Alosetron

Summary

Alosetron (CHEMBL1110) is an approved small-molecule serotonergic antagonist (ATC A03AE01); indicated across 2 conditions including irritable bowel syndrome.

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• ATC class: A03AE01
• Indications: 2 conditions
• Clinical trials: 3
• Chemistry: 294.35 Da · C17H18N4O

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL1110
Name	Alosetron
Type	Small molecule
Max phase	4
FDA approved	yes
PubChem CID	2099
ChEBI	CHEBI:253342
ATC	A03AE01
Molecular formula	C17H18N4O
Molecular weight	294.35
InChIKey	JSWZEAMFRNKZNL-UHFFFAOYSA-N

SMILES: CC1=C(N=CN1)CN2CCC3=C(C2=O)C4=CC=CC=C4N3C

IUPAC name: 5-methyl-2-[(5-methyl-1H-imidazol-4-yl)methyl]-3,4-dihydropyrido[4,3-b]indol-1-one

ChEBI definition: A pyrido[4,3-b]indole compound having a 5-methyl-1H-imidazol-4-ylmethyl group at the 2-position.

Pharmacological roles (ChEBI): serotonergic antagonist, antiemetic, gastrointestinal drug.

Also known as: A03AE01, Alosetron, alosetron, ALOSETRON, Alosetron_HCL

Parent form; salt/anhydrous children: CHEMBL1200885

Patent coverage: 2,793 distinct patent families (10,794 SureChEMBL compound mentions), from 3 matched compound structure(s). Mentions count patents naming the compound (not distinct inventions), so promiscuous / reference molecules inflate the mention figure — families are the dedup metric.

Targets

Targets

Primary targets (GtoPdb curated mechanism): the Cancer dependency column is the DepMap CRISPR fitness signal (% of screened cell lines dependent on the target).

Gene	Target	Action	pAffinity	Cancer dependency	UniProt
	5-HT3A	Antagonist	9.5

Broader ChEMBL bioactivity targets: 9 (assay-derived). Sample: 5-hydroxytryptamine receptor 2B, 5-hydroxytryptamine receptor 3A, Alpha-2C adrenergic receptor, 5-hydroxytryptamine receptor 2A, 5-hydroxytryptamine receptor 2C, Alpha-1A adrenergic receptor, Voltage-gated inwardly rectifying potassium channel KCNH2, Cytochrome P450 1A2, Cytochrome P450 3A4.

Bioactivity

ChEMBL activities: 23 potent at pChembl ≥ 5 of 24 total. Top 100 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
HTR3A	9.3	Ki	0.5	nM	CHEMBL_ACT_14668344
HTR3A	9.3	Ki	0.5	nM	CHEMBL_ACT_17684869
HTR3A	9.3	Ki	0.5	nM	CHEMBL_ACT_3523728
HTR3A	9.3	Ki	0.5	nM	CHEMBL_ACT_5125663
HTR3A	8.74	AC50	1.8	nM	CHEMBL_ACT_25149528
HTR2B	7.5	AC50	31.4	nM	CHEMBL_ACT_25164214
HTR2B	7.19	Ki	64	nM	CHEMBL_ACT_7630818
HTR2B	7	IC50	100	nM	CHEMBL_ACT_7630817
HTR2B	6.72	AC50	190	nM	CHEMBL_ACT_25227913
CYP3A4	6.22	IC50	600	nM	CHEMBL_ACT_14668402
CYP3A4	6.22	IC50	600	nM	CHEMBL_ACT_3523743
CYP3A4	6.22	IC50	600	nM	CHEMBL_ACT_5125694
CYP1A2	6.22	IC50	604.7	nM	CHEMBL_ACT_7629455
KCNH2	5.64	IC50	2300	nM	CHEMBL_ACT_3523763
KCNH2	5.5	IC50	3200	nM	CHEMBL_ACT_2295035
KCNH2	5.5	IC50	3200	nM	CHEMBL_ACT_2295146
KCNH2	5.49	IC50	3236	nM	CHEMBL_ACT_1031111
KCNH2	5.49	IC50	3236	nM	CHEMBL_ACT_1523696
KCNH2	5.49	IC50	3236	nM	CHEMBL_ACT_2358263
HTR2A	5.35	AC50	4425	nM	CHEMBL_ACT_25173745
HTR2C	5.17	AC50	6800	nM	CHEMBL_ACT_25132203
KCNH2	5.04	AC50	9120	nM	CHEMBL_ACT_25118455
ADRA2C	5.03	AC50	9300	nM	CHEMBL_ACT_25148296

Target pathways

No target-pathway data for this drug (no mapped target genes).

Indications & clinical

Indications

1 disease in clinical trials (phase 1–3, investigational — not approved indications). Highest ChEMBL trial phase per disease; a non-cancer approved use is occasionally logged at phase 3 here.

Disease (in trials)	Phase	MONDO	EFO
irritable bowel syndrome	3	MONDO:0005052	EFO:0000555

1 further indication record had no mapped disease name (EFO/MeSH-only) or were duplicates, and are omitted.

Clinical trials

Total trials: 3.

Phase distribution

Phase	Trials
PHASE3	2
PHASE4	1

Top trials by phase / activity

NCT	Phase	Status	Title
NCT00370032	PHASE4	COMPLETED	Study to Assess the Effect Of Alosetron On Mucosal Blood Flow
NCT00067457	PHASE3	COMPLETED	Study In Women With Severe Diarrhea-Predominant Irritable Bowel Syndrome Having Failed Conventional Therapy
NCT00067561	PHASE3	COMPLETED	Study Of Women With Severe Diarrhea-Predominant Irritable Bowel Syndrome Having Failed Conventional Therapy

Clinical evidence (CIViC)

No CIViC predictive evidence (expected for non-precision-medicine drugs).

Pharmacology

Pharmacogenomics

No CPIC/DPWG dosing guideline or drug-level clinical/variant annotations in PharmGKB for this molecule.

Related molecules

Related molecules

No competitor molecules sharing a primary target (ChEMBL phase ≥2 or PubChem drug-class).