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Term of the Day

Natural history study

A natural history study is a preplanned observational study intended to track the course of a disease over time, identifying demographic, genetic, environmental and other variables that correlate with its development and outcomes in the absence of intervention, or under standard of care. Designs may be retrospective (chart review of existing records) or prospective (longitudinal follow-up of a cohort or registry).

Natural history data is particularly important in rare and paediatric diseases, where randomised placebo-controlled trials may be infeasible or unethical. The FDA (guidance on rare disease natural history studies, 2019) and the EMA accept well-designed natural history studies to define endpoints and biomarkers, identify patient subgroups, estimate sample sizes and, in some cases, serve as external or historical control arms for single-arm trials supporting orphan products.

Because they are non-interventional, natural history studies fall outside the CTR and are governed by national law (for example France's MR-003 or MR-004 reference methodologies) and by the GDPR. They typically involve secondary use of medical records, long-term follow-up, genetic data and small populations in which anonymisation is rarely achievable, so pseudonymisation, a DPIA and a robust research legal basis under Art. 9(2)(j) are essential. Registries maintained by patient organisations or academic consortia raise additional questions of joint controllership and data access governance.

M

Me-too drug

A me-too drug is a medicine developed within an established therapeutic class, with similarities to an earlier medicine used for the same purpose. The term describes a relationship between products, not a conclusion that the later product is better or worse. Differences in selectivity, safety or interactions may still matter clinically.

Key takeaways

  • Similarity does not establish therapeutic equivalence.
  • A me-too drug is not necessarily a generic.
  • Support comparative claims with relevant evidence.

Comparing Development Terms

An academic definition by Aronson and Green discusses structurally related medicines, including examples from statins and beta blockers. The FDA’s first-in-class description focuses on a mechanism of action different from existing therapies.

TermWhat it describes
First-in-classA different mechanism from existing therapies.
Me-tooA later, related medicine in an established class.
Best-in-classA comparative claim that needs a defined outcome and evidence.

Why It Matters for Data Protection

Our recommendation is to separate the scientific development question from the data-use question. An established drug class is not, by itself, a justification for accessing another trial’s participant-level dataset. Before planning comparative analyses, document the proposed purpose, the data needed and the permissions and safeguards to be assessed. Avoid collecting additional identifiable information simply because a competitor studied it.

Hypothetical example: A biotech develops a new medicine in an established class and proposes a tolerability advantage. The team defines the population, comparator and relevant measurements before selecting datasets. Its privacy review then examines the proposed data access and reuse; the commercial description ‘me-too’ does not decide those questions.

Frequently Asked Questions

Does me-too mean generic?

No. Generic approval has requirements concerning the reference medicine, including the same active ingredient and demonstrated equivalence.

Does me-too mean clinically inferior?

No. The label alone cannot establish relative benefit or risk.

How should best-in-class claims be assessed?

Specify the comparator, endpoint and population, then review the supporting evidence and its limitations.

Related reading: first-in-class drugs, best-in-class drugs. For practical support, see support for biotech and pharma sponsors.

Updated: 27 October 2026