PENNVAX-B

Vaccine: PENNVAX-B
Company: Inovio Pharmaceuticals
Target: HIV infection

In another entry for Inovio Pharmaceuticals ($INO), but in a break away cancer, PENNVAX-B is a SynCon synthetic DNA vaccine that has potential to both treat and prevent infection with HIV from clade B, the subtype of virus mostly seen in North America and Western Europe. The vaccine, which includes DNA fragments coding for the gag, pol, and env proteins from HIV, is helped into the cell with the company's CELLECTRA electroporation device, which uses a small electric pulse to disrupt the cell membrane.

Targeting HIV infection is a huge market--according to UNAIDS, nearly 30 million people have died from HIV-related causes and roughly 34 million are living with HIV. While antiretroviral therapy has made a massive difference in the developed world, and the cost of the drugs has dropped, there is still a cost implication for the developing world, and market and patient access can be difficult. Therapeutic vaccines could be a more patient-friendly approach, with improved convenience and potentially fewer side effects.

In a Phase I trial of PENNVAX-B, 12 people who were chronically infected with HIV and maintained at undetectable levels of viral load on a highly active antiretroviral therapy (HAART) regimen were given four doses of the vaccine over 16 weeks. In an interim evaluation of the results, the vaccine triggered a robust T-cell immune response to at least one antigen in three-quarters of the people in the study, and to two antigens in at least half of the group. The vaccine was also generally well-tolerated.

According to the company, this is a first for a DNA vaccine in this patient group, who have immune systems that can be described as "not normal" and who typically do not generate strong T-cell responses to any immune-stimulating approach. The final results from this trial are expected in the fourth quarter. While this was a small trial, designed to evaluate the safety and levels of immune response, it suggests potential worth further investigation, and Inovio is making plans for the next step.

In HIV-negative people, in an assessment as a preventive vaccine, PENNVAX-B also triggered a T-cell response, with immune responses reported to be better than those seen in other recombinant HIV vaccine trials conducted by the HIV Vaccine Trials Network (HVTN). The company is also developing therapeutic and prophylactic vaccines against clades A, C, and D for Africa and Asia.

In 2008, the PENNVAX vaccine technology got a major vote of confidence when the originator, VGX Pharmaceuticals, got a $23 million award from the National Institutes of Health to complete the development and manufacturing of its preventive HIV vaccine, PENNVAX-G. This targets clades A, C, and D, which are found in developing regions of Africa and Asia. VGX Pharmaceuticals merged with Inovio later in 2008.