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Protein / target

Programmed cell death protein 1

Encoded byPDCD1Q15116Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
9
Approved medicines
Open Targets target-level
View by indication →
30
Clinical trials
Small-molecule tractable
Druggability
Structure with Ligand

Protein at a glance

Biological role

Transmembrane signaling receptor

Strongest disease association

Melanoma

Via encoding gene PDCD1 · Literature evidence · score 0.63

Therapeutic position

Established drug target

Antibodies

Research activity

Extensively researched

161 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 overview

Inhibitory receptor on antigen activated T-cells that plays a critical role in induction and maintenance of immune tolerance to self.

View complete UniProt function annotation

Inhibitory receptor on antigen activated T-cells that plays a critical role in induction and maintenance of immune tolerance to self (PubMed:21276005, PubMed:31754127, PubMed:32184441, PubMed:37208329). Delivers inhibitory signals upon binding to ligands CD274/PDCD1L1 and CD273/PDCD1LG2 (PubMed:21276005, PubMed:26602187). Following T-cell receptor (TCR) engagement, PDCD1 associates with TCR-CD3 in the immunological synapse and directly inhibits T-cell activation (PubMed:32184441). Suppresses T-cell activation through the recruitment of PTPN11/SHP-2: following ligand-binding, PDCD1 is phosphorylated within the ITSM motif, leading to the recruitment of the protein tyrosine phosphatase PTPN11/SHP-2 that mediates dephosphorylation of key TCR proximal signaling molecules, such as ZAP70, PRKCQ/PKCtheta and CD247/CD3zeta (PubMed:32184441)

Subcellular location

Cell membrane
Domains and Gene Ontology detail (14)

Domains & features

Ig-like V-type

Gene Ontology

  • Cexternal side of plasma membrane
  • Cplasma membrane
  • Fsignaling receptor activity
  • Ftransmembrane signaling receptor activity
  • Padaptive immune response
  • Papoptotic process
  • Phumoral immune response
  • Pnegative regulation of immune response
  • Pnegative regulation of inflammatory response
  • Pnegative regulation of T cell activation
  • Pnegative regulation of T cell mediated immune response to tumor cell
  • Pnegative regulation of T cell receptor signaling pathway

288 aa · 32 kDa

Biological roles

Reactome v97

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

Immune signallingUniProt · GO
View supporting evidence

Immune signalling

  • ·Inhibitory receptor on antigen activated T-cells that plays a critical role in induction…
  • ·adaptive immune response
  • ·humoral immune response
  • ·negative regulation of immune response
View underlying pathways (3)

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.

CD274PDCD1L…PTPN11CD80CD86CTLA4LGALS9PTPN6CD4LAG3PDCD1

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

5 medicines · 15 areas

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.

Carcinoma, Non-Small-Cell Lung2 medicines
Carcinoma, Squamous Cell2 medicines
Endometrial Neoplasms2 medicines
Adenocarcinoma1 medicine
Carcinoma, Renal Cell1 medicine
Carcinoma, Transitional Cell1 medicine
Esophageal Neoplasms1 medicine
Esophageal Squamous Cell Carcinoma1 medicine
Hodgkin's Disease1 medicine
Lung Neoplasms1 medicine
Melanoma1 medicine
Nasopharyngeal Carcinoma1 medicine
Squamous Cell Carcinoma of Head and Neck1 medicine
Stomach Neoplasms1 medicine
Broader indication categories (1)

Broad umbrella indications (e.g. “Neoplasms”). Shown here because every medicine also appears under a more specific disease above — kept for completeness, de-emphasised for clarity.

9 medicines meet Open Targets' target-level approved-medicine definition; the 5 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

11

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.

pembrolizumab
Narrow target profileApprovedInhibitor

Programmed cell death protein 1 inhibitor

Indicated for Carcinoma, Non-Small-Cell Lung, Carcinoma, Renal Cell, Carcinoma, Squamous Cell, Carcinoma, Transitional Cell

