Purpose-Built for the Complexity of Rare Disease Research

Small patient populations. Dispersed geographies. High patient burden. Castor’s unified EDC, ePRO, and eConsent platform is designed for the realities of rare disease, not adapted from them.

Patients in a single national genetics and rare disease biobank on Castor
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ePRO compliance in recent rare disease interventional trials
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Rare disease studies on the platform
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Error Rate vs. 6.6% Manual Extraction
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The Challenge

Why rare disease trials demand a different approach

Rare disease research operates under constraints that standard trial platforms were never designed to handle. Patient populations are small, often geographically scattered, and frequently include pediatric or vulnerable cohorts. The result: sponsors face protocol deviations driven by site burden, dropout rates exacerbated by onerous visit schedules, and data quality errors that cannot be tolerated when every patient is irreplaceable.

Challenge 1

Finding and keeping patients

Rare disease trials struggle with enrollment. Every patient who drops out due to travel burden or confusing assessments represents a material setback to a program with no replacement pool. Patient compliance is not a quality metric. It is the study itself.

Challenge 2

Data quality at small N

In large trials, a handful of data entry errors are a rounding error. In a rare disease study with 40 patients, a 6.6% manual extraction error rate means 2-3 corrupted records that could invalidate an endpoint. Data accuracy is a scientific imperative, not an operational preference.

Challenge 3

Managing complex, multi-modal endpoints

Rare disease protocols often combine EDC data capture with validated patient-reported outcomes, caregiver-reported outcomes, and functional assessments, typically handled by separate vendors, creating reconciliation overhead and data integrity risk.

Challenge 4

Global reach without global headcount

Reaching patients in 160+ countries requires multi-language support, local regulatory compliance, and the ability to onboard sites quickly. Decentralized clinical trials tools remove the need for dedicated in-country infrastructure for each market.

How Castor Helps

One platform. Everything rare disease needs.

Lower data entry errors with Castor Catalyst

Manual data extraction averages a 6.6% error rate across the industry. Castor Catalyst’s AI extraction layer turns uploaded site source documents (PDFs, EHR exports, and paper worksheets) into structured eCRF data with human review, delivering a post-QC error rate under 0.7%, versus a 6.6% manual chart-review baseline, with AI extraction reviewed and confirmed by your team. In small-N rare disease studies, this is the difference between reliable data and a compromised endpoint.

Natural history studies and registries, natively

Castor Catalyst’s AI extraction layer turns uploaded site source documents (PDFs, EHR exports, and paper worksheets) into structured eCRF data with human review. For patient-mediated data, Catalyst supports Direct-to-Patient retrieval where the patient authorizes FHIR access. Combined with prospective ePRO/EDC data capture on the same platform, rare disease teams can build a complete natural history baseline alongside an active interventional study. This approach to real-world evidence generation requires no separate system or additional validation overhead.

ePRO that patients actually complete

Castor Connect delivers eCOA solutions deployable as BYOD or on provisioned devices, with ClinRO for site-administered assessments. SMS and WhatsApp reminders via Twilio, offline mode with automatic sync, and 24/7 multilingual patient support in 15 to 20 languages drive up to 95%+ compliance in recent rare disease interventional trials, a best-case recent figure rather than a guarantee. All data captured securely in Castor Connect, 21 CFR Part 11 and HIPAA/GDPR compliant. The platform is available in 15-20 languages.

Eliminate the swivel chair — zero cross-vendor reconciliation

eCOA data flows directly into the electronic data capture system, with no manual data transfer, no reconciliation delays between separate vendor platforms, and no integration tax. One source of truth from first patient in to database lock, with no second vendor relationship to manage.

eConsent for complex, vulnerable populations

Dynamic, multimedia-supported eConsent for pediatric, caregiver, and adult rare disease populations. Supports guardian and legally authorized representative (LAR) consent, re-consent workflows for protocol amendments, and multi-country regulatory requirements.

190+ validated instruments out of the box

Supports 190+ validated instruments including PROMIS, EORTC, and EQ-5D, with the flexibility to quickly configure pediatric and caregiver-reported assessments. No custom build required for the most commonly used rare disease endpoint instruments.

Built for global compliance — 21 CFR Part 11, ICH E6(R2/R3), EU Annex 11

Full regulatory compliance built in across all study types and jurisdictions. FDA 21 CFR Part 11, ICH E6(R2/R3), EU Annex 11, GDPR, and HIPAA validated, with support for FDA rare disease guidance and the February 2026 single-pivotal-trial framework for orphan drug programs. No separate implementation project required when adding a new indication or market.

A unified EDC, ePRO, eConsent, and RWE platform designed for the precision, patient-centricity, and global reach that rare disease research demands.

Prevent Outcomes

Rare disease teams trust Castor

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40+ rare disease studies across 160+ countries. Whatever your trial throws at you, small-N, complex endpoints, or multi-country logistics, you are working on a platform that has handled the full spectrum of rare disease research before.

Patients in a single national genetics and rare disease biobank on Castor. Your most complex genetic and rare disease datasets are handled at scale.

