The two agencies are traditionally 90%+ in agreement on drug approvals, but that could be changing.

A new study conducted by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) suggests that the EMA may be less likely to approve new drugs than the FDA.

For 107 new drug applications submitted to both the EMA and the FDA from 2014 to 2016, the two agencies were in agreement on approvals more than 90% of the time. Out of the 107 applications, the FDA initially declined to approve eight that EMA approved directly, but eventually approved all of them. For one drug, it was the opposite –– the FDA initially approved the product while the EMA did not, but then later did.

Ultimately, there were only two different decisions. In both cases, the EMA approved the drugs, but the FDA did not.

That seems to be changing, however. In 2018 and 2019, the EMA’s Committee for Medicinal Products for Human Use (CHMP) did not recommend approval of three drugs that FDA approved previously. CHMP also raised questions about another drug approved by the FDA, and that application was ultimately withdrawn in Europe.

The difference in these decisions appears to be related to differing conclusions regarding efficacy. For instance, for a sickle cell anemia drug, the FDA found that the data showed that the drug led to fewer hospital visits for sickle cell crises compared with a placebo, while the CHMP determined the drug did not reduce the number of crises or hospital visits.

The FDA was also found to grant more accelerated approvals than the EMA granted conditional marketing authorization or authorization under exceptional circumstances. One difference here, though