September 2026 Biotech Catalysts: 7 FDA Dates & Phase 3 Readouts

Phase 2 Seabreeze STAT topline data for rademikibart in acute asthma exacerbations

Rademikibart · Acute exacerbations of asthma (COPD readout to follow)

Connect Biopharma is testing its IL-4Rα antibody rademikibart in a setting no biologic has cracked: treating asthma attacks as they happen, rather than preventing them. Topline data from the placebo-controlled Seabreeze STAT asthma study is guided for early September, with the parallel COPD readout following shortly after.

A positive asthma result followed by supportive COPD data would let the market start pricing a Phase 3 program in acute exacerbations — a large, unowned indication. For a small-cap, this is a heavily binary setup in both directions; position sizing matters more than conviction here.

Phase 3 DAYBREAK one-year topline data for Zenkuda and KSI-501 in wet AMD

Zenkuda (tarcocimab tedromer) / KSI-501 · Treatment-naive neovascular (wet) age-related macular degeneration

Kodiak's registrational DAYBREAK study (~690 patients) tests both Zenkuda and the bispecific IL-6/VEGF inhibitor KSI-501 against aflibercept in treatment-naive wet AMD, with one-year topline data guided for September. After tarcocimab's earlier mixed Phase 3 history, this readout is close to company-defining.

This is a non-inferiority study against an entrenched standard of care. A clean hit on durability with extended dosing intervals revives the franchise story; a miss leaves Kodiak with limited pipeline shots. Expect an outsized single-day stock move in either direction.

PDUFA decision for UX111 gene therapy in MPS IIIA (Sanfilippo syndrome type A) — resubmitted BLA

UX111 (rebisufligene etisparvovec) · Mucopolysaccharidosis type IIIA (Sanfilippo syndrome type A)

Ultragenyx is back in front of the FDA with UX111, its AAV9 gene therapy for Sanfilippo syndrome type A — a fatal pediatric neurodegenerative disease with no approved treatment. The FDA issued a CRL in July 2025 over manufacturing (CMC) issues, not efficacy; the resubmitted BLA was accepted in April 2026 with a September 19 action date.

Because the CRL was CMC-focused, the question is whether Ultragenyx fixed the manufacturing findings — the efficacy case (CSF heparan sulfate reduction plus developmental gains) is already on file for accelerated approval. Approval makes UX111 the first therapy ever for Sanfilippo A and de-risks the broader Ultragenyx gene therapy pipeline; a second CRL would hit both the stock and sentiment on AAV manufacturing across the sector.

PDUFA decision for Aqneursa (levacetylleucine) sNDA in ataxia-telangiectasia

Aqneursa (levacetylleucine) · Ataxia-telangiectasia (A-T), adult and pediatric

Privately held IntraBio's Aqneursa, already approved for Niemann-Pick disease type C, is under priority review for ataxia-telangiectasia — a rare neurodegenerative disease with no approved therapy. Its pivotal crossover study met its primary and all key secondary endpoints.

No direct stock trade here since IntraBio is private, but an approval would be the first therapy ever for A-T and another data point that the FDA's rare-neurology division is rewarding well-controlled small-population studies — relevant context for public rare-disease names with similar regulatory strategies.

PDUFA decision for zilganersen in Alexander disease

Zilganersen · Alexander disease (AxD)

Ionis' antisense oligonucleotide zilganersen is under priority review for Alexander disease, a progressive and often fatal genetic leukodystrophy with no approved treatment. The pivotal study met its primary endpoint, showing statistically significant stabilization of gait speed at week 61, with supportive motor-function results in children ages 2-4.

Approval probability looks high given clean pivotal data and priority review. For Ionis, a mid/large-cap with several launches underway, the single-day stock impact should be moderate — but a first-ever AxD approval extends Ionis' wholly-owned rare neurology franchise and validates its independent commercialization strategy.

Phase 3 LUCIDITY topline data for avexitide in post-bariatric hypoglycemia

Avexitide · Post-bariatric hypoglycemia (PBH)

Amylyx — rebuilding after the Relyvrio withdrawal — reads out its Phase 3 LUCIDITY study of avexitide, a GLP-1 receptor antagonist for post-bariatric hypoglycemia, guided for Q3 2026. PBH affects a meaningful share of the growing bariatric-surgery population and has no approved therapy.

Avexitide carries FDA Breakthrough Therapy designation with earlier Phase 2 studies showing consistent reductions in hypoglycemic events. A clean Phase 3 hit sets up an NDA and gives Amylyx a genuine second act; a miss returns the story to its earlier-stage pipeline.

Phase 3 Panorama topline data for DT120 ODT in generalized anxiety disorder

DT120 ODT (lysergide D-tartrate, formerly MM120) · Generalized anxiety disorder (GAD)

Definium Therapeutics — MindMed's new name and ticker since January 2026 — expects topline data from Panorama, the second pivotal Phase 3 study of its LSD-based DT120 ODT in generalized anxiety disorder, in the second half of 2026. The window opens this quarter, so watch for timing updates on Q3 earnings calls.

Panorama's primary endpoint is HAM-A change at week 12 for the 100 µg dose versus placebo across ~250 patients. DT120 holds Breakthrough Therapy designation; a second positive pivotal would substantially de-risk the first serious psychedelic-derived NDA filing in psychiatry and re-rate the whole category.