Novavax faces new vaccine trial challenge — enrolling enough participants

Jan. 21, 2021

Novavax has already dealt with manufacturing stumbles on its race to get its vaccine candidate approved. Now the company is grappling with a new challenge — finding enough trial participants over the age of 65. 

With more states opening up vaccination opportunities to their 65 and over population, Novavax is struggling to recruit and retain enough patients for a double-blind trial that’s administering placebos to one-third of its participants.

According to a Washington Post report, Novavax has recruited about 9,000 participants for its phase 3 trial so far but is aiming to include 30,000 people — 25 percent of which will be in the critical 65-plus age category. Yet, with the Moderna and Pfizer vaccines being made more broadly available, many participants are now dropping out in the hopes they can receive a sure-fire vaccination and not end up with a placebo.

It’s the latest setback for Novavax, which had to delay the start of its late-stage trial twice due to manufacturing issues. The first batches of Novavax’s candidate were made by Emergent BioSolutions, one of the biggest contract manufacturers involved in Operation Warp Speed’s efforts to mass-produce vaccines. But OWS moved Novavax’s candidate out of Emergent’s facility to make way for J&J’s vaccine candidate — forcing Novavax to turn to Fujifilm for production. Novavax then had to prove to the FDA it could it could scale up production at Fujifilm’s facility, 

Novavax said that if it is now unable to recruit enough 65-plus participants for its late-stage trial in the U.S., it may ask the FDA to consider data from another trial it is running in the UK.

The issue underscores challenges for drugmakers who are farther behind in the development and testing of their COVID-19 vaccines. J&J and AstraZeneca have reported that their late-stage trials are close to or fully enrolled. But Sanofi, which is developing a vaccine candidate with GlaxoSmithKline and does not expect to roll out its candidate until late this year, is now opting for a non-inferiority trial, which compares one candidate to an already approved vaccine.