FDA AdComm rejects BrainStorm ALS stem cell therapy

Sept. 29, 2023

An FDA advisory committee has voted against recommending approval for NurOwn, BrainStorm Cell Therapeutics’ experimental stem cell therapy for amyotrophic lateral sclerosis (ALS). 

The Cellular, Tissue, and Gene Therapies Advisory Committee's 17-1 vote followed a presentation by officials who raised concerns regarding study findings and the company's capability to safely manufacture the therapy, which involves utilizing a patient's own stem cells. NurOwn uses autologous mesenchymal stem cells (MSC) cells to secrete neurotrophic factors targeting ALS, and while it showed promise for those with less advanced ALS, it fell short of statistical significance in the phase 3 pivotal trial.

The committee’s determination didn’t necessarily come as a surprise, as BrainStorm’s data for NurOwn has been subject to agency scrutiny in every step of its regulatory journey. In 2021, the FDA’s initial review of BrainStorm's phase 3 trial found insufficient evidence to support a marketing application for their technology. But despite this initial determination, BrainStorm was still allowed to proceed with a BLA submission.

But last November, the agency rejected NurOwn's BLA due to phase 3 trial outcomes not meeting pre-specified criteria. The company submitted an amendment addressing their concerns and requested fast-tracking through a process known as "File Over Protest" to secure an AdComm meeting promptly. This process involves the applicant asking the FDA to accept their application, despite the initial rejection.

At this week’s meeting, members expressed feeling compelled by patient and physician stories but hesitant by the data provided. Niraeli Shah, who abstained, said BrainStorm presented “A fair amount of conflicting information and [gave] a lot of emphasis on mechanism of action of something that we don’t really understand.” She added being worried that the company was “asking for the impossible,” and that overall there are still aspects  of mesenchymal stem cells drug products regulatory journey to be figured out. Other members echoed feelings of insufficient data. Lisa Lee, said “Taken together the data does not provide enough evidence. Conflicting information presented led to less clarity.” 

In the U.S., there are currently no FDA-approved MSC therapies, although products have received regulatory clearance in other countries.