Novavax begins Phase III COVID-19 vaccine efficacy trial

Novavax Inc. has initiated a Phase III study evaluating the efficacy, safety and immunogenicity of NVX-CoV2373, the company’s COVID-19 vaccine candidate. The UK trial is expected to enrol up to 10,000 individuals between 18 and 84 years of age, with and without relevant comorbidities, over the next four to six weeks.

The randomised, placebo-controlled, observer-blinded study will evaluate the efficacy, safety and immunogenicity of two intramuscular injections of vaccine comprising 5µg of protein antigen with 50µg Matrix‑M adjuvant, administered 21 days apart. Half of the patients will receive NVX-CoV2373 while the other half receive placebo. The trial is being conducted in partnership with the UK Government’s Vaccines Taskforce.

“With a high level of SARS-CoV-2 transmission observed and expected to continue in the UK, we are optimistic that this pivotal Phase III clinical trial will enroll quickly and provide a near-term view of NVX-CoV2373’s efficacy,” said Dr Gregory Glenn, President of Research and Development at Novavax. “The data from this trial is expected to support regulatory submissions for licensure in the UK, EU and other countries. We are grateful for the support of the UK Government, including from its Department of Health and Social Care and National Institute for Health Research, to advance this important research.”

NVX-CoV2373 is a stable, prefusion protein made using the enterprise’s recombinant protein nanoparticle technology and also includes its proprietary MatrixM™ adjuvant. The product profile should allow handling in an unfrozen, liquid formulation that can be stored at 2°C to 8°C, allowing for distribution using standard cold-chain distribution channels.

The company is also scaling-up its vaccine manufacturing capacity, which is expected to be at approximately 2 billion annualised doses, once all capacity has been brought online by mid-2021.

Further NVX-CoV2373 trial information

The Phase III trial is designed to enrol at least 25 percent of participants over the age of 65, as well as to prioritise groups that are most affected by COVID-19, including racial and ethnic minorities. Additionally, up to 400 participants will also receive a licensed seasonal influenza vaccine as part of a co-administration sub-study.

The trial has two primary endpoints: i) first occurrence of PCR-confirmed symptomatic COVID-19 with onset at least 7 days after the second study vaccination in volunteers who have not been previously infected with SARS-CoV-2 and ii) first occurrence of PCR-confirmed symptomatic moderate or severe COVID-19 with onset at least 7 days after the second study vaccination in volunteers who have not been previously infected with SARS-CoV-2. The primary efficacy analysis will be an event-driven analysis based on the number of participants with symptomatic or moderate/severe COVID-19 disease. An interim analysis will be performed when 67 percent of the desired number of these cases has been reached.