OncoSignal
Live from Open Targets Platform, fetched 2026-11-12 04:01 UTC. Every row links to its source record.

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}.

15 of the 35 drugs recorded against HTR1A are approved, and 8 more reached Phase 3

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.

14 small molecule drugs at Approved: GEPIRONE HYDROCHLORIDE, VORTIOXETINE HYDROBROMIDE, METHYSERGIDE, BUSPIRONE HYDROCHLORIDE, VILAZODONE HYDROCHLORIDE, GEPIRONE, ALVERINE, ARIPIPRAZOLE, VILAZODONE, VORTIOXETINE, BREXPIPRAZOLE, BUSPIRONE…8 small molecule drugs at Phase 3: BIFEPRUNOX, NALUZOTAN, SARIZOTAN, XALIPRODEN, ULOTARONT, PARDOPRUNOX, LECOZOTAN HYDROCHLORIDE, LECOZOTAN7 small molecule drugs at Phase 2: BEFIRADOL, ROBALZOTAN, SARIZOTAN HYDROCHLORIDE, GSK163090, PICLOZOTAN, DU 125530, OSEMOZOTAN1 small molecule drug at Phase 1: ADOPRAZINE4 small molecule drugs at Withdrawn: DEXFENFLURAMINE, ZIMELDINE HYDROCHLORIDE, ZIMELDINE, DEXFENFLURAMINE HYDROCHLORIDE1 unknown drug at Approved: ERGOLOID MESYLATESSmall molecule 34Unknown 1Approved 15Phase 3 8Phase 2 7Phase 1 1Withdrawn 4

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.

In 3 of 15 cancers, the evidence for HTR1A comes mainly from inherited variants

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.

Inherited (germline) variantsMutations in tumours (somatic)
00.250.50.751cervical carcinomacervical carcinomacervical carcinoma: germline 0.48ovarian neoplasmovarian neoplasmovarian neoplasm: germline 0.40rectosigmoid junction neoplasmrectosigmoid junction neoplasmrectosigmoid junction neoplasm: germline 0.37breast carcinomabreast carcinomabreast cancerbreast cancerglioblastomaglioblastomalymphomalymphomacentral nervous system cancercentral nervous system cancermyelodysplastic syndromemyelodysplastic syndrometriple-negative breast carcinomatriple-negative breast carcinomaneuroblastomaneuroblastomaacute myeloid leukemiaacute myeloid leukemiagliomagliomaprostate carcinomaprostate carcinomaprostate cancerprostate cancer

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.

68 of 157 trials of drugs against HTR1A have sites only in United States

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.

Sites only in this groupSites here and elsewhere
United StatesUnited States: 68 trials with sites only hereUnited States: 14 trials with sites here and elsewhere82ChinaChina: 20 trials with sites only hereChina: 0 trials with sites here and elsewhere20EuropeEurope: 20 trials with sites only hereEurope: 5 trials with sites here and elsewhere25JapanJapan: 10 trials with sites only hereJapan: 1 trials with sites here and elsewhere11OtherOther: 25 trials with sites only hereOther: 14 trials with sites here and elsewhere39

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 · Aripiprazole
    No 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.

  • 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 2016
    Rule: 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, amisulpride
    Rule: 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 more
    Rule: 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 link
    Rule: 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, amisulpride
    Rule: 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 active
    Rule: 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.

