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Protein / target

Orexin receptor type 2

Encoded byHCRTR2O43614Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
4
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

Neuropeptide receptor

Strongest disease association

Hyperuricemia

Via encoding gene HCRTR2 · Genetic evidence · score 0.63

Therapeutic position

Established drug target

Small molecules

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function overview

G protein-coupled receptor that binds neuropeptides orexin-A and orexin-B, two neuropeptides derived from a common precursor, prepro-orexin.

View complete UniProt function annotation

G protein-coupled receptor that binds neuropeptides orexin-A and orexin-B, two neuropeptides derived from a common precursor, prepro-orexin (PubMed:26950369, PubMed:33547286, PubMed:35614071, PubMed:9491897). Upon neuropeptide ligand binding, HCRTR2 can couple with both G(q)/11 and G(i)/o heterotrimeric G proteins thereby initiating distinct downstream signaling cascades (PubMed:35614071). Involved in regulating the sleep-wake cycle (By similarity). Contributes to central regulation of glucose homeostasis (By similarity)

Subcellular location

Cell membrane
Domains and Gene Ontology detail (14)

Gene Ontology

  • Cplasma membrane
  • Csynapse
  • Fneuropeptide receptor activity
  • Forexin receptor activity
  • Fpeptide hormone binding
  • Pcellular response to hormone stimulus
  • Pchemical synaptic transmission
  • Pcircadian sleep/wake cycle process
  • Pfeeding behavior
  • Pglucose homeostasis
  • Plocomotion
  • Pneuropeptide signaling pathway

444 aa · 51 kDa

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

Synaptic signallingGO
View supporting evidence

Synaptic signalling

  • ·synapse
  • ·chemical synaptic transmission
View underlying pathways (2)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

HCRTGNB1HCRTR1GNAI1GNASGNG2POMCOXR1GRK2GRK5HCRTR2

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Approved medicines with mapped indications

1 medicine · 1 area

Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.

Sleep Initiation and Maintenance Disorders1 medicine

4 medicines meet Open Targets' target-level approved-medicine definition; the 1 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.

Drugs targeting this protein

1

How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.

suvorexant
ApprovedAntagonist

Orexin receptor antagonist

Indicated for Sleep Initiation and Maintenance Disorders

Acts on a complex — shared with HCRTR1 · 1 of 2 recorded protein targets — narrow recorded profile

ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.

Translational evidence

Open Targets 26

Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.

Strongest disease associations · via encoding gene HCRTR2

Gene-level evidence surfaced through the gene HCRTR2that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.

Sleep Initiation and Maintenance Disorders
0.75Moderately supported

Clinical evidence dominant · Open Targets 0.60

Hyperuricemia
0.63Moderately supported

Genetic evidence dominant · Open Targets 0.38

Gout
0.57Moderately supported

Genetic evidence dominant · Open Targets 0.34

Placental retention
0.49Limited support

Genetic evidence dominant · Open Targets 0.30

Major depressive disorder
0.48Limited support

Clinical evidence dominant · Open Targets 0.38

View evidence synthesis (5)
Sleep Initiation and Maintenance DisordersModerately supported
0.75
agreement 0.590.90
Clinical96%Literature4%

Open Targets aggregate 0.60 · 2 independent evidence families

HyperuricemiaModerately supported
0.63
agreement 0.510.75
Genetic100%

Open Targets aggregate 0.38 · 1 independent evidence family

GoutModerately supported
0.57
agreement 0.430.70
Genetic100%Literature0%

Open Targets aggregate 0.34 · 2 independent evidence families

Placental retentionLimited support
0.49
agreement 0.370.61
Genetic100%

Open Targets aggregate 0.30 · 1 independent evidence family

Major depressive disorderLimited support
0.48
agreement 0.330.64
Clinical96%Literature4%

Open Targets aggregate 0.38 · 2 independent evidence families

The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.

Show all associations
Sleep Initiation and Maintenance Disorders0.60
Major depressive disorder0.38
Hyperuricemia0.38
Gout0.34
Alzheimer's Disease0.31
Placental retention0.30
Alcoholism0.29
Dislocation0.27

Drug development

9 compounds recorded · 4 approved · 5 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 1 drug that targets this protein in Forefront's canonical graph (1 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (9)
LEMBOREXANTApproval
ALMOREXANTPhase 3
FILOREXANTPhase 2
SB-649868Phase 2
SELTOREXANTPhase 3
DARIDOREXANT HYDROCHLORIDEApproval
ORN-0829 HYDRATEPhase 3
DARIDOREXANTApproval
SUVOREXANTApproval

Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.

Tractability

Small moleculesStrong

Approved Drug and Structure with Ligand support this modality.

AntibodiesEmerging

Feasibility evidence (uniprot loc high conf and go cc high conf) — no clinical-stage drug of this modality recorded.

Protein degradersEmerging

Feasibility evidence (small molecule binder) — no clinical-stage drug of this modality recorded.

Other modalitiesStrong

Advanced Clinical support this modality.

View underlying tractability evidence (10)
SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMAB · Human Protein Atlas locPR · Small Molecule BinderOC · Advanced Clinical

Raw Open Targets tractability assessment buckets, by modality.

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.

View all trials (26)

RECRUITING · via suvorexant · NCT06484075

RECRUITING · via suvorexant · NCT04629547

RECRUITING · via suvorexant · NCT06326684

RECRUITING · via suvorexant · NCT05630781

COMPLETED · via suvorexant · NCT04014387

ClinicalTrials.gov via the drug-target graph.

What's happening now

5

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.

  1. New publication2024-09-14
    Orexin receptor antagonists in the treatment of insomnia associated with psychiatric disorders: a systematic review.

    Translational psychiatry · 2024 · 12 citations · Europe PMC · via suvorexant

  2. New publication2024-08-01
    Suvorexant for Reduction of Delirium in Older Adults After Hospitalization: A Randomized Clinical Trial.

    JAMA network open · 2024 · 9 citations · Europe PMC · via suvorexant

  3. New publication2016-01-01
    Effects of Suvorexant, an Orexin Receptor Antagonist, on Respiration during Sleep In Patients with Obstructive Sleep Apnea.

    Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2016 · 58 citations · Europe PMC · via suvorexant

  4. New publication2015-01-05
    Effects of suvorexant, an orexin receptor antagonist, on breathing during sleep in patients with chronic obstructive pulmonary disease.

    Respiratory medicine · 2015 · 34 citations · Europe PMC · via suvorexant

  5. New publication2012-11-28
    Orexin receptor antagonism for treatment of insomnia: a randomized clinical trial of suvorexant.

    Neurology · 2012 · 239 citations · Europe PMC · via suvorexant

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.

Related family literature

2

Papers about “orexin receptors” — a broader family this protein belongs to. Shown as context; not counted as papers specifically about this protein.

Europe PMC literature, reached through curated HGNC family membership. Membership is a taxonomic relationship — it does not imply this protein participates in every mechanism these papers discuss.