Antisense 'proof-of-concept' study demonstrates activity of ATL1101 in psoriasis patients

Antisense Therapeutics (ASX:ANP) has produced positive results from a 'proof-of-concept' study of its second generation antisense drug ATL1101 to suppress the insulin-like growth factor-1 receptor (IGF-1R), which is under development as a cream for the topical treatment of the skin disorder psoriasis.

"We were pleased we achieved what we set out to do with the conduct of this proof-of-concept study -- and that was to make an early assessment of the drug's activity in psoriasis patients," said Antisense managing director Mark Diamond. "An important aspect is that this was achieved in a timely and cost-effective manner."

The trial was a double-blind, placebo-controlled, randomised study for patients with psoriasis. Two concentrations of ATL1101 cream were evaluated in 11 patients with mild to moderate severity of the disease. Comparisons were made against a placebo cream, and also against reference cream products that are currently marketed as prescription medications for treatment of psoriasis. The ATL1101 was applied once every two days, over a one month period.

The primary endpoint was a clinical assessment of the treated skin areas using a severity index score -- Local Plaque Severity Index (LPSI).

"We were able to show that both formulations of the 1 per cent and 10 per cent concentrations demonstrated an improvement over placebo; however, it was the 1 per cent formulation that showed a statistically significant improvement. The 10 per cent showed a trend towards an effect, though it did not reach statistical significance. The company has concluded these results demonstrate the activity of ATL1101 in psoriasis patients in this study," Diamond said.

As another primary endpoint of the study, ATL1101 was compared to two currently marketed prescription medications for the treatment of psoriasis (calcipotriol and betamethasone).

"These drugs both showed improvement versus placebo. While the ATL1101 has shown an effect in patients with psoriasis, it was less effective than the reference products in this study.

"ATL1101 is at an early stage of development, and therefore has not been as fully optimised as is the case with the reference products -- both of which have shortcomings as treatments based on their tolerance and general side-effect profiles," he said.

Antisense plans to assess, with the assistance of psoriasis researchers and other relevant experts, if ATL1101 is likely to show improved efficacy in a larger, longer-term clinical trial, or if the compound's activity may be improved through enhancement of the formulation. The company will also evaluate development opportunities for ATL1101 with relevant pharmaceutical companies.

The trial took place in Adelaide under the management of CMAX, a Division of the Institute of Drug Technology Australia Limited.