A HAART salvage regimen with the fusion inhibitor T-20 added is significantly more effective at lowering viral load than a salvage regimen that doesn't include the drug.
Preliminary 24 week-study data from the ongoing open label 48 week phase III trial TORO 2, released by developers Roche and Trimeris, shows that the addition of T-20 to an individualised HAART regimen provided a significant additional decrease in the amount of plasma viral load compared to a standard individualised HAART regimen alone. The results come four weeks after a similar trial TORO 1, reported similar results (click here to see the report). Data from the planned preliminary analysis must be released by the companies as soon as it is completed in order to comply with US regulations designed to combat insider trading.
The TORO 2 safety and efficacy study has enrolled 504 people in Europe and Australia who had previously been treated with and, or, have documented resistance to each of the three classes of currently available anti-HIV drugs. Patients were randomised into two study arms to receive either T-20, plus a HAART regimen composed of drugs from the three existing classes, or just a standard HAART regimen from the existing classes of drugs. In each arm, the othe drugs were selected by resistance testing to give the best possible chance of viral load suppression. At the start of the trial all the participants had viral load above 5,000 copies/ml with an average viral load across the two groups of 100,000 copies/ml. After 24 weeks, people who received T-20 as part of their treatment had experienced an average fall of viral load of approximately 94%, whilst the average fall in viral load the treatment arm taking standard HAART was 65%.
Both groups had a similar side effect profile, although the T-20 treatment arm was more likely to report headache, fever and asthenia, a loss of muscle strength without muscular atrophy.
Moderately serious lab abnormalities were seen more frequently in the T-20 arm, but serious abnormalities occurred more frequently in the standard HAART group.
The T-20 arm saw higher rates of discontinuation, 17%, with 3% withdrawing because of problems with injecting T-20. Five percent of the other treatment arm withdrew. This difference was not seen in TORO-1.
It is expected that further data will be presented to the World AIDS Conference in Barcelona this July.
Trimeris and Roche have said that the TORO 1 and TORO 2 trial results will form the basis for a licensing application in the EU and USA.
Further information on T-20 is available in the A to Z of treatments on this site. Click here to read more about T-20.