The decades-long endeavor to develop a prophylactic vaccine against respiratory syncytial virus (RSV) has so far only resulted in failure, with Novavax’s experimental RSV-F vaccine for the elderly seemingly joining a long list of casualties in 2016. However, its demise may have been greatly exaggerated, as the clinical-stage vaccine developer recently initiated a Phase II dose-finding study to further evaluate the safety and immunogenicity of its beleaguered RSV-F vaccine in adults 60 years of age and older.
Given the disproportionate, though some may argue justified, amount of criticism dumped on Novavax by industry pundits following last year’s setback – mostly centered on an inconsistent message from company executives on the trial’s chances of demonstrating the vaccine’s efficacy – the firm should be credited for its persistence, as GlobalData believes the RSV vaccine marketplace harbors billions in untapped commercial potential due to its high level of unmet medical need. Simply put, Novavax’s commitment to pursuing the pipeline vaccine’s licensure in the elderly is a sound business decision that should also be applauded by the medical community and public health advocates.
Regrouping after last year’s disappointing data from the RESOLVE Phase III trial, Novavax is betting that it can improve efficacy by enhancing the vaccine’s immunogenicity – through an adjuvanted formulation, a second dose, or a combination of both approaches. Specifically, the recently initiated Phase II dose-finding study seeks to randomize approximately 300 elderly patients into 11 active comparator groups, all of which will explore various formulation (no adjuvant vs. aluminum phosphate vs. Novavax’s proprietary Matrix-M1) and dosing (1-dose vs. 2-dose series) strategies, all while comparing safety and immunogenicity with placebo. The company hopes that by identifying a more immunogenic approach outside of the RSV season, it can refine its strategy for subsequent Phase III studies, thereby maximizing its chance of success in the clinic.
Despite RSV being one of the most frequent causes of lower respiratory infections in infants and the elderly, Medimmune’s Synagis (palivizumab) is currently the only agent licensed for the prevention of severe RSV infection, and its use is restricted to premature infants who have the highest risk of severe RSV infections. Key opinion leaders (KOLs) interviewed by GlobalData unanimously stated that the lack of interventions for the elderly represents an urgent medical unmet need, and payers emphasized that they would be incentivized to include a first-in-class RSV vaccine for the elderly in their formularies, particularly if annual or biannual vaccinations allowed it to be integrated into routine immunization schedules.
In a marketplace this ripe with clinical and commercial opportunity, the potential benefits of investing in further elderly trials far outweigh the risks for Novavax. Furthermore, the ultimate fate of Novavax’s RSV vaccine program is not tied exclusively to the vaccine’s performance in the elderly, as the company is also exploring its use in protecting infants via maternal immunization. Regardless of future outcomes, Novavax’s persistence should be commended by its investors and the wider healthcare industry, as the company continues to pursue development where many others have failed.