Plethora Solutions Holdings has unveiled further results and analysis from a Phase II clinical trial backing its PSD597 as a safe and effective treatment for interstitial cystitis, which affects up to 16 million people worldwide, and painful bladder syndrome.

The randomised, double-blind, placebo controlled trial of 102 patients at 22 centres across the USA and Canada, designed to assess the immediate and longer-term effects of a course of the drug, met its primary endpoint in demonstrating that patients taking PSD597 experienced “clear and substantial improvements” in Global Response Assessment, a patient-rated scale of improvement in bladder symptoms.

Results showed that, at day eight, 30% of patients reported moderate or marked improvement after PSD597 treatment, versus just 10% of patients in the placebo arm, and improvements at day 15 were 24% and 12% respectively. Furthermore, the positive results were echoed in all secondary endpoints, with patient reporting improvements in bladder pain, urinary frequency and urgency, and the drug was shown to be was well tolerated, devoid of systemic side effects often experienced with oral therapies.

Majority continued therapy

Importantly, 86% of patients elected to continue therapy with PSD597 in an open-label extension trial, providing “direct evidence of treatment acceptability and the lack of alternative treatment options”, according to the firm. At day 22, 63% of those who had received the drug in the double-blind study phase reported moderate or marked improvement in GRA after the second treatment, providing further evidence of its efficacy.

“These full results confirm and extend previous findings and show that PSD597 offers a simple, effective treatment for patients suffering from interstitial cystitis,” according to Dr Mike Wyllie, Plethora’s Chief Scientific Officer. “These longer term studies confirm that the product produces rapid and effective relief of symptoms and that the effect is maintained over several weeks.”

The next step, he said, is for Plethora to initiate discussions with regulatory authorities to define the Phase III programme for registration, as well as try to find potential licensing partners, presumably to help fund the latter stage of development.