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

zimberelimab
Narrow target profilePhase 3Inhibitor

Programmed cell death protein 1 inhibitor

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

camrelizumab
Narrow target profilePhase 3Antagonist

Programmed cell death protein 1 antagonist

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

dostarlimab
Narrow target profileApprovedAntagonist

Programmed cell death protein 1 antagonist

Indicated for Endometrial Neoplasms, Neoplasms

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

tislelizumab
Narrow target profileApprovedInhibitor

Programmed cell death protein 1 inhibitor

Indicated for Adenocarcinoma, Carcinoma, Non-Small-Cell Lung, Esophageal Neoplasms, Esophageal Squamous Cell Carcinoma

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

spartalizumab
Narrow target profilePhase 3Antagonist

Programmed cell death protein 1 antagonist

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

View all 11 targeting drugs
sintilimab
Narrow target profileApprovedAntagonist

Programmed cell death protein 1 antagonist

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

cemiplimab
Narrow target profileApprovedInhibitor

Programmed cell death protein 1 inhibitor

Indicated for Carcinoma, Squamous Cell, Lung Neoplasms, Neoplasms

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

Serplulimab
Narrow target profileApprovedAntagonist

Programmed cell death protein 1 antagonist

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

toripalimab
Narrow target profileApprovedAntagonist

Programmed cell death protein 1 antagonist

Indicated for Nasopharyngeal Carcinoma, Neoplasms

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

penpulimab
Narrow target profilePhase 3Inhibitor

Programmed cell death protein 1 inhibitor

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

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 PDCD1

Gene-level evidence surfaced through the gene PDCD1 that 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.

Melanoma
0.78Well supported

Clinical evidence dominant · Open Targets 0.63

Carcinoma, Non-Small-Cell Lung
0.78Well supported

Clinical evidence dominant · Open Targets 0.63

Carcinoma, Renal Cell
0.76Well supported

Clinical evidence dominant · Open Targets 0.61

Esophageal Squamous Cell Carcinoma
0.75Well supported

Clinical evidence dominant · Open Targets 0.61

Neoplasms
0.75Well supported

Clinical evidence dominant · Open Targets 0.60

View evidence synthesis (5)
MelanomaWell supported
0.78
agreement 0.620.93
Clinical83%Literature17%

Open Targets aggregate 0.63 · 2 independent evidence families

Carcinoma, Non-Small-Cell LungWell supported
0.78
agreement 0.620.93
Clinical83%Literature17%

Open Targets aggregate 0.63 · 2 independent evidence families

Carcinoma, Renal CellWell supported
0.76
agreement 0.610.92
Clinical85%Literature15%

Open Targets aggregate 0.61 · 2 independent evidence families

Esophageal Squamous Cell CarcinomaWell supported
0.75
agreement 0.600.91
Clinical84%Literature16%

Open Targets aggregate 0.61 · 2 independent evidence families

NeoplasmsWell supported
0.75
agreement 0.600.91
Clinical83%Literature18%

Open Targets aggregate 0.60 · 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
Melanoma0.63
Carcinoma, Non-Small-Cell Lung0.63
Carcinoma, Renal Cell0.61
Esophageal Squamous Cell Carcinoma0.61
Neoplasms0.60
Nasopharyngeal Carcinoma0.59
Squamous Cell Carcinoma of Head and Neck0.59
Hodgkin's Disease0.58
Carcinoma, Squamous Cell0.56

Drug development

26 compounds recorded · 9 approved · 17 in clinical development

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 11 drugs that target this protein in Forefront's canonical graph (5 with a mapped approved indication, shown above): these count different sets and are not a subset relation.

View all recorded compounds (10)
CAMRELIZUMABPhase 3
DOSTARLIMABApproval
FINOTONLIMABPhase 3
RETIFANLIMABApproval
SINTILIMABApproval
SERPLULIMABApproval
APL-501Phase 2
TORIPALIMABApproval
ZIMBERELIMABPhase 3
BALSTILIMABPhase 3

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 moleculesEmerging

Feasibility evidence (structure with ligand and high-quality ligand) — no clinical-stage drug of this modality recorded.

AntibodiesStrong

Approved Drug and UniProt loc high conf support this modality.

Protein degradersEmerging

Feasibility evidence (literature and uniprot ubiquitination) — no clinical-stage drug of this modality recorded.

Other modalitiesStrong

Advanced Clinical support this modality.

