Last reviewed 2026-04-22 · How we verify

DSP-5423P Active-to-Flex

Sumitomo Pharma Co., Ltd. · Phase 3 active Small molecule

DSP-5423P Active-to-Flex is a Dopamine D1 receptor partial agonist Small molecule drug developed by Sumitomo Pharma Co., Ltd.. It is currently in Phase 3 development for Parkinson's disease (in development).

DSP-5423P is a selective dopamine D1 receptor partial agonist designed to modulate dopaminergic signaling in the central nervous system.

DSP-5423P is a selective dopamine D1 receptor partial agonist designed to modulate dopaminergic signaling in the central nervous system. Used for Parkinson's disease (in development).

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 name	DSP-5423P Active-to-Flex
Sponsor	Sumitomo Pharma Co., Ltd.
Drug class	Dopamine D1 receptor partial agonist
Target	Dopamine D1 receptor (DRD1)
Modality	Small molecule
Therapeutic area	Neurology/Psychiatry
Phase	Phase 3

Mechanism of action

The drug acts as a partial agonist at the dopamine D1 receptor, which plays a key role in motor control, motivation, and cognitive function. By selectively activating D1 receptors, DSP-5423P aims to provide therapeutic benefit while minimizing the side effects associated with full dopamine agonism. The 'Active-to-Flex' designation suggests a flexible dosing or formulation approach to optimize therapeutic outcomes.

Approved indications

Parkinson's disease (in development)

Common side effects

Nausea
Dizziness
Dyskinesia
Headache

Key clinical trials

Confirmatory Study of DSP-5423P in Patients With Schizophrenia (PHASE3)

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:

DSP-5423P Active-to-Flex CI brief — competitive landscape report
DSP-5423P Active-to-Flex updates RSS · CI watch RSS
Sumitomo Pharma Co., Ltd. portfolio CI

Frequently asked questions about DSP-5423P Active-to-Flex

What is DSP-5423P Active-to-Flex?

DSP-5423P Active-to-Flex is a Dopamine D1 receptor partial agonist drug developed by Sumitomo Pharma Co., Ltd., indicated for Parkinson's disease (in development).

How does DSP-5423P Active-to-Flex work?

DSP-5423P is a selective dopamine D1 receptor partial agonist designed to modulate dopaminergic signaling in the central nervous system.

What is DSP-5423P Active-to-Flex used for?

DSP-5423P Active-to-Flex is indicated for Parkinson's disease (in development).

Who makes DSP-5423P Active-to-Flex?

DSP-5423P Active-to-Flex is developed by Sumitomo Pharma Co., Ltd. (see full Sumitomo Pharma Co., Ltd. pipeline at /company/sumitomo-pharma-co-ltd).

What drug class is DSP-5423P Active-to-Flex in?

DSP-5423P Active-to-Flex belongs to the Dopamine D1 receptor partial agonist class. See all Dopamine D1 receptor partial agonist drugs at /class/dopamine-d1-receptor-partial-agonist.

What development phase is DSP-5423P Active-to-Flex in?

DSP-5423P Active-to-Flex is in Phase 3.

What are the side effects of DSP-5423P Active-to-Flex?

Common side effects of DSP-5423P Active-to-Flex include Nausea, Dizziness, Dyskinesia, Headache.

What does DSP-5423P Active-to-Flex target?

DSP-5423P Active-to-Flex targets Dopamine D1 receptor (DRD1) and is a Dopamine D1 receptor partial agonist.

Drug class: All Dopamine D1 receptor partial agonist drugs
Target: All drugs targeting Dopamine D1 receptor (DRD1)
Manufacturer: Sumitomo Pharma Co., Ltd. — full pipeline
Therapeutic area: All drugs in Neurology/Psychiatry
Indication: Drugs for Parkinson's disease (in development)

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