DUSA off 22% on predictable failure of underpowered PDT acne study:
>>WILMINGTON, Mass. (AP) -- Dusa Pharmaceuticals Inc. said Wednesday that a mid-stage study of its photodynamic acne therapy was not large enough for any significant results, meaning the company will have to run another trial with more patients.
"We had said there was a possibility that we'd have to do another Phase II study" because of changes to regulatory guidelines, said Scott Lundahl, the company's vice president of regulatory affairs and intellectual property. The inconclusive results from the most recent study made the additional trial necessary, Lundahl said.
The company's shares dove more than 29 percent to $7.22 in afternoon trading on the Nasdaq, after touching a new 52-week low of $6.72 earlier in the session. The stock previously had been trading between $8.33 and $14.60.
The 72-patient study failed to find any significant difference between patients whose faces were pretreated with a topical solution and those who only underwent a blue-light therapy.
The company said response rates to the light therapy alone were higher than expected, meaning there were no meaningful differences between the treatment groups. After eight weeks, the group on light therapy alone appeared to have greater acne reduction and more overall acne improvement. Dusa did say that the combined treatment appeared to be more effective in a subset of patients with more than 60 inflamed lesions.
The therapy is designed to be a two-step process that starts with Dusa's Levulan Kerastick solution to prime the skin, making affected areas more sensitive to light treatment. This is then followed by treatment with the blue light device to clear the skin. Patients were given up to four light therapy treatments at two-week intervals then assessed at eight weeks.
The patients were split into three groups undergoing different light exposure times. Dusa said it only used data from the 24 patients with the shortest light exposure, about 15 minutes, because that setting showed equal or better safety and effectiveness than treatment for 60 minutes or 120 minutes.
Dusa said none of those in the 15-minute group discontinued treatment because of pain. Lundahl said some patients in the larger groups did drop out, but that these were not necessarily because of negative side effects.<<
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Cheers, Tuck |
