Novavax unveils phase 3 COVID jab data, but has it missed the boat in US?

The top-line phase 3 data for Novavax' COVID-19 vaccine look good, with a 90% overall efficacy rate, but a dip in its share price indicates investors fear it could be too late for the programme.

Novavax' price spiked 9% after the data were announced today, but fell back just as quickly, despite the company's assertions that it should now be in a position to file for emergency use authorisation (EUA) of NVX-CoV2373 in the third quarter.

Novavax said last month it would have to delay the completion of filings in the US, UK and Europe, originally scheduled for this month, because there was still work to be done on the chemistry, manufacturing and controls (CMC) data that would be needed for an EUA.

Given the positive results – which also showed suggested the shot was 100% effective at preventing moderate-to-severe COVID-19 and had 93% efficacy against variants of concern – it seems there are some doubts about its long-term prospects as cases decline and supplies of already-approved vaccines firm up.

Shareholders may also have the jitters because another late-stage COVID-19 vaccine developer – Ocugen – was told by the FDA it would have to file for full approval rather than going down the speedier EUA route, becoming the first drugmaker to be affected by the regulator's stricter stance on emergency approvals.

AstraZeneca meanwhile has already said that it may forego the EUA approach for its AZD1222 vaccine and go straight for a full marketing application.

"Novavax continues to work with a sense of urgency to complete our regulatory submissions and deliver this vaccine, built on a well understood and proven platform, to a world that is still in great need of vaccines," said the company's chief executive Stanley Erck.

He told a conference call today that it may well be that in the US NVX-CoV2373 is used primarily in booster programmes.

Novavax' phase 3 PREVENT-19 trial was conducted in 30,000 patients in the US and Mexico, with 63 cases of COVID-19 in the placebo group compared to 14 of the vaccine arm. That's in line with an ex-US study that generated results in March.

By sequencing virus from COVID-19 cases seen among patients in the trial, the Maryland-based biotech said the shot seemed to have good efficacy against the alpha or B.1.1.7 variant first identified in the UK, as well as other variants of concern including the beta (B.1.351) strain that emerged in South Africa.

It is also testing another version of the vaccine that has shown stronger immune responses against beta and other variants and could also be used as a booster shot.

The UK has ordered 60 million doses of NVX-CoV2373 and a further 1.1 billion doses are due to go to the COVAX programme, which distributes vaccines to poorer countries.

Novavax said it remains on track to reach manufacturing capacity of 100 million doses per month by the end of the third quarter of this year, and 150 million doses per month by the end of the fourth quarter.

The vaccine is based on a protein subunit that mimics the spike protein on SARS-CoV-2 and can be stored at regular refrigeration temperatures.