Novavax RSV vaccine misses mark with infants

Stumble in Study

Novavax’s fusion protein nanoparticle shot against respiratory syncytial virus (RSV) has failed to achieve its primary endpoint in the maternal immunization of infants in a Phase 3 clinical trial. The fusion protein nanoparticle shot, ResVax, once thought by the company to have the chance t become “the largest selling vaccine in the history of vaccines,” also failed to meet its efficacy objectives in a placebo-controlled study of nearly 12,000 adults, age 60 and over in 2016.

The recent clinical trial, funded by an $89.1 million grant from the Bill & Melinda Gates Foundation, was a four-year study of 4,600 pregnant women, with the vaccine administered in the third trimester. It was designed to determine whether immunity could be passed on after birth and through at least the first 90 days of life, reported Conor Hale in Fierce Biotech.

ResVax was well-tolerated but only 39 percent effective against the study’s primary objective of preventing medically significant RSV-related lower respiratory tract infections, Hale explained. However, Novavax said that its secondary data showed that all-cause LRTI hospitalizations were reduced by 25 percent. Additionally, the vaccine was 44 percent effective against RSV-related LRTI hospitalizations.

After the company’s lack of success in 2016, it cut 30 percent of its workforce. The most recent news caused Novavax’s stock price to lose about two-thirds of its remaining value in premarket trading.

RSV, which is the leading cause of infant hospitalizations in the U.S., is second only to malaria in causing infant deaths worldwide. Lifelong susceptibility to RSV is common, Novavax said. The company stated in May 2018 that the RSV vaccine could attain $1.5 billion in sales. Company executives believed that half of the sales would come from the U.S., before adding potential revenues from middle-income markets and low-income countries. Novavax had started to take precommercialization steps.

Novavax claimed that the new study’s secondary objective numbers were the first phase 3 efficacy seen from any RSV vaccine. The company believes that “exploratory endpoints and post-hoc analyses” could portend a possibility of improving global health. Novavax added that its next steps will be to meet with U.S. and European regulators to talk about licensure pathways.

Keith Klugman, director of the Gates Foundation’s pneumonia program, said, “We are very encouraged that the Novavax maternal RSV vaccine reduced severe RSV hypoxemia by 60 percent in the first months of life and believe this vaccine has great potential for reducing RSV-associated deaths in young babies. The 60 percent figure comes from a pre-specified exploratory analysis and includes additional data from hospitalization records, while the study’s secondary efficacy endpoint of the same measure reached 48 percent.”

Therapy for RSV has also been slow to materialize. Late in 2018 Johnson & Johnson revealed that it took a $630 million hit after Phase 2b trials of the company’s oral lumicitabine treatment were put on hold last August. The impairment charge came after J&J’s $1.75 billion takeover of the antiviral developer Alios, with lumicitabine, also known as AL-8176, being the lead drug in the deal. J&J said in an SEC filing last October, that it would “reassess the carrying value of the AL-8176 in-process research and development asset,” and will “monitor the remaining $900 million intangible asset for further impairment.”

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