Caplacizumab

證據等級: L5

預測適應症: 10 個

Caplacizumab: From Acquired Thrombotic Thrombocytopenic Purpura to Thrombotic Thrombocytopenic Purpura

One-Sentence Summary

Caplacizumab is an anti-von Willebrand factor nanobody that is internationally approved (EMA, FDA) for the treatment of acquired immune-mediated thrombotic thrombocytopenic purpura (iTTP/aTTP), yet is currently not recorded as marketed in Denmark. The TxGNN model predicts it as highly relevant for Thrombotic Thrombocytopenic Purpura (TxGNN score: 99.9965%), confirming its established therapeutic target — and this prediction is supported by 14 registered clinical trials (including three completed Phase 3 studies) and 20 publications, among them the pivotal HERCULES and TITAN Phase 3/2 RCTs published in The New England Journal of Medicine.

Quick Overview

Item	Content
Original Indication	Not recorded in Danish regulatory dataset (internationally approved for acquired/immune-mediated TTP)
Predicted New Indication	Thrombotic Thrombocytopenic Purpura (TTP)
TxGNN Prediction Score	99.9965%
Evidence Level	L1
Denmark Market Status	Not marketed
Number of Marketing Authorisations	0 (Danish regulatory registry)
Recommended Decision	Proceed with Guardrails

Why Is This Prediction Reasonable?

Currently, detailed mechanism of action data is not available in this evidence pack. Based on published information, caplacizumab is a humanised, bivalent variable-domain-only immunoglobulin fragment (nanobody) that specifically targets the A1 domain of von Willebrand factor (vWF). Its efficacy in immune-mediated TTP has been demonstrated in two pivotal randomised controlled trials, and its direct mechanistic alignment with TTP pathology is one of the clearest target-disease matches in modern hematology.

In iTTP, a severe autoantibody-mediated deficiency of the ADAMTS13 protease leads to accumulation of ultra-large vWF multimers (UL-vWF) in the circulation. These UL-vWF multimers bind to the GPIb receptor on platelets, triggering widespread platelet aggregation and microvascular thrombosis — causing microangiopathic haemolytic anaemia, severe thrombocytopenia, and ischaemic end-organ injury (brain, kidneys, heart) with historically >90% untreated mortality. Caplacizumab directly blocks the UL-vWF A1 domain–platelet GPIb interaction, interrupting this thrombotic cycle rapidly and within days while plasma exchange and immunosuppression work to restore ADAMTS13 activity.

The TxGNN model assigns high prediction scores across several rare platelet disorders for caplacizumab (see Multi-Indication Overview below), which is consistent with the drug’s mechanistic influence on the vWF–GPIb adhesion axis broadly shared among these conditions. However, only TTP has direct mechanistic alignment (★★★★★) and clinical evidence at the L1 level. Notably, pseudo-von Willebrand disease (platelet-type vWD, rank 3) shares a closely related pathological GPIb–vWF interaction and merits further research attention (★★★★☆), while the remaining high-scoring predictions reflect likely graph-proximity artefacts rather than genuine mechanistic overlap.

Multi-Indication Overview

The TxGNN model identified five unique platelet-disorder indications for caplacizumab. The following table summarises each prediction (duplicate rank entries have been de-duplicated):

Rank	Predicted Indication	TxGNN Score	Evidence Level	Recommendation	Mechanistic Relevance
1	Primary release disorder of platelets	99.9998%	L5	Hold	★☆☆☆☆ — Dense granule secretion defect; no overlap with vWF–GPIb adhesion pathway. Likely graph proximity artefact.
3	Pseudo-von Willebrand disease	99.9998%	L4	Research Question	★★★★☆ — Gain-of-function GPIb mutation causes pathological GPIb–vWF binding; caplacizumab’s vWF A1 blockade directly addresses this mechanism.
5	Glanzmann thrombasthenia	99.9997%	L5	Hold	★☆☆☆☆ — GPIIb/IIIa (αIIbβ3 integrin) aggregation defect; entirely different target from vWF A1–GPIb pathway.
7	Scott syndrome	99.9975%	L5	Hold	★☆☆☆☆ — TMEM16F (Anoctamin-6) mutation; phosphatidylserine externalisation defect unrelated to vWF–GPIb axis.
9	Thrombotic thrombocytopenic purpura	99.9965%	L1	Proceed with Guardrails	★★★★★ — Direct on-target mechanism; three completed Phase 3 studies; international guidelines endorse caplacizumab as standard of care.

