FDA AdComm Votes Against Recommending Deramiocel Approval, Tazbentetol Shows Durable Cognitive Benefit in AD, Salanersen's FDA Breakthrough Designation Meaning

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Welcome to the Neurology News Network, my name is Louie Pasculli and here’s a look at some of the top stories in Neurology.

Beginning with FDA news, The FDA's Cellular, Tissue, and Gene Therapies Advisory Committee voted 9 to 3, with no abstentions, that the available evidence does not provide substantial evidence of effectiveness to recommend approval for deramiocel in treating cardiomyopathy in patients with Duchenne muscular dystrophy (DMD).¹ The vote is nonbinding, but it signals a difficult path ahead for Capricor Therapeutics' biologics license application (BLA) ahead of the FDA's August 22, 2026, PDUFA target action date.²

Members who voted no generally cited concerns about the stability of the statistical results, saying that outcomes on the left ventricular ejection fraction (LVEF) endpoint, and to a lesser extent the upper-limb endpoint, appeared highly sensitive to how missing data were handled and which analytic assumptions were applied. Several said they had not seen evidence that LVEF, as measured in the trial, functions as a validated surrogate for clinical benefit in this population, and some noted that earlier versions of the sponsor's own statistical analysis had not met the pre-specified endpoint.

A few members also raised questions about a potential safety signal related to increases in left ventricular volume that they said warranted further evaluation. Several no-voting members emphasized the significant unmet medical need in DMD cardiomyopathy and characterized their vote as reflecting the narrow scope of the question posed rather than a broader judgment on the therapy's underlying scientific rationale.

At the 2026 Alzheimer's Association International Conference (AAIC), held July 12-15, in London, Spinogenix presented new data showing that tazbentetol, an investigational oral synaptic regenerative therapy, produced durable cognitive improvement in patients with mild-to-moderate Alzheimer disease (AD) who continued treatment for up to 84 weeks under a compassionate use program following a completed phase 2a trial. Group-level cognitive scores remained improved over baseline beyond one year of continuous treatment.^3,4

The completed phase 2a trial (NCT06427668) was a multicenter study that randomized 24 patients with mild-to-moderate AD (MMSE, 16-26) 2:1 to placebo or active tazbentetol at 150 mg or 300 mg once daily. The design included a 28-day double-blind, placebo-controlled (DBPC) period, followed by a 24-week open-label extension (OLE) during which all participants received 300 mg, and a long-term follow-up period extending to 12 months; efficacy assessments included standard Mini Mental State Exam (SMMSE), Clinical Dementia Rating Scale-Sum of Boxes (CDR-SB), the ADCS-Activities of Daily Living Inventory (ADCS-ADL), resting-state EEG, and P300 auditory event-related potentials.⁴

Overall, tazbentetol was safe and well tolerated, with no treatment-related adverse events or serious adverse events, and plasma pharmacokinetics were similar to those seen in phase 1 healthy volunteers. At the 300 mg dose, SMMSE improved significantly during the DBPC period and remained significant and durable through the 24-week OLE, with a 2.20-point (SEM, 0.8) increase over baseline.

Switching gears, In early June, Biogen announced that the FDA granted Breakthrough Therapy Designation for salanersen for the treatment of spinal muscular atrophy (SMA), based on Phase 1b data showing clinically meaningful improvements in motor function and reductions in neurofilament light chain levels in children who had a suboptimal response to prior gene therapy. The designation is designed to expedite the development and review of drugs intended to treat serious conditions where preliminary clinical evidence suggests substantial improvement over available therapy. For context, salanersen is an investigational antisense oligonucleotide with a novel chemical backbone designed to increase potency and enable high efficacy with once-yearly dosing.

The Phase 1b findings drew particular attention for what was observed in children who had previously received gene therapy but clinically plateaued. Of 24 children treated with salanersen, all experienced improvement on at least one endpoint, 12 achieved at least one new WHO motor milestone, and those with elevated baseline neurofilament levels saw a 75% reduction within six months that was sustained through follow-up. Three Phase 3 studies, STELLAR-1, STELLAR-2, and SOLAR, are now underway or expected to begin recruitment imminently.

In this Q&A, Stephanie Fradette, PhD, Senior Vice President, Head of Rare Neurology Development Unit at Biogen, discusses what the Breakthrough Therapy Designation signals about remaining unmet needs in SMA and how clinicians should interpret the motor gains observed in children after prior gene therapy. The conversation also covers what the neurofilament data suggest about salanersen's biological impact, how once-yearly dosing could reshape treatment burden, and what the Phase 3 program is designed to answer about the drug's future role in SMA.

To read the full piece and to get more direct access to expert insight, head to NeurologyLive.com. Be sure to tune in next week to remain informed on the latest in neurology. I’m Louie Pasculli, thanks for watching Neurology News Network.

REFERENCES
1. Cellular, Tissue, and Gene Therapies Advisory Committee; Notice of Meeting; Establishment of a Public Docket. Federal Register. June 29, 2026. Accessed July 29, 2026. https://www.federalregister.gov/documents/2026/06/29/2026-13096/cellular-tissue-and-gene-therapies-advisory-committee-notice-of-meeting-establishment-of-a-public
2. Capricor Therapeutics Announces FDA Advisory Committee Meeting to Review BLA for Deramiocel for the Treatment of Duchenne Muscular Dystrophy. News release. Capricor Therapeutics. June 26, 2026. Accessed July 29, 2026. https://www.capricor.com/investors/news-events/press-releases/detail/348/capricor-therapeutics-announces-fda-advisory-committee
3. Spinogenix Reports Positive Data on Alzheimer's Patients Who Continued Treatment With Tazbentetol For Up To 84 Weeks. News release. Spinogenix, Inc. July 14, 2026. Accessed July 24, 2026. https://www.prnewswire.com/news-releases/spinogenix-reports-positive-data-on-alzheimers-patients-who-continued-treatment-with-tazbentetol-for-up-to-84-weeks-302825473.html
4. Brew B, Priest L, Gargosky S, Vanderklish P, Erickson C, Pedapati E, Sarraf S. Rapid and Durable Improvements in Cognitive and Neurophysiological Outcomes in Tazbentetol Treated Mild-Moderate AD Patients. Presented at: Alzheimer's Association International Conference; July 2026; London, England. ClinicalTrials.gov identifiers: NCT06427668, NCT06833281.