Protein / target
Complement factor D
Protein at a glance
Biological role
Serine-type endopeptidase
Strongest disease association
Gastrointestinal disease
Therapeutic position
Established drug target
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
Serine protease that initiates the alternative pathway of the complement system, a cascade of proteins that leads to phagocytosis and breakdown of pathogens and signaling that strengthens the adaptive immune system.
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Serine protease that initiates the alternative pathway of the complement system, a cascade of proteins that leads to phagocytosis and breakdown of pathogens and signaling that strengthens the adaptive immune system (PubMed:21205667, PubMed:22362762, PubMed:6769474, PubMed:874324, PubMed:9748277). In contrast to other complement pathways (classical, lectin and GZMK) that are directly activated by pathogens or antigen-antibody complexes, the alternative complement pathway is initiated by the spontaneous hydrolysis of complement C3 (PubMed:21205667, PubMed:22362762, PubMed:6769474, PubMed:874324). The alternative complement pathway acts as an amplification loop that enhances complement activation by mediating the formation of C3 and C5 convertases (PubMed:21205667, PubMed:22362762, PubMed:6769474, PubMed:874324). Activated CFD cleaves factor B (CFB) when the latter is complexed with complement C3b, activating the C3 convertase of the alternative pathway (PubMed:21205667, PubMed:6769474, PubMed:874324, PubMed:9748277)
Subcellular location
Domains and Gene Ontology detail (14)Hide
Domains & features
Gene Ontology
- Cextracellular exosome
- Cextracellular region
- Cextracellular space
- Cficolin-1-rich granule lumen
- Cplatelet alpha granule lumen
- Csecretory granule lumen
- Fserine-type endopeptidase activity
- Fserine-type peptidase activity
- Pcomplement activation
- Pcomplement activation, alternative pathway
- Pprotein maturation
- Pproteolysis
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
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Proteolysis
- ·Serine protease that initiates the alternative pathway of the complement system, a casca…
- ·serine-type endopeptidase activity
- ·serine-type peptidase activity
- ·proteolysis
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Approved medicines with mapped indications
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.
Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
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.
Complement factor D inhibitor
Indicated for Hemoglobinuria, Paroxysmal, Hemolysis
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
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 CFD
Gene-level evidence surfaced through the gene CFDthat 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.
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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 per-type scores above show the calculation.
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Drug development
2 compounds recorded · 1 approved · 1 in clinical development
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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 molecules — Strong
Antibodies — Strong
Protein degraders — Emerging
View underlying tractability evidence (10)Hide
Raw Open Targets tractability assessment buckets, by modality.
Clinical trials
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 (19)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets 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.
- Regulatory approval
Approval: Voydeya (EMA)
- New publicationAddition of danicopan to ravulizumab or eculizumab in patients with paroxysmal nocturnal haemoglobinuria and clinically significant extravascular haemolysis (ALPHA): a double-blind, randomised, phase 3 trial.
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.