French Biosantech Reports HIV Vaccine is Safe

Earlier this month, researchers from French-based Biosantech Company reported that the company's HIV vaccine candidate is not toxic to 48 HIV-positive patients enrolled in a double-blind study that is taking place in France. The data was presented at the International Conference on Retroviruses and Novel Drugs in suburban Chicago.

"There were no adverse side effects or drug interactions in the 48 patients who were randomized in the Phase 1 Trial," said Dr. Sonia Escaich, Executive Director at Biosantech.

Escaich reported there were no adverse side effects or drug interactions from the 48 patients who were separated into four groups, with one group of 12 receiving a placebo and the other three groups receiving different amounts of the HIV vaccine.

Data from this arm of the Phase II study that includes these 48 patients will be published later this summer, according to Corinne Treger, chief executive officer of Biosantech. She reported that a preliminary analysis of this data suggested the proof of concept of the vaccine candidate is obtained in HIV positive patients. This will allow further developments and in particular the study of combinations with booster of the immune system such as IMMUNOREX, a treatment developed by Dr. Donatien Mavoungou.

Biosantech's vaccine uses a mutant form of the transactivator of transcription (Tat) of HIV-1 because Tat is a good target for inhibition of the retrovirus's expression. Escaich explained that Tat protein expression is a first step of the virus life cycle to activate its own expression.

The company's focus on Tat dates to when the HIV-Oyi variant was isolated in 1989 in a group of pregnant Gabonese women. The Oyi strains contained a mutated Tat protein that was unable to activate HIV in these women, who remained asymptomatic.

Several studies have shown that the presence of the Anti-Tat immune response is correlated to long-term survival in humans. A later study with seven monkeys immunized with the Tat Oyi found that one resisted to infection after two challenges, six of the seven monkeys had lower viremia levels and the virus-infected cells disappeared over time.

Despite the success of antiretroviral tritherapy ART developed in the 1990s, there are still 35 million people living with HIV in the world and only 37 percent of those have access to current therapies. The development of an effective vaccine is hampered by the highly mutagenic nature of HIV. An effective therapeutic vaccine against several HIV subtypes such as Tat Oyi could represent a major advance for a cost effective treatment of the HIV infection.

"It is our hope we can develop a therapy that can make a difference to the people suffering from this disease," Treger said.

Biostantech is a private company founded by M. Roger Treger in 2011, and is based on the licensing of patients and technology from CNRS.