FDA Lifts Clinical Hold on Novavax's Flu Vaccine Trials After Adverse Event Review

Key Insights

• The FDA has lifted the clinical hold on Novavax's Phase 3 trial for its combination COVID-19 and influenza vaccine, as well as its standalone flu shots.
• The hold was initiated following a serious adverse event of motor neuropathy in a Phase 2 trial participant, which has now been reclassified as ALS and deemed unrelated to the vaccine.
• Novavax plans to resume trial activities as quickly as possible, aiming to advance its protein-based vaccine alternative.

The Food and Drug Administration (FDA) has authorized Novavax to proceed with its Phase 3 clinical trial of a combination vaccine for COVID-19 and influenza, along with its standalone influenza vaccine program. This decision follows the lifting of a clinical hold that was initiated after a serious adverse event was reported in October.

The clinical hold was implemented on October 16 after a participant in a Phase 2 trial of the combination vaccine developed motor neuropathy, characterized by muscle weakness. The participant had received the vaccine in January 2023. Subsequent review of the case and additional information led to a reclassification of the event as amyotrophic lateral sclerosis (ALS), a rare neurodegenerative disease. According to Novavax, the FDA supported the assessment that the adverse event was not related to the vaccine.

"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," said Robert Walker, Novavax’s chief medical officer, in a statement.

Novavax aims to provide a protein-based alternative to the mRNA vaccines developed by Pfizer and Moderna for COVID-19. The company faced challenges due to late market entry and slow vaccine uptake, leading to a decrease in share value and subsequent staff reductions. To address these issues, Novavax is focusing on developing a combination vaccine. Earlier this year, Sanofi endorsed this strategy, providing Novavax with $500 million to support the development of the combination program and other multi-pronged vaccines.

Novavax has not yet specified when the results from its Phase 3 trial are expected. Following the announcement, the company's shares experienced a slight increase of approximately 2% in early trading.