HRH1 histamine receptor H1
ENSG00000196639 · protein coding · Open Targets profile
G protein-coupled receptor for histamine, a biogenic amine that functions as an immune modulator and a neurotransmitter (PubMed:33828102, PubMed:8280179). Through the H1 receptor, histamine mediates the contraction of smooth muscles and increases capillary permeability due to contraction of terminal venules. Also mediates neurotransmission in the central nervous system and thereby regulates circadian rhythms, emotional and locomotor activities as well as cognitive functions (By similarity). {ECO:0000250|UniProtKB:P70174, ECO:0000269|PubMed:33828102, ECO:0000269|PubMed:8280179}.
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 Withdrawn means the drug was pulled from the market or from development.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, Med-Quality Pocket, Druggable Family
- Antibody
- UniProt loc high conf, GO CC high conf, UniProt SigP or TMHMM, Human Protein Atlas loc
- PROTAC
- Database Ubiquitination, Small Molecule Binder
gnomAD loss of function constraint: o/e 0.5829300284385681 (upper bound 1.1505999565124512). 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 166 registry trials, updated in the last three years, of the most advanced drugs against HRH1 (betahistine, chlorpheniramine, dexchlorpheniramine, dimethindene, bromodiphenhydramine, triprolidine, emedastine, histamine, cinnarizine, ebastine, propiomazine, azatadine), ranked by Phase 2+ trials. Live from ClinicalTrials.gov.
- KIMIHIRO OKUBONippon Medical School · 3 of 3 trials Phase 2+
- Aleix PratHospital Clinic · 1 of 1 trials Phase 2+
- Ali RabaniProfessor of Pediatric Endocrinology & Metabolism, Department of Pediatrics · 1 of 1 trials Phase 2+
- Andreas MuthVästra Götalandsregionen, Sahlgrenska University Hospital · 1 of 1 trials Phase 2+
- Anish ThomasNational Cancer Institute (NCI) · 1 of 1 trials Phase 2+
- Anne-Laure KAMINSKYCHU de Saint-Etienne · 1 of 1 trials Phase 2+
- Antoine BENARDUniversity Hospital, Bordeaux · 1 of 1 trials Phase 2+
- Bruce GivenArrowhead Pharmaceuticals, Inc. · 1 of 1 trials Phase 2+
- Cédrick ZAOUTERUniversity Hospital, Bordeaux · 1 of 1 trials Phase 2+
- Claudio BassettiInselspital Bern, Department of Neurology, Bern, Switzerland · 1 of 1 trials Phase 2+
- Corey CutlerDana-Farber Cancer Institute · 1 of 1 trials Phase 2+
- Craig A FriesenChildren's Mercy Hospital Kansas City · 1 of 1 trials Phase 2+
- David A KhanUniversity of Texas Southwestern Medical Center · 1 of 1 trials Phase 2+
- David BernsteinUniversity of Cincinnati · 1 of 1 trials Phase 2+
- Eric DAUGASNephrology department, Bichat Hospital, APHP, Paris · 1 of 1 trials Phase 2+
Registry trials of betahistine, chlorpheniramine, dexchlorpheniramine, dimethindene, bromodiphenhydramine, triprolidine, emedastine, histamine, cinnarizine, ebastine, propiomazine, azatadine 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; 129 of 150 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. 16 trials list no sites and are left out. Source: ClinicalTrials.gov, fetched live.
47 trials of drugs against HRH1 were stopped early; 4 give no reason
Terminated, withdrawn and suspended interventional trials of betahistine, chlorpheniramine, dexchlorpheniramine, dimethindene, bromodiphenhydramine, triprolidine, emedastine, histamine, cinnarizine, ebastine, propiomazine, azatadine, 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 47.
- withdrawn · 2026-09-04 · University of Cincinnati · Antihistamine“no funding for clinical research space”
- terminated · 2026-08-04 · Genzyme, a Sanofi Company · Dexchlorpheniramine“Enrolment formally closed earlier than planned due to recruitment challenges.”
- terminated · 2026-06-22 · University Hospital, Bordeaux · dexchlorpheniramine (Polaramine®) injection“stop due to medication error with the placebo”
- terminated · 2026-03-18 · Centre Oscar Lambret · matched by the registry's drug synonyms“This decision was taken on June 20 2022 due to low recruitment over the past 4 years.”
- terminated · 2026-02-05 · National Institute of Allergy and Infectious Diseases (NIAID) · matched by the registry's drug synonyms“The study was terminated early based on disease flare/lack of efficacy in the early phase of the trial.”