Clinical Trial Evidence (Thrombotic Thrombocytopenic Purpura)

Trial Number	Phase	Status	Enrollment	Key Findings
NCT02553317	Phase 3	Completed	145	HERCULES pivotal trial: double-blind, placebo-controlled RCT. Caplacizumab + plasma exchange + immunosuppression significantly reduced time to platelet normalisation, composite TTP events (death, recurrence, major thromboembolism), and exacerbation rate vs placebo. Formed the regulatory basis for EMA and FDA approval.
NCT02878603	Phase 3	Completed	104	Post-HERCULES: prospective long-term follow-up of HERCULES completers, evaluating safety and efficacy of repeated caplacizumab use over multi-year observation. Provides long-term outcome data strengthening L1 classification.
NCT05468320	Phase 3	Completed	51	Phase 3 single-arm open-label study evaluating caplacizumab + immunosuppressive therapy without first-line therapeutic plasma exchange (TPE) in iTTP adults. Completed December 2024; results expand evidence base for TPE-sparing regimens.
NCT01151423	Phase 2	Completed	75	TITAN: Phase 2 single-blind, placebo-controlled RCT. First randomised study establishing the efficacy and safety of anti-vWF nanobody as adjunct to plasma exchange in aTTP.
NCT04985318	N/A	Recruiting	350	REACT-2020: Large German national prospective multi-centre real-world study describing prescription practices, confirming real-world efficacy, and identifying predictors of persistent autoimmune activity and complications. Estimated completion 2034.
NCT04720261	Phase 2	Terminated	58	Phase 2 non-inferiority study of personalised caplacizumab dosing guided by ADAMTS13 activity monitoring. Terminated for reasons unrelated to safety; provides exploratory data on treatment-duration optimisation strategies.
NCT04074187	Phase 2/3	Completed	21	Open-label Phase 2/3 study in Japanese aTTP patients. Evaluated prevention of TTP recurrence, platelet count restoration, and composite aTTP-related outcomes in an Asian population.
NCT06291025	N/A	Recruiting	131	Multicentre non-inferiority study evaluating caplacizumab + immunosuppression + plasma infusion without TPE in iTTP. Recruiting; anticipated completion August 2026. Results may further redefine first-line management standards.
NCT05876221	N/A	Completed	223	Observational study of platelet count dynamics under caplacizumab. Demonstrates rapid normalisation within 3–4 days and highlights the decoupling of platelet counts from ADAMTS13 activity as a potential monitoring pitfall for over- and undertreatment decisions.
NCT07205861	N/A	Recruiting	1,200	TWI-LIGHT: Large French retrospective epidemiological study of iTTP patients in the national TMA registry. Provides disease burden and real-world treatment pattern data. Anticipated completion December 2028.

Literature Evidence (Thrombotic Thrombocytopenic Purpura)

PMID	Year	Type	Journal	Key Findings
30625070	2019	RCT (HERCULES Phase 3)	N Engl J Med	Caplacizumab added to standard therapy significantly reduced time to platelet count response, composite TTP-related event rate, and exacerbation rate; established caplacizumab as standard of care for aTTP.
26863353	2016	RCT (TITAN Phase 2)	N Engl J Med	First Phase 2 randomised trial of caplacizumab as adjunctive therapy in aTTP; demonstrated faster platelet recovery and trend toward reduction in recurrence vs placebo.
40533296	2025	Clinical Guidelines (Update)	J Thromb Haemost	2025 focused update of the ISTH 2020 iTTP/cTTP management guidelines; integrates new evidence on treatment optimisation, monitoring, and management of congenital TTP.
32914526	2020	Clinical Guidelines	J Thromb Haemost	ISTH 2020 treatment guidelines for TTP; formally includes caplacizumab as part of recommended triple therapy (plasma exchange + immunosuppression + caplacizumab) for iTTP.
32914582	2020	Clinical Guidelines	J Thromb Haemost	ISTH 2020 diagnostic guidelines for TTP; standardises ADAMTS13 activity-based diagnosis criteria and patient stratification approach.
40388146	2025	Systematic Review	JAMA	Comprehensive JAMA review of iTTP covering epidemiology (2–6 cases/million/year worldwide), pathophysiology, diagnostic approach, and current treatment including the role of caplacizumab.
37045600	2023	Systematic Review & Meta-analysis	Expert Rev Hematol	Meta-analysis of caplacizumab efficacy and safety in iTTP across multiple studies; confirms reduction in recurrence, composite events, and disease-related mortality.
40235949	2025	Multicentre Cohort Study	EClinicalMedicine	Capla 1000+ international retrospective cohort (>1,000 iTTP patients); addresses the effect of caplacizumab on mortality and identifies optimal timing of initiation.
33540569	2021	Review	J Clin Med	Comprehensive review of TTP pathophysiology, diagnosis, and the evolving management paradigm including caplacizumab and ADAMTS13-guided treatment strategies.
36890095	2023	Review	Transfus Apher Sci	Review of individualised TTP management in the caplacizumab era; discusses ADAMTS13-guided treatment duration, stopping criteria, and long-term disease monitoring.

Denmark Market Information

Caplacizumab is currently recorded as not marketed in Denmark, with no marketing authorisations registered in the Danish regulatory dataset.

Note for healthcare professionals: Caplacizumab is marketed internationally as Cablivi® (Sanofi/Ablynx) and holds a centralised marketing authorisation from the European Medicines Agency (EMA), which in principle covers all EU/EEA member states including Denmark. The absence of records in this dataset may reflect a gap in national marketing, pricing/reimbursement, or data capture of centralised EMA authorisations. Healthcare professionals are advised to verify the current access and reimbursement status directly with the Danish Medicines Agency (Lægemiddelstyrelsen) and the EMA product register before drawing conclusions about availability.

Safety Considerations

Please refer to the approved Summary of Product Characteristics (SmPC) for safety information.

No drug–drug interactions were identified in the structured interaction database search conducted on 10 March 2026.

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: Caplacizumab has the strongest possible mechanistic alignment with iTTP (★★★★★) and the highest clinical evidence level (L1), supported by multiple completed Phase 3 RCTs, a growing real-world evidence base across thousands of patients, and incorporation into international clinical guidelines (ISTH 2020, updated 2025). The drug already holds EMA marketing authorisation. However, Danish regulatory records show no active marketing authorisation or reimbursement pathway in Denmark, formal safety documentation is unavailable in this dataset, and there are specific monitoring considerations (bleeding risk, ADAMTS13-guided treatment duration) that require structured clinical safeguards.

To proceed, the following is needed:

Market access verification: Confirm EMA centralised authorisation status and current commercial/reimbursement availability of Cablivi® in Denmark through Lægemiddelstyrelsen and the manufacturer (Sanofi)
Safety documentation: Obtain and review the full SmPC for bleeding risk management, contraindications, special population data (pregnancy, renal/hepatic impairment, paediatric use), and administration guidance
Reimbursement assessment: Engage with the Danish Medicines Council (Medicinrådet) regarding an iTTP orphan drug reimbursement application given the drug’s high unit cost and ultra-rare disease context
MOA documentation: Resolve data gap DG002 (mechanism of action) by querying DrugBank API for internal records completeness
Pseudo-vWD follow-up: The rank 3 prediction for pseudo-von Willebrand disease (platelet-type vWD) merits academic investigation given strong mechanistic plausibility (★★★★☆) and no currently registered clinical trials — consider proposing a prospective case series or registry study

This report is generated for research reference purposes only and does not constitute medical advice. Drug repurposing candidates require clinical validation before therapeutic application. All website content should include a YMYL disclaimer.

Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.