HTR3A 5-hydroxytryptamine receptor 3A
ENSG00000166736 · protein coding · Open Targets profile
Forms serotonin (5-hydroxytryptamine/5-HT3)-activated cation- selective channel complexes, which when activated cause fast, depolarizing responses in neurons. {ECO:0000269|PubMed:10521471, ECO:0000269|PubMed:12867984, ECO:0000269|PubMed:17392525, ECO:0000269|PubMed:9950429}.
Each band is a group of drugs. It runs from the kind of drug on the left to the furthest stage that drug has reached in any disease on the right. Thicker bands mean more drugs.
Approved bands are highlighted. Withdrawn means the drug was pulled from the market or from development. A combined phase counts as the later one (Phase 1/2 is shown as Phase 2). Hover a band for the drug names. Source: Open Targets Platform, fetched live.
Each row is a cancer, strongest overall evidence first. The two dots show how strong the inherited (germline) and tumour-mutation (somatic) evidence is; the line between them is the gap.
Scores run from 0 (no evidence) to 1 (strongest). A missing dot at 0 means Open Targets holds no evidence of that kind. Source: Open Targets Platform, fetched live.
Tractability
- Small molecule
- Approved Drug, Structure with Ligand, High-Quality Ligand, Druggable Family
- Antibody
- UniProt loc high conf, GO CC high conf, UniProt SigP or TMHMM
- PROTAC
- Database Ubiquitination, Small Molecule Binder
gnomAD loss of function constraint: o/e 0.8211100101470947 (upper bound 1.0528000593185425). Low values mean loss of function is poorly tolerated, a safety flag for inhibition.
Who runs trials of these drugs
Principal investigators and study chairs on 366 registry trials, updated in the last three years, of the most advanced drugs against HTR3A (dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulpride), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Benjamin FriedmanMontefiore Medical Center · 3 of 3 trials Phase 2+
- Benjamin W FriedmanMontefiore Medical Center · 2 of 2 trials Phase 2+
- Chunling JiangWest China Hospital · 1 of 3 trials Phase 2+
- Alice P ChenNational Cancer Institute (NCI) · 1 of 2 trials Phase 2+
- Scott M NorbergNational Cancer Institute (NCI) · 1 of 2 trials Phase 2+
- Abdelrahman H MohammedAssiut University · 1 of 1 trials Phase 2+
- Abdelrahman Hamdy MohamedAssiut University · 1 of 1 trials Phase 2+
- Abdelrahman MahmoudSuez Canal University · 1 of 1 trials Phase 2+
- Adil E BharuchaMayo Clinic · 1 of 1 trials Phase 2+
- Ahmed DabourDepartment of Internal Medicine, Faculty of Medicine, Benha University, Benha, Egypt · 1 of 1 trials Phase 2+
- Aimee RolstonUniversity of Michigan Rogel Cancer Center · 1 of 1 trials Phase 2+
- AKM AkhtaruzzamanBangladesh Medical University · 1 of 1 trials Phase 2+
- Alana KoehlerSUNY Buffalo · 1 of 1 trials Phase 2+
- Alden MilamOrthoCarolina Research Institute, Inc. · 1 of 1 trials Phase 2+
- Alex MolasiotisUniversity of Derby · 1 of 1 trials Phase 2+
Registry trials of dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulpride updated in the last three years, counted by the country group of their listed sites. A trial with sites in several groups counts in each; 314 of 323 have all sites in one country.
Site counts are not patients per country, and trials registered only outside ClinicalTrials.gov are not covered. Where sites are is a fact about the record, not a judgement of its quality. Europe is the EU and EEA, the UK and Switzerland. 43 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
119 trials of drugs against HTR3A were stopped early; 14 give no reason
Terminated, withdrawn and suspended interventional trials of dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulpride, newest update first, live from ClinicalTrials.gov. Each reason is quoted exactly as the registry gives it; we do not sort reasons into safety, efficacy or business. Dates are the last registry update. Showing the 25 most recent of 119.
