Chloroquine

Summary

Chloroquine (CHEMBL76) is an approved small-molecule antirheumatic drug (ATC P01BA01) targeting MRGPRX1 and TAS2R3; indicated across 21 conditions including malaria and glioblastoma; with CIViC clinical evidence for 1 variant-indication association (e.g. ASS1 Loss in sarcoma).

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• ATC class: P01BA01
• Targets: 2 (MRGPRX1, TAS2R3)
• Indications: 21 conditions
• Clinical trials: 118
• Precision-oncology evidence (CIViC): 1 variant–indication association
• Chemistry: 319.9 Da · C18H26ClN3

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL76
Name	Chloroquine
Type	Small molecule
Max phase	4
FDA approved	yes
PubChem CID	2719
ChEBI	CHEBI:3638
ATC	P01BA01
Molecular formula	C18H26ClN3
Molecular weight	319.9
InChIKey	WHTVZRBIWZFKQO-UHFFFAOYSA-N

SMILES: CCN(CC)CCCC(C)NC1=C2C=CC(=CC2=NC=C1)Cl

IUPAC name: 4-N-(7-chloroquinolin-4-yl)-1-N,1-N-diethylpentane-1,4-diamine

ChEBI definition: An aminoquinoline that is quinoline which is substituted at position 4 by a [5-(diethylamino)pentan-2-yl]amino group at at position 7 by chlorine. It is used for the treatment of malaria, hepatic amoebiasis, lupus erythematosus, light-sensitive skin eruptions, and rheumatoid arthritis.

Pharmacological roles (ChEBI): antimalarial, antirheumatic drug, dermatologic drug, autophagy inhibitor, anticoronaviral agent.

Also known as: Chloroquine, Cloroquina, NSC-187208, chloroquine, chloroquin, chloroquinine, Chloroquin, choloroquine, Chloroquinec, GNF-Pf-4216, SID90340711, SID124879700

Parent form; salt/anhydrous children: CHEMBL58510, CHEMBL1669, CHEMBL2052012, CHEMBL2095223, CHEMBL4297165, CHEMBL5399629, CHEMBL5411819, CHEMBL5422185, CHEMBL5427439, CHEMBL5435980

Patent coverage: 17,084 distinct patent families (58,679 SureChEMBL compound mentions), from 2 matched compound structure(s). One matched structure accounts for 58,400 (100%) of the total. 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
MRGPRX1	MRGPRX1	Agonist	3.53	1%	Q96LB2
TAS2R3	TAS2R3	Agonist		0.2%	Q9NYW6

Broader ChEMBL bioactivity targets: 27 (assay-derived). Sample: Dihydrofolate reductase, Muscarinic acetylcholine receptor M4, Alpha-2A adrenergic receptor, Alpha-2C adrenergic receptor, Histidine-rich protein PFHRP-II, Alpha-2B adrenergic receptor, Riboflavin-binding protein, Muscarinic acetylcholine receptor M5, C-X-C chemokine receptor type 4, Muscarinic acetylcholine receptor M2.

