Last reviewed 2026-06-02 · How we verify

AN2690, 2.5%

Pfizer · Phase 2 active Small molecule Under review

AN2690, 2.5% is a sodium-activated potassium channel inhibitor Small molecule drug developed by Pfizer. It is currently in Phase 2 development for Treatment of essential tremor.

AN2690 is a small molecule that acts as a selective and potent inhibitor of the sodium-activated potassium channel, KCNN4.

AN2690 is a treatment being studied for onychomycosis, specifically distal, subungual onychomycosis, and onychomycosis, in clinical trials. The treatment is being tested in different concentrations, including 2.5%, 5%, and 7.5%, in a randomized, double-blind, vehicle-controlled study.

Likelihood of approval

15.3% 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).
Big-pharma sponsor +3.0pp
Pfizer is a top-20 pharma sponsor — historical approval rates run ~3pp above average due to scale, regulatory experience, and trial-design quality.

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	AN2690, 2.5%
Sponsor	Pfizer
Drug class	sodium-activated potassium channel inhibitor
Target	KCNN4
Modality	Small molecule
Therapeutic area	Neurology
Phase	Phase 2

Mechanism of action

By inhibiting KCNN4, AN2690 is thought to reduce the excitability of neurons and potentially alleviate symptoms of certain neurological disorders. The exact mechanism of action is still being investigated, but it is believed to involve a reduction in the release of neurotransmitters and a decrease in neuronal excitability.

Approved indications

Treatment of essential tremor

Common side effects

Headache
Dizziness
Nausea

Key clinical trials

Cumulative Irritation Test (PHASE1)
Study of Different Doses of a Novel Treatment for Onychomycosis (PHASE2)
Study of Different Doses of a Novel Treatment for Onychomycosis (PHASE2)

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:

AN2690, 2.5% CI brief — competitive landscape report
AN2690, 2.5% updates RSS · CI watch RSS
Pfizer portfolio CI

Frequently asked questions about AN2690, 2.5%

What is AN2690, 2.5%?

AN2690, 2.5% is a sodium-activated potassium channel inhibitor drug developed by Pfizer, indicated for Treatment of essential tremor.

How does AN2690, 2.5% work?

AN2690 is a small molecule that acts as a selective and potent inhibitor of the sodium-activated potassium channel, KCNN4.

What is AN2690, 2.5% used for?

AN2690, 2.5% is indicated for Treatment of essential tremor.

Who makes AN2690, 2.5%?

AN2690, 2.5% is developed by Pfizer (see full Pfizer pipeline at /company/pfizer).

What drug class is AN2690, 2.5% in?

AN2690, 2.5% belongs to the sodium-activated potassium channel inhibitor class. See all sodium-activated potassium channel inhibitor drugs at /class/sodium-activated-potassium-channel-inhibitor.

What development phase is AN2690, 2.5% in?

AN2690, 2.5% is in Phase 2.

What are the side effects of AN2690, 2.5%?

Common side effects of AN2690, 2.5% include Headache, Dizziness, Nausea.

What does AN2690, 2.5% target?

AN2690, 2.5% targets KCNN4 and is a sodium-activated potassium channel inhibitor.

Drug class: All sodium-activated potassium channel inhibitor drugs
Target: All drugs targeting KCNN4
Manufacturer: Pfizer — full pipeline
Therapeutic area: All drugs in Neurology
Indication: Drugs for Treatment of essential tremor

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