The UK’s Plethora Solutions Holdings has excited analysts with the news that its topical spray for premature ejaculation, PSD502, has moved into late-stage trials.

PSD502 (lidocaine and prilocaine) is dispensed by a metered dose aerosol and is applied locally when needed. What’s more, the treatment is effective within five minutes, has a good safety profile and offers “minimal partner transfer”, eliminating the need to use a condom for protection from

the product.

The compound is being moved into Phase III because it has been shown to increase ejaculation latency time substantially when compared with placebo in a multi-centre Phase II study. That data demonstrated that PSD502 increases the time between penetration and ejaculation from 0.93 minutes with placebo to 3.7 minutes using the spray.

Two Phase III studies (carried out in the USA and Europe) will involve 540 patients in total who will be treated for a 12-week period with an optional five-month open label phase. The primary endpoints will be intra-vaginal ejaculation latency time, sexual satisfaction and ejaculatory control, while secondary endpoints will include sexual quality of life and partner satisfaction.

Importantly, Plethora noted that it has also been agreed with regulators that one-year open label extensions to the studies are not required and

“this will reduce time to study closure considerably”. Chief executive Steven Powell added that if patient recruitment proceeds as planned, “we would expect to see headline data towards the end of 2008 which will be a major milestone in the life of both this product and Plethora”.

Following the announcement, Jacob Plieth, an analyst at Edison Investment Research, said that PSD502 could become the first prescription product to be approved for premature ejaculation, depending on the extent of the delay to Johnson & Johnson’s dapoxetine. The latter received a non-approvable letter from the US Food and Drug Administration in October 2005 and Mr Plieth noted that while dapoxetine has been studied in over 5,000 patients, J&J has yet to resolve the issues raised by the FDA on dapoxetine, a selective serotonin reuptake inhibitor, and is now targeting Europe for its first launch.

There is clearly a market for such a product as the disorder affects up to 30% of men in Europe and the USA. Up to now, premature ejaculation has been managed using behavioural therapy or older, 'off-label' drugs, mainly antidepressants.

PSD502 is licensed to Schiele Pharma in the USA, though Plethora retains some co-promotion rights. Mr Plieth also noted that the UK firm is in discussions with potential partners outside the USA, as well as seeking a licensee for the additional indication of wound pain.

These are interesting times for Plethora which also has products in its mid-to-late-stage pipeline for erectile dysfunction and women’s health. Last month it unveiled further results and analysis from a Phase II clinical trial backing PSD597 as a safe and effective treatment for interstitial cystitis, which affects up to 16 million people worldwide, and painful bladder syndrome.