-charged molecules through the skin and into the target tissue.
"We look forward to initiating Phase II clinical trials this year to demonstrate the efficacy of SST-6006 in patients with the goal of commercialising a safe and effective topical OTC product for men with ED," Fossel added.
In the trial, SST-6006 was found to be well tolerated, with a significantly reduced number of side-effects compared with oral sildenafil.
According to the company, the peak concentration of sildenafil detected in the blood after a single application of SST-6006 (formulated to deliver 50mg of sildenafil) was more than twenty-fold lower than what was detected from a 50mg oral dose of sildenafil.
The presence of sildenafil in the blood from SST-6006 confirms successful delivery of sildenafil across the skin, the company said.
The company intends to show in its development programme that the very low systemic absorption of sildenafil from SST-6006 application, compared with oral sildenafil, will significantly reduce the side-effects long associated with oral phosphodiesterase type-5 (PDE-5) inhibitors.
Data from the trial supports the company's efforts to show that a single application of SST-6006 will deliver a concentration of sildenafil to the local target tissue (penis) that is equal to or greater than that delivered from a single 50mg oral dose of sildenafil.
Alvarado Hospital sexual medicine and San Diego sexual medicine director Irwin Goldstein said: "With a growing concern about systemic side-effects associated with the current oral forms of PDE-5 inhibitors, a topical treatment approach such as SST-6006 could enable patients with ED to benefit from a local therapeutic dose of sildenafil directly into the penile tissue, while reducing the risk of unwanted systemic side-effects."