ANTISENSE TO INITIATE "PROOF OF CONCEPT" STUDY OF ATL1101.

Antisense Therapeutics Limited, Melbourne, Australia will conduct a "proof of concept" study of ATL1101 in patients with psoriasis. The study will take place in Adelaide, Australia under the management of CMAX, a Division of the Institute of Drug Technology Australia Limited.

ATL1101 is a second-generation antisense drug designed to block the synthesis of the IGF-1 receptor, a protein involved in the regulation of cell overgrowth in psoriasis. ATL 1101 is based on Isis Pharmaceuticals' proprietary second-generation antisense chemistry called 2'-O-methoxyethyl, and is being developed as a cream for the topical treatment of mild to moderate cases of psoriasis.

Proof of Concept -- Microplaque Assay

In the "proof of concept" clinical trial (also referred to as Small Plaque Assay or Microplaque Assay), 100 micronL of ATL1101 cream will be applied to areas of patients' skin, once every two days, over a one-month period.

A comparison will be made against a placebo cream (cream without the active agent ATL1101), and also against some reference cream products that are currently marketed as prescription medications for the treatment of psoriasis.

The patients will be monitored over the duration of the trial and on completion of dosing for signs of response and improvement in their skin condition. The final evaluations will include clinical assessments, as well as assessments of laboratory indices of psoriasis from skin biopsies.

The primary end point will be a clinical assessment of the treated skin areas using a severity index score. The trial will be double-blinded, placebo-controlled, randomized, and two concentrations of ATL1101 cream will be evaluated in 14 psoriasis patients with mild to moderate severity of the disease.

Mark Diamond, CEO of Antisense commented: "Although a drug's efficacy is typically not established until completion of Phase II clinical trials, this "proof of concept" study serves as a relatively inexpensive and efficient method of indicating the activity of ATL1101, while providing valuable data. If early indications of the drug's effectiveness are demonstrated, we will have both increased confidence in the potential commercial prospects of the drug, as well as appropriate data to pursue early partnering opportunities."

Completion of the study is anticipated in the second quarter of 2005.

The Psoriasis project is supported by a Commonwealth Government R&D Start grant of $1.1 million.

Psoriasis is a chronic, non-contagious skin disorder, which affects 2% of the population. While the precise cause of psoriasis is unknown, it is thought to be triggered by an immune system defect leading to excessive skin cell division. Severity varies, with around 75% of psoriasis cases classified as "mild to moderate," and the remainder classified as "moderate to severe." Topical therapies are first-line treatments for mild to moderate cases of the disease. The worldwide market for psoriasis treatments was more than US$500 million in 2000 and there is an acknowledged unmet medical need for more effective and safer treatments. The market is forecast to grow to beyond US$2 billion with the emergence of new therapies.

About Antisense Therapeutics Limited

Antisense Therapeutics Limited is an Australian publicly listed biopharmaceutical drug discovery and development company. ANP's mission is to create, develop and commercialize novel antisense pharmaceuticals for large unmet markets. Its two most advanced projects target Multiple Sclerosis (ATL1102), and Psoriasis (ATL1101).

ANP plans to commercialize its pipeline via licensing/collaboration agreements with major biotechnology and pharmaceutical companies.

ANP's major shareholders include Circadian Technologies Limited , Isis Pharmaceuticals Inc (NASDAQ:ISIS) and Queensland Investment Corporation.

For more information, visit http://www.antisense.com.au or call 212/983-1702 ext. 207.