US FDA lifts clinical hold on Novavax's combo Covid-flu shot

The US Food and Drug Administration has lifted its clinical hold on a late-stage trial of Novavax's COVID-influenza and its standalone flu vaccines after a safety concern was found to be unrelated to the combination shot, the company said.

Shares of the vaccine maker, which is scheduled to report third-quarter results on Tuesday, rose nearly 17% to $10.39 on Monday. They pared their gains and were last up 2%.

The Maryland-based biotech announced the clinical hold last month after a participant who had received its COVID-influenza combination vaccine had reported symptoms of motor neuropathy, or damage to the nerve cells that control muscles or movement.

The person was administered the vaccine in January last year as part of a mid-stage study.

Novavax said on Monday it had changed the participant's symptoms to amytrophic lateral sclerosis, a condition that affects nerve cells in the brain and spinal cord, in additional details provided to the US health regulator.

Assessment showed the symptoms were not related to its shot, the company said.

"The information provided to the FDA supported our assessment that the serious adverse event was not related to our vaccine," said Chief Medical Officer Robert Walker.

The company will resume late-stage trial activities as quickly as possible, he said.

Shares of Novavax fell 19% when the hold was announced on Oct. 16.

The COVID vaccine is Novavax's lone marketed product after over 35 years in business and the company is banking on its combination shot and flu vaccine to drive future growth.

Novavax's traditional protein-based COVID shot offers an alternative technology to messenger RNA-based rivals from Pfizer -BioNTech and Moderna but has failed to make a mark in the US vaccine market.

In May, Novavax signed a licensing deal worth at least $1.2 billion with French drugmaker Sanofi for the COVID vaccine, gaining access to much-needed liquidity.

Last year, the company had raised doubts about its ability to remain in business.