Of continuous data capture in a rare disease and natural history registry, the platform’s longest-running continuous registry. The decades of follow-up your natural history study needs are supported.

A global sponsor cut endpoint transcription effort from 40 hours to under 4 hours per patient on Castor Catalyst RWE, with EDC data available in 1 hour, capturing eCRF plus caregiver ObsRO and surveys with minimal site burden.

Rated by clinical researchers on independent review platforms

Recognized by independent analysts

Rated strongly for customer loyalty in ISR’s 2025 eCOA/ePRO Benchmarking.

About Castor For rare disease clinical trials

A unified platform built for the realities of rare disease research

If you run rare disease trials, you know the data lives everywhere: clinical, patient-reported, caregiver-reported, and historical. Castor brings it together. EDC, eCOA and ePRO, eConsent, and Castor Catalyst’s AI extraction layer all sit in a single unified database, so there is less cross-vendor reconciliation to manage.

It works at the scale rare disease research demands. The platform holds a single national genetics and rare disease biobank of 19,000+ patients, and it supports the decades-long follow-up these studies require, with 119+ months of continuous data capture in a rare disease and natural history registry.

It also reduces the burden of legacy data work. On one Castor Catalyst RWE study, a global sponsor cut endpoint transcription effort from 40 hours to under 4 hours per patient, with EDC data available in 1 hour, while capturing multi-modal endpoints (eCRF plus caregiver ObsRO and surveys).

And it keeps patients engaged. Castor reaches up to 95%+ ePRO compliance in recent rare disease interventional trials, a best-case recent figure rather than a guarantee, with data collection available in 15-20 languages and 24/7 patient support in 15 to 20 languages.

AI extraction with human review

Castor Catalyst’s AI extraction layer turns uploaded site source documents (PDFs, EHR exports, and paper worksheets) into structured eCRF data with human review. For patient-mediated data, Catalyst supports Direct-to-Patient retrieval where the patient authorizes FHIR access. It delivers a post-QC error rate under 0.7%, versus a 6.6% manual chart-review baseline, with AI extraction reviewed and confirmed by your team, supporting orphan drug programs that depend on retrospective patient registry data.

Validated for global regulatory standards

Full regulatory compliance across FDA 21 CFR Part 11, ICH E6(R3), EU Annex 11, GDPR, and HIPAA, with support for FDA rare disease guidance and the February 2026 single-pivotal-trial framework for orphan drug programs.

Predictable study build timelines

Castor scopes each study build with managed Professional Services. Low-to-medium complexity studies typically move from kickoff (KOM) to user acceptance testing (UAT) in 4 to 8 weeks. High-complexity studies take 8 to 12 weeks.

Common questions

Frequently asked questions

Yes. Castor is designed for the precision that small-N rare disease studies demand. The unified EDC and eCOA platform captures clinical, patient-reported, and caregiver-reported data in a single database, reducing reconciliation errors. Castor Catalyst delivers a post-QC error rate under 0.7%, versus a 6.6% manual chart-review baseline, with AI extraction reviewed and confirmed by your team. In a 40-patient rare disease study, data accuracy is not an operational preference. It is a scientific requirement.

Castor’s DCT toolkit includes remote eConsent, ePRO deployable as BYOD or on provisioned devices, SMS and WhatsApp reminders, offline mode with automatic sync for low-connectivity settings, and telemedicine visit scheduling, enabling patients to participate from home across 160+ countries without frequent site visits. 24/7 multilingual patient support further reduces the burden on sites. This is particularly valuable for rare disease patients who may live far from specialist centers or who have limited mobility.

Yes. Castor supports 190+ validated instruments out of the box, including PROMIS, EORTC, and EQ-5D, with the flexibility to quickly configure pediatric and caregiver-reported assessments. Castor’s eConsent supports guardian and legally authorized representative consent workflows for pediatric and cognitively vulnerable populations.

The Castor platform is available in 15-20 languages and has been used in studies across 160+ countries. 24/7 multilingual patient support is available in 15 to 20 languages, reducing site burden for tech issues throughout the study. Site onboarding, regulatory compliance, and data capture standards are all configured per-country within the same unified platform, without requiring country-specific software instances. The platform is validated for FDA 21 CFR Part 11, ICH E6(R2/R3), EU Annex 11, GDPR, and HIPAA.

Yes. Castor Catalyst’s AI extraction layer turns uploaded site source documents (PDFs, EHR exports, and paper worksheets) into submission-ready eCRF data, reviewed and confirmed by your team. For patient-mediated data, Catalyst supports Direct-to-Patient retrieval where the patient authorizes FHIR access. It delivers a post-QC error rate under 0.7%, versus a 6.6% manual chart-review baseline, which makes it well suited for orphan drug development programs that rely on retrospective patient data and registries prior to interventional trial design.

Castor is compliant with FDA 21 CFR Part 11, ICH E6(R2) and E6(R3), EU Annex 11, GDPR, and HIPAA. For rare disease and orphan drug programs, the platform supports FDA’s February 2026 single-pivotal-trial guidance framework and decentralized trial designs required to enroll geographically dispersed patient populations.

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