Novavax, Inc., a clinical-stage biopharmaceutical company creating novel vaccines to address a broad range of infectious diseases worldwide,  has announced a clinical development partnership with international nonprofit organization, PATH to develop its RSV (respiratory syncytial virus) vaccine to protect infants through maternal immunization in low-resource countries.

 Novavax has been awarded approximately $2 million by PATH for initial funding under the partnership to partially support a phase II dose-ranging clinical trial in women of childbearing age planned for the second half of this year.

Following this initial study, PATH may elect to continue to partner with Novavax and provide support for the external clinical development costs through commercialization for this indication.

RSV is the most common cause of childhood respiratory infection globally, with a  disease burden of 64 million cases and approximately 160,000 deaths  annually. Severe RSV disease necessitates 3.4 million hospital admissions per year and disproportionately affects infants below six months of age. A severe episode of RSV bronchiolitis can lead to recurrent bouts of reactive airway disease/asthma for many years after the initial event. It is a highly contagious virus that occurs as a predictable epidemic from late fall through early spring in the US and other northern hemisphere regions and can have more than two annual peaks in tropical climates. RSV disease burden in low-resource countries is  significant, and available data indicate that the virus is responsible for a high proportion of childhood acute lower respiratory infection in these settings, particularly in the first few months of life. Currently, there is no approved RSV prophylactic vaccine available. Maternal immunization is a widely practiced strategy for protecting infants in a variety of diseases, such as neonatal tetanus. Maternal immunization  leads to heightened antibodies in infants and thereby protects them against the targeted disease, and thus may be a viable strategy to protect young infants from RSV illness.

Under the collaboration, Novavax’s phase II clinical trial  planned for later this year will be designed to evaluate the immune response to different doses of this vaccine candidate in women of childbearing age.  PATH will fund  on a non-dilutive basis  approximately $2 million of Novavax’s external clinical development costs for that trial.  PATH and Novavax may then progress the clinical development of Novavax’s  recombinant RSV fusion (F) protein vaccine candidate with the goal of immunizing pregnant women, such that high levels of maternal RSV antibodies will be transmitted to their offspring through the placenta before birth, providing protection against infection in the early infancy period, when the disease burden is the highest.

Thereafter, Novavax and  PATH can elect to continue  to collaborate on  additional  phases  to develop the vaccine for maternal immunization in low-resource countries, with PATH potentially funding 50 per cent of Novavax’s external clinical development costs. Novavax will retain global rights to commercialize the product and has made a commitment to make the product affordable and available in low-resource countries.

“We are very proud to  partner with PATH, an internationally recognized organization transforming global health through innovation, on  our RSV  vaccine candidate that has the potential to impact health conditions in the developing world. This partnership further validates the promise of our recombinant nanoparticle vaccines,” said Stanley C. Erck, president and CEO of Novavax. “This partnership with PATH complements our corporate strategy to develop this RSV vaccine for multiple indications in affected patient populations, in all markets throughout the world with multiple partners. We estimate that the world-wide market for an RSV vaccine could exceed $5 billion.”

“Based on Novavax’s Phase I clinical trial results, we view this RSV vaccine as  a promising candidate to address a very large unmet need in infant populations throughout the world, but particularly in  low-resource countries,” said Dr. Kathleen Neuzil, director  of PATH’s RSV vaccine project. “This collaboration with Novavax also fits well with our goal to collaborate with  private and public-sector partners to advance the development of promising vaccines that can be  affordable and accessible for people in low-resource countries.”

Novavax’s recombinant nanoparticle vaccine for the prevention of RSV is comprised of a highly purified RSV fusion (F) protein. In 2011, Novavax announced the results from a blinded, placebo-controlled, dose-escalating Phase I trial to assess the safety and tolerability of aluminum phosphate-adjuvanted and unadjuvanted formulations of our RSV vaccine candidate. The primary safety findings were local pain and tenderness at the site of injection, the majority of which were mild in nature with no dose-related increase observed. There were no observed vaccine-related serious adverse events or trends for related systemic side effects. A secondary objective of the study was to evaluate total  and neutralizing anti-RSV antibody responses and assess the impact of the adjuvant. The study enrolled 150 healthy adults 18 to 49 years old who were allocated to six cohorts that included four dose levels of vaccine. The antibody response to the RSV F protein was significantly increased compared to placebo (p<0.001) in all groups and increased by 19-fold in the highest-dose group at day 60. A significant dose-response pattern was observed. High rates of seroconversion were seen at all doses including a rate of 100 per cent at the highest-dose-adjuvant group.