New Genital Herpes vaccine entrants require improved efficacy to compete, says GlobalData analyst

While the collaboration between Sanofi Pasteur (Sanofi) and Immune Design to develop a genital herpes vaccine presents a strong scientific foundation and difficult-to-match financial clout, the partnership needs to create a product with better clinical performance to compete with more advanced pipeline vaccine candidates, says an analyst with research and consulting firm GlobalData.

According to a recent announcement, Sanofi’s HSV-529, currently in Phase I of clinical trials, and Immune Design’s G103, a preclinical vaccine candidate, will be tested together in various formulations. Sanofi will cover all development costs, with Immune Design receiving milestone and royalty payments from any resulting commercialised product.

Daian Cheng, Ph.D., GlobalData’s Analyst covering Infectious Diseases, states that the combination of these two agents could bring improved host immune response, which is a major challenge to genital herpes vaccine development and therefore a vital attribute of a successful product.

Cheng comments: “As with previous and current genital herpes vaccine candidates, Sanofi’s HSV-529 mainly focuses on inducing B and T cell immune responses. While this vaccine demonstrated solid immunogenicity and protection against genital herpes in guinea pigs, there is no guarantee that these results can be replicated in humans.

“The addition of Immune Design’s dendritic cell-targeting G103, with a new mechanism of action affecting a different part of host immune response, is certainly an indication that Sanofi believes an alternative approach is needed.”

The analyst adds that while Sanofi and Immune Design may benefit from increased research and development expertise and financial backing, they face competition from several firms possessing more advanced pipeline candidates.

Cheng explains: “Genocea recently presented positive Phase I/IIa trial data on its investigational vaccine, GEN-003, highlighting substantial reductions in viral shedding and lesion rate. Meanwhile, Agenus announced in June that its vaccine candidate, HerpV, produced significant reduction in viral load in a Phase II clinical trial, which is near completion.

“Furthermore, given the difficulties in developing an effective therapy for genital herpes, exemplified by GlaxoSmithKline’s Herpevac and AuRx’s ICP-10-deltaPK, the collaboration between Sanofi and Immune Design must result in a product that exhibits excellent clinical efficacy to successfully compete in the genital herpes vaccine race.”