Avexa Data's Ripple Effect

An exciting new HIV drug from Down Under may reverberate here in the U.S.

On Monday, Australian biotech firm Avexa reported positive data from a phase IIb study of its drug apricitabine in patients with drug-resistant HIV.

Avexa's stock is listed only on the Australian stock exchange, so it's not the most convenient or accessible investment for the average U.S. investor. But that won't stop Avexa from affecting the fortunes (and not necessarily in a good way) of smaller HIV drug companies, including Achillion Pharmaceuticals(ACHN), Panacos Pharamceuticals (PANC)and Trimeris(TRMS).

This latest clinical data appears to make apricitabine one of the most exciting unpartnered HIV drugs in development. That puts Avexa in the driver's seat when it comes to negotiating a potential partnership or acquisition, while simultaneously pushing companies such as Achillion, Trimeris and Panacos further back in the deal-making line.

Avexa owns worldwide rights to apricitabine, having acquired North American rights from Shire in January.

Apricitabine belongs to the current class of HIV drugs known as nucleoside reverse transcriptase inhibitors, or NRTIs, which are a key component of today's triple-combination HIV therapies. Avexa is developing apricitabine as the NRTI of choice for patients who have developed resistance to other drugs, including other NRTIs.

In the phase IIb data released Monday, patients taking aprictabine achieved a greater and statistically significant reduction in viral load compared with patients taking 3TC, a commonly prescribed NRTI owned by GlaxoSmithKline(GSK). Patients enrolled in this 21-day study had drug-resistant virus, including a strain of the virus known to reduce the efficacy of certain NRTIs, including 3TC (also known as lamivudine).