Protein / target

Proprotein convertase subtilisin/kexin type 9

PCSK9Q8NBP7Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
4
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Structure with Ligand

Protein at a glance

Biological role

Very-low-density lipoprotein particle receptor binding

Primary system

Endocrine & metabolic

Strongest disease association

hypercholesterolemia, autosomal dominant, 3

Genetic evidence · score 0.94

Therapeutic maturity

Clinically validated target

4 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Structure with Ligand

Clinical development

4 approved · 6 in clinical development

30 linked trials

Research activity

Actively researched

43 papers · latest 2026

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

Crucial player in the regulation of plasma cholesterol homeostasis. Binds to low-density lipid receptor family members: low density lipoprotein receptor (LDLR), very low density lipoprotein receptor (VLDLR), apolipoprotein E receptor (LRP1/APOER) and apolipoprotein receptor 2 (LRP8/APOER2), and promotes their degradation in intracellular acidic compartments (PubMed:18039658). Acts via a non-proteolytic mechanism to enhance the degradation of the hepatic LDLR through a clathrin LDLRAP1/ARH-mediated pathway. May prevent the recycling of LDLR from endosomes to the cell surface or direct it to lysosomes for degradation. Can induce ubiquitination of LDLR leading to its subsequent degradation (PubMed:17461796, PubMed:18197702, PubMed:18799458, PubMed:22074827). Inhibits intracellular degradation of APOB via the autophagosome/lysosome pathway in a LDLR-independent manner. Involved in the disposal of non-acetylated intermediates of BACE1 in the early secretory pathway (PubMed:18660751). Inhibits epithelial Na(+) channel (ENaC)-mediated Na(+) absorption by reducing ENaC surface expression primarily by increasing its proteasomal degradation. Regulates neuronal apoptosis via modulation of LRP8/APOER2 levels and related anti-apoptotic signaling pathways

Subcellular location

CytoplasmSecretedEndosomeLysosomeCell surfaceEndoplasmic reticulumGolgi apparatus
Domains and Gene Ontology detail (53)

Domains & features

Inhibitor I9Peptidase S8

Gene Ontology

  • Ccell surface
  • CCOPII-coated ER to Golgi transport vesicle
  • Ccytoplasm
  • Cearly endosome
  • Cendolysosome membrane
  • Cendoplasmic reticulum
  • Cendoplasmic reticulum lumen
  • Cextracellular region
  • Cextracellular space
  • Cextrinsic component of external side of plasma membrane
  • CGolgi apparatus
  • Clate endosome

692 aa · 74 kDa · 2 isoforms

Biological roles

Reactome v97

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

Apoptosis & cell deathGOProteolysisGOKinase signallingReactomeMetabolic enzyme activityGO
View supporting evidence

Apoptosis & cell death

  • ·apoptotic process
  • ·positive regulation of neuron apoptotic process
  • ·regulation of neuron apoptotic process

Proteolysis

  • ·endopeptidase activity
  • ·serine-type endopeptidase activity

Kinase signalling

  • ·Post-translational protein phosphorylation

Metabolic enzyme activity

  • ·cholesterol metabolic process
View underlying pathways (4)

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.

LDLRAPOBVLDLRHMGCRIGLL5IGKV1D…IGKV1-…IGHV3-…GOLPH3PCSK5PCSK9

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.

Drugs targeting this protein

1

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

evolocumab
Narrow target profileApprovedInhibitor

Subtilisin/kexin type 9 inhibitor

Appears in clinical studies involving familial hypercholesterolemia, coronary artery disorder, Hypercholesterolemia, cardiovascular disorder

Direct interaction with this protein · Only this protein recorded as a target

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

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

hypercholesterolemia, autosomal dominant, 30.94

Genetic · overall 0.82

metabolic disease0.93

Genetic · overall 0.71

Hypercholesterolemia0.92

Genetic · overall 0.82

coronary artery disorder0.91

Genetic · overall 0.72

hyperlipidemia0.90

Genetic · overall 0.66

Highest-confidence therapeutic associations

Diseases where a drug acting on this target has already reached clinical development.

familial hypercholesterolemia0.97

Clinical · overall 0.85

cardiovascular disorder0.96

Clinical · overall 0.72

homozygous familial hypercholesterolemia0.81

Clinical · overall 0.65

myocardial infarction0.72

Clinical · overall 0.65

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

Disorder of lipid metabolism0.65

Genetic

Show all associations
familial hypercholesterolemia0.85
Hypercholesterolemia0.82
hypercholesterolemia, autosomal dominant, 30.82
cardiovascular disorder0.72
coronary artery disorder0.72
metabolic disease0.71
hyperlipidemia0.66
myocardial infarction0.65
homozygous familial hypercholesterolemia0.65
Disorder of lipid metabolism0.65

Open Targets ranks 959 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 10 total

