HTR2B 5-hydroxytryptamine receptor 2B
ENSG00000135914 · protein coding · Open Targets profile
G protein-coupled receptor for 5-hydroxytryptamine (serotonin) (PubMed:18703043, PubMed:23519210, PubMed:7926008, PubMed:8078486, PubMed:8143856, PubMed:8882600). Also functions as a receptor for various ergot alkaloid derivatives and psychoactive substances (PubMed:12970106, PubMed:18703043, PubMed:23519210, PubMed:23519215, PubMed:24357322, PubMed:28129538, PubMed:30127358, PubMed:36087581, PubMed:7926008, PubMed:8078486, PubMed:8143856). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors (PubMed:23519215, PubMed:28129538, PubMed:8078486, PubMed:8143856, PubMed:8882600). HTR2B is coupled to G(q)/G(11) G alpha proteins and activates phospholipase C-beta, releasing diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) second messengers that modulate the activity of phosphatidylinositol 3- kinase and promote the release of Ca(2+) ions from intracellular stores, respectively (PubMed:18703043, PubMed:23519215, PubMed:28129538, PubMed:30127358, PubMed:36087581, PubMed:8078486, PubMed:8143856, PubMed:8882600). Beta-arrestin family members inhibit signaling via G proteins and mediate activation of alternative signaling pathways (PubMed:23519215, PubMed:28129538, PubMed:30127358, PubMed:36087581). Plays a role in the regulation of dopamine and 5- hydroxytryptamine release, 5-hydroxytryptamine uptake and in the regulation of extracellular dopamine and 5-hydroxytryptamine levels, and thereby affects neural activity. May play a role in the perception of pain (By similarity). Plays a role in the regulation of behavior, including impulsive behavior (PubMed:21179162). Required for normal proliferation of embryonic cardiac myocytes and normal heart development (By similarity). Protects cardiomyocytes against apoptosis (By similarity). Plays a role in the adaptation of pulmonary arteries to chronic hypoxia (By similarity). Plays a role in vasoconstriction (By similarity). Required for normal osteoblast function and proliferation, and for maintaining normal bone density (By similarity). Required for normal proliferation of the interstitial cells of Cajal in the intestine (By similarity). {ECO:0000250|UniProtKB:Q02152, ECO:0000269|PubMed:12970106, ECO:0000269|PubMed:18703043, ECO:0000269|PubMed:21179162, ECO:0000269|PubMed:23519210, ECO:0000269|PubMed:23519215, ECO:0000269|PubMed:24357322, ECO:0000269|PubMed:28129538, ECO:0000269|PubMed:30127358, ECO:0000269|PubMed:36087581, ECO:0000269|PubMed:7926008, ECO:0000269|PubMed:8078486, ECO:0000269|PubMed:8143856, ECO:0000269|PubMed:8882600}.
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 0.7780900001525879 (upper bound 1.0500999689102173). 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 27 registry trials, updated in the last three years, of the most advanced drugs against HTR2B (methylergonovine, clothiapine, methysergide, amisulpride, PRX-08066, vabicaserin), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Tiffany E AngeloStony Brook University Hospital Department of Anesthesiology · 2 of 2 trials Phase 2+
- Angela M SousaUniversity of Sao Paulo · 1 of 1 trials Phase 2+
- Benedicto Crespo FacorroAndalusian Health Service · 1 of 1 trials Phase 2+
- Biswa R MishraAll India Institute of Medical Sciences, Bhubaneswar · 1 of 1 trials Phase 2+
- DengTang LiuShanghai Mental Health Center · 1 of 1 trials Phase 2+
- F. Markus LewekeCentral Institute of Mental Health · 1 of 1 trials Phase 2+
- Justin S LibermanVirginia Mason Medical Center · 1 of 1 trials Phase 2+
- Kumar BelaniUniversity of Minnesota Masonic Children's Hospital · 1 of 1 trials Phase 2+
- Mirella MouradColumbia University · 1 of 1 trials Phase 2+
- Naida M ColeBrigham and Women's Hospital, 75 Francis Street, Boston MA 02115 · 1 of 1 trials Phase 2+
- Christian KeicherCharite University, Berlin, Germany · 0 of 1 trials Phase 2+
- Diego PizzagalliMclean Hospital · 0 of 1 trials Phase 2+
- Gang ChenSir Run Run Shaw Hospital · 0 of 1 trials Phase 2+
- Guido FrankUniversity of California, San Diego · 0 of 1 trials Phase 2+
- Jack StecherBUMC Labor and Delivery · 0 of 1 trials Phase 2+
Registry trials of methylergonovine, clothiapine, methysergide, amisulpride, PRX-08066, vabicaserin 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; 21 of 22 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. 5 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
11 trials of drugs against HTR2B were stopped early; 5 give no reason
Terminated, withdrawn and suspended interventional trials of methylergonovine, clothiapine, methysergide, amisulpride, PRX-08066, vabicaserin, 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 11 most recent of 11.
- terminated · 2026-01-26 · Baylor Research Institute · matched by the registry's drug synonyms“Difficulty in acquiring patients in a reasonable amount of time.”
- withdrawn · 2024-06-24 · University of California, Los Angeles · Amisulpride 50 MG“Action of PI. Loss of sponsor”
- terminated · 2020-11-25 · RWTH Aachen University · matched by the registry's drug synonyms“slow patient recruitment, low patient-commpliance, high dropout rates,”
- withdrawn · 2020-08-03 · Johns Hopkins University · Methylergonovine“Collaborators left the institution.”
- terminated · 2018-02-28 · Hannover Medical School · AmisulprideNo reason given
- terminated · 2017-04-19 · Institute of Psychiatry, London · matched by the registry's drug synonyms“Failure to recruit people with very late onset schizophrenia like psychosis”
- terminated · 2016-03-01 · Kaohsiung Kai-Suan Psychiatric Hospital · full-dose amisulprideNo reason given
- withdrawn · 2015-12-09 · Geha Mental Health Center · Amisulpride, Clozapine+AmisulprideNo reason given
- withdrawn · 2013-01-29 · Wyeth is now a wholly owned subsidiary of Pfizer · matched by the registry's drug synonymsNo reason given
- terminated · 2009-07-30 · Epix Pharmaceuticals, Inc. · PRX-08066No reason given
- terminated · 2008-09-16 · University of Jena · Amisulpride“Recruitment issues”
Paediatric incentives and obligations for HTR2B's drugs
For methylergonovine, clothiapine, methysergide, amisulpride, PRX-08066, vabicaserin: 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 · HTR2B 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: no · No EMA paediatric investigation plan decision names methylergonovine, clothiapine, methysergide, amisulpride, prx-08066, vabicaserinRule: 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 methylergonovine, clothiapine, methysergide, amisulpride, prx-08066, vabicaserinRule: 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: no · EMA lists no centrally authorised medicine of methylergonovine, clothiapine, methysergide, amisulpride, prx-08066, vabicaserinRule: 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 methylergonovine, clothiapine, methysergide, amisulpride, prx-08066, vabicaserinRule: 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 · 8 interventional studies of methylergonovine, clothiapine, methysergide, amisulpride, prx-08066, vabicaserin include patients under 18; 0 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 13 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.