Whether your first trial should be US-only or multinational depends on where the patients are, your regulatory path, your budget and your team's capacity to manage complexity. Adding countries can widen enrollment reach. It also adds regulatory submissions, vendors, drug supply logistics and oversight burden. Many emerging sponsors underestimate the second half of that equation.
When does a US-only first trial make sense?
When the indication has ample patients in the US, the study is a small Phase 1 or 1b, the internal team is lean, and the sponsor's immediate priority is building its relationship with FDA. A single regulatory framework, one currency and one primary language remove a great deal of operational risk from a company's first study.
When does adding countries make sense?
When the patient population is small and dispersed, as in many rare diseases. When the US competitive landscape makes enrollment slow because several trials are chasing the same patients. When specific centers of excellence or investigator networks sit outside the US. When certain regions offer genuine timeline or cost advantages. And when the long-term registration strategy is global anyway.
What are the hidden costs of going global?
Regulatory and ethics submissions in each country, each with its own requirements and timelines.
Translation of consent forms, participant materials and sometimes the protocol.
Import and export permits for investigational product and samples, plus local depots.
Local representation requirements for sponsors based outside a region.
Differences in standard of care that change eligibility and comparator assumptions.
Data privacy obligations that differ by jurisdiction.
More vendors, more time zones and more oversight for a small sponsor team.
How should you decide?
Start with evidence rather than assumptions: patient epidemiology, competing trials and site feasibility data. Map each country's regulatory and ethics timelines against your critical path. Count the oversight cost honestly by asking who on your team will manage each region. And consider a staged approach: start in the US or one region and add countries if enrollment lags, but prepare submissions and supply in advance so expansion is quick rather than reactive.
Will FDA accept data from sites outside the US?
FDA can accept data from foreign clinical studies conducted in accordance with good clinical practice, under 21 CFR 312.120 or as part of an IND. The practical questions are whether the population and standard of care are relevant to US patients and whether the data will support your intended label. Discuss your country strategy early, ideally as part of your regulatory planning.
What does this mean for CRO selection?
Geography should be one of the first criteria you define. A CRO with deep US site networks may be a weak partner in Europe or Asia, and vice versa. Ask for recent, country-specific experience, not a global footprint map.
Choosing a CRO with the right geographic reach? Learn about ABRA's CRO Selection & Management support.
