Provectus Pharmaceuticals, a development-stage oncology and dermatology biopharmaceutical company, reported top-line data for the company's randomized controlled trial of PH-10, a topical aqueous hydrogel, for mild-to-moderate plaque psoriasis.

"Despite the complexity of this four-arm study, we are pleased that it clearly showed that the low dose level was optimal of the three doses tested, with similar activity to that seen in our earlier single-arm trial, and that it was superior to vehicle,” said Dr. Craig Dees, Ph.D., CEO of Provectus.

The phase II trial compared safety and efficacy of three dose levels of PH-10 (0.002% Rose Bengal, 0.005% Rose Bengal and 0.01% Rose Bengal) against vehicle. Ninety-nine subjects with mild-to-moderate plaque psoriasis of the trunk and/or extremities were randomized into one of four study arms and applied their assigned test article once daily for 28 consecutive days. Subjects were assessed weekly during the treatment interval, and returned one week and four weeks after their final application for final assessment of safety and efficacy. The trial’s patient population, study events schedule and study assessments were similar to a previous randomized trial at a lower dose level, allowing the two to be compared side-by-side.

Results for all three efficacy parameters showed improvement in psoriasis symptoms over the treatment interval, with the low dose of PH-10 (0.002%) providing uniformly consistent improvement, while reduced therapeutic activity was observed at the two higher doses. Response for PH-10 at 0.002% Rose Bengal was comparable to that observed previously using PH-10 at 0.001% Rose Bengal.

After 28 days of treatment with PH-10 (all strengths), 23%-29% of subjects achieved complete or nearly complete resolution of all Psoriasis Severity Index (PSI) component symptoms (erythema, induration and desquamation) compared to no subjects in the vehicle arm. Of the patients receiving the low dose of PH-10, 38% reported no itching after 28 days compared with 14% of those receiving vehicle. In the earlier study, 45% of subjects receiving 0.001% Rose Bengal reported no itching after 28 days.

PH-10 at 0.002% and 0.005% (along with 0.001% in the prior study) exhibited maximum improvement in Plaque Response Assessment, with the improvements for 0.002% achieving high significance (p < 0.001) after two weeks of treatment; all strengths proved superior to vehicle after 28 days, with the highest strength exhibiting the least activity.

As noted in prior studies, PH-10 was generally well tolerated with only transient mild to occasionally moderate adverse experiences limited to the application site.