- withdrawn · 2026-10-05 · Health Sciences North Research Institute · Oral metoclopramide and ibuprofen, Intravenous metoclopramide and ketorolac“The project proved not feasible to launch at Health Sciences North.”
- terminated · 2026-05-22 · OrthoCarolina Research Institute, Inc. · matched by the registry's drug synonyms“Low enrollment and subject followup rates”
- terminated · 2026-04-24 · Emory University · Ondansetron“Study was terminated due to enrollment challenges following the relocation of orthopedic procedures to a different hospital.”
- terminated · 2025-12-02 · National Cancer Institute (NCI) · Ondansetron“Site plans to become a site for a multicenter study of this therapy”
- terminated · 2025-11-17 · Hackensack Meridian Health · Prophylactic use of ibuprofen and ondansetron post misoprostol administration, Use of ibuprofen and ondansetron at symptom onset post misoprostol administration“Inability to recruit and staffing changes”
- terminated · 2025-09-11 · DAS-MG, Inc · matched by the registry's drug synonyms“lack of enrollment”
- terminated · 2025-09-08 · Assistance Publique - Hôpitaux de Paris · Metoclopramide“It has been determined that continuing with enrollments in this study is no longer justified due to the lack of significant impact on the expected outcomes.”
- withdrawn · 2025-07-29 · United States Naval Medical Center, Portsmouth · Metoclopramide 10mg“No recruitment occurred and PI retired”
- terminated · 2025-06-18 · University of Michigan Rogel Cancer Center · Ondansetron“Lack of Patient Population”
- terminated · 2025-05-21 · Corewell Health South · Ondansetron 8mg“Lost too many patients to follow up, unable to enroll enough patients”
- terminated · 2025-05-04 · Helsinn Healthcare SA · matched by the registry's drug synonyms“Sponsor's decision”
- withdrawn · 2025-04-27 · University of Alabama at Birmingham · matched by the registry's drug synonyms“No staff or funding to do the study.”
- terminated · 2025-02-27 · Insel Gruppe AG, University Hospital Bern · matched by the registry's drug synonyms“Low recruiting rate”
- terminated · 2024-12-03 · St. Petersburg State Pavlov Medical University · matched by the registry's drug synonyms“Poor recruitment”
- withdrawn · 2024-11-29 · Corewell Health South · matched by the registry's drug synonyms“Did not recruit any participants”
- terminated · 2024-11-29 · Corewell Health South · matched by the registry's drug synonyms“Not able to recruit enough patients; many patients lost to follow up”
- withdrawn · 2024-08-07 · Australasian Leukaemia and Lymphoma Group · matched by the registry's drug synonyms“Study halted prematurely, prior to enrollment of first participant due to protracted logistical and subsequent funding matters.”
- withdrawn · 2024-08-01 · AdventHealth · matched by the registry's drug synonyms“PI Decision based on no enrollment”
- withdrawn · 2024-07-26 · Kyowa Kirin Pharmaceutical Development Ltd · IV granisetron“The company currently does not have plans to conduct this study”
- withdrawn · 2024-07-26 · Kyowa Kirin Pharmaceutical Development Ltd · IV granisetron“The company currently does not have plans to conduct this study”
- withdrawn · 2024-06-24 · University of California, Los Angeles · Amisulpride 50 MG“Action of PI. Loss of sponsor”
- terminated · 2024-03-04 · Mike O'Callaghan Military Hospital · matched by the registry's drug synonyms“study goals met”
- terminated · 2023-12-28 · University of Texas Southwestern Medical Center · matched by the registry's drug synonyms“interim analysis completed”
- terminated · 2023-11-13 · Albert Einstein College of Medicine · Ondansetron 16 MG“Expired IRB approval on 2/11/21”
- withdrawn · 2023-08-14 · University of Nebraska · matched by the registry's drug synonyms“Screenings yielded inadequate eligible subjects to enroll.”
