From MHRA/EMA to FDA: Navigating the Clinical Data Divide for US Market Access




Clinical data from trials conducted in the UK or EU may not meet the FDA expectations. Find out why and what to do about it.

The FDA has its own set of concerns and limitations that differ significantly from those in the UK (regulated by the MHRA – Medicines and Healthcare products Regulatory Agency) and the EU (regulated by the EMA – European Medicines Agency and other bodies for medical devices). In the past, the physiological and cultural differences from the US to the rest of the world along with genetic and other differences have caused FDA reviewers to be cautious about accepting data from outside the US, however they also realize this needs to be based on the risk of any differences.

As a result, clinical data from trials conducted in the UK or EU may not always be directly applicable or acceptable for FDA approval due to several factors related to the design, conduct, and population of the studies. Here are some aspects of the data that might lead to the need for additional trials or bridging studies.

Regulatory Standards and Guidelines

Differences in Regulatory Expectations

Because the FDA has its own set of guidelines and expectations for the information on safety and effectiveness, it can mean that the endpoints or data collected in a trial might not meet the FDA’s specific requirements for demonstrating safety, efficacy, or quality.

“Understanding the FDA’s expectations is critical. It’s not just about the data you present; it’s about presenting it in a way that aligns with the FDA’s unique framework. At QRx Partners, we help you translate your clinical trial results into the language of the FDA.”

Thomas Wells

Mark Swanson

Partner, QRx Partners

Clinical Trial Design

Study Population

The demographic characteristics of the study population, such as ethnicity, age, and gender distribution, can affect the applicability of the clinical data. The FDA may require data showing that the drug or device is safe and effective in a population representative of the U.S. demographic, which may not align with a trial conducted exclusively in the UK or EU.


The primary and secondary endpoints that are chosen for a study can impact its acceptability to the FDA. For instance, the FDA may not accept surrogate endpoints used in the EU or UK trials and may require clinical endpoints that directly measure clinical benefit.

Dosage and Administration

The FDA may have different requirements for the dosage, formulation, or administration of a product than those used in UK or EU trials. The difference in measurement methods can be problematic.

If your company is poised to navigate the FDA approval process or needs specialized guidance, connect with GTM’s US FDA experts at QRX. Book a free consultation here.

Data Quality and Integrity

Data Collection and Monitoring

The FDA has stringent requirements for data collection and monitoring. If the UK or EU trials do not align with FDA expectations for data quality and integrity, the FDA may require additional data.

Good Clinical Practice (GCP) Compliance

The FDA requires that clinical trials adhere to GCP requirements. If there are concerns about compliance with GCP in foreign trials, the FDA may not accept the data without additional assurances or studies.

Statistical Considerations

Statistical Power and Significance

The statistical design of the study must be robust enough to satisfy the FDA that the results are statistically significant and clinically meaningful.

Data Analysis

The methods of data analysis used in the trials must meet the FDA’s standards. Differences in statistical analysis approaches between regulatory bodies can lead to the need for re-analysis or additional studies.

Ethical Standards

The FDA requires that clinical trials be conducted in accordance with ethical principles that have their origin in the Declaration of Helsinki. Any discrepancies in the ethical conduct of trials between the UK/EU and the U.S. could lead to the FDA rejecting the data.

“The FDA’s approval process can be labyrinthine, with more nuances than many expect. Our experience at QRX shows that early and strategic engagement with the FDA can significantly streamline the approval journey for UK and EU companies.”

Thomas Wells

Steve Gompertz

Chief Operating Officer & Partner, QRx Partners

Bridging Studies

If the FDA determines that the data from UK or EU trials are not directly applicable to the U.S. population or do not meet FDA regulatory requirements, they may require “bridging studies.” Bridging studies are additional studies conducted to provide a link between the foreign clinical data and the U.S. population or to supplement the existing data to satisfy FDA-specific concerns. These studies might involve pharmacokinetic evaluations, limited clinical trials, or additional safety and efficacy data collection in a U.S. population.

FAQs: Navigating US Healthcare Regulations with UK/EU Clinical Data

Can UK or EU clinical trial data be used for FDA approval?

Yes, UK or EU clinical trial data may be used as part of an FDA submission. However, the data must meet FDA standards, which can differ from EMA or MHRA requirements. Companies often need to conduct additional studies or provide supplementary information to ensure compliance with FDA regulations.

What are the key differences between FDA and EMA/MHRA clinical trial requirements?

While there are many similarities, key differences include trial design, patient population, endpoints, and post-market safety reporting. The FDA may also require trials to be conducted under U.S. Investigational New Drug (IND) regulations.

How can a company from the UK or EU navigate the U.S. healthcare regulatory environment?

Companies should engage with U.S. legal and regulatory experts familiar with FDA processes, consider strategic planning for regulatory submission, and maintain flexibility to adapt to the FDA’s feedback and changing guidelines.

Are there specific challenges for UK/EU companies regarding U.S. healthcare compliance?

Yes, challenges include aligning clinical trial data with FDA expectations, understanding federal vs. state laws, and keeping up with the constantly evolving regulatory landscape, particularly for digital health technologies.

What happens if UK/EU clinical trial data is not accepted by the FDA?

If the FDA deems the data insufficient, the company may need to modify the trial protocol, collect additional data, or even start new clinical trials, leading to increased costs and delays in product approval.

Why is it important for UK/EU companies to understand both federal and state healthcare regulations in the U.S.?

Compliance with both federal and state regulations is essential to legally distribute products in the U.S. market. Discrepancies between these laws can affect marketing practices, pricing, insurance coverage, and distribution.

What are the consequences of non-compliance with U.S. healthcare regulations?

Non-compliance can result in financial penalties, legal action, product seizures, and damage to a company’s reputation. It can also significantly delay product approval or lead to market access restrictions.

Can a UK/EU company manage U.S. regulatory processes internally, or is external expertise necessary?

Due to the complexity of U.S. regulations, it is often necessary to hire external experts who specialize in FDA law and practice to guide through the approval processes and ensure compliance.


In summary, the FDA has the responsibility to ensure that any product it approves is safe and effective for the U.S. population. Discrepancies in trial design, population, data collection, and regulatory standards may necessitate additional trials or bridging studies to meet FDA requirements.

Companies looking to gain FDA approval with non-U.S. clinical data should engage with the FDA early in the development process through pre-IND (Investigational New Drug) meetings and other consultations to understand the specific requirements and reduce the likelihood of costly additional studies.

If your company is poised to navigate the FDA approval process or needs specialized guidance, connect with GTM’s US FDA experts at QRX. Book a free consultation here.

Other Useful Resources

Disclaimer: The information provided in this article is for general informational purposes only and should not be construed as professional advice. Readers should not rely on any information contained herein as a substitute for professional guidance and should seek independent expert assistance when making decisions related to transfer pricing or US expansion.


Mark Swanson
Mark Swanson
Mark has been a leader in Quality and Regulatory for over 25 years. His career includes roles in quality engineering, design assurance, audit, and quality management for companies, including St. Jude Medical and Medtronic, and has provided guidance to numerous medical device and pharmaceutical manufacturers of all sizes.