Bioactivity

ChEMBL activities: 32 potent at pChembl ≥ 5 of 47 total. Top 30 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
P00376	7.52	IC50	30.1	nM	CHEMBL_ACT_18210699
P00376	7.52	IC50	30.1	nM	CHEMBL_ACT_18259255
P00376	7.51	IC50	31	nM	CHEMBL_ACT_25601701
P05227	7.12	IC50	76.5	nM	CHEMBL_ACT_1185783
SIGMAR1	7.1	Ki	79.43	nM	CHEMBL_ACT_18838720
P0DTC2	6.8	IC50	160	nM	CHEMBL_ACT_23175937
MTOR	6.57	IC50	270	nM	CHEMBL_ACT_24861825
MTOR	6.57	IC50	270	nM	CHEMBL_ACT_25044915
P05227	6.4	IC50	400	nM	CHEMBL_ACT_1803504
TMEM97	6.3	Ki	501.2	nM	CHEMBL_ACT_18838721
ACE2	5.95	IC50	1130	nM	CHEMBL_ACT_24992606
NQO2	5.82	IC50	1500	nM	CHEMBL_ACT_3603402
P02752	5.68	Kd	2100	nM	CHEMBL_ACT_8028751
KCNH2	5.6	IC50	2500	nM	CHEMBL_ACT_1449655
KCNH2	5.6	IC50	2500	nM	CHEMBL_ACT_15175570
KCNH2	5.6	IC50	2500	nM	CHEMBL_ACT_2395352
KCNH2	5.6	IC50	2512	nM	CHEMBL_ACT_5218919
KCNH2	5.5	Ki	3162	nM	CHEMBL_ACT_18838719
CHRM3	5.48	Ki	3311	nM	CHEMBL_ACT_18838727
PRNP	5.4	EC50	4000	nM	CHEMBL_ACT_829599
ADRA2A	5.36	Ki	4365	nM	CHEMBL_ACT_18838722
CHRM2	5.33	Ki	4677	nM	CHEMBL_ACT_18838726
CHRM4	5.24	Ki	5754	nM	CHEMBL_ACT_18838728
CXCR4	5.19	EC50	6500	nM	CHEMBL_ACT_25108490
APP	5.16	IC50	7000	nM	CHEMBL_ACT_18580011
BACE1	5.16	IC50	7000	nM	CHEMBL_ACT_18731952
P0DTC2	5.16	IC50	7000	nM	CHEMBL_ACT_23296554
P0DTD1	5.14	IC50	7280	nM	CHEMBL_ACT_25045122
KCNH2	5.14	AC50	7313	nM	CHEMBL_ACT_25117903
KCNH2	5.12	Ki	7500	nM	CHEMBL_ACT_13860058

Target pathways

Aggregated over 2 target gene(s): MRGPRX1, TAS2R3.

Top Reactome pathways

9 total, by targets touching each:

Pathway	Targets	Genes
Signal Transduction	1	TAS2R3
Signaling by GPCR	1	TAS2R3
GPCR downstream signalling	1	TAS2R3
G alpha (i) signalling events	1	TAS2R3
Class C/3 (Metabotropic glutamate/pheromone receptors)	1	TAS2R3
GPCR ligand binding	1	TAS2R3
Sensory Perception	1	TAS2R3
Sensory perception of taste	1	TAS2R3
Sensory perception of sweet, bitter, and umami (glutamate) taste	1	TAS2R3

Dominant GO biological processes

GO term	Targets
signal transduction	2
G protein-coupled receptor signaling pathway	2
acute-phase response	1
cell surface receptor signaling pathway	1
adenylate cyclase-inhibiting G protein-coupled receptor signaling pathway	1
phospholipase C-activating G protein-coupled receptor signaling pathway	1
sneeze reflex	1
sensory perception of itch	1
response to chloroquine	1
negative regulation of sensory perception of pain	1
detection of chemical stimulus involved in sensory perception of bitter taste	1
sensory perception of taste	1

Indications & clinical

Indications

21 indications (1 at ChEMBL trial phase 4). Phase below is the highest clinical-trial phase recorded for this drug against each disease — not the molecule’s overall approval status (that is in the Summary).

Indication	Trial phase	MONDO	EFO
malaria	4	MONDO:0005136	EFO:0001068
glioblastoma	3	MONDO:0018177	EFO:0000519
Plasmodium vivax malaria	3	MONDO:0005921	EFO:0007445
Plasmodium falciparum malaria	3	MONDO:0005920	EFO:0007444
rheumatoid arthritis	3	MONDO:0008383	EFO:0000685
severe acute respiratory syndrome	3	MONDO:0005091	MONDO:0100096
brain disorder	2	MONDO:0005560	EFO:0005774
HIV infectious disease	2	MONDO:0005109	EFO:0000764
AIDS	2	MONDO:0012268	EFO:0000765
plasma cell myeloma	2	MONDO:0009693	EFO:0001378
influenza	2	MONDO:0005812	EFO:0007328
breast neoplasm	2	MONDO:0021100	MONDO:0007254
sickle cell disease	2	MONDO:0011382	MONDO:0011382
systemic lupus erythematosus	2	MONDO:0007915	MONDO:0007915
small cell lung carcinoma	1	MONDO:0008433	EFO:0000702
exocrine pancreatic carcinoma	1	MONDO:0005192	EFO:0002618
Dengue hemorrhagic fever	1	MONDO:0005358	EFO:0004227
ductal breast carcinoma in situ	1	MONDO:0005023	EFO:0000432
gliosarcoma	1	MONDO:0016681	EFO:1001465
neoplasm	1	MONDO:0005070	MONDO:0004992

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

Clinical trials

Total trials: 118.

