The unfinished business of target trial emulation

Adigens Health helps pharmaceutical and rare disease companies design real-world evidence strategies built around the target trial framework: from early development planning through HTA submission. Get in touch at info@adigenshealth.com.

Methodological frameworks tend to attract two kinds of attention as they mature. The first is advocacy: conference sessions that explain the framework to newcomers, journal articles that apply it to a fresh disease area, regulatory guidance that cites it approvingly. The target trial framework has had plenty of this in the past several years, and deservedly so. The second kind of attention is rarer and more valuable: a room of people who already use the framework professionally, spending their time not explaining it but interrogating it.

That second kind of room convened at the GetReal Institute's annual conference in Utrecht this June, where Adigens Health led a workshop bringing together practitioners from pharmaceutical industry, regulatory science, academic epidemiology, health economics and clinical research consulting. The brief was not to celebrate the target trial framework's rise; it was to ask where it will head next.

A framework that grew up fast

Some context helps explain why that question felt urgent. The principles underlying the target trial framework—explicit specification of eligibility, treatment strategies, time-zero and outcomes before analysis begings—are not new; rigorous epidemiologists have applied versions of this discipline for decades. What changed, over a remarkably compressed period, is that Adigens Health co-founder Miguel Hernán and colleagues gave those principles a name, a structure and a vocabulary borrowed deliberately from the trial world. That framing let physicians, trialists and data scientists who had never engaged with technical causal inference literature grasp why they should consider observational research as rigorous and capable of answering causal questions.

Regulatory endorsement converted that intuitive appeal into something closer to an expectation. Once agencies began citing the framework in formal guidance, adoption accelerated the way methodological ideas rarely do: not over the twenty or thirty years such transitions typically take, but within one. The pace has been the framework's triumph. It is also, as discussion in Utrecht made clear, shaping its future developments.

The issues on the table

The context for the workshop was mainly related to the speed of applications.:

•     Label versus substance. How to tell a genuine target trial emulation from one that has simply borrowed the terminology.

•     Treatment strategies that evolve. Extending the framework beyond point-in-time assignment to the dynamic, real-world treatment pathways patients actually follow.

•     A closer alliance with the estimands framework. A real momentum behind bringing TTF and estimand together.

•     HTA's next frontier. Considerations about how far the framework can extend into cost-effectiveness modelling.

•     AI as accelerant and risk. A framework built for rigour having to face a technology built for speed, with most stakeholders determined to make sure the first shapes the second.

Where this goes next

What made Utrecht energising rather than merely diagnostic was the debate about the future use cases, the need for improvements in how feasibility is done and the evolution of stakeholder thinking - including that of patients. Regulators and HTA bodies are exploring what a framework built for comparative effectiveness could do for other use cases. And the field itself is converging on a shared next chapter: sequential and dynamic treatment strategies, deeper integration with adjacent frameworks, and reporting standards precise enough to make rigorous and superficial applications of the framework instantly distinguishable.  The consistent view across the room was that the target trial framework's core structure does not need reinventing; it needs building on.

The Utrecht workshop was not the end of this conversation but the start of a documented one. GetReal Institute is preparing a white paper drawing on the expert discussion the workshop generated, with the focus on the likely future evolution of the framework and its applications.  The paper aims to set a research agenda for regulators, HTA bodies, clinicians and industry alike. It is expected in the coming months, and it will be essential reading for anyone building a real-world evidence strategy around the target trial framework.