Genocea Biosciences, a biopharmaceutical company developing T cell-directed vaccines and immunotherapies, has announced positive 12 month efficacy data from its phase II dose optimization trial evaluating GEN-003 for the treatment of genital herpes. GEN-003 demonstrated sustained and statistically significant reductions compared to baseline in the rate of viral shedding 12 months after dosing across multiple dose groups as well as sustained efficacy at multiple dose levels across secondary endpoints measuring the impact on clinical disease. GEN-003 was safe and well-tolerated by patients, with no serious adverse events related to the vaccine in the trial.

"We are very pleased with these data, which show that GEN-003 has strong and durable effects on both HSV-2 viral activity and genital herpes clinical disease, supporting our belief that GEN-003 could become a cornerstone treatment for patients affected by this serious disease. Specifically, a single course of treatment of GEN-003 may offer benefits similar to a full year of daily administration of oral antivirals—but with greatly improved convenience,” said Chip Clark, president and chief executive officer of Genocea. "We anticipate reporting virologic efficacy data for GEN-003 from our recently-initiated phase IIb study in the third quarter of 2016, clinical efficacy data at six months post dosing around the end of 2016 and conducting our end of phase II meeting with the FDA in the first quarter of 2017."

”These 12 month data highlight the potential of GEN-003 to significantly enhance the genital herpes treatment landscape,”  said Lori A. Panther, M.D., MPH, infectious diseases specialist at Beth Israel Deaconess Medical Center and assistant professor of Medicine at Harvard Medical School. “Because of the physical and psychological impact of this disease, both patients and treating physicians would be eager to use an effective treatment that more conveniently improves control of outbreaks. The reduction in viral shedding, which is thought to cause the epidemic spread of genital herpes, is also encouraging.”

Genocea has already advanced the two most promising doses, 60µg per protein combined with either 50 or 75µg of Matrix-M2TM adjuvant, from this phase II dose optimization study into an ongoing phase IIb efficacy trial. The efficacy of GEN-003 at these two dose levels over the course of the phase II dose optimization trial is as follows:

Genocea plans to present the full data from the Phase 2 dose optimization trial at an upcoming scientific meeting.

This phase II study enrolled 310 subjects from 17 institutions in the U.S. Subjects were randomized to one of six dosing groups of either 30µg or 60µg per protein paired with one of three adjuvant doses (25µg, 50µg or 75µg). A seventh group received placebo. Subjects received three doses of GEN-003 or placebo at 21-day intervals. Baseline viral shedding and genital lesion rates were established for each subject in a 28-day observation period prior to the commencement of dosing by collecting 56 genital swab samples (two per day), which were analyzed for the presence of HSV-2 DNA, and by recording the days on which genital lesions were present.

This 28-day observation period was repeated immediately after the completion of dosing and at six and, twelve months following dosing. No booster doses were given. After the 28-day observation period immediately after dosing, patients in the placebo arm were rolled over across the six active combinations of GEN-003 and Matrix-M2 under a separate protocol.