Phase distribution

Phase	Trials
PHASE4	29
PHASE3	22
Not specified	22
PHASE2	18
PHASE1	17
PHASE2/PHASE3	9
PHASE1/PHASE2	1

Top trials by phase / activity

NCT	Phase	Status	Title
NCT04704999	PHASE4	RECRUITING	Southeast Asia Dose Optimization of Tafenoquine
NCT06083688	PHASE4	ACTIVE_NOT_RECRUITING	Preventing Malaria in School Children to Protect the Whole Community in Rural Blantyre District, Malawi
NCT07352566	PHASE4	NOT_YET_RECRUITING	Utilization of a Microdevice for Psoriasis and Atopic Dermatitis
NCT00137514	PHASE4	COMPLETED	Chloroquine and Amodiaquine for Treatment of Malaria in Children
NCT00290420	PHASE4	WITHDRAWN	Prevention of P. Vivax Malaria During Pregnancy in Bolivia
NCT00426439	PHASE4	COMPLETED	Chloroquine and Coartem for Treatment of Symptomatic Children With Plasmodium Falciparum in Guinea Bissau
NCT00680732	PHASE4	COMPLETED	Prevention of Intrauterine Growth Retardation in Burkina Faso: the Malaria Component
NCT00805519	PHASE4	COMPLETED	Efficacy and Safety of Prednisolone and Chloroquine Add on Therapy in Osteoarthritis of the Knee
NCT00964691	PHASE4	TERMINATED	A Randomized Controlled Trial for Intermittent Preventive Treatment in Pregnancy With Fansidar in Solomon Islands
NCT01019408	PHASE4	COMPLETED	Extended-dose Chloroquine (ECQ) for Resistant Falciparum Malaria Among Afghan Refugees in Pakistan
NCT01107145	PHASE4	TERMINATED	Efficacy of Artemisinin Combination Therapies for the Treatment of Uncomplicated P. Vivax in Pregnancy in Brazil (PAACT-PV)
NCT01178021	PHASE4	COMPLETED	Estimating the Risk of Plasmodium Vivax Relapses in Afghanistan
NCT01662700	PHASE4	UNKNOWN	Comparison of Two Antimalarial Drugs Regimens in Patient With Plasmodium Vivax Malaria in Thailand
NCT01680406	PHASE4	COMPLETED	Ethiopia Antimalarial in Vivo Efficacy Study 2012
NCT01887821	PHASE4	COMPLETED	Antimalarial Drug Susceptibility and Molecular Characterization of Plasmodium Vivax Isolates in Vietnam
NCT02058173	PHASE4	COMPLETED	Pharmacoepidemiological Evaluation of Autophagy Inhibition in Treatment of HCV Patients Resistant to Standard Therapy. Pilot Study
NCT02143934	PHASE4	COMPLETED	Effect of Liver and Blood-stage Treatment on Subsequent Plasmodium Reinfection and Morbidity
NCT02192944	PHASE4	COMPLETED	Comparison of the ECG Effects Related to Pharmacokinetic Profile of Chloroquine and Piperaquine
NCT02389374	PHASE4	COMPLETED	A Study to Assess Safety of Current Standard Malaria Treatment and an Assessment of G6PD Status in South-east Bangladesh
NCT02564471	PHASE4	COMPLETED	Effect of Antimalarial Drugs to Rabies Vaccine for Post-exposure Prophylaxis.
NCT02610686	PHASE4	UNKNOWN	Evaluating the Efficacy of Chloroquine for the Treatment of Plasmodium Vivax Infections in Central Vietnam
NCT02876549	PHASE4	COMPLETED	G6PD Assessment Before Primaquine for Radical Treatment of Vivax Malaria
NCT03337152	PHASE4	TERMINATED	Assessing a Risk Model for G6PD Deficiency
NCT03449758	PHASE4	COMPLETED	Effect of Sarilumab on Patient-reported Outcomes in Patients With Active Rheumatoid Arthritis
NCT04346667	PHASE4	TERMINATED	Post-Exposure Prophylaxis for Asymptomatic SARS-CoV-2 COVID-19 Patients With choloroquinE Compounds
NCT04351191	PHASE4	TERMINATED	PRophylaxis of Exposed COVID-19 Individuals With Mild Symptoms Using choloroquinE Compounds
NCT05244954	PHASE4	COMPLETED	Comparing Chemoprevention Approaches for School-based Malaria Control
NCT05980156	PHASE4	COMPLETED	Comparing Chemoprevention Drugs for School-based Malaria Control
NCT06044805	PHASE4	COMPLETED	Therapeutic Efficacy of Chloroquine Plus Primaquine in the Treatment of Uncomplicated Plasmodium Vivax
NCT06666491	PHASE3	RECRUITING	An Interventional Study to Compare the Efficacy and Safety of Tafenoquine (TQ) and Primaquine (PQ) When Either Are Taken Together With Chloroquine (CQ) for the Treatment of P. Vivax Malaria in Indian Participants Aged 2 Years and Older
NCT00074841	PHASE2/PHASE3	COMPLETED	Trial of Azithromycin Plus Chloroquine Versus Sulfadoxine-Pyrimethamine Plus Chloroquine for the Treatment of Uncomplicated Malaria in India
NCT00082576	PHASE2/PHASE3	COMPLETED	Azithromycin Plus Chloroquine Versus Mefloquine for the Treatment of Uncomplicated Malaria in Africa
NCT00084227	PHASE2/PHASE3	COMPLETED	Azithromycin Plus Chloroquine Versus Atovaquone-Proguanil For The Treatment Of Uncomplicated Plasmodium Falciparum Malaria In South America
NCT00084240	PHASE2/PHASE3	TERMINATED	Azithromycin Plus Chloroquine Versus Sulfadoxine-Pyrimethamine Plus Chloroquine For The Treatment Of Uncomplicated, Symptomatic Falciparum Malaria In Southeast Asia
NCT00131703	PHASE3	COMPLETED	Efficacy and Safety of Sulphadoxine-pyrimethamine and Amodiaquine in Ghanaian Pregnant Women
NCT00158548	PHASE3	COMPLETED	ACT With Chloroquine, Amodiaquine & Sulphadoxine-pyrimethamine in Pakistan
NCT00224978	PHASE3	COMPLETED	Chloroquine for Treatment of Glioblastoma Multiforme
NCT00379821	PHASE3	COMPLETED	Chloroquine Alone or in Combination for Malaria in Children in Malawi
NCT00391313	PHASE3	TERMINATED	CuraChik : A Trial of the Efficacy and Safety of Chloroquine as Therapeutic Treatment of Chikungunya Disease
NCT00440999	PHASE3	COMPLETED	Pyronaridine Artesunate (3:1) in Children and Adults With Acute Plasmodium Vivax Malaria