BOCOCIZUMABPhase 3

chronic obstructive pulmonary disease · hyperlipidemia · familial hypercholesterolemia

LERODALCIBEPPhase 3

familial hypercholesterolemia · cardiovascular disorder · familial hypercholesterolemia

ONGERICIMABPhase 3

Combined hyperlipidemia · familial hypercholesterolemia · colorectal cancer

TAFOLECIMABPhase 3

familial hypercholesterolemia · Hypercholesterolemia · Combined hyperlipidemia

INCLISIRAN SODIUMApproval

familial hypercholesterolemia · Hypercholesterolemia · Abnormal circulating lipid concentration

ALIROCUMABApproval

familial hypercholesterolemia · coronary artery disorder · familial hypercholesterolemia

INCLISIRANApproval

cardiovascular disorder · familial hypercholesterolemia · diabetes mellitus

RALPANCIZUMABPhase 1

Hypercholesterolemia

EVOLOCUMABApproval

familial hypercholesterolemia · coronary artery disorder · Hypercholesterolemia

FROVOCIMABPhase 2

cardiovascular disorder · Hypercholesterolemia

Tractability

SM · Structure with LigandSM · High-Quality LigandSM · High-Quality PocketAB · Approved DrugAB · GO CC high confAB · UniProt loc med confAB · UniProt SigP or TMHMMPR · Database UbiquitinationPR · Small Molecule BinderOC · Advanced Clinical

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.

Show remaining trials (24)

ClinicalTrials.gov via the drug-target graph.

Research activity

43 papers · to 2026

Papers linked directly to this protein. This is the protein's own literature — descriptor-derived papers are kept separate below.

Most cited

Recent

177Lu-LNC1004 Radioligand Therapy in Patients with End-stage Metastatic Cancers: A Single-Center, Single-Arm, Phase II Study.

Fu H · Clinical cancer research : an official journal of the American Association for Cancer Research · 2025

Circulating Tumor DNA Assessment for Treatment Monitoring Adds Value to PSA in Metastatic Castration-Resistant Prostate Cancer.

Sweeney CJ · Clinical cancer research : an official journal of the American Association for Cancer Research · 2024

Europe PMC papers linked directly to this protein.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

HypercholesterolemiaWell supported
0.98
agreement 0.881.00
Genetic52%Clinical41%Literature7%Genetic literaturedup

Open Targets aggregate 0.82 · 3 independent evidence families · 1 not counted as duplicate

coronary artery disorderWell supported
0.98
agreement 0.871.00
Genetic52%Clinical40%Literature8%

Open Targets aggregate 0.72 · 3 independent evidence families

familial hypercholesterolemiaWell supported
0.97
agreement 0.881.00
Genetic45%Clinical38%Animal model11%Literature6%Genetic literaturedup

Open Targets aggregate 0.85 · 4 independent evidence families · 1 not counted as duplicate

cardiovascular disorderWell supported
0.97
agreement 0.861.00
Genetic53%Clinical43%Literature4%

Open Targets aggregate 0.72 · 3 independent evidence families

hyperlipidemiaWell supported
0.95
agreement 0.851.00
Genetic61%Clinical33%Literature6%

Open Targets aggregate 0.66 · 3 independent evidence families

This ranking differs from Open Targets' own: re-weighting moves genetically-evidenced diseases above more heavily co-mentioned ones. 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 underlying per-type scores are shown above so the calculation can be checked.

What's happening now

28

Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.

  1. Label change2026-07-15

    Label change: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  2. Label change2025-08-21

    Label change: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  3. Label change2024-11-20

    Label change: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  4. Label change2024-08-20

    Label change: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  5. New publication2022-08-29
    Long-Term Evolocumab in Patients With Established Atherosclerotic Cardiovascular Disease.

    Circulation · 2022 · 268 citations · Europe PMC · via evolocumab

  6. Label change2022-08-16

    Label change: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  7. Indication expanded2021-09-24

    Indication expansion: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  8. Label change2021-09-24

    Label change: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  9. Regulatory approval2021-02-26

    Approval: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  10. New publication2020-12-24
    Effects of Evolocumab on the Postprandial Kinetics of Apo (Apolipoprotein) B100- and B48-Containing Lipoproteins in Subjects With Type 2 Diabetes.

    Arteriosclerosis, thrombosis, and vascular biology · 2021 · 23 citations · Europe PMC · via evolocumab

  11. Supplemental approval2020-05-06

    Supplemental approval: EVOLOCUMAB (BLA125522)

    fda · regulatory · fda · via evolocumab

  12. New publication2019-12-12
    Impact of proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab on the postprandial responses of triglyceride-rich lipoproteins in type II diabetic subjects.

    Journal of clinical lipidology · 2020 · 20 citations · Europe PMC · via evolocumab

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.