View underlying tractability evidence (10)
SM · Structure with LigandSM · High-Quality LigandAB · Approved DrugAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMPR · LiteraturePR · UniProt UbiquitinationPR · 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)

ClinicalTrials.gov via the drug-target graph.

What's happening now

12

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 3 drugs that target 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. Trial status changed2026-09-02

    A Phase 3 Open-Label, Randomized Study of PDS0101 and Pembrolizumab vs Pembrolizumab Alone in First-Line Treatment of Unresectable Recurrent and/or Metastatic HPV16+ Head and Neck Squamous Cell Carcinoma

    Status changed to Terminated · ClinicalTrials.gov · via pembrolizumab

  2. Indication expanded2026-08-25

    Indication expansion: TISLELIZUMAB-JSGR (BLA761232)

    fda · regulatory · fda · via tislelizumab

  3. Product recall2026-07-28

    Recall (Class II): CEMIPLIMAB-RWLC

    fda · safety · fda · via cemiplimab

  4. Trial results posted2026-07-27

    Cemiplimab in High-risk or Locally Advanced Luminal and Triple Negative Breast Cancer (CemiHALT )

    Results posted · ClinicalTrials.gov · via cemiplimab

  5. Trial results posted2026-07-20

    A Phase 3, Randomized Study to Evaluate the Efficacy and Safety of Pembrolizumab (MK-3475) + Lenvatinib (E7080/MK-7902) + Chemotherapy Compared With Standard of Care as First-line Intervention in Participants With Metastatic Esophageal Carcinoma.

    Results posted · ClinicalTrials.gov · via pembrolizumab

  6. Trial status changed2026-07-20

    A Phase 3, Randomized Study to Evaluate the Efficacy and Safety of Pembrolizumab (MK-3475) + Lenvatinib (E7080/MK-7902) + Chemotherapy Compared With Standard of Care as First-line Intervention in Participants With Metastatic Esophageal Carcinoma.

    Status changed to Completed · ClinicalTrials.gov · via pembrolizumab

  7. Indication expanded2026-07-10

    Indication expansion: PEMBROLIZUMAB (BLA125514)

    fda · regulatory · fda · via pembrolizumab

  8. Indication expanded2026-07-10

    Indication expansion: PEMBROLIZUMAB AND BERAHYALURONIDASE ALFA-PMPH (BLA761467)

    fda · regulatory · fda · via pembrolizumab

  9. Indication expanded2026-06-24

    Indication expansion: PEMBROLIZUMAB (BLA125514)

    fda · regulatory · fda · via pembrolizumab

  10. New publication2026-01-28
    Fecal microbiota transplantation plus pembrolizumab and axitinib in metastatic renal cell carcinoma: the randomized phase 2 TACITO trial.

    Nature medicine · 2026 · 8 citations · Europe PMC · via pembrolizumab

  11. New publication2026-01-01
    Sacituzumab Govitecan plus Pembrolizumab for Advanced Triple-Negative Breast Cancer.

    The New England journal of medicine · 2026 · 3 citations · Europe PMC · via pembrolizumab

  12. New publication2025-08-01
    Phase I and II Clinical Studies of the STING Agonist Ulevostinag with and without Pembrolizumab in Participants with Advanced or Metastatic Solid Tumors or Lymphomas.

    Clinical cancer research : an official journal of the American Association for Cancer Research · 2025 · 20 citations · Europe PMC · via pembrolizumab

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.

Research activity

161 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

Topalian SL · The New England journal of medicine · 2012

Finn RS · The New England journal of medicine · 2020

Robert C · The New England journal of medicine · 2015

Robert C · The New England journal of medicine · 2015

Keir ME · Annual review of immunology · 2008

Recent

Sacituzumab Govitecan plus Pembrolizumab for Advanced Triple-Negative Breast Cancer.

Tolaney SM · The New England journal of medicine · 2026

Primary and Acquired Resistance to Immunotherapy with Checkpoint Inhibitors in NSCLC: From Bedside to Bench and Back.

Mariniello A · BioDrugs : clinical immunotherapeutics, biopharmaceuticals and gene therapy · 2025

Immune checkpoint inhibition perturbs neuro-immune homeostasis and impairs cognitive function.

Ifejeokwu OV · Journal of experimental & clinical cancer research : CR · 2025

Europe PMC papers linked directly to this protein.