FDA PDUFA Watch: Neurology Decisions to Track Through Late September

Over the next month and a half, the FDA is expected to hand down decisions on six PDUFA dates spanning Alzheimer disease diagnostics, Duchenne muscular dystrophy (DMD), Sanfilippo syndrome, Alexander disease, developmental and epileptic encephalopathies (DEEs), and spinal muscular atrophy (SMA).

Three additional neurology adjacent programs, Takeda's oveporexton, Bayer's asundexian, and AbbVie's tavapadon, don't have confirmed PDUFA dates but are expected to see FDA action in the coming months.

Below is a rundown of each, what the data show, and what an approval would mean for its respective treatment landscape.

August 13: MK-6240 (Lantheus) | Tau PET Imaging Agent in Alzheimer Disease

MK-6240 is an F-18 labeled PET imaging agent designed to detect tau neurofibrillary tangles, a core pathological hallmark of Alzheimer disease, in patients with cognitive impairment being evaluated for the condition. The agent binds selectively to aggregated tau with minimal off target signal, distinguishing it from earlier generation tau tracers that struggled with off target binding. Lantheus acquired rights to the compound in 2023 and has since expanded its use across nearly 100 active clinical trials.

The new drug application (NDA) is supported by two pivotal phase 3 trials that met co primary endpoints of sensitivity and specificity for detecting tau pathology. If cleared, MK-6240 would give clinicians a validated tool for earlier disease detection, staging, and therapy selection, and could eventually support use of tau as a surrogate endpoint for measuring treatment efficacy, a capability increasingly relevant as anti amyloid and anti tau therapeutics reach the market. The FDA granted the application Fast Track designation ahead of its PDUFA date.¹

August 22: Deramiocel (Capricor Therapeutics) | Cell Therapy for DMD Cardiomyopathy

Deramiocel (CAP 1002) is an allogeneic cardiosphere derived cell therapy administered by infusion, intended to treat the cardiomyopathy that develops in Duchenne muscular dystrophy as cardiac muscle progressively deteriorates, the leading cause of death in DMD. The cells are thought to exert immunomodulatory and anti-fibrotic effects on damaged heart tissue. If approved, Capricor has positioned it as the first therapy to address both the skeletal and cardiac manifestations of the disease.²

This is a resubmission. The FDA issued a complete response letter in July 2025 citing insufficient evidence of effectiveness, after which Capricor supplied additional randomized, placebo controlled data from the phase 3 HOPE-3 trial, including an ejection fraction endpoint the agency had specifically requested.² HOPE-3 results were subsequently published in The Lancet.³

The regulatory picture became more complicated on July 29, 2026, when the FDA's Cellular, Tissue, and Gene Therapies Advisory Committee voted that available evidence did not support deramiocel's effectiveness for DMD cardiomyopathy, even as it acknowledged encouraging signals on skeletal muscle function.⁴ That negative vote, while non-binding, adds uncertainty heading into the August 22 decision.

September 19: UX111 (Ultragenyx) | Gene Therapy for Sanfilippo Syndrome Type A

UX111 (rebisufligene etisparvovec) is a one time, in vivo AAV9 gene therapy designed to correct the underlying enzyme deficiency in Sanfilippo syndrome type A (MPS IIIA), a fatal, primarily neurodegenerative lysosomal storage disorder caused by loss of sulfamidase activity. The resulting buildup of heparan sulfate drives progressive cognitive and motor decline in affected children. No pharmacological treatment for MPS IIIA currently exists anywhere in the world.⁵

This is also a resubmission, following a 2025 complete response letter centered on chemistry, manufacturing, and controls issues rather than clinical data.⁶ The current BLA includes updated long term follow up, up to eight years in some patients, from the Transpher A trial, showing durable reductions in cerebrospinal fluid heparan sulfate and statistically significant gains on the Bayley III cognitive and motor scales in a younger, earlier stage subgroup, alongside a generally favorable tolerability profile.⁷

An approval would mark the first disease modifying treatment for MPS IIIA and a notable proof point for AAV9 gene therapy in pediatric neurodegenerative disease more broadly.⁵

September 22: Zilganersen (Ionis Pharmaceuticals) | Antisense Therapy for Alexander Disease

