Novavax, Inc. today announced that the journal Vaccine has published the company's data from its 2011 Phase I clinical trial of its respiratory syncytial virus (RSV) fusion (F) recombinant nanoparticle vaccine candidate. The paper was authored by a team of researchers and clinicians at Novavax and Dr. Pedro Piedra of Baylor College of Medicine.
Findings from the trial were announced in October 2011 and presented in September 2012 by Novavax at the Respiratory Virus Symposium (RSV 2012) meeting in Santa Fe, New Mexico. The paper is currently available at www.novavax.com under Publications & Presentations/Publications and is expected to be published in the print edition shortly.
Novavax had conducted the blinded, placebo-controlled, dose-escalating Phase I trial to assess the safety and tolerability of aluminum phosphate-adjuvanted and unadjuvanted formulations of its RSV vaccine candidate. A secondary objective of the study was to evaluate total and neutralizing anti-RSV antibody responses and assess the impact of the adjuvant. The authors reported that Novavax' vaccine was well-tolerated, with no evident dose-related toxicity or attributable severe adverse events. At day 60, both RSV A and B microneutralization titers were significantly increased in subjects treated with the Novavax vaccine versus placebo. The authors also reported a 7- to 19-fold increase in the anti-F IgG and a 7- to 24-fold increase in the levels of antigenic site II binding antibodies in vaccine recipients, as well as the induction of serum antibodies capable of competing with palivizumab, a humanized monoclonal antibody (mAb) with known protective efficacy against RSV disease in animals and humans.
"We are encouraged with the tolerability profile demonstrated in this trial as no attributable SAEs or significant dose-related toxicities were observed," said Dr. Gregory Glenn, Novavax' Chief Medical Officer. "In addition, the data suggest that neutralizing responses induced by our RSV F nanoparticle vaccine attain levels previously reported to be associated with a decrease in the risk of RSV hospitalization in selected populations. The presence of high-titered antibodies capable of competitively inhibiting palivizumab binding to the RSV F protein in sera of vaccine recipients but not the majority of sera of unimmunized adults or placebo recipients is novel and should be studied further. This observation suggests that the vaccine induces antibodies with specificities closely similar to palivizumab (Synagis®) that has been shown to have prophylactic efficacy in large clinical trials. Such an observation supports the likely clinical impact of the vaccine-induced antibodies and will assist the planning of future clinical efficacy evaluation of the vaccine."
Novavax is currently conducting a Phase II clinical trial in women of childbearing age to further evaluate the immunogenicity and safety of the RSV F vaccine candidate. This data will inform the future development of the RSV F vaccine to address infant RSV-related lower respiratory tract disease via maternal immunization. The company is also carrying out a Phase I clinical trial in elderly adults to evaluate the immunogenicity and safety of the vaccine candidate in this important population.