Strategic Science & Technologies Initiates Phase I Study to Evaluate Topical Sildenafil

Strategic Science & Technologies recently announced the initiation of a Phase I trial of SST-6006, a first-in-class topical sildenafil product candidate in development for the treatment of women with Female Sexual Arousal Disorder (FSAD).

“With SST-6006’s novel topical delivery and potential review by the FDA as an OTC product, we believe it could be a groundbreaking new therapy that positively impacts sexual health in both men and women.”

The Phase I trial is designed to assess the safety, tolerability, and pharmacokinetics of SST-6006 in healthy, post-menopausal women following a single dose applied topically to the vaginal tissue. A single center, open-label, placebo-controlled, within-subject dose-escalation study design will be used to evaluate 3 dose levels of SST-6006. Safety assessments will include physical examination, clinical laboratory evaluations, ECG, and adverse events. Pharmacokinetic analyses to determine concentrations of sildenafil in plasma will be completed at pre-specified time points from pre-dose up to 32 hours post-dose.

In non-clinical studies and clinical studies in healthy men, the topical application of SST-6006 has resulted in very low systemic absorption of sildenafil, compared to a comparable oral dose of sildenafil, offering the potential to significantly reduce the side effects long associated with oral phosphodiesterase type-5 (PDE-5) inhibitors. SST intends to demonstrate that SST-6006 is a safe and effective treatment for women with FSAD, and plans to pursue potential registration of SST-6006 as an OTC topical product.

“Based on the positive results in the Phase I trial in men, we are excited to begin our clinical evaluation of SST-6006 in women with FSAD. This marks an important milestone for the treatment of FSAD, a significant unmet and under-discussed need for many women,” noted Eric T. Fossel, Scientific Founder and Chief Executive Officer of SST. “With SST-6006’s novel topical delivery and potential review by the FDA as an OTC product, we believe it could be a groundbreaking new therapy that positively impacts sexual health in both men and women.”

Female sexual arousal disorder (FSAD), is a disorder characterized by a persistent or recurrent inability to attain sexual arousal or to maintain arousal until the completion of a sexual activity. FSAD affects women of all ages, though it is most common in post-menopausal women, with urogenital atrophy being the most common cause. While there are currently no FDA-approved therapies available for the treatment of FSAD, estrogen therapy can be an effective treatment for post-menopausal women. However, there are limited treatment options for premenopausal women with arousal disorders, women who do not respond to estrogen therapy, and those who are unable or unwilling to take estrogen.

Dr. Irwin Goldstein, MD, Director of San Diego Sexual Medicine and a leading expert in Sexual Medicine, said “Female sexual dysfunction is highly prevalent, and treatment for this condition is not available. There is an enormous unmet need. Both clinicians and patients alike in this field welcome research that will one day lead to a therapy that alleviates the problem and distress that accompanies it. SST-6006 in women for FSAD is a promising therapy, which has just begun its clinical development program.”

SST-6006, developed with SST’s proprietary KNOSIS technology, is a patented topical cream product containing 5% sildenafil citrate by weight. Sildenafil is a specific PDE-5 inhibitor that enhances nitric oxide-mediated dilation of blood vessels. When sexual stimulation causes local release of nitric oxide, inhibition of PDE-5 by sildenafil results in smooth muscle relaxation and inflow of blood to the target tissue (corpus cavernosum in men, vaginal tissue in women). In the oral form, sildenafil is available as a prescription drug for men; however it is not approved for use in women. Its use is contraindicated in some men due to its systemic vasodilatory properties that result in decreased supine blood pressure. In patients without these cardiovascular risk factors, mild and temporary side effects include headache, facial flushing, upset stomach and nausea. The FDA-approved labeling for PDE-5 inhibitors also includes warnings about the risk for sudden loss of vision in one or both eyes and sudden decrease or loss of hearing.

SST-6006 was found to be well tolerated in a Phase I trial in healthy men, with a significantly reduced number of side effects compared to oral sildenafil. The peak concentration of sildenafil detected in the blood after a single application of SST-6006 (formulated to deliver 50 mg of sildenafil) was more than twenty-fold lower than what was detected from a 50-mg oral dose of sildenafil. The presence of sildenafil in the blood from SST-6006 confirmed successful delivery of sildenafil across the skin. These data support SST’s efforts to demonstrate 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 50-mg oral dose of sildenafil. SST intends to demonstrate that SST-6006 is a safe and effective treatment for men with ED, and plans to pursue potential registration of SST-6006 as an OTC topical product.

SST’s novel topical technology, KNOSIS, is based on the pioneering work of its Scientific Founder Eric T. Fossel, formerly in the Biochemistry, Biophysics, and Radiology Departments at Harvard Medical School. Due to the skin’s highly protective barrier, the stratum corneum, success with topical delivery approaches has been mostly limited to smaller, uncharged molecules. SST’s proprietary topical delivery technology overcomes these historical challenges through at least two novel features. First, the KNOSIS formulation technology produces a hostile biophysical environment for the API, increasing its free energy and creating a positive chemical potential that drives the API from the delivery vehicle into the tissue. Second, this novel formulation prevents the formation of hydrogen bonds between the API and the stratum corneum, which can inhibit the ability of the API to permeate into the tissue. These two complementary actions support SST’s efforts to achieve the desired local therapeutic effect in the target tissue and, due to the minimal uptake of the drug into the bloodstream, greatly reduce or eliminate any known side effects associated with its systemic absorption.

Strategic Science & Technologies LLC (SST) is a clinical-stage biotechnology company developing first-in-class topical formulations of known pharmaceutical products. SST has been successful in delivering several highly charged molecules across the skin in therapeutic areas, including pain, dermatology, and men’s and women’s sexual health. For more information, visit www.strategicscience.com.