HTR1A 5-hydroxytryptamine receptor 1A
ENSG00000178394 · protein coding · Open Targets profile
G protein-coupled receptor for 5-hydroxytryptamine (serotonin) (PubMed:22957663, PubMed:3138543, PubMed:33762731, PubMed:37935376, PubMed:37935377, PubMed:8138923, PubMed:8393041). Also functions as a receptor for various drugs and psychoactive substances (PubMed:22957663, PubMed:3138543, PubMed:33762731, PubMed:38552625, PubMed:8138923, PubMed:8393041). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as adenylate cyclase (PubMed:22957663, PubMed:3138543, PubMed:33762731, PubMed:8138923, PubMed:8393041). HTR1A is coupled to G(i)/G(o) G alpha proteins and mediates inhibitory neurotransmission: signaling inhibits adenylate cyclase activity and activates a phosphatidylinositol-calcium second messenger system that regulates the release of Ca(2+) ions from intracellular stores (PubMed:33762731, PubMed:35610220). Beta-arrestin family members regulate signaling by mediating both receptor desensitization and resensitization processes (PubMed:18476671, PubMed:20363322, PubMed:20945968). Plays a role in the regulation of 5- hydroxytryptamine release and in the regulation of dopamine and 5- hydroxytryptamine metabolism (PubMed:18476671, PubMed:20363322, PubMed:20945968). Plays a role in the regulation of dopamine and 5- hydroxytryptamine levels in the brain, and thereby affects neural activity, mood and behavior (PubMed:18476671, PubMed:20363322, PubMed:20945968). Plays a role in the response to anxiogenic stimuli (PubMed:18476671, PubMed:20363322, PubMed:20945968). {ECO:0000269|PubMed:22957663, ECO:0000269|PubMed:3138543, ECO:0000269|PubMed:33762731, ECO:0000269|PubMed:35610220, ECO:0000269|PubMed:37935376, ECO:0000269|PubMed:37935377, ECO:0000269|PubMed:38552625, ECO:0000269|PubMed:8138923, ECO:0000269|PubMed:8393041, ECO:0000303|PubMed:18476671, ECO:0000303|PubMed:20363322, ECO:0000303|PubMed:20945968}.
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 Withdrawn means the drug was pulled from the market or from development.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
- Other modalities
- Approved Drug
gnomAD loss of function constraint: o/e 0.691569983959198 (upper bound 1.0372999906539917). 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 176 registry trials, updated in the last three years, of the most advanced drugs against HTR1A (gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, amisulpride), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- Wei-Fen XieDirector of department of gastroenterology · 4 of 4 trials Phase 2+
- Benedicto Crespo FacorroFundación para la Gestión de la Investigación en Salud de Sevilla · 3 of 3 trials Phase 2+
- Christoph U CorrellNorth Shore LIJ · 2 of 2 trials Phase 2+
- Eric LenzeWashington University School of Medicine · 2 of 2 trials Phase 2+
- Rudolf UherNova Scotia Health Authority · 2 of 2 trials Phase 2+
- Takeshi TsunodaOtsuka Pharmaceutical Co., Ltd. · 2 of 2 trials Phase 2+
- Gagan JoshiMassachusetts General Hospital · 1 of 2 trials Phase 2+
- albert KK ChungThe University of Hong Kong · 1 of 1 trials Phase 2+
- Anders Fink-JensenPsychiatric Centre Copenhagen. University of Copenhagen. · 1 of 1 trials Phase 2+
- Andrew D. KrystalUniversity of California, San Francisco · 1 of 1 trials Phase 2+
- Angela M SousaUniversity of Sao Paulo · 1 of 1 trials Phase 2+
- Angela Maxwell-HornVanderbilt University Medical Center · 1 of 1 trials Phase 2+
- Aristotle VoineskosCentre for Addiction and Mental Health · 1 of 1 trials Phase 2+
- Atilla CeranogluMassachusetts General Hospital · 1 of 1 trials Phase 2+
- Aysegul OzerdemMayo Clinic · 1 of 1 trials Phase 2+
Registry trials of gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, 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; 142 of 157 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. 19 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
98 trials of drugs against HTR1A were stopped early; 11 give no reason
Terminated, withdrawn and suspended interventional trials of gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, 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 98.
- terminated · 2026-09-14 · Denovo Biopharma LLC · Aripiprazole“The decision to stop the trial was based on efficacy results in the overall schizophrenia participant population.”
- suspended · 2026-06-30 · Global Coalition for Adaptive Research · Intervention B Vilazodone Hydrochloride (HCl)“The trial has been temporarily suspended due to administrative issues”
- terminated · 2026-02-25 · Ohio State University · matched by the registry's drug synonyms“Not able to recruit enough subjects”
- terminated · 2026-02-06 · University of Miami · Aripiprazole Lauroxil“Recruitment issues”
- terminated · 2025-10-02 · Northwestern University · aripiprazole (Abilify)“unable to secure additional funding”
- withdrawn · 2025-01-20 · Children's Hospital of Fudan University · Drug Aripiprazole“The study has been temporarily halted due to a malfunction with the biofeedback equipment we are using. At present, we do not have the necessary funds to repair the equipment, and as a result, the research has been suspended for the time being.”
