Australian firm Biota Holdings Ltd. partnered its discovery-stage antiviral nucleoside analogue program with Boehringer Ingelheim GmbH in a potential $102 million deal.

The firms will work together to develop and commercialize antiviral therapies against hepatitis C and other diseases, with Biota handling "the front end of the program," said Biota CEO Peter Cook, and Ingelheim, Germany-based Boehringer taking responsibility for clinical, regulatory and marketing activities.

In exchange, Biota will be eligible for payments of up to $102 million in access fees, research support and milestones, and would be entitled to royalties. Specific terms of the arrangement were not disclosed, but Cook told BioWorld Today the deal is "consistent with current industry practice."

It's also similar to a collaboration Biota signed a year ago with Gaithersburg, Md.-based MedImmune Inc., in which it licensed rights to its early stage respiratory syncytial virus program. In that deal, MedImmune gained exclusive marketing rights in the U.S., Europe, Japan and other countries for small-molecule compounds discovered by Biota against RSV, and agreed to pay Biota up to $112 million in up-front and milestone payments, plus royalties. (See BioWorld Today, Dec. 16, 2005.)

The collaboration with Boehringer will focus on a class of antiviral nucleoside analogues discovered by Biota. As nucleosides, their mechanism of action is well known and is found in marketed products for HIV and herpes virus, Cook said.

Biota's program joins an already crowded space. About 30 HCV drugs - ranging from polymerase and protease inhibitors to revamped formulations of interferon - are in development, including valopicitabine, a nucleoside inhibitor from Cambridge, Mass.-based Idenix Pharmaceuticals Inc. that is in Phase II, and Cambridge, Mass.-based Vertex Pharmaceuticals Inc.'s telaprevir, a protease inhibitor, which also is in Phase II.

Though still in the discovery stage, Biota's compounds have demonstrated an ability to inhibit the HCV polymerase to shut down viral replication, and might prove apt in discouraging resistance, which is one of the biggest problems in treating chronic HCV patients, Cook said.

In the U.S., an estimated 4.1 million people are infected with HCV, according to figures from the Centers for Disease Control and Prevention in Atlanta. Of those, about 3.2 million suffer chronic infections, with 70 percent of those ultimately progressing with chronic liver disease. Existing therapy involves a frequently dose-limiting combination of oral ribavirin and interferon, and sales of those products exceed $1 billion each year.

Beyond HCV, the compounds "appear to have some spectrum of activity in other areas," Cook said. "HCV is BI's principal area of interest, but there are opportunities with other indications."

Besides its ongoing programs with Boehringer and MedImmune, Biota, a 40-employee firm based in Melbourne, Australia, is developing long-acting neuraminidase inhibitors (LANI), second-generation antivirals for influenza. That program finished Phase I, and Tokyo-based Sankyo Co. Ltd., which co-owns the program, agreed to commit funding for Phase II testing in Japan.

The LANI program also has received two awards totaling $14 million from the National Institutes of Health.

Biota recently completed dosing in a Phase I trial of another product, a compound for human rhinovirus, and expects data from the study in the first quarter of 2007. A Phase IIa trial is expected "in the not-too-distant future," Cook said.

The compound is designed to treat rhinovirus complications stemming from underlying diseases such as chronic obstructive pulmonary disease and asthma, or in patients whose respiratory systems are compromised. Biota holds all rights to that program, though Cook said the company plans to seek a partner following completion of at least the Phase IIa trial.

Three of Biota's products have made it to the market. Two are influenza diagnostics - FLU OIA and FLU OIA A/B - marketed by Waltham, Mass.-based Inverness Medical Innovations Inc., and one is antiviral compound Relenza (zanamivir), which is sold by London-based GlaxoSmithKline plc.

Biota's shares are listed on the Australian Stock Exchange (ASX:BTA) and closed Thursday at A$1.50 (US$1.18).