Last reviewed · How we verify

ESL - Part II

Bial - Portela C S.A. · Phase 3 active Small molecule

ESL - Part II is a Voltage-gated sodium channel inhibitor Small molecule drug developed by Bial - Portela C S.A.. It is currently in Phase 3 development for Partial-onset seizures (adjunctive therapy), Generalized tonic-clonic seizures (adjunctive therapy). Also known as: Eslicarbazepine acetate (ESL), BIA 2-093.

ESL (eslicarbazepine acetate) is a voltage-gated sodium channel blocker that reduces neuronal excitability to prevent seizures.

ESL (eslicarbazepine acetate) is a voltage-gated sodium channel blocker that reduces neuronal excitability to prevent seizures. Used for Partial-onset seizures (adjunctive therapy), Generalized tonic-clonic seizures (adjunctive therapy).

Likelihood of approval
55.3% vs 58.3% industry baseline
If approved by FDA: likely 2028–2030
Steps remaining: NDA/BLA submission
Confidence: High
Why this estimate
  • Baseline phase 3 → approval rate +58.3pp
    Industry-wide phase 3 drugs reach approval ~58.3% 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 2028–2030
EMA EU 2029–2031 +0.7 yr
MHRA GB 2029–2031 +0.7 yr
Health Canada CA 2029–2032 +0.9 yr
TGA AU 2029–2032 +1.2 yr
PMDA JP 2029–2032 +1.5 yr
NMPA CN 2030–2033 +2.3 yr
MFDS KR 2029–2032 +1.4 yr
CDSCO IN 2029–2033 +1.8 yr
ANVISA BR 2030–2033 +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 nameESL - Part II
Also known asEslicarbazepine acetate (ESL), BIA 2-093
SponsorBial - Portela C S.A.
Drug classVoltage-gated sodium channel inhibitor
TargetVoltage-gated sodium channels (Nav)
ModalitySmall molecule
Therapeutic areaNeurology
PhasePhase 3

Mechanism of action

ESL is a prodrug that is rapidly converted to eslicarbazepine, its active metabolite, which selectively inhibits voltage-gated sodium channels in their inactive state. This stabilization of the inactive channel conformation reduces repetitive neuronal firing and propagation of seizure activity. The drug also has weak inhibitory effects on calcium channels, contributing to its anticonvulsant properties.

Approved indications

Common side effects

Key clinical trials

Primary sources

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

SourceUsed for
ClinicalTrials.govTrial 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:

Frequently asked questions about ESL - Part II

What is ESL - Part II?

ESL - Part II is a Voltage-gated sodium channel inhibitor drug developed by Bial - Portela C S.A., indicated for Partial-onset seizures (adjunctive therapy), Generalized tonic-clonic seizures (adjunctive therapy).

How does ESL - Part II work?

ESL (eslicarbazepine acetate) is a voltage-gated sodium channel blocker that reduces neuronal excitability to prevent seizures.

What is ESL - Part II used for?

ESL - Part II is indicated for Partial-onset seizures (adjunctive therapy), Generalized tonic-clonic seizures (adjunctive therapy).

Who makes ESL - Part II?

ESL - Part II is developed by Bial - Portela C S.A. (see full Bial - Portela C S.A. pipeline at /company/bial-portela-c-s-a).

Is ESL - Part II also known as anything else?

ESL - Part II is also known as Eslicarbazepine acetate (ESL), BIA 2-093.

What drug class is ESL - Part II in?

ESL - Part II belongs to the Voltage-gated sodium channel inhibitor class. See all Voltage-gated sodium channel inhibitor drugs at /class/voltage-gated-sodium-channel-inhibitor.

What development phase is ESL - Part II in?

ESL - Part II is in Phase 3.

What are the side effects of ESL - Part II?

Common side effects of ESL - Part II include Dizziness, Somnolence, Headache, Diplopia, Ataxia, Hyponatremia.

What does ESL - Part II target?

ESL - Part II targets Voltage-gated sodium channels (Nav) and is a Voltage-gated sodium channel inhibitor.

Related

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