Biotech firm Novavax has initiated a pivotal Phase III study of its Covid-19 vaccine candidate, NVX-CoV2373, in the US and Mexico.

A full-length, prefusion spike protein, NVX-CoV2373 was created using Novavax’s recombinant nanoparticle technology along with its proprietary saponin-based Matrix-M adjuvant.

A single vaccine dose contains 5mcg of protein and 50mcg of adjuvant.

The vaccine is stable at 2-8°C and is transported in a ready-to-use liquid formulation that allows supply with the help of standard vaccine supply chain channels.

The Phase III PRE-fusion protein subunit Vaccine Efficacy Novavax Trial | COVID-19 trial (PREVENT-19) was initiated after data from Phase I/II studies showed that the vaccine triggered a robust immune response, produced highly neutralising antibodies against the virus, and was well-tolerated.

Novavax president and CEO Stanley Erck said: “With the Covid-19 pandemic raging around the globe, this trial is a critical step in building the global portfolio of safe and effective vaccines to protect the world’s population.”

Being carried out with support from Operation Warp Speed partners, PREVENT-19 is an observer-blinded, placebo-controlled, randomised study to analyse the effectiveness, safety and immunogenicity of NVX-CoV2373 with Matrix-M versus placebo.

The trial will have around 30,000 adult participants who will be randomised in a 2:1 ratio to receive two intramuscular injections of NVX-CoV2373—administered 21 days apart—or placebo.

The primary and secondary endpoint of the trial will be the prevention of PCR-confirmed, symptomatic Covid-19 and moderate or severe disease, respectively.

Analysis of both the endpoints will be conducted at least seven days after the second dose.

Currently, Novavax is conducting a Phase III trial of the vaccine candidate in the UK, a Phase IIb safety and efficacy study in South Africa, and a Phase I/II trial in the US and Australia.

The company anticipates data from these trials to be available by the first quarter of next year.