Herpes simplex virus (HSV-2) infections cause recurring and painful genital sores, with the disease being most severe in people with suppressed immune systems. There is no preventive vaccine or cure, but Genocea Biosciences has a prophylactic HSV-2 vaccine moving into a first in-human clinical trial in third quarter 2012, Chip Clark, president and CEO told FierceVaccines at BIO2012. Seth Hetherington, CMO, was also at the meeting, presenting in the session "Therapeutic Vaccines Against Chronic Infectious Diseases: Vaccines versus Microbes Part 2."
The planned trial is a Phase I/IIa study, which will involve 150 otherwise healthy people with HSV-2 infection, explained Hetherington in the presentation. The trial will measure safety and immune response, and will also look at viral shedding and the frequency of and severity of recurrent genital sores. Data should be available in the third quarter of 2013, according to Hetherington.
Five years ago, Genocea Biosciences set out to create a new class of vaccines, Clark explained, which were designed to trigger a T cell response, in contrast with the traditional focus on the B cell (antibody) response. To create the HSV-2 vaccine, Genocea Biosciences screened the blood from hundreds of people who had been exposed to the virus, including people with frequent disease, infrequent disease or asymptomatic disease, using the company's high-throughput T cell antigen discovery technology: AnTigen Lead Acquisition System (ATLAS). This technology was created at The University of California at Berkeley and Harvard Medical School.
For the HSV-2 project, the ATLAS technology identified a number of proteins that are associated with protection against HSV-2 infection. The vaccine includes two of these, a T cell antigen and a B cell antigen, as well as a T cell adjuvant to increase the immune response.
The company now has five T cell-based vaccines in preclinical development, with one poised to enter the clinic, and is interested in speaking with potential collaborators.
"There is no other discovery platform for T cell vaccines," said Clark. "We are interested in speaking with potential collaborators, as we now have five vaccines in the pipeline, and that is a lot for a small company. We created these to show the versatility of the platform, and we have two vaccines against HSV-2, and vaccines against bacteria (Chlamydia trachomatis and Streptococcus pneumoniae) and protozoa (Plasmodium falciparum; malaria). These are all large targets, with lots of proteins, and we feel that ATLAS gives us a comparative advantage."
The next step will be to move the company's pneumococcal vaccine into the clinic, likely to be around the end of 2013. Because Genocea's vaccines target T cells rather than B cells, this could be used in combination with existing vaccines.
- check out the session abstract
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