Trimeris, Roche to begin phase III pivotal trials of T-20 HIV fusion inhibitor

Durham, North Carolina-based Trimeris and development partner Hoffman-La Roche plan to begin two phase III pivotal trials of the investigational HIV fusion inhibitor T-20 within the next few weeks, the companies said on Tuesday.

The firms call T-20 “the first member” of the fusion inhibitor class of drugs, which are designed to prevent fusion of HIV with host cells so that the virus does not have a chance to enter the cell and begin replication. Current HIV drugs work inside the cell to fight replication once the virus has already fused with the host cell.

Primary endpoint data from the two new studies “will form the bulk of the application package” that the companies plan to submit to US and European regulatory agencies to secure marketing approval for the drug, a Trimeris spokesperson told Reuters Health. Data on use of the drug in children also will be included in the applications. Together, the two new studies are expected to enrol 700 advanced antiretroviral-experienced adults with HIV/AIDS at over 100 sites.

The first study will be conducted in North, South and Central America with a focus on the US and Canada, the spokesperson noted, while the second will be conducted at sites in Europe and Australia. The primary efficacy endpoint for the trials is a change in the amount of virus in the blood after 24 weeks in patients who have received twice-daily subcutaneous injections of T-20 compared with patients who have not received the drug. The study will continue through 48 weeks for secondary-endpoint evaluation, the spokesperson noted.

T-20 is being studied for use in combination with other HIV/AIDS drugs, including protease inhibitors, non-nucleoside reverse transcriptase inhibitors and nucleoside reverse transcriptase inhibitors, he said. Patients enrolled in the trials’ treatment groups will simply add T-20 to their current drug regimens, whatever those regimens may be, he explained.

“The way that we’re designing the trials, and the way the drug will probably be used once it is approved is in combination with any [drug regimen] that makes sense, because each patient is different and comes from a different treatment history,” the spokesperson said. “The trials are set up so that it will be their choice of drugs and then, on top of that, there’ll be a randomisation to either T-20 or no T-20 so that we can discern the contribution of T-20 within the combination regimen.”

Although Trimeris and Roche expect that T-20’s initial commercial use will be as a supplement to current regimens, the firms also plan to explore use of the drug in place of one or more components of the existing combinations, he said. “We have an active phase IIIb/IV program where we’ll be looking at swapping out some of the current drugs and inserting T-20 in their place to see if there’s an advantage,” he noted.