Zilganersen is an antisense oligonucleotide designed to reduce production of glial fibrillary acidic protein (GFAP), the protein whose overexpression drives Alexander disease, a rare and often fatal astrocytopathy marked by progressive motor and cognitive decline. There are currently no approved disease modifying therapies for Alexander disease.⁸

The NDA rests on a pivotal, randomized, controlled phase 1-3 study of 53 to 54 patients ages roughly 1.5 to 53 years, dosed every 12 weeks over a 60 week double blind period. The trial met its primary endpoint in patients age 5 and older, showing statistically significant stabilization of gait speed on the 10 Meter Walk Test versus control, while younger children ages 2 to 4 showed supportive gains on a gross motor function scale.⁹

An exploratory analysis also showed a roughly one third reduction in plasma GFAP, consistent with the drug's mechanism, and safety was reported as favorable with fewer serious adverse events than control. Zilganersen holds FDA Priority Review, Breakthrough Therapy, Orphan Drug, and Rare Pediatric Disease designations. An approval would establish the first targeted, disease modifying option for Alexander disease.⁸

September 30: Apitegromab (Scholar Rock) | Myostatin Inhibitor for SMA

Apitegromab is a fully human monoclonal antibody that selectively binds the pro and latent forms of myostatin, a negative regulator of muscle growth, to preserve and build skeletal muscle mass in patients with spinal muscular atrophy.

Unlike approved SMN targeted therapies, which address the underlying genetic cause of SMA, apitegromab works directly on muscle and is intended as an add on to existing SMN therapy, positioning it as the first muscle directed treatment candidate in the SMA space.

The BLA is supported by the pivotal phase 3 SAPPHIRE trial, which Scholar Rock says demonstrated a statistically significant and clinically meaningful functional benefit, the first such result for a muscle targeted agent in SMA.¹⁰

Like the deramiocel and UX111 programs above, this is also a resubmission. An earlier complete response letter flagged manufacturing inspection findings at a third party fill finish facility unrelated to the drug substance itself, and the current filing includes a second, U.S. based fill finish site to help resolve that gap.¹¹ Scholar Rock has said it is prepared to launch immediately upon approval.¹⁰

A note on timing: Relutrigine's PDUFA has moved

Praxis Precision Medicines' relutrigine, a first in class small molecule sodium channel modulator for SCN2A and SCN8A developmental and epileptic encephalopathies, originally carried a September 27, 2026, PDUFA date after the FDA accepted its NDA under Priority Review.¹²

On June 29, 2026, however, the FDA extended the review by three months, to December 27, 2026, after classifying additional sensitivity analyses Praxis submitted as a "major amendment." The agency did not request new clinical studies or cite safety or manufacturing concerns.¹³

Because that date now falls outside the six-week window this piece covers, relutrigine isn't detailed further here, but it remains a program worth tracking later this year. If approved, it would be the first therapy specifically indicated for SCN2A/SCN8A DEE.

On the Radar Without a Confirmed PDUFA Date

Oveporexton (Takeda) | Orexin Agonist for Narcolepsy Type 1

Oveporexton (TAK 861) is an oral, orexin receptor 2 selective agonist designed to directly address the orexin deficiency that causes narcolepsy type 1, rather than simply managing symptoms like excessive daytime sleepiness and cataplexy. The FDA accepted the NDA and granted Priority Review in February 2026, based on the phase 3 FirstLight and RadiantLight trials, with a PDUFA goal date set for the third quarter of 2026 but no specific date disclosed. Common adverse events in trials included insomnia and urinary urgency and frequency.¹⁴

If cleared, it would be the first orexin agonist approved for narcolepsy type 1, a mechanistic first for the field rather than an incremental addition to existing stimulant and oxybate-based regimens.

Asundexian (Bayer) | Factor XIa Inhibitor for Secondary Stroke Prevention

Asundexian is an oral Factor XIa inhibitor being developed for secondary prevention of stroke following a non-cardioembolic ischemic stroke or high risk transient ischemic attack. The Factor XIa target is thought to contribute more to pathological clot formation than to normal hemostasis, raising the prospect of reducing thrombotic risk without a proportional rise in bleeding risk, a long-standing limitation of anticoagulants in stroke populations without atrial fibrillation.¹⁵

The FDA granted Priority Review in May 2026 based on the phase 3 OCEANIC-STROKE trial, which showed a 26% relative reduction in recurrent stroke versus placebo on top of antiplatelet therapy, without an increase in major bleeding.