- terminated · 2026-01-13 · Arrowhead Pharmaceuticals · chlorpheniramine“Company decision to discontinue trial”
- terminated · 2026-01-13 · Arrowhead Pharmaceuticals · antihistamine“Company decision to discontinue trial”
- terminated · 2026-01-13 · Arrowhead Pharmaceuticals · antihistamine“Company decision to discontinue trial”
- terminated · 2026-01-13 · Arrowhead Pharmaceuticals · antihistamine“Company decision to discontinue trial”
- terminated · 2026-01-13 · Arrowhead Pharmaceuticals · antihistamine“Company decision to discontinue trial”
- terminated · 2026-01-12 · Arrowhead Pharmaceuticals · antihistamine“Company decision to discontinue trial”
- terminated · 2025-07-17 · Emory University · matched by the registry's drug synonyms“Study was terminated due to lack of funding.”
- withdrawn · 2024-11-22 · Aalborg University · matched by the registry's drug synonyms“The Imiquimod 3.75% was ineffective”
- terminated · 2024-08-09 · Bioprojet · matched by the registry's drug synonyms“Lack of recruitment”
- terminated · 2024-04-16 · Ultragenyx Pharmaceutical Inc · matched by the registry's drug synonyms“Sponsor decision not related to safety concerns”
- terminated · 2024-02-02 · National Cancer Institute (NCI) · matched by the registry's drug synonyms“Study was closed early due to slow accrual.”
- withdrawn · 2023-10-16 · Larkin Community Hospital · matched by the registry's drug synonyms“Study Period Ended/Not Completed”
- withdrawn · 2023-08-23 · University of Nebraska · matched by the registry's drug synonyms“Not approved by IRB”
- withdrawn · 2021-10-28 · Bryan Martin, DO · saline with 1mg/ml Histamine base“Funding for the trial was lost so study was ended. No participants were enrolled.”
- terminated · 2021-10-08 · Novartis Pharmaceuticals · matched by the registry's drug synonyms“Lack of efficacy”
- withdrawn · 2021-07-29 · University of Miami · matched by the registry's drug synonyms“Withdrawn as more data drug analysis is recommended before the study.”
- terminated · 2021-01-20 · Centre Hospitalier Universitaire de Saint Etienne · matched by the registry's drug synonyms“Difficulties for recruting patients”
- withdrawn · 2021-01-07 · Children's Mercy Hospital Kansas City · matched by the registry's drug synonyms“Study withdrawn and combined with a new protocol”
- terminated · 2019-09-27 · Sephoris Pharmaceuticals LLC · SP160412 Ibuprofen 400 mg and Chlorpheniramine maleate 4 mg, capsule Chlorpheniramine 4mg and 1 Placebo“Sponsor decided to stop for lack of efficacy”
- terminated · 2019-04-16 · Dynavax Technologies Corporation · Histamine base“Interim data indicated that subjects exhibited no meaningful allergic disease during the first ragweed season, making it impossible to measure treatment effect.”
Paediatric incentives and obligations for HRH1's drugs
For betahistine, chlorpheniramine, dexchlorpheniramine, dimethindene, bromodiphenhydramine, triprolidine, emedastine, histamine, cinnarizine, ebastine, propiomazine, azatadine: 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 · HRH1 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-002652-PIP01-19 (betahistine, Treatment of peripheral vertigo): W: decision granting a waiver in all age groups for all conditions or indications, 17 Jun 2020Rule: An EMA PIP decision (agreement, modification or waiver) lists the drug as its active substance, exact name. Source: EMA EMEA-002652-PIP01-19, 2026-11-11
- EU orphan designation: yes · EU/3/05/272 expired 11 Apr 2005: Treatment of acute myeloid leukaemia; - negative 24 Aug 2004: Treatment of malignant melanomaRule: 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 · Emadine: authorised since 27 Jan 1999; Ceplene: authorised since 7 Oct 2008, exceptional circumstancesRule: 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 betahistine, chlorpheniramine, dexchlorpheniramine, dimethindene, bromodiphenhydramine, triprolidine, emedastine, histamine, cinnarizine, ebastine, propiomazine, azatadineRule: FDA's Pediatric Oncology Drug Approvals table names the drug. Source: FDA Pediatric Oncology Drug Approvals (content current as of 2026-03-03), 2026-11-11
- Registered studies open to children: yes · 68 interventional studies of betahistine, chlorpheniramine, dexchlorpheniramine, dimethindene, bromodiphenhydramine, triprolidine, emedastine, histamine, cinnarizine, ebastine, propiomazine, azatadine include patients under 18; 13 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, 2026-11-11
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 95 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.