Last reviewed 2026-06-02 · How we verify

mesuximide

Assistance Publique - Hôpitaux de Paris · Phase 2 active Biologic ✓ Verified Jun 2026

mesuximide is a Biologic drug developed by Assistance Publique - Hôpitaux de Paris. It is currently in Phase 2 development for Absence seizure, Epilepsy.

Mesuximide is a succinimide anticonvulsant medication sold under the tradenames Petinutin and Celontin. It is used to treat epilepsy, with its therapeutic efficacy attributed to its pharmacologically active metabolite, N-desmethylmethosuximide.

Likelihood of approval

12.3% vs 15.3% industry baseline

If approved by FDA: likely 2031–2034

Steps remaining: Phase 3 → NDA/BLA submission

Confidence: Medium

Why this estimate

Baseline phase 2 → approval rate +15.3pp
Industry-wide phase 2 drugs reach approval ~15.3% of the time (BIO/Informa 2023 industry benchmark across all therapeutic areas).
CNS / neurology attrition -3.0pp
CNS drugs have historically high Phase 3 failure rates (notably in Alzheimer disease + major depression).

Predicted approval windows by jurisdiction (conditional on FDA approval)

Regulator	Country	Likely year	Lag vs FDA
FDA	US	2031–2034	—
EMA	EU	2032–2035	+0.7 yr
MHRA	GB	2032–2035	+0.7 yr
Health Canada	CA	2032–2036	+0.9 yr
TGA	AU	2032–2036	+1.2 yr
PMDA	JP	2032–2036	+1.5 yr
NMPA	CN	2033–2037	+2.3 yr
MFDS	KR	2032–2036	+1.4 yr
CDSCO	IN	2032–2037	+1.8 yr
ANVISA	BR	2033–2037	+2.3 yr

Hover any row for the lag rationale. Lag estimates are reduced when the drug has FDA Breakthrough or EMA PRIME designation (sponsors file globally in parallel).

Estimate based on the BIO/Informa industry phase transition rates plus per-drug modifiers for therapeutic area, sponsor type, FDA designations, mechanism, and trial design. Per-jurisdiction lags from Tufts CSDD international approval studies. Not investment, clinical or regulatory advice. Methodology: /methodology#likelihood.

At a glance

Generic name	mesuximide
Sponsor	Assistance Publique - Hôpitaux de Paris
Target	Voltage-gated T-type calcium channel
Modality	Biologic
Therapeutic area	Neuroscience
Phase	Phase 2

Approved indications

Absence seizure
Epilepsy

Common side effects

No common side effects on file.

Key clinical trials

Population Pharmacokinetics of Antiepileptic in Pediatrics

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Source	Used for
ClinicalTrials.gov	Trial enrolment, design, endpoints, results

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

mesuximide CI brief — competitive landscape report
mesuximide updates RSS · CI watch RSS
Assistance Publique - Hôpitaux de Paris portfolio CI

Frequently asked questions about mesuximide

What is mesuximide?

mesuximide is a Biologic drug developed by Assistance Publique - Hôpitaux de Paris, indicated for Absence seizure, Epilepsy.

What is mesuximide used for?

mesuximide is indicated for Absence seizure, Epilepsy.

Who makes mesuximide?

mesuximide is developed by Assistance Publique - Hôpitaux de Paris (see full Assistance Publique - Hôpitaux de Paris pipeline at /company/assistance-publique-h-pitaux-de-paris).

What development phase is mesuximide in?

mesuximide is in Phase 2.

What does mesuximide target?

mesuximide targets Voltage-gated T-type calcium channel.

Target: All drugs targeting Voltage-gated T-type calcium channel
Manufacturer: Assistance Publique - Hôpitaux de Paris — full pipeline
Therapeutic area: All drugs in Neuroscience
Indication: Drugs for Absence seizure
Indication: Drugs for Epilepsy

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing