Castor vs. Clario: choosing the right eCOA and clinical data platform

A comprehensive feature-by-feature comparison to help clinical teams select the best platform for their trial.

Clario combines eCOA/endpoint software with full-service endpoint capabilities, including cardiac safety monitoring and imaging core labs. Castor EDC is a unified eClinical software platform focused on EDC, eCOA, eConsent, and RTSM. The right choice depends on whether you need integrated endpoint services or a self-service unified software platform.

Quick comparison summary

Feature Castor Clario
Best for Academic, IIT, emerging biopharma, EDC + eCOA in one platform Late-phase studies with cardiac safety, imaging, or specialty endpoints
Platform type Unified eClinical software SaaS eClinical software + endpoint services
EDC included (native) Yes Yes, but secondary to eCOA
eCOA / ePRO Yes, no-code builder Yes, extensive validated library
Cardiac safety / ECG monitoring No (specialist needed) Yes, in-house Holter, ECG monitoring
Imaging endpoints No (specialist needed) Yes, core lab included
eConsent Yes (native) Available but not primary
RTSM Yes (native) Limited / via integration
EU MDR / PMCF Strong compliance Standard EU compliance
Implementation No-code, rapid (weeks) Service-led, standard timeline (months)
Pricing Transparent per-study Enterprise contract, service-bundled

Detailed feature comparison

Feature Castor Clario Advantage
Cloud-native SaaS Yes, hosted globally Yes, enterprise cloud Comparable
No-code eCRF / eCOA builder Full no-code capabilities Limited, more configuration-based Castor
Unified EDC + eCOA (native) All in one system, no integration Both available, may require integration Castor
ePRO instrument library Growing library, flexible custom design Extensive, clinically validated library Clario
Cardiac safety / ECG monitoring No (external specialist required) In-house capability, Holter, ECG services Clario
Imaging endpoint services No (external core lab required) In-house core lab and review Clario
eConsent (native) Native, no-code Available, often via workflow Castor
RTSM (native) Native module Limited or via integration Castor
EU MDR / PMCF support Strong, built-in support Standard compliance Castor
BYOD support Full BYOD and provisioned support BYOD supported, less emphasized Castor
Implementation speed Rapid no-code (weeks typical) Standard timeline (months) Castor
Pricing transparency Clear per-study pricing Custom enterprise contracts Castor

Platform deep-dives

About Castor

Castor EDC is a cloud-native, unified eClinical platform developed in Amsterdam and deployed across 90+ countries. Its core strength is bringing EDC, eCOA (ePRO, eClinRO, eObsRO), eConsent, RTSM, and RWE capabilities into a single integrated system. No integrations or third-party connectors required.

Castor strengths

  • Unified platform: EDC, eCOA, eConsent, RTSM all native and deeply integrated
  • No-code study builder: clinical teams can design instruments and workflows without IT or coding
  • Transparent pricing: clear per-study costs with no hidden enterprise licensing
  • Speed: rapid setup and go-live (typically weeks, not months)
  • EU focus: strong support for EU MDR, PMCF, GDPR, and ISO 27001
  • Academic and IIT strength: widely used by academic medical centers and investigator-initiated research
  • BYOD and provisioned device support: flexible participant enrollment models

Castor limitations

Castor is not a full-service endpoint CRO. Studies requiring integrated cardiac safety monitoring, ECG interpretation, Holter services, or central imaging core labs will need to engage specialist vendors for those services. Castor handles the EDC and eCOA infrastructure; endpoint expertise remains external.

About Clario

Clario (formed from the merger of ERT, BioClinica, and related acquisitions) is a global eClinical services company and technology provider. Clario is unique in that it combines eCOA/endpoint software capabilities with full-service endpoint operations, offering in-house cardiac safety services, central imaging core labs, and specialized endpoint expertise.

Clario strengths

  • Validated ePRO/eCOA library: extensive catalog of clinically validated instruments across therapeutic areas
  • Cardiac safety expertise: in-house Holter monitoring, ECG interpretation, and central cardiac monitoring services
  • Central imaging core lab: integrated imaging endpoint services and review
  • Full-service model: single vendor relationship for eCOA, cardiac safety, and imaging
  • Enterprise scale: strong deployment history in late-phase pharma and global partnerships
  • Specialty endpoint support: deep clinical expertise for rare disease and specialty therapeutic areas

Clario limitations

  • Higher cost and complexity: full-service model means higher fees and longer implementation cycles, even for studies that don’t need cardiac safety or imaging
  • Less self-service: configuration typically requires Clario services team involvement
  • EDC is secondary: the platform is optimized for eCOA and endpoints, not as a primary EDC solution
  • Enterprise contract required: less suitable for small, cost-conscious, or rapid-deployment studies

Decision guide: how to choose

Choose Castor if...

  • You need unified EDC + eCOA + eConsent in a single platform with no integrations
  • Running an academic study or investigator-initiated trial (IIT)
  • Compliance with EU MDR / PMCF is a priority
  • You represent an emerging biopharma company and need cost-effective solutions
  • You want transparent, predictable per-study pricing without enterprise negotiations
  • Fast time-to-study-start is critical (no-code setup in weeks, not months)

Choose Clario if...

  • Your study requires cardiac safety monitoring with integrated ECG or Holter services
  • You need central imaging core lab services as part of your endpoint strategy
  • You require validated specialty ePRO/eCOA instruments with full clinical support
  • You prefer a full-service endpoint partner to reduce vendor management overhead
  • You’re a large pharma running late-phase multi-site trials

If you need both...

Many organizations use a hybrid approach: Castor for unified EDC/eCOA/eConsent infrastructure and Clario (or another specialist) for specialized endpoint services like cardiac safety or imaging. This gives you the efficiency of a single unified platform for core trial operations while preserving best-in-class endpoint expertise where it matters most.

Frequently asked questions

Yes, for many studies. Castor offers a no-code eCOA platform with native EDC integration. However, if you need specialty ePRO/eCOA instruments that are clinically validated by Clario’s team (for rare diseases or specialized assessment scales), you may prefer Clario. For most standard eCOA use cases, Castor is competitive and faster to implement.

Yes, Clario has EDC capabilities, but EDC is not their primary focus. Clario was formed from multiple acquisitions (ERT, BioClinica) and is primarily known for endpoint services (eCOA, cardiac safety, imaging). If EDC is a core requirement alongside eCOA, Castor’s unified approach may be more efficient.

Both offer eCOA/ePRO capabilities. Clario has a larger library of pre-validated instruments and deep clinical expertise in specialty areas. Castor offers a more flexible, no-code builder and faster deployment. For standard studies, Castor’s eCOA is fully capable. For specialty or rare-disease indications requiring deeply validated instruments, Clario’s library may be advantageous.

Castor has a stronger emphasis on BYOD (bring-your-own-device) and provisioned device support. Both platforms support BYOD, but Castor’s design is more mobile-first and BYOD-centric, making it ideal for decentralized or in-home studies.

Castor can capture cardiac safety data via eCOA/ePRO. However, Castor does not provide in-house cardiac safety services like ECG interpretation, Holter monitoring, or central monitoring. Studies requiring these services would need Clario or a separate cardiac safety vendor alongside Castor EDC/eCOA.

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