Agenus Inc said a trial of its experimental genital herpes vaccine has succeded in reducing the rate at which patients released the virus, reducing the probability of infecting others, sending its shares up 32 percent in premarket trading. Companys two core technology platforms are: (1) the heat shock protein technology that is the basis of therapeutic and preventive vaccines for cancer and infectious disease, and (2) the QS-21 Stimulon adjuvant that is being used by Agenus and other vaccine developers to enhance the effectiveness of their vaccines.
Vaccines generally work by boosting the bodies own inherent immune responses to certain pathogens, but for certain kinds of infections this kind of vaccination has proven difficult. The vaccine, HerpV, also reduced the severity of the infection by 34 percent.
This was preoved in a mid trial. The trial included 80 patients with a history of 1-9 herpes recurrences within the prior 12 months. Among them 70 got vaccine and 10 placebo. The trial tested the efficacy of the vaccine by measuring the release of the virus by patients 45 days before and after three injections of HerpV.
Genital herpes is a sexually transmitted disease caused by herpes simplex virus type 2. The infection can provoke repeated painful genital sores. At unpredictable times in those carrying the infection, the herpes virus will come out of hiding and surface on the genitals, sometimes producing blisters and discomfort, and sometimes arising without any noticeable symptoms. An estimated 50 million to 60 million Americans are affected. One out of six people aged 14 to 49 years suffers from genital HSV-2 infection.
Most individuals infected with HSV-2 experience either no symptoms or have very mild symptoms that go unnoticed or are mistaken for another skin condition and as a result are often unaware of their infection until an outbreak occurs.
The high infection rates make for a large market, which is estimated to be worth up to $6 billion.
The associates are also testing the QS-21 Stimulon adjuvant in combination with other vaccines.