Randomised controlled trials (RCTs) remain the evidentiary backbone of regulatory approval, yet every sponsor faces the same practical limitations: trials enroll highly selected patients, follow them for limited periods, and occur within protocol‑driven settings that diverge from everyday practice. The result is a widening knowledge gap between the efficacy demonstrated at approval and the effectiveness, safety, utilisation, and patient experience observed once a therapy is commercialised.

Patient registries can help close this gap. Defined by the Agency for Healthcare Research and Quality (AHRQ) as observational systems that evaluate specified outcomes for a population defined by disease, condition, or exposure, registries are designed to capture routine‑care data prospectively and longitudinally.(1) Importantly, modern registries are built on electronic data‑capture platforms that enforce common data elements, real‑time validation, and secure governance—making their outputs credible to regulators and payers. FDA’s 2023 guidance on registry‑derived RWE calls such infrastructures “fit for purpose” when they reliably answer a specific regulatory question.(2)

Internally, a registry therefore can serve multiple purposes across a product’s lifecycle and can be extremely informative for effective healthcare decision-making:

I. Post-Marketing Surveillance

Registries are frequently used after drug approval to monitor long-term safety and rare adverse events in broader populations. Regulatory agencies (like FDA and EMA) increasingly accept registry-based RWE to fulfill post-approval safety commitments and even to support new indications.(2)

Proactive analyses allow teams to investigate and contextualize events before they escalate, helping to maintain regulatory confidence or indeed intervene quickly should patient health be at risk.

II. Real‑World Evidence Across Diverse Populations

Crucially, registry data are more representative than trial data. Elderly patients, those with comorbidities, pregnant women, or minority populations routinely excluded from RCTs appear in registry cohorts, revealing real‑world effectiveness—and risk—across the full treatment spectrum. This representativeness resonates with payers increasingly demanding evidence of outcomes in covered populations. In other words, a registry’s RWE reduces evidentiary blind spots and arms internal teams with patient‑level insights that reflect actual market heterogeneity.

III. Natural History and Unmet‑Need Mapping

For rare diseases or conditions with limited trial data, registries document the disease’s course, epidemiology, and outcomes under standard care. These data help identify unmet needs and can be used to inform trial design and may even provide external control arms for single arm studies. (1, 3-5)

IV. Real-World Effectiveness and Comparative Outcomes

Registries allow comparison of treatment patterns and outcomes in routine practice. They can support comparative effectiveness research by including diverse treatments and patient subgroups, helping answer which therapies work best for whom. (6)

V. Supporting Label Expansion and Indication Extension

Companies may leverage registry data to bolster evidence for expanding a drug’s indications or securing regulatory approvals in new populations. For example, registries can provide historical control data or demonstrate benefit in off-label use, supplementing and building on clinical trial findings. In Europe, cystic‑fibrosis modulators and haemophilia factor products expanded labels in part through registry analyses confirming benefit in genetic or age subgroups absent from pivotal RCTs.(7)

VI. Accelerating Trial Design and Recruitment

Registries facilitate trial planning and recruitment by identifying eligible patients and providing contemporary data on standard-of-care outcomes. Investigators can query registry data to refine inclusion criteria, estimate event rates, or select relevant endpoints, thereby optimizing trial design.

In early drug development, registries help identify high unmet needs or niche patient segments and generate hypotheses. They can point to biomarkers or clinical features correlated with outcomes, informing translational research and trial focus areas.

VII. Patient‑Centered Outcomes and Quality Improvement

Many registries incorporate patient-reported outcomes and long-term follow-up, yielding insights into health-related quality of life, functional status, as well as treatment satisfaction. (8)

VIII. Policy and Guidelines Development

Because registries reflect “real-world” practice and outcomes, their findings often shape clinical guidelines and health policy. (6) Public health agencies utilize disease registry data to track trends (e.g., incidence, treatment uptake) and to evaluate interventions at the population level.

IX. Conclusion

Although patient registries require significant time, resources and budget to plan and execute, the evidence returns for Medical Affairs departments can be significant. Expedited development, reduced post‑approval risk, improved market access, and contemporary insights that steer future innovation can all be gained from a well-planned and considered registry. Anchored in rigorous protocols, dynamic data management, and transparent governance, a registry can transform research from a post-launch regulatory requirement into a competitive differentiator.