FDA Pushes Pause On Axsome Fibromyalgia Drug, New Trial Required

The U.S. Food and Drug Administration (FDA) sent a “refusal to file” letter to Axsome Therapeutics, Inc. AXSM on Monday regarding its AXS-14 (esreboxetine) treatment of fibromyalgia.

The FDA states that upon preliminary review, the New Drug Application (NDA) was not sufficiently complete to permit a substantive review.

Fibromyalgia is a chronic disorder characterized by widespread pain, fatigue, disturbed sleep, depression, and cognitive impairment.

Approximately 17 million Americans, 90% of whom are women, are estimated to suffer from fibromyalgia.

Also Read: Axsome’s Solriamfetol Fails Primary Goal In Depression Study But Shows Improvements In Associated Sleep Disorder

Specifically, the FDA does not consider the second of the two placebo-controlled trials in the submission adequate and well-controlled because its primary endpoint was at 8 weeks, and it used a flexible-dose paradigm.

The FDA indicated that the first of the two placebo-controlled trials in the submission, which utilized a 12-week endpoint and a fixed-dose paradigm, is adequate and well-controlled.

The FDA did not raise any questions relating to the positive results of the studies, both of which met their primary endpoints.

To address the FDA’s feedback, Axsome will conduct an additional controlled trial. As requested by the FDA, this trial will use a fixed-dose paradigm and a 12-week primary endpoint. Axsome anticipates initiating this trial in the fourth quarter of 2025.

Axsome CEO Herriot Tabuteau said the company is “well positioned to initiate a new controlled trial that will incorporate the FDA’s feedback by the end of 2025.”

While the RTF is disappointing, William Blair had ascribed only $3.38 for the AXS-14 fibromyalgia program to total $199.98 sum-of-the-parts fair value in the model.

With the requirement for an additional study, analyst Myles Minter has delayed the launch of AXS-14 in the model to the second half of 2028 and now ascribes $1.89 for the program to the fair value.

Investor focus remains on the Alzheimer's disease agitation (AD-A), which is on track for the third quarter of 2025.

After talking with the company's management, William Blair said they believe the recent Refusal to File (RTF) is limited to the Division of Anesthesiology, Addiction Medicine, and Pain Medicine and the fibromyalgia program.

It should not impact the separate submission for AXS-05 in Alzheimer's disease agitation, which will go through the Psychiatry division in Q3 2025.

The firm added that getting a PDUFA date for this application, supported by the ADVANCE and ACCORD studies, and possibly receiving priority review due to its breakthrough therapy status, would be a key milestone and help reduce concerns about FDA-related delays caused by its internal restructuring.

Price Action: AXSM stock is down 0.60% at $111.24 at the last check on Monday.

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