Pecan Biotherapeutics, Inc.
Using more advanced laboratory assays, the HIV incidence in the US was recently updated to 56,300 new cases annually. Worldwide, HIV / AIDS is a larger epidemic. The World Health Organization (WHO) for 2007 states that 33.2 million [30.6 – 36.1 million] people were estimated to be living with HIV, 2.5 million [1.8 – 4.1 million] people became newly infected and 2.1 million [1.9 – 2.4 million] people died of AIDS.
The natural history of HIV infection has rapidly improved, largely due to the development of highly active antiretroviral therapy (HAART). Essentially, infection with HIV has changed from a rapidly fatal process to a chronic disease. Unfortunately, HAART does not cure HIV, requires life-long therapy, and has significant side effects. For several reasons, many have concluded that “it is unlikely…that the development…of additional antiviral medications for the treatment of HIV infection will change [the epidemic] substantially.” Clearly, new therapeutic approaches to HIV must be developed.
Pecan Biotherapeutic's vaccine is directed at a component of the HIV virus referred to as Tat. Pecan Biotherapeutic's Tat vaccine is not based on the usual Tat found in HIV, but an interesting variant called Tat Oyi. Tat Oyi is provocative for three reasons. First, Gabonese infected with Tat Oyi mutant do not develop AIDS, which suggests that a Tat Oyi vaccine may prevent HIV from progressing to AIDS. Second, Tat is secreted outside of cells, which makes it susceptible to elimination by immunization. Third, antibodies to Tat Oyi cross-react with the Tat of all tested HIV strains. This implies that a single Tat vaccine could be used for everyone.
The full length (101 amino acids) Tat Oyi protein (a protein is usually defined as a sequence of more than 100 amino acids) was successfully produced by synthetic technology. Usually, proteins are produced by recombinant technology (inserting DNA into cells in a laboratory). Protein expression by recombinant technology is expensive, time consuming, provokes intense FDA scrutiny, and can contaminate the protein with foreign substances. The ability to synthesize Tat Oyi is not only a scientific breakthrough, but also can accelerate vaccine development and reduce manufacturing costs.
Animal studies with the second generation Tat Oyi vaccine were published in 2006. Macaques immunized with Tat Oyi were challenged with SHIV (a non-human HIV virus). All macaques developed anti-Tat antibodies and demonstrated enhanced immunity (CD8 cells). This is consistent with the clinical observation from Gabon and serves as a proof of principal.
To further enhance the potential of a Tat Oyi vaccine, the vaccine was modified (Tat Oyi-Cys22) to enhance immunogenicity (potency). Recent results in mice indicate that Pecan’s goal has been met; the third generation vaccine is more immunogenic than the second generation vaccine. In addition, mice vaccinated with Tat Oyi-Cys22 developed antibodies to all clades (types) of HIV. This suggests that a single vaccine could be effective for all subjects. With these two milestones met, Pecan Biotherapeutics is proceeding to a formal dose response experiment. Pecan Biotherapeutics plans to advance the third generation vaccine to clinical trials.
Therapeutic HIV Vaccine:
Pecan Biotherapeutic's HIV vaccine was developed by Dr. Erwann Loret.Previous HIV vaccines have failed clinical testing. There are no approved or marketed HIV vaccines. Pecan Biotherapeutic's goal is to develop the first successful HIV vaccine. “Successful” can be defined as a vaccine which: