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OPC-41061

Otsuka Pharmaceutical Co., Ltd. · Phase 3 active Small molecule ✓ Verified May 2026

OPC-41061 is a Vasopressin V2 receptor antagonist (vaptан) Small molecule drug developed by Otsuka Pharmaceutical Co., Ltd.. It is currently in Phase 3 development for Hyponatremia associated with heart failure, Hyponatremia associated with cirrhosis, Hyponatremia associated with syndrome of inappropriate antidiuretic hormone secretion (SIADH). Also known as: Tolvaptan.

OPC-41061 is a vasopressin V2 receptor antagonist (vaptан) that blocks water reabsorption in the kidney collecting duct, promoting aquaresis and increasing serum sodium levels.

OPC-41061 is a small molecule that acts as a vasopressin V2 receptor antagonist. It has been studied in clinical trials for various conditions, including Autosomal Dominant Polycystic Kidney Disease, Heart Failure, and Syndrome of Inappropriate Antidiuretic Hormone Secretion.

Likelihood of approval
56.3% 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).
  • Cardiovascular Phase 3 risk -2.0pp
    Modern cardiovascular outcome trials are large + long; many fail to beat aggressive standard-of-care.
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 nameOPC-41061
Also known asTolvaptan
SponsorOtsuka Pharmaceutical Co., Ltd.
Drug classVasopressin V2 receptor antagonist (vaptан)
TargetVasopressin V2 receptor
ModalitySmall molecule
Therapeutic areaCardiovascular / Nephrology
PhasePhase 3

Mechanism of action

By antagonizing the V2 vasopressin receptor on the collecting duct principal cells, OPC-41061 prevents aquaporin-2 water channel insertion and reduces water reabsorption. This leads to increased urine output and free water excretion while retaining sodium, effectively raising serum osmolality and sodium concentration. The drug is used to treat hyponatremia and fluid overload conditions associated with heart failure, cirrhosis, and SIADH.

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 OPC-41061

What is OPC-41061?

OPC-41061 is a Vasopressin V2 receptor antagonist (vaptан) drug developed by Otsuka Pharmaceutical Co., Ltd., indicated for Hyponatremia associated with heart failure, Hyponatremia associated with cirrhosis, Hyponatremia associated with syndrome of inappropriate antidiuretic hormone secretion (SIADH).

How does OPC-41061 work?

OPC-41061 is a vasopressin V2 receptor antagonist (vaptан) that blocks water reabsorption in the kidney collecting duct, promoting aquaresis and increasing serum sodium levels.

What is OPC-41061 used for?

OPC-41061 is indicated for Hyponatremia associated with heart failure, Hyponatremia associated with cirrhosis, Hyponatremia associated with syndrome of inappropriate antidiuretic hormone secretion (SIADH).

Who makes OPC-41061?

OPC-41061 is developed by Otsuka Pharmaceutical Co., Ltd. (see full Otsuka Pharmaceutical Co., Ltd. pipeline at /company/otsuka).

Is OPC-41061 also known as anything else?

OPC-41061 is also known as Tolvaptan.

What drug class is OPC-41061 in?

OPC-41061 belongs to the Vasopressin V2 receptor antagonist (vaptан) class. See all Vasopressin V2 receptor antagonist (vaptан) drugs at /class/vasopressin-v2-receptor-antagonist-vapt.

What development phase is OPC-41061 in?

OPC-41061 is in Phase 3.

What are the side effects of OPC-41061?

Common side effects of OPC-41061 include Thirst, Dry mouth, Hypernatremia, Polyuria, Dehydration.

What does OPC-41061 target?

OPC-41061 targets Vasopressin V2 receptor and is a Vasopressin V2 receptor antagonist (vaptан).

Related

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