Mepazine

Summary

Mepazine (CHEMBL395110) is an approved small molecule targeting MALT1.

At a glance

• Status: Approved (max clinical phase 4)
• Modality: Small molecule
• Targets: 1 (MALT1)
• Chemistry: 310.5 Da · C19H22N2S

Identifiers

Drug identity and classification

Field	Value
ChEMBL ID	CHEMBL395110
Name	Mepazine
Type	Small molecule
Max phase	4
FDA approved	no
PubChem CID	6075
Molecular formula	C19H22N2S
Molecular weight	310.5
InChIKey	CBHCDHNUZWWAPP-UHFFFAOYSA-N

SMILES: CN1CCCC(C1)CN2C3=CC=CC=C3SC4=CC=CC=C42

IUPAC name: 10-[(1-methylpiperidin-3-yl)methyl]phenothiazine

Also known as: III-2318, Lacumin, Mepasin, Mepazin, Mepazine base, Meprazine, Mesapin, Nothiazine, P-391, Pacatal, Pacatal base, Pacatol

Parent form; salt/anhydrous children: CHEMBL1712842

Patent coverage: 253 distinct patent families (615 SureChEMBL compound mentions), from 2 matched compound structure(s). One matched structure accounts for 503 (82%) 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
MALT1	MALT1 paracaspase	Inhibition	6.29	0%	Q9UDY8

Broader ChEMBL bioactivity targets: 28 (assay-derived). Sample: Muscarinic acetylcholine receptor M4, 5-hydroxytryptamine receptor 2B, Alpha-2A adrenergic receptor, Alpha-2B adrenergic receptor, Muscarinic acetylcholine receptor M5, D(1A) dopamine receptor, Muscarinic acetylcholine receptor M2, Muscarinic acetylcholine receptor M1, Prostaglandin G/H synthase 1, Sodium-dependent noradrenaline transporter.

Bioactivity

ChEMBL activities: 49 potent at pChembl ≥ 5 of 55 total. Top 30 by potency (10 = 0.1 nM, 6 = 1 µM):

Target	pChembl	Type	Value	Unit	Activity ID
HRH1	8.51	Ki	3.13	nM	CHEMBL_ACT_7770670
CHRM1	7.72	Ki	19	nM	CHEMBL_ACT_7770698
CHRM4	7.72	Ki	19	nM	CHEMBL_ACT_7770704
HRH1	7.57	IC50	27	nM	CHEMBL_ACT_7770669
CHRM5	7.55	Ki	28	nM	CHEMBL_ACT_7770706
P15823	7.47	Ki	34	nM	CHEMBL_ACT_7768570
CHRM3	7.4	Ki	40	nM	CHEMBL_ACT_7770702
CHRM5	7.4	IC50	40	nM	CHEMBL_ACT_7770705
P43140	7.24	Ki	58	nM	CHEMBL_ACT_7768568
P15823	7.21	IC50	61	nM	CHEMBL_ACT_7768569
ADRA1D	7.17	Ki	67	nM	CHEMBL_ACT_7768572
SIGMAR1	7.12	Ki	76	nM	CHEMBL_ACT_7772801
CHRM1	7.1	IC50	79	nM	CHEMBL_ACT_7770697
HTR2A	6.96	Ki	110	nM	CHEMBL_ACT_7770780
ADRA1D	6.86	IC50	137	nM	CHEMBL_ACT_7768571
CHRM4	6.86	IC50	137	nM	CHEMBL_ACT_7770703
P43140	6.84	IC50	144	nM	CHEMBL_ACT_7768567
SIGMAR1	6.75	IC50	180	nM	CHEMBL_ACT_7772800
ADRA2B	6.74	Ki	181	nM	CHEMBL_ACT_7768576
CHRM3	6.72	IC50	191	nM	CHEMBL_ACT_7770701
CHRM2	6.7	Ki	201	nM	CHEMBL_ACT_7770700
CHRM1	6.67	AC50	213.7	nM	CHEMBL_ACT_25210449
HTR2C	6.59	Ki	259	nM	CHEMBL_ACT_7770784
HTR2B	6.49	Ki	327	nM	CHEMBL_ACT_7770782
CHRM2	6.46	AC50	347	nM	CHEMBL_ACT_25196018
HTR2A	6.42	IC50	385	nM	CHEMBL_ACT_7770779
ADRA1A	6.41	AC50	391.2	nM	CHEMBL_ACT_25219089
ADRA2B	6.4	IC50	397	nM	CHEMBL_ACT_7768575
MALT1	6.38	IC50	420	nM	CHEMBL_ACT_16618070
HTR2C	6.3	IC50	495	nM	CHEMBL_ACT_7770783

Target pathways

Aggregated over 1 target gene(s): MALT1.

Top Reactome pathways

13 total, by targets touching each:

Pathway	Targets	Genes
Downstream signaling events of B Cell Receptor (BCR)	1	MALT1
Activation of NF-kappaB in B cells	1	MALT1
Adaptive Immune System	1	MALT1
Innate Immune System	1	MALT1
Immune System	1	MALT1
TCR signaling	1	MALT1
Downstream TCR signaling	1	MALT1
Fc epsilon receptor (FCERI) signaling	1	MALT1
FCERI mediated NF-kB activation	1	MALT1
CLEC7A (Dectin-1) signaling	1	MALT1
C-type lectin receptors (CLRs)	1	MALT1
CLEC7A/inflammasome pathway	1	MALT1
Signaling by the B Cell Receptor (BCR)	1	MALT1

Dominant GO biological processes

GO term	Targets
B-1 B cell differentiation	1
positive regulation of T cell cytokine production	1
proteolysis	1
defense response	1
response to fungus	1
positive regulation of protein ubiquitination	1
lipopolysaccharide-mediated signaling pathway	1
positive regulation of interleukin-1 beta production	1
positive regulation of interleukin-2 production	1
T cell proliferation	1
B cell activation	1
regulation of apoptotic process	1
negative regulation of apoptotic process	1
positive regulation of canonical NF-kappaB signal transduction	1
innate immune response	1

Indications & clinical

Indications

0 indications (0 at ChEMBL trial phase 4).

Clinical trials

Total trials: 0.

Clinical evidence (CIViC)

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

Pharmacology

Pharmacogenomics

No PharmGKB pharmacogenomic data curated for this drug.

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.

4 molecules share ≥1 primary target. Top 4 by shared-target count:

Molecule	Source	Status	Shared targets
THIORIDAZINE	ChEMBL + PubChem	Phase 4 (approved)	MALT1
PROMAZINE	ChEMBL	Phase 4 (approved)	MALT1
LAPACHONE	ChEMBL	Phase 2	MALT1
SAFIMALTIB	ChEMBL	Phase 2	MALT1