The late-stage clinical trial is designed to enrol up to 10,000 volunteers across the UK to evaluate the efficacy of its Covid-19 vaccine NVX-CoV2373


Novavax to study its NVX-CoV2373 vaccine in Phase 3 trial. (Credit: Myriam Zilles from Pixabay.)

Novavax, a biotech firm focused on vaccine development, has commenced its first Phase 3 trial to evaluate the efficacy, safety and immunogenicity of its potential Covid-19 vaccine candidate, dubbed NVX-CoV2373.

Conducted in partnership with the UK Government’s Vaccines Taskforce, the Phase 3 trial is a randomised, placebo-controlled, observer-blinded study, designed to evaluate the efficacy, safety and immunogenicity of NVX-CoV2373.

The company has developed the vaccine candidate from the genetic sequence of SARSCoV2, using its recombinant nanoparticle technology. The vaccine contains the company’s patented saponin-based Matrix-M adjuvant to induce the immune response and stimulate neutralising antibodies.

Novavax said that its Covid-19 vaccine candidate can be handled in an unfrozen, liquid formulation, stored at 2°C to 8°C, and can be easily distributed across standard vaccine channels.

Novavax research and development president Gregory M Glenn said: “With a high level of SARS-CoV-2 transmission observed and expected to continue in the UK, we are optimistic that this pivotal Phase 3 clinical trial will enrol quickly and provide a near-term view of NVX-CoV2373’s efficacy.

“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.”

Novavax to test its NVX-CoV2373 vaccine in up to 10,000 individuals for four to six weeks

The clinical trial is expected to enrol up to 10,000 individuals, aged between 18 and 84 years, regardless of related co-morbidities, and immunise them for four to six weeks.

The participants in the study will be randomised in a 1:1 ratio to receive two doses of the vaccine comprising 5 µg of protein antigen with 50µg Matrix‑M adjuvant, administered as intramuscular injections 21 days apart, or placebo.

The clinical trial is expected to enrol at a minimum of 25% of participants aged more than 65 years and prioritise groups that are more incidences of Covid-19 infections, including racial and ethnic minorities.

Also, the company will enrol up to 400 participants who will receive a licensed seasonal influenza vaccine as part of its co-administration sub-study.

The trial has two primary endpoints, with the first occurrence of symptomatic Covid-19, as confirmed by PCR test, onset at least seven days after the second vaccination in participants with no previous SARS-CoV-2 infection as the first primary endpoint.

The first incidence of symptomatic moderate or severe Covid-19, as confirmed by a PCR test, onset at least seven days after the second vaccination in participants with no previous SARS-CoV-2 infection is the second primary endpoint.

The event-driven primary efficacy analysis will be based on the number of participants with symptomatic, moderate or severe Covid-19 disease, and an interim analysis is planned for reaching of 67% of the desired number of cases.