Elicitation of a Key Precursor for Broadly Neutralizing Antibody for the HIV CD4 Binding Site
GeoVax Labs, Inc. (OTCQB: GOVX), a biotechnology company developing human vaccines, today announced results of a study demonstrating successful elicitation of a key precursor to broadly neutralizing antibody for the HIV CD4 binding site, an important step forward in HIV vaccine development. The study, conducted in non-human primates, used GeoVax’s vaccine technology to express the natural form of an HIV envelope gene from an infection that developed broadly neutralizing antibody to the CD4 binding site. This envelope gene (CH0505) was identified by researchers at Duke University, the US National Institutes of Health, the Los Alamos National Laboratory and the University of Pennsylvania. The National Institute of Allergy and Infectious Diseases funded the vaccine study. The findings, published today in the peer-reviewed open access journal PLOS ONE, can be viewed at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0177863.
A central and ongoing challenge for HIV vaccine development is the generation of broadly neutralizing antibody against the diverse and difficult to neutralize “tier 2” virus variants undergoing transmission in the AIDS epidemic. A preferred target for such neutralizing antibody is the relatively conserved CD4 binding site on the HIV envelope protein. The ability to elicit even precursors to broadly neutralizing antibody to the CD4 binding site is a goal that has largely eluded HIV vaccine development efforts to date.
The paper published today reports the successful elicitation of a key precursor to broadly neutralizing Ab to the CD4 binding site – the induction of autologous tier 2 neutralizing antibody. This step was accomplished by expressing the natural form of the CH0505 envelope protein on virus-like particles (VLPs) delivered by GeoVax’s DNA prime, Modified Vaccinia Ankara (MVA) boost vaccine. A Duke gp120 subunit of the CH0505 envelope protein was co-delivered with the final MVA boost.
Harriet L. Robinson, PhD, Director of HIV Vaccines at GeoVax, commented, “In this first attempt to elicit broadly neutralizing antibody to the CD4 binding site, our VLP vaccine expressing the natural CH0505 envelope protein achieved a key precursor, autologous tier 2 neutralizing antibody, in 2 out of 4 non-human primates. Now that the GeoVax-Duke vaccine has achieved this critical step, we can test the ability of additional immunizations to broaden the neutralizing activity.”
“This is an important advance in the development of a vaccine with the potential to elicit broadly neutralizing antibody to the CD4 binding site,” Dr. Robinson continued. “We intend to push this technology forward for the development of a vaccine for the clade C subtype of HIV that is devastating populations in Africa.”
GeoVax Labs, Inc., is a clinical-stage biotechnology company developing human vaccines against infectious diseases using its MVA-VLP vaccine platforms. The Company’s HIV vaccine for the clade B epidemic in the Americas and Europe is advancing in human trials conducted by the HIV Vaccine Trials Network. Preclinical programs are focused on preventive vaccines for Zika Virus, hemorrhagic fever viruses (Ebola, Sudan, Marburg, and Lassa), and malaria, as well as therapeutic vaccines for HIV, chronic Hepatitis B infections and cancers. GeoVax’s vaccine platform supports in vivo production of non-infectious VLPs from the cells of the very person receiving the vaccine, mimicking a natural infection and stimulating both the humoral and cellular arms of the immune system to recognize, prevent, and control the target infection. For more information, visit www.geovax.com.
Certain statements in this document are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act. These statements are based on management’s current expectations and are subject to uncertainty and changes in circumstances. Actual results may differ materially from those included in these statements due to a variety of factors, including whether: GeoVax can develop and manufacture its vaccines with the desired characteristics in a timely manner, GeoVax’s vaccines will be safe for human use, GeoVax’s vaccines will effectively prevent targeted infections in humans, GeoVax’s vaccines will receive regulatory approvals necessary to be licensed and marketed, GeoVax raises required capital to complete vaccine development, there is development of competitive products that may be more effective or easier to use than GeoVax’s products, GeoVax will be able to enter into favorable manufacturing and distribution agreements, and other factors, over which GeoVax has no control. GeoVax assumes no obligation to update these forward-looking statements, and does not intend to do so. More information about these factors is contained in GeoVax’s filings with the Securities and Exchange Commission including those set forth at “Risk Factors” in GeoVax’s Form 10-K.