Biota boosted by antiviral find

Biota Holdings (ASX:BTA) has developed a new class of orally-effective antivirals against respiratory syncytial virus (RSV) infection that the company hopes will go to Phase I trials by 2006.

The drugs arose from discovery research conducted completely in-house, and have proven effective in animal models, Biota claimed. The company has filed worldwide patents for the drugs. RSV infects people of all ages, causes similar symptoms to influenza and occurs at about the same frequency. It can have serious consequences in children and the elderly.

The small molecule, low molecular weight synthetic drugs that Biota has developed act by targeting and inhibiting a protein on the surface of the virus -- the fusion glycoprotein.

RSV is an envelope virus that attaches or fuses with the host cell, in this case cells in the lung, via its outer envelope. The fusion glycoprotein is integral to this fusion process and the drugs bind to this fusion glycoprotein, preventing it from functioning.

"A key advantage of this traditional type of drug is that you can put it into a tablet," said Dr Simon Tucker, Biota's vice-president of research. "Unlike antibodies, which are digested in the gut and therefore need to be injected, these drugs go through the system into the blood."

US-based company MedImmune sells a monoclonal antibody drug to prevent RSV, but it is delivered by injection. Other advantages of Biota's candidate drugs are that they address both prevention and treatment of the disease.

Biota said it had selected a lead candidate with a series of back-ups for further preclinical development prior to moving into human clinical trials. "The lead candidate will go into preclinical studies to prove safety this year," said Tucker. "We anticipate Phase I trials will begin in 2006."

The current compounds are the result of research conducted by the Biota team over several years. Since 2003, the research has been supported by a AUD$2.7 million R&D Start grant from the Australian government.

Biota shares soared up to 8 per cent on the news, and at press time had steadied, trading at AUD$0.48.

-- Additional reporting by Reuters