Paediatric incentives and obligations for HTR3A's drugs
For dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulpride: what EMA and FDA publish about paediatric plans, orphan status and pediatric approvals, and how many registered studies take children. Each line is a yes, no or not published fact from the record linked under it; none of it is a forecast.
- FDA pediatric target list: no · HTR3A is not on the listRule: Target is on FDA's Pediatric Molecular Target List (relevant targets). Source: FDA Pediatric Molecular Target List (Listed as February 2026 on the FDA Pediatric Oncology page; the file served is 9.7.22_the_relevant_molecular_target_list.xlsx, whose Summary of Changes sheet is headed 'SEPTEMBER 2022 UPDATE' (footnote date 2022-09-01)), 2026-11-11
- EU paediatric investigation plan: yes · EMEA-001198-PIP04-23 (netupitant;palonosetron, Prevention of chemotherapy-induced nausea and vomiting): W: decision granting a waiver in all age groups for all conditions or indications, 4 Dec 2024; EMEA-001198-PIP03-17-M05 (Fosnetupitant;palonosetron, Prevention of chemotherapy-induced nausea and vomiting): PM: decision on the application for modification of an agreed PIP, 25 Oct 2023; EMEA-002623-PIP01-19 (ondansetron (hydrochloride), Treatment of alcohol use disorder): P: decision agreeing on a investigation plan, with or without partial waiver(s) and or deferral(s), 15 Jul 2020; EMEA-001198-PIP02-16 (Fosnetupitant;palonosetron, Prevention of chemotherapy-induced nausea and vomiting): RW: decision refers to a refusal on a request for waiver in all age groups for the listed condition(s), 21 Dec 2016; +1 moreRule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA data download (dated snapshot), 2026-11-11
- EU orphan designation: no · No EU orphan designation names dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulprideRule: An EU orphan designation lists the drug as its active substance (exact name) or belongs to a medicine that does; withdrawn and expired designations are listed with their status. Source: EMA data download (dated snapshot), 2026-11-11
- Authorised in the EU: yes · Akynzeo: authorised since 27 May 2015; Palonosetron Accord: authorised since 26 May 2016; Sancuso: authorised since 20 Apr 2012; Aloxi: authorised since 22 Mar 2005; +1 moreRule: An EMA medicine record lists the drug as its active substance or INN, exact name; national-only authorisations are not in this file. Source: EMA data download (dated snapshot), 2026-11-11
- FDA orphan designation: not published · FDA's orphan designation database turns away automated requests, so this app does not read it; search it by hand at the linkRule: Would be: an FDA orphan designation names the drug. Source: FDA orphan designations search
- FDA pediatric oncology approval: no · FDA's table lists no pediatric approval of dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulprideRule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-12
- Registered studies open to children: yes · 166 interventional studies of dolasetron, ramosetron, palonosetron, clothiapine, metoclopramide, granisetron, alosetron, ondansetron, cilansetron, vortioxetine hydrobromide, mosapride, amisulpride include patients under 18; 14 are recruiting, not yet recruiting or activeRule: The registry's age group includes Child (birth to 17 years), which also counts studies that set no minimum age. Source: ClinicalTrials.gov search, 2026-11-12
Rare pediatric disease voucher. FDA, content current as of 29 Apr 2026: “As of February 3, 2026, enactment of the Consolidated Appropriations Act, 2026, the rare pediatric disease PRV program will sunset after September 30, 2029. FDA may not award any PRVs under this program after September 30, 2029.” Voucher sale prices are not shown here; they appear only as company-reported news. FDA: Rare Pediatric Disease Designation and Priority Review Voucher Programs
All 29 drugs and clinical candidates as a table
Each drug, stage and indication links to its Open Targets record, where the trials and approvals behind it are listed. Salt forms (for example a mesylate) are listed as Open Targets records them, as separate entries.