CAMBRIDGE, Mass.—Genocea Biosciences Inc., a biopharmaceutical company developing T cell-directed vaccines and immunotherapies, announced recently positive 12-month efficacy data from its Phase 2 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 CEO of Genocea. “We anticipate reporting virologic efficacy data for GEN-003 from our recently initiated Phase 2b 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 2 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 Dr. Lori A. Panther, an 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.”
This Phase 2 study enrolled 310 subjects from 17 institutions in the United States. Subjects were randomized to one of six dosing groups of either 30 µg or 60 µg per protein paired with one of three adjuvant doses (25 µg, 50 µg or 75 µg). 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 12 months following dosing. No booster doses were given. After the 28-day observation period immediately following dosing, patients in the placebo arm were rolled over across the six active combinations of GEN-003 and Matrix-M2 under a separate protocol.
GEN-003 is a first-in-class T cell-directed immunotherapy designed to elicit both a T cell and B cell immune response. The immunotherapy was designed using Genocea's ATLAS platform, which profiles the comprehensive spectrum of actual T cell responses mounted by humans in response to disease, to identify antigen targets that drive T cell response. GEN-003 includes the antigens ICP4 and gD2 along with Matrix-M2TM adjuvant, which Genocea licenses from Novavax Inc.
Genital herpes affects more than 400 million people worldwide and causes recurrent, painful genital lesions. It can be transmitted to sexual partners, even when the disease is asymptomatic. Current genital herpes therapies only partially control clinical symptoms and viral shedding, a process which drives disease transmission. Incomplete control of genital lesions and transmission risk, expense and the perceived inconvenience of taking a daily medication are hurdles for long-term disease management. Immunity through T cells is believed to be particularly critical to the control and possible prevention of genital herpes infections.