Highly negative FDA advisory committee review and subsequent discussions with the agency made clear the only path forward was a new study, company executives said. Troubled application shows the limits of FDA’s willingness to exercise regulatory flexibility.

The European Medicines Agency stood by its initial decision to recommend against EU approval of Amylyx’s ALS drug Albrioza after a re-examination, but the company remains hopeful that further trial evidence could support a future EU authorization.

The European Medicines Agency is this week due to decide whether to recommend pan-EU marketing authorization for a number of new products.

Litany of deficiencies, including product quality shortcomings and a failed Phase III clinical efficacy study, may make it impossible for the agency to exercise the type of flexibility it has with the approval of other treatments for ALS and neurodegenerative diseases.