Clinical evidence (CIViC)

Variant × indication × effect (1 predictive associations from 1 curated evidence items):

Variant	Indication	Effect	Therapy	Level	CIViC
ASS1 Loss	Sarcoma	Sensitivity/Response	Chloroquine + Pegargiminase	CIViC D	EID5988

Pharmacology

Pharmacogenomics

PharmGKB dosing guidelines (1) — CPIC / DPWG genotype-guided dosing for this drug (drug × pharmacogene):

Guideline	Source	Gene(s)	Dosing	Recommendation
Annotation of CPIC Guideline for aminosalicylic acid, chloramphenicol,	CPIC	G6PD

PharmGKB also curates 1 clinical and 8 variant annotation(s) for this drug (gene-keyed; see PharmGKB).

Related molecules

Related molecules

Molecules sharing ≥1 of this drug’s curated primary targets, merged from two biobtree sources and ranked by shared-target count, then clinical phase: ChEMBL clinical-stage candidates (development phase ≥2) and PubChem drug-class bioactivity (approved / known drugs acting on the target). Deduplicated by drug name; the drug’s own salt forms are excluded. Note: for a drug with few primary targets a shared-target match can reflect off-target / promiscuous binding rather than the same therapeutic mechanism — the phase ordering surfaces bona-fide therapeutics first.

1 molecules share ≥1 primary target. Top 1 by shared-target count:

Molecule	Source	Status	Shared targets
ISOPROTERENOL	ChEMBL	Phase 4 (approved)	TAS2R3