For you who have been following for a while, this is the Antigenics AG-707 vaccine.
Agenus advances herpes vaccine in clinic
By Lori Valigra, Mass High Tech correspondent
Agenus Inc., a therapeutic vaccine maker based in Lexington, said it has positive results from a Phase 1 study of its HerpV vaccine for genital herpes, and plans to move it into a Phase 2 study in 2012.
The results were published in the scientific journal Vaccine. The herpes simplex virus type 2 (HSV-2) vaccine is based on Agenus’ heat shock protein platform technology and contains the company’s proprietary QS-21 Stimulon adjuvant, an agent that modifies the effect of other agents.
HSV-2 affects more than 60 million Americans, or 16 percent of people aged 14-49, and there are 1.5 million new cases each year, according to the Centers for Disease Control and Prevention.
“This is the first evidence that a therapeutic genital herpes vaccine has elicited both CD4+ and CD8+ T-cell responses in humans,” said Anna Wald, MD and professor of Medicine, Epidemiology and Laboratory Medicine at the University of Washington, who was lead author of the paper. “We are very encouraged by these clinical results as published literature suggest that cellular immunity needs to be stimulated for successful treatment of genital herpes – a physically painful and emotionally debilitating disease that affects one in six adults in the U.S.”
In the Phase 1 study, 35 HSV-2 seropositive patients received the vaccine plus QS-21 (HerpV), the vaccine without QS-21, QS-21 alone, or placebo. Patients received three treatments at two-week intervals.
All patients who could be evaluated for an immune response and who received HerpV showed a statistically significant CD4+ T cell response to HSV-2 antigens. The majority of those patients showed a CD8+ T cell response. The vaccine was well tolerated, with injection site pain as the most common adverse event.
Garo Armen, chairman and CEO of Agenus, said the planned Phase 2 study in 2012 will measure the effect of vaccination on viral shedding in individuals infected with HSV-2, and that a reduction in clinical shedding could be clinically beneficial. He expects the trial to run 18 months and involve 60-70 people.
“The technology platform based on heat shock proteins is at the core of what we do,” Armen said. “They activate the immune system in a very targeted fashion. They can direct the immune system. This is a timely development because this is a major disease target, and to the best of my knowledge there isn’t a vaccine candidate in active development that has reached where we are with getting both a CD4+ and CD8+ mediated immune response.”
Heat shock proteins, also called stress proteins, are found in all cells and are believed to play an essential role in proteins on the cell surface to help the immune system recognize diseased cells. Agenus’ initial focus of development is HSV-2, but the company said heat shock protein technology can potentially be used for off-the-shelf treatment of infectious diseases including HPV, HIV, hepatitis, malaria and tuberculosis.
The trial results were well received by George B. Zavoico, senior equity analyst at McNicoll, Lewis, Vlak, who wrote in a Sept. 27 update note: “We consider Agenus’ achievement of developing what we think is the first potential therapeutic vaccine for genital herpes capable of eliciting critical T cell responses to be a key milestone. In our view, demonstration of efficacy in the next Phase 2 trial could be a significant value driver for the company. We look forward to the initiation of the Phase 2 trial and are maintaining our BUY recommendation with a one year price target of $2.50.”
Zavoico also noted that if development of vaccine and adjuvant candidates in Agenus’ pipeline
proceeds without any significant delays, unfavorable trial results, or other negative surprises, Agenus could become profitable in 2015. That is based on regulatory approvals and the launch of QS-21 for use in therapeutic cancer and chronic disease vaccines in the United States and the successful development of at least one Prophage Series of vaccines in the United States and European Union. He added that after a several year delay, he also expects a distribution partner for Oncophage to soon be identified in Russia, which will allow Agenus to start collecting revenue in 2014.
Armen of Agenus added that over the next 18 months, the company expects pivotal data from other clinical programs that incorporate QS-21 and that are being developed by its corporate partners. The first will be a malaria vaccine for children on which GlaxoSmithKline plans to file for registration by the end of the year. Agenus will get royalties on sales once the vaccine is approved. GSK also has a non small cell lung cancer and melanoma vaccine that it has said it plans to file for registration on by the end of next year. In addition, plans call for Johnson & Johnson to advance an Alzheimer’s indication into Phase 3. All three use Agenus’s QS-21 technology.
In separate news, Armen said the company expects to resolve its issues with the Nasdaq exchange shortly. Agenus received a delisting notice in February from the Nasdaq Stock Market LLC because it has not met the minimum $1 per share price for 30 consecutive business days.