Peplin Inc announced positive results for PEP005 (ingenol mebutate) Gel in Region-I, its Australian and US based phase III actinic (solar) keratosis (AK) clinical trial for the treatment of lesions on non-head locations, which include the trunk and extremities. AK is a common pre-cancerous skin condition caused by sun exposure, which can develop into skin cancers if left untreated.
Peplin's chief executive officer, Tom Wiggans, is pleased with the positive results and said, "Once again, our team has done an excellent job of obtaining great clinical results while completing our first phase-III trial within the expected timeframe." He continues, "These strong results achieve an important step towards commercialisation. In addition, they confirm efficacy signals with prior trials and market need, since no currently marketed product has proven efficacy for this range of locations for non-head lesions, especially with a two-day course of therapy. PEP005 Gel continues to provide patients the potential for a compelling alternative."
Region-I tested a 0.05 per cent concentration of PEP005 Gel applied once a day for only two consecutive days. This resulted in a median reduction in the number of AK lesions of 66.7 per cent (p-value<0.0001), a total clearance rate across all anatomical non-head sites, including the extremely difficult-to-treat back of hand and arm locations, equal to 27.4 per cent (p-value<0.0001) and a partial clearance rate of 44.4 per cent (p-value <0.0001). In addition, statistical significance was established in back of hand, arm and chest locations. These highly statistically significant results, as evidenced in the favourable p-values, suggest that the drug has significant benefit over vehicle.
As anticipated, the inclusion of treatment sites for all non-head AK lesions contributed to the lower clearance rates when compared to previous trials, but the total clearance rates ranged from 16 to 89 per cent by anatomical location with chest, back of hand and arms achieving statistical significance. The other areas did not show statistical significance due to the low number of patients that enrolled with these types of AK lesions.
Dr Robert Rosen, a Sydney dermatologist and scientific advisor to Peplin, who has also been involved in the PEP005 clinical trial program, said that current treatment options for solar keratosis have a number of shortfalls, including pain, persisting skin irritation and redness during prolonged treatment periods.
"As a result, patients are often unwilling to use their medications," he said. "A topical agent like PEP005 Gel, which can effectively and conveniently treat lesions in two days, will be of significant benefit to doctors and their patients."
Brian Berman, professor of Dermatology and Internal Medicine at the University of Miami, Miller School of Medicine, stated, "Practicing dermatologists recognise that the successful treatment of AK lesions found on the arms or back of hands is a challenge generally unmet by topical treatments currently on the market. PEP005 Gel's strong results across these difficult treatment areas provide the opportunity to satisfy our AK patients' unmet need."
As seen in previous non-head trials, the local skin responses (LSRs) peaked at Day 8 and returned to baseline by Day 29. The most frequent LSRs included erythema, flaking and scaling with no significant adverse effects reported.
Peplin will conduct its End-of-phase-II meeting with the FDA on June 3, 2009. Peplin was notified by the FDA of their need to postpone the meeting by two weeks from the originally scheduled date due to internal scheduling conflicts at the FDA. Peplin will initiate the phase-III programme for patients with AK lesions on the head, an estimated 70 per cent of the AK market, in the second quarter of 2009.
Peplin is a development stage specialty pharmaceutical company focused on advancing and commercialising innovative medical dermatology products.