Myriad halts HIV maturation inhibitor drug programme

Keith Alcorn
Published: 08 June 2010

Myriad Pharmaceuticals is to halt its research programme designed to develop an HIV maturation inhibitor, the company announced on June 7th.

Maturation is the last stage in the production of HIV before it buds from a human cell, and an effective and safe maturation inhibitor would offer another new class of drug for patients with extensive drug resistance.

Myriad had the only remaining research programme in this area, having bought bevirimat, the maturation inhibitor developed by struggling biotechnology pioneer Panacos. Myriad was engaged in pre-clinical research into another promising maturation inhibitor, MPI-461359.

Bevirimat was being tested in a phase IIb study which began in December 2009. The drug was being tested in patients resistant to three antiretroviral drug classes, and compared to a two- or three-drug regimen optimised by resistance testing.

The company did not reveal whether adverse results from that study had been the cause of its decision to halt the maturation inhibitor programme, but said in a press statement that it will now seek to partner with another company to develop its maturation inhibitors further.

This week’s decision indicates the difficulties now faced by small drug companies as they attempt to develop new agents at a time of venture capital famine. The development of bevirimat had been dogged with formulation difficulties, and and an analysis of an earlier study indicated that the drug would be ineffective for a significant minority of patients due to naturally occurring resistance present before the drug was taken.