Notably, Bayer previously stopped its phase 3 OCEANIC-AF trial of asundexian in atrial fibrillation in November 2023 after an independent monitoring committee found inferior efficacy against apixaban, so the stroke prevention indication represents a distinct, and so far, more successful, use case for the drug.¹⁶ No specific PDUFA date has been disclosed beyond the third quarter of 2026.¹⁵

Tavapadon (AbbVie) | Dopamine D1/D5 Partial Agonist for Parkinson Disease

Tavapadon is an investigational, once daily oral dopamine D1/D5 receptor partial agonist for Parkinson disease, studied both as monotherapy in early stage disease and as an adjunct to levodopa in patients with more advanced motor fluctuations. Unlike traditional dopamine agonists that primarily target D2/D3 receptors, tavapadon's selective D1/D5 activity is intended to preserve efficacy while reducing side effects like impulse control disorders and excessive daytime sleepiness that have limited use of older agents.¹⁷

AbbVie submitted the NDA in September 2025, supported by the phase 3 TEMPO program: TEMPO 1 and TEMPO 2 in monotherapy for early Parkinson disease, and TEMPO 3 as adjunctive therapy with levodopa. A decision has been widely expected in the first half of 2026, though AbbVie has not publicly disclosed a specific PDUFA date.

If approved, tavapadon would become the first selective D1/D5 dopamine agonist available in the U.S., offering a mechanistically distinct option within a drug class that hasn't changed meaningfully since the 1990s.

