Antisense launches Phase I MS trials

Antisense Therapeutics has initiated its first Phase I clinical trial for antisense inhibitor ATL1102, which is being trialled as a treatment for multiple sclerosis.

The first cohort of healthy patients in the safety and pharmacokinetics study has been dosed with the inhibitor, said CEO Dr Mark Diamond yesterday. The double-blinded and placebo-controlled trial is being held at the Charterhouse Clinical Research Unit at the Ravenscourt Park Hospital in the UK, and results are expected by the middle of 2004.

"We're very pleased to say that this is the first antisense drug to enter the clinic for the treatment of multiple sclerosis," Diamond said. "It's very exciting for us."

The trial marks a milestone for Antisense, which was set up in December 2001 as a collaboration between Australian pooled development fund Circadian Technologies and US-based antisense pioneers Isis Pharmaceuticals. ATL1102 was licensed from Isis as part of the agreement, which has Antisense responsible for clinical development and commercialisation of the drug.

The drug is a second-generation antisense inhibitor of lymphocyte receptor VLA-4 (very late antigen 4), which has been shown to have positive effects in a number of animal models of inflammatory diseases including multiple sclerosis.

Other inflammatory diseases linked to VLA-4 include asthma, rheumatoid arthritis and Crohn's disease, and according to Diamond, the company has exclusive rights from Isis to develop ATL1102 for those conditions as well.

"We're taking it forward [initially] for multiple sclerosis but we have conducted animal studies for other diseases and it has demonstrated positive effects," he said.

Competitors for the drug include existing interferon drugs and Antegren, a monoclonal drug developed by Biogen and Élan Corporation, which also binds VLA-4. Antegren is currently in Phase III trials.

"Clearly we hope to have a good competitor," said Diamond. Potential advantages of the antisense therapeutic include cheaper and simpler synthetic manufacturing, and subcutaneous delivery.

Success in the Phase I clinical study will lead to a Phase II trial to look at efficacy in patients with multiple sclerosis, and at the earliest will start in mid-2004. But a successful therapy is at least five or six years away from the market, according to Diamond.

He said that Antisense would most likely be looking for commercialisation partners after completion of Phase IIa studies.