New gene therapy for HIV considered promising

The phase I trial evaluated the safety and tolerability of VRX496, enrolling five subjects with HIV infection who had failed to respond to the standard treatment for HIV, antiretroviral drug regimens. Each of the five patients who tolerated the gene therapy treatment experienced decreases in viral load.

VRX496 is also able to be administered once and will keep protecting against the virus, unlike antiretroviral drugs that have to be taken repeatedly. As a result this therapy may have the potential to be an alternative to antiretroviral drugs.

“Gene therapy has long been discussed as an alternative treatment to HIV,” said Carl June, from University of Pennsylvania School of Medicine.

Additionally, the research showed some patients that reached the three year post-infusion safety visit continued to exhibit a decreased viral load.

VRX496 is an HIV-based lentiviral vector from which the disease-causing aspects of the virus have been removed, leaving behind an efficient gene-delivery vehicle. In the trial patients were given an infusion of their own immune cells (CD4 T cells) which were genetically modified with VRX496. This is in order to block HIV replication.

“VRX496 is engineered in a way that debilitates HIV’s ability to replicate and mutate around the therapy, overcoming a common problem with current drug treatments,” said Riku Rautsola, CEO of VIRxSYS. “The results of this trial also contribute to the growing opinion that lentiviral vectors are the most promising viral vectors for clinical applications.”

Although the results are encouraging the trial was on a small scale and patients will continue to have follow-up safety visits every year for 15 years. Two phase II trials testing the safety and tolerability of single and repeated doses of VRX496 are underway.