DrugTypeHighest stageIndicationsSource records
GEPIRONE HYDROCHLORIDESmall moleculeapprovalmajor depressive disorderOpen Targets · ChEMBL
VORTIOXETINE HYDROBROMIDESmall moleculeapprovalmajor depressive disorder, depressive disorderOpen Targets · ChEMBL
METHYSERGIDESmall moleculeapprovalmigraine disorderOpen Targets · ChEMBL
BUSPIRONE HYDROCHLORIDESmall moleculeapprovalanxiety disorder, depressive disorder, generalized anxiety disorder, VomitingOpen Targets · ChEMBL
VILAZODONE HYDROCHLORIDESmall moleculeapprovalmajor depressive disorder, post-traumatic stress disorderOpen Targets · ChEMBL
ERGOLOID MESYLATESUnknownapprovalcardiovascular disorder, vascular dementia, fragile X syndromeOpen Targets · ChEMBL
GEPIRONESmall moleculeapprovalmajor depressive disorder, anxiety disorder, psychotic disorder, cocaine dependence, depressive disorderOpen Targets · ChEMBL
ALVERINESmall moleculeapprovalgastrointestinal disease, portal hypertension, cirrhosis of liverOpen Targets · ChEMBL
ARIPIPRAZOLESmall moleculephase 4schizophrenia, psychotic disorder, bipolar disorder, bipolar I disorder, major depressive disorder, autism spectrum disorder, Agitation, autism, +35 moreOpen Targets · ChEMBL
VILAZODONESmall moleculephase 4major depressive disorder, generalized anxiety disorder, depressive disorder, cannabis dependence, memory impairment, post-traumatic stress disorder, social phobia, bipolar disorderOpen Targets · ChEMBL
VORTIOXETINESmall moleculephase 4major depressive disorder, mood disorder, depressive disorder, generalized anxiety disorder, hoarding disorder, burning mouth syndrome, Pain, schizophrenia, +7 moreOpen Targets · ChEMBL
BREXPIPRAZOLESmall moleculephase 4schizophrenia, major depressive disorder, psychotic disorder, Alzheimer disease, Agitation, Irritability, post-traumatic stress disorder, bipolar I disorder, +6 moreOpen Targets · ChEMBL
BUSPIRONESmall moleculephase 4anxiety, anxiety disorder, schizophrenia, schizoaffective disorder, Apnea, Parkinson disease, Vertigo, generalized anxiety disorder, +17 moreOpen Targets · ChEMBL
ARIPIPRAZOLE LAUROXILSmall moleculephase 4schizophrenia, schizoaffective disorderOpen Targets · ChEMBL
AMISULPRIDESmall moleculephase 4schizophrenia, Nausea and vomiting, post operative nausea and vomiting, psychotic disorder, Drooling, bipolar disorder, Intellectual disability, schizoaffective disorder, +6 moreOpen Targets · ChEMBL
BIFEPRUNOXSmall moleculephase 3schizophrenia, major depressive disorder, depressive disorder, bipolar disorder, psychotic disorder, Atypical behavior, schizoaffective disorderOpen Targets · ChEMBL
NALUZOTANSmall moleculephase 3generalized anxiety disorder, mood disorder, major depressive disorder, epilepsy, SeizureOpen Targets · ChEMBL
SARIZOTANSmall moleculephase 3Parkinson disease, movement disorder, Rett syndrome, cognitive disorder, Cognitive impairmentOpen Targets · ChEMBL
XALIPRODENSmall moleculephase 3Alzheimer disease, juvenile idiopathic arthritis, lateral sclerosis, sensory peripheral neuropathy, psoriasis vulgarisOpen Targets · ChEMBL
ULOTARONTSmall moleculephase 3schizophrenia, generalized anxiety disorder, Parkinson disease, major depressive disorder, narcolepsy-cataplexy syndromeOpen Targets · ChEMBL
PARDOPRUNOXSmall moleculephase 3Parkinson disease, DyskinesiaOpen Targets · ChEMBL
LECOZOTAN HYDROCHLORIDESmall moleculephase 2 3Cognitive impairment, Alzheimer diseaseOpen Targets · ChEMBL
LECOZOTANSmall moleculephase 2 3Alzheimer diseaseOpen Targets · ChEMBL
BEFIRADOLSmall moleculephase 2Parkinson diseaseOpen Targets · ChEMBL
ROBALZOTANSmall moleculephase 2anxiety disorderOpen Targets · ChEMBL
SARIZOTAN HYDROCHLORIDESmall moleculephase 2Parkinson disease, movement disorderOpen Targets · ChEMBL
GSK163090Small moleculephase 2anxiety disorder, major depressive disorder, depressive disorderOpen Targets · ChEMBL
PICLOZOTANSmall moleculephase 2coronary artery disorder, ischemic strokeOpen Targets · ChEMBL
DU 125530Small moleculephase 2mood disorder, major depressive disorderOpen Targets · ChEMBL
OSEMOZOTANSmall moleculephase 2mood disorderOpen Targets · ChEMBL
ADOPRAZINESmall moleculephase 1schizophrenia, schizoaffective disorderOpen Targets · ChEMBL
DEXFENFLURAMINESmall moleculewithdrawalobesity disorderOpen Targets · ChEMBL
ZIMELDINE HYDROCHLORIDESmall moleculewithdrawal–Open Targets · ChEMBL
ZIMELDINESmall moleculewithdrawaldepressive disorder, major depressive disorderOpen Targets · ChEMBL
DEXFENFLURAMINE HYDROCHLORIDESmall moleculewithdrawal–Open Targets · ChEMBL