REFERENCES
1. Lantheus Holdings, Inc. Lantheus announces FDA acceptance of New Drug Application for MK-6240, a PET imaging agent targeting tau in Alzheimer's disease [press release]. Bedford, MA: Lantheus Holdings, Inc.; October 28, 2025. Accessed August 4, 2026. https://lantheusholdings.gcs-web.com/news-releases/news-release-details/lantheus-announces-fda-acceptance-new-drug-application-mk-6240
2. Capricor Therapeutics, Inc. Capricor Therapeutics announces establishment of new PDUFA date for deramiocel BLA [press release]. San Diego, CA: Capricor Therapeutics, Inc.; March 10, 2026. Accessed August 4, 2026. https://www.capricor.com/investors/news-events/press-releases/detail/338/capricor-therapeutics-announces-establishment-of-new-pdufa
3. Capricor Therapeutics, Inc. The Lancet publishes HOPE-3 data for Capricor Therapeutics' deramiocel in Duchenne muscular dystrophy [press release]. San Diego, CA: Capricor Therapeutics, Inc.; July 29, 2026. Accessed August 4, 2026. https://www.capricor.com/investors/news-events/press-releases/detail/350/the-lancet-publishes-hope-3-data-for-capricor
4. Capricor Therapeutics, Inc. Capricor Therapeutics provides update on FDA Advisory Committee meeting for deramiocel [press release]. San Diego, CA: Capricor Therapeutics, Inc.; July 2026. Accessed August 4, 2026. https://www.capricor.com/investors/news-events/press-releases/detail/351/capricor-therapeutics-provides-update-on-fda-advisory
5. Ultragenyx Pharmaceutical Inc. Ultragenyx announces U.S. FDA acceptance of BLA resubmission for UX111 AAV gene therapy to treat Sanfilippo syndrome type A (MPS IIIA) [press release]. Novato, CA: Ultragenyx Pharmaceutical Inc.; April 2, 2026. Accessed August 4, 2026. https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-us-fda-acceptance-bla-resubmission-ux111
6. Ultragenyx Pharmaceutical Inc. Ultragenyx resubmits Biologics License Application for UX111 AAV gene therapy to treat Sanfilippo syndrome type A (MPS IIIA) to U.S. FDA [press release]. Novato, CA: Ultragenyx Pharmaceutical Inc.; January 30, 2026. Accessed August 4, 2026. https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-resubmits-biologics-license-application-ux111-aav
7. Ultragenyx Pharmaceutical Inc. Ultragenyx announces positive longer-term data demonstrating treatment with UX111 gene therapy results in sustained, significant reductions in CSF-HS and continued meaningful improvements in clinical function across multiple developmental domains in children with Sanfilippo syndrome (MPS IIIA) [press release]. Novato, CA: Ultragenyx Pharmaceutical Inc.; February 3, 2026. Accessed August 4, 2026. https://ir.ultragenyx.com/news-releases/news-release-details/ultragenyx-announces-positive-longer-term-data-demonstrating
8. Ionis Pharmaceuticals, Inc. Ionis announces zilganersen New Drug Application for Alexander disease (AxD) accepted by FDA for Priority Review [press release]. Carlsbad, CA: Ionis Pharmaceuticals, Inc.; March 23, 2026. Accessed August 4, 2026. https://ir.ionis.com/news-releases/news-release-details/ionis-announces-zilganersen-new-drug-application-alexander
9. Ionis Pharmaceuticals, Inc. Ionis presents new data from pivotal study of zilganersen in Alexander disease (AxD) at AAN 2026 Annual Meeting [press release]. Carlsbad, CA: Ionis Pharmaceuticals, Inc.; April 21, 2026. Accessed August 4, 2026. https://ir.ionis.com/news-releases/news-release-details/ionis-presents-new-data-pivotal-study-zilganersen-alexander
10. Scholar Rock, Inc. Scholar Rock reports first quarter 2026 financial results and recent business highlights [press release]. Cambridge, MA: Scholar Rock, Inc.; May 7, 2026. Accessed August 4, 2026. https://investors.scholarrock.com/news-releases/news-release-details/scholar-rock-reports-first-quarter-2026-financial-results-and
11. Scholar Rock, Inc. Scholar Rock resubmits Biologics License Application (BLA) to FDA for apitegromab for treatment of children and adults with spinal muscular atrophy (SMA) [press release]. Cambridge, MA: Scholar Rock, Inc.; March 2026. Accessed August 4, 2026. https://investors.scholarrock.com/news-releases/news-release-details/scholar-rock-resubmits-biologics-license-application-bla-fd
12. Praxis Precision Medicines, Inc. Praxis Precision Medicines announces FDA acceptance and Priority Review of New Drug Application for relutrigine in patients with SCN2A and SCN8A DEEs [press release]. Boston, MA: Praxis Precision Medicines, Inc.; March 30, 2026. Accessed August 4, 2026. https://ir.praxismedicines.com/news-releases/news-release-details/praxis-precision-medicines-announces-fda-acceptance-and-priority
13. Praxis Precision Medicines, Inc. Praxis Precision Medicines announces extension period for relutrigine for treatment of SCN2A and SCN8A developmental and epileptic encephalopathies [press release]. Boston, MA: Praxis Precision Medicines, Inc.; June 29, 2026. Accessed August 4, 2026. https://investors.praxismedicines.com/news-releases/news-release-details/praxis-precision-medicines-announces-extension-period
14. Takeda Pharmaceutical Company Limited. U.S. Food and Drug Administration accepts New Drug Application and grants Priority Review for Takeda's oveporexton (TAK-861) as a potential first-in-class therapy for narcolepsy type 1 [press release]. Osaka, Japan and Cambridge, MA: Takeda Pharmaceutical Company Limited; February 10, 2026. Accessed August 4, 2026. https://www.takeda.com/newsroom/newsreleases/2026/fda-accepts-nda-priority-review-oveporexton-narcolepsy-type-1/
15. Bayer AG. Bayer granted Priority Review by U.S. FDA for asundexian in patients after a non-cardioembolic ischemic stroke or transient ischemic attack [press release]. Whippany, NJ: Bayer AG; May 18, 2026. Accessed August 4, 2026. https://www.businesswire.com/news/home/20260518787299/en/Bayer-Granted-Priority-Review-by-U.S.-FDA-for-Asundexian-in-Patients-After-a-Non-Cardioembolic-Ischemic-Stroke-or-Transient-Ischemic-Attack
16. Bayer AG. OCEANIC-AF study stopped early due to lack of efficacy [press release]. Berlin, Germany: Bayer AG; November 19, 2023. Accessed August 4, 2026. https://www.bayer.com/media/en-us/oceanic-af-study-stopped-early-due-to-lack-of-efficacy/
17. AbbVie Inc. AbbVie submits New Drug Application to U.S. FDA for tavapadon for the treatment of Parkinson's disease [press release]. North Chicago, IL: AbbVie Inc.; September 26, 2025. Accessed August 4, 2026. https://news.abbvie.com/2025-09-26-AbbVie-Submits-New-Drug-Application-to-U-S-FDA-for-Tavapadon-for-the-Treatment-of-Parkinsons-Disease