Novavax, Inc. today announced that positive clinical data for the company's virus-like particle (VLP) vaccine candidate against A(H7N9) influenza were published online in the Correspondence section of The New England Journal of Medicine.
The correspondence can be found at: http://www.nejm.org/doi/full/10.1056/NEJMc1313186 and will appear in the December 26, 2013 print edition.
The study, conducted in 284 adult male and female subjects, examined the safety and immunogenicity of two administrations of Novavax' A(H7N9) VLP vaccine candidate on day 0 and day 21. Subjects were administered either placebo, 15 or 45 µg of vaccine alone, or 5 or 15µg of vaccine with either 30 or 60 ISCO® units of the saponin-based ISCOMATRIX® adjuvant, developed by CSL Limited in Australia. Serology was assessed at Days 0, 21 and 35 post-first immunization.
The Novavax A(H7N9) VLP vaccine candidate was generally well tolerated, and the safety was in line with the company's previous findings with its influenza VLP antigens using ISCOMATRIX® adjuvant. Overall, as with other adjuvanted influenza vaccines, there was an increase in transient local and systemic reactions in the adjuvanted in contrast to the non-adjuvanted formulations, but there were no treatment-related SAEs in the active groups. The A(H7N9) VLP vaccine candidate induced hemagglutination-inhibition (HAI) antibody titers of ≥1:40 (seroprotection) and a four-fold HAI antibody rise (serconversion) against H7N9 in 81% of subjects at the 5mg dose of A(H7N9) antigen with 60 ISCO® units of adjuvant, and 73% of subjects receiving 5mg dose of A(H7N9) antigen with either adjuvant dose level. The vaccine also elicited anti-neuraminidase (NA) antibodies against N9 in 92 to 97% of subjects receiving 5mg with either adjuvant dose level.
The A(H7N9) influenza strain has emerged recently as a potential pandemic concern. Less than ten (10) days after the Chinese Health authorities announced an outbreak of this novel avian influenza in humans (137 total confirmed cases, including 45 deaths, to date), Novavax obtained the genetic sequence of the strain and commenced production of a recombinant vaccine. Clinical trial material was manufactured and released in late June 2013 with the first doses injected in humans in early July 2013. Less than four months after the novel A(H7N9) virus had been identified and sequenced, Novavax' H7N9 VLP vaccine, with the higher-dose of ISCOMATRIX® adjuvant, has achieved immune responses likely to be protective in 81% of recipient subjects with as little as 5µg of antigen.
"The production and testing of a vaccine for a novel, lethal influenza virus in such a short time period validates the agility of Novavax' technology in addressing pandemic threats," said Dr. Lou Fries, the company's Vice President of Clinical and Medical Affairs. "The performance of our vaccine candidate is particularly important in light of the speed with which pandemic outbreaks can unfold. Often, an initial outbreak of a novel influenza virus is followed by a more severe and widespread outbreak at the onset of the next fall and winter respiratory virus season, as seen in 2009 with H1N1. Unfortunately, vaccine makers in 2009 were unable to produce vaccine in advance of the second wave and there was little impact of vaccine upon H1N1 disease in the first year. Past H7-based vaccine candidates have been poorly immunogenic and thus could not be advanced as viable vaccine candidates. This risk appears to have been overcome by our H7N9 adjuvanted VLP vaccine."
Stanley C. Erck, President and Chief Executive Officer of Novavax, added, "As evidenced by our correspondence in The New England Journal of Medicine, this is a critical accomplishment for pandemic preparedness. Building on the positive clinical results with our H5N1 VLP vaccine candidate from last October, these recently gathered data from our A(H7N9) influenza vaccine give further confirmation that the Novavax vaccine platform deserves to play a key role in addressing evolving pandemic threats. We have used recombinant VLP technology to demonstrate that timely responses are possible, and we are proud to be the first company to produce a viable H7N9 vaccine. Furthermore, we are pleased that HHS-BARDA has recognized this achievement and asked us to focus our pandemic vaccine development under our HHS-BARDA contract on our H7N9 vaccine candidate."
About H7N9 Avian Flu
Following recognition of the first human infections with avian-origin influenza A(H7N9) and their attendant severity in March 2013, public health officials from around the world called for immediate and preemptive development of surveillance, diagnostic and clinical intervention tools in the event that the A(H7N9) virus becomes transmissible among humans. According to Keiji Fukuda of the WHO, there is high concern over potential for A(H7N9) to gain sustainable person-to-person transmissibility. He noted that over a two-month period in China, as many H7N9 cases occurred as caused by H5N1 cases over 10 years. Additionally, molecular genetic changes occurred, suggesting adaptation of the virus to humans. After a quiescent period during the summer months, four new cases of human A(H7N9) disease have been reported since October 7, prompting concerns and expectations over the virus reemerging in human populations in the coming winter season.
Press release avilable from http://www.globenewswire.com/