Novavax has announced that the US Food and Drug Administration (FDA) has lifted its clinical hold on a late-stage study of the company’s COVID-19/influenza combination and stand-alone influenza vaccine candidates.
The clinical hold was placed in October following a spontaneous report of a serious adverse event, initially reported as motor neuropathy, in a participant who received the investigational combination vaccine in a phase 2 trial that was completed in 2023.
The additional information provided to the FDA on the event included a change in the term to amytrophic lateral sclerosis, a condition that is not known to be immune-mediated or associated with vaccination.
The regulator has now determined that Novavax satisfactorily addressed all clinical hold issues, meaning the company can begin enrolment to the planned phase 3 trial.
Novavax said it will be working with the clinical trial investigators and other partners to “resume trial activities as quickly as possible”.
The company’s chief medical officer, Robert Walker, said: “We thank the FDA for its partnership and thorough review of the additional information provided as part of our response package.
“The information provided to the FDA supported our assessment that the serious adverse event was not related to our vaccine. We plan to start our phase 3 trial as soon as possible.”
Novavax’s vaccines incorporate its Matrix-M adjuvant, which helps the immune system better recognise what is in a vaccine and remember it for longer, increasing the amount of time that a vaccine may offer protection.
The clinical hold lift comes less than three months after Novavax’s JN.1-adapted COVID-19 vaccine was granted emergency use authorisation by the FDA for use in individuals aged 12 years and older.
The authorisation was supported by non-clinical data that showed the updated vaccine provides cross-reactivity against JN.1 and multiple JN.1 lineage viruses, including KP.2.3, KP.3, KP.3.1.1 and LB.1.
The company also recently entered into a licensing agreement worth over $1.2bn with Sanofi to co-commercialise its COVID-19 vaccine and develop combination vaccines for COVID-19 and influenza.
The deal gave Sanofi a co-exclusive licence to co-commercialise Novavax’s current stand-alone adjuvanted COVID-19 vaccine globally, except in countries that Novavax has existing partnership agreements with, including Japan, India and South Korea, as well as those with advance purchase agreements.