- withdrawn · 2024-09-26 · Massachusetts General Hospital · Buspirone“This study was withdrawn due to competing research interests and slow recruitment.”
- withdrawn · 2024-06-28 · Massachusetts General Hospital · Buspirone“This study was withdrawn due to competing research interests and slow recruitment.”
- withdrawn · 2024-06-24 · University of California, Los Angeles · Amisulpride 50 MG“Action of PI. Loss of sponsor”
- withdrawn · 2024-02-02 · Noam Soreni · Vortioxetine Tablets“COVID-19 pandemic”
- terminated · 2024-01-23 · Otsuka Pharmaceutical Development & Commercialization, Inc. · matched by the registry's drug synonyms“The decision to terminate the trial early was not based on safety concerns. The trial was terminated early due to some implausible blood pressure values being captured, which was the primary endpoint of the study.”
- withdrawn · 2024-01-05 · VA Office of Research and Development · Aripiprazole“Study funding was withdrawn by study sponsor (CSR\&D) prior to enrollment due to budget constraints.”
- terminated · 2023-11-28 · University of California, Los Angeles · Aripiprazole Lauroxil“Withdraw of financial support by industry collaborator”
- terminated · 2023-11-15 · Northwell Health · AripiprazoleNo reason given
- withdrawn · 2023-01-30 · Otsuka Pharmaceutical Development & Commercialization, Inc. · Brexpiprazole“Sponsor strategic decision”
- terminated · 2023-01-05 · H. Lundbeck A/S · Vortioxetine“The study was terminated based on new efficacy data from another study.”
- terminated · 2022-12-28 · H. Lundbeck A/S · Vortioxetine“The study was terminated based on new efficacy data from another study.”
- withdrawn · 2022-11-29 · Todd Doyle · Vortioxetine“COVID-19 Pandemic interfered with Pt recruitment”
- withdrawn · 2022-09-14 · Shanghai Mental Health Center · Aripiprazole“Loss of finacial support”
- terminated · 2022-09-07 · Denovo Biopharma LLC · Aripiprazole“The decision to stop the trial was based on efficacy results in the overall schizophrenia participant population.”
- withdrawn · 2022-08-10 · University Hospital Freiburg · Aripiprazole“Initiation of study was stopped due to administrative reasons before first subject was enrolled.”
- withdrawn · 2022-04-28 · Otsuka Pharmaceutical Co., Ltd. · Brexpiprazole LAI: Dose 1, Brexpiprazole LAI: Dose 2, Brexpiprazole LAI: Dose 3, Brexpiprazole LAI: Dose 4“Sponsor decision:Change the Development plan”
- terminated · 2021-12-22 · Otsuka Pharmaceutical Development & Commercialization, Inc. · Aripiprazole“The study was terminated early due to Sponsor decision; no safety issues.”
- terminated · 2021-12-21 · Otsuka Pharmaceutical Development & Commercialization, Inc. · Aripiprazole“The study was terminated early due to Sponsor decision, closure of this combination therapy program is unrelated to any safety issues, no signals of concern.”
- terminated · 2021-10-26 · Otsuka Pharmaceutical Development & Commercialization, Inc. · Aripiprazole“The study was terminated early due to Sponsor decision, closure of this combination therapy program is unrelated to any safety issues, no signals of concern.”
Paediatric incentives and obligations for HTR1A's drugs
For gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, 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 · HTR1A 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 · EMA/PE/0000183866 (brexpiprazole, Treatment of schizophrenia): PM: decision on the application for modification of an agreed PIP, 5 Dec 2024; EMEA-000455-PIP02-10-M09 (vortioxetine, Treatment of major depressive disorder): PM: decision on the application for modification of an agreed PIP, 10 Aug 2022; compliance positive 20 Jan 2023; EMEA-000235-PIP02-10-M02 (aripiprazole, Treatment of bipolar affective disorder;Treatment of schizophrenia): PM: decision on the application for modification of an agreed PIP, 26 Oct 2012; compliance positive 24 Jun 2016Rule: 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 gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, 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 · Aripiprazole Sandoz: authorised since 20 Aug 2015; Rxulti: authorised since 26 Jul 2018; Aripiprazole Zentiva: authorised since 25 Jun 2015; Aripiprazole Mylan Pharma (previously Aripiprazole Pharmathen): authorised since 30 Jun 2015; +8 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 gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, 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 · 134 interventional studies of gepirone, vortioxetine hydrobromide, methysergide, buspirone, vilazodone, ergoloid mesylates, alverine, aripiprazole, vortioxetine, brexpiprazole, aripiprazole lauroxil, amisulpride include patients under 18; 7 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 35 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.