Last reviewed · How we verify

Comparator: ondansetron IV

Merck Sharp & Dohme LLC · Phase 3 active Small molecule ✓ Verified May 2026

Comparator: ondansetron IV is a 5-HT3 receptor antagonist Small molecule drug developed by Merck Sharp & Dohme LLC. It is currently in Phase 3 development for Prevention of nausea and vomiting induced by chemotherapy, Prevention of postoperative nausea and vomiting, Prevention of radiation-induced nausea and vomiting.

Ondansetron is a selective 5-HT3 receptor antagonist that blocks serotonin signaling in the chemoreceptor trigger zone and gastrointestinal tract to prevent nausea and vomiting.

Ondansetron IV is a small molecule used as a comparator in clinical trials for conditions such as chemotherapy-induced nausea and vomiting, post-operative nausea and vomiting, and pruritus. It has been compared to other interventions, including fosaprepitant dimeglumine, aprepitant, and dexamethasone, in studies such as NCT00619359.

Likelihood of approval
61.3% 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).
  • Big-pharma sponsor +3.0pp
    Merck Sharp & Dohme LLC 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 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 nameComparator: ondansetron IV
SponsorMerck Sharp & Dohme LLC
Drug class5-HT3 receptor antagonist
Target5-HT3 receptor
ModalitySmall molecule
Therapeutic areaSupportive Care / Antiemetic
PhasePhase 3

Mechanism of action

Ondansetron selectively antagonizes 5-hydroxytryptamine (serotonin) at the 5-HT3 receptor, which is located on vagal afferent nerves in the gastrointestinal tract and in the chemoreceptor trigger zone of the brain. By blocking these receptors, it prevents the transmission of emetic signals that would otherwise trigger the vomiting center, making it highly effective for chemotherapy-induced nausea and vomiting (CINV) and postoperative nausea and vomiting (PONV).

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 Comparator: ondansetron IV

What is Comparator: ondansetron IV?

Comparator: ondansetron IV is a 5-HT3 receptor antagonist drug developed by Merck Sharp & Dohme LLC, indicated for Prevention of nausea and vomiting induced by chemotherapy, Prevention of postoperative nausea and vomiting, Prevention of radiation-induced nausea and vomiting.

How does Comparator: ondansetron IV work?

Ondansetron is a selective 5-HT3 receptor antagonist that blocks serotonin signaling in the chemoreceptor trigger zone and gastrointestinal tract to prevent nausea and vomiting.

What is Comparator: ondansetron IV used for?

Comparator: ondansetron IV is indicated for Prevention of nausea and vomiting induced by chemotherapy, Prevention of postoperative nausea and vomiting, Prevention of radiation-induced nausea and vomiting.

Who makes Comparator: ondansetron IV?

Comparator: ondansetron IV is developed by Merck Sharp & Dohme LLC (see full Merck Sharp & Dohme LLC pipeline at /company/merck).

What drug class is Comparator: ondansetron IV in?

Comparator: ondansetron IV belongs to the 5-HT3 receptor antagonist class. See all 5-HT3 receptor antagonist drugs at /class/5-ht3-receptor-antagonist.

What development phase is Comparator: ondansetron IV in?

Comparator: ondansetron IV is in Phase 3.

What are the side effects of Comparator: ondansetron IV?

Common side effects of Comparator: ondansetron IV include Headache, Constipation, Diarrhea, Fatigue, Dizziness.

What does Comparator: ondansetron IV target?

Comparator: ondansetron IV targets 5-HT3 receptor and is a 5-HT3 receptor antagonist.

Related

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