Profectus begins PhI HIV vax trial with 'prime-boost' delivery

Profectus BioSciences, a vaccine developer with a focus on DNA-based applications, began a Phase I clinical trial of its HIV vaccine, which makes use of the TriGrid electroporation delivery system the company licensed from Ichor Medical Systems.

Using a "prime-boost" vaccination regimen, Profectus hopes to spur a heightened immune response to fight the virus--the two-pronged approach can do this more fully than either of the vaccines alone, the company attests.

First, a priming vaccine is delivered using Ichor's TriGrid system. The TriGrid electrode array system uses electric pulses to distribute plasmid DNA via intramuscular or intradermal delivery. With this electroporation method, the delivery shows improved efficiency and minimized risk of focal tissue damage, according to Ichor. The DNA plasmid to be delivered is Profectus's multi-antigen DNA vaccine with its Genevax interleukin-12 pDNA adjuvant--these serve to induce an immune response against several of the proteins present on the virus, according to Profectus.

The second step delivers a booster immunization of Profectus's recombinant vesicular stomatitis virus (rVSV) via intramuscular injection. The company says the "gag vaccine" is designed to cause an immune response of the HIV-1 gag protein after the pDNA priming. The rVSV must be frozen, however, limiting its distribution to the developing world, but Profectus is looking to develop one that doesn't require refrigeration.

The clinical trial will enroll 30 HIV-infected adults, and Profectus is working in collaboration with the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH.

In preclinical trials, the prime-boost delivery of the vaccines resulted in "an HIV-specific cell-mediated immune (CMI) response of significantly increased magnitude and functionality as compared to delivery of the HIV pDNA or HIV rVSV vaccines alone," according to the Profectus release.

"While current antiretroviral therapy is wonderfully effective at controlling HIV, unfortunately, we know that stopping antiretroviral therapy results in a rapid return of high level HIV into the bloodstream," Profectus Chief Scientific Officer John Eldridge said in a statement. "As a first step toward 'the cure,' in this clinical trial we will investigate the effect of our prime-boost therapeutic vaccination strategy on the decay of the persistent HIV reservoir in infected individuals who initiated ART during the early/acute phase of HIV infection. This trial represents an early step towards the ultimate goal of eradication or drug-free control of HIV infection."

- here's the release