HIV/AIDS

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blocking entry of the virus at the mucosal level, the gateway of human infections 

 

With over 34 million victims, HIV/AIDS is the fourth cause of mortality worldwide, and the leading cause of death in sub-Saharan Africa. In 2014, the number of people living with HIV was estimated at 37 million. That same year 2.0 million new people were infected with the virus and 1.2 million deaths were caused by HIV (source: WHO).

Target population and market size

The target population for Mymetics prophylactic HIV vaccine candidate is the global population, which provides another major block-buster opportunity in developed countries.

Mymetics’ HIV/AIDS Preventive Vaccine Approach

Most HIV infections are sexually transmitted1 through direct contact of an infected mucosal membrane. Therefore, mucosal tissues represent the primary HIV entry door, as for many other pathogens.

Mymetics’ vaccine targets earlier transmission and infection events that take place at the mucosal level during the first minutes or hours following exposure to HIV.

Observations made on certain persons that are naturally resistant to HIV-12 infection revealed that despite their exposure to multiple HIV-1 positive individuals, they remain HIV-1 negative. This natural resistance is linked to the presence of mucosal antibodies against the HIV-1 present in their vaginal secretions. Similar resistance was also noted in males3.

By using an influenza virosome and specifically designed antigens Mymetics’ aim is to transpose the mucosal antibody response in the vaccine design, therefore reproducing Mother Nature. Our preventive HIV-1 vaccine formulation triggers not only blood antibodies but also mucosal antibodies, whereas all the other vaccine candidates are aimed only at the production of blood antibodies.

As a result, Mymetics' virosome based vaccine stimulates a defence mechanism effectively blocking entry of the virus at the mucosal level, the gateway of human infections.

100% protection in vaccinated primates

In 2008, Mymetics performed a 12 months pre-clinical trial at ILAS (Institute of Animal Laboratory Science) in Beijing, China.  The study involved several groups of female Chinese macaques, which received multiple challenges with the live virus. The results were overwhelmingly convincing: The group that was vaccinated with Mymetics’ preventive HIV vaccine candidate showed 100% protection, while the non-vaccinated control group was fully infected. These ground breaking scientific results have been presented at key world leading HIV congresses and have triggered strong attention from the HIV scientific community. See more

In 2011, Mymetics successfully completed a Phase I human clinical trial involving 24 healthy women in Belgium. The results showed a good safety and tolerance profile. All vaccinated women confirmed the high efficacy of the influenza virosomes as carriers/adjuvants for inducing a Th2 (T helper type 2) response. The functional antiviral activity of these mucosal antibodies was demonstrated by the inhibition of HIV-1 trancytosis, as reported by Dr. Morgane Bomsel (INSERM/Cochin Institute, France), a key academic partner. See more

Next Steps

In April 2016 Mymetics annouced a new blinded non human primate study led by Dr. Ruth Ruprecht, Scientist & Director of the Texas Biomed AIDS Research Program, which was funded by the Bill & Melinda Gates foundation, showed significant vaccine efficacy in a part of the study. During the first part of the study the Mymetics’ two-component virosome-based HIV vaccine was able to show significant efficacy of 87% in delaying the time to persistent infection versus the control group after 7 intravaginal virus challenges.  The study aimed to mimic the exposure of women to semen from HIV-infected men, although the viral dose of each of these 7 animal challenges represented about 70,000 times the average human HIV dose passed during sexual intercourse from an HIV-infected male to an uninfected female. During the second part of the study the animal viral challenge dose was increased by 50% starting from the 8th challenge onward, reaching more than 100,000 times the average amount of virus passed from an infected man to a female partner.  At this virus dose, the vaccine did not show significant protection in the animals as the immune system was overloaded.

Mymetics is currently evaluating the funding opportunities for further development of the vaccine.

References

1 Chin J. The AIDS Pandemic: the collision of epidemiology with political correctness. Oxford: Radcliffe Publishing (2007)

2 There are two species of HIV known to exist: HIV-1 and HIV-2. HIV-1 is the virus that was initially discovered and the cause of the majority of HIV infections globally. HIV-2 has a relatively poor transmission capability

3 Bomsel M. HIV-1 gp41-specific monoclonal mucosal IgAs derived from highly exposed but IgG-seronegative individuals block HIV-1 epithelial transcytosis and neutralize CD4 + cell infection: an IgA gene and functional analysis. Nature: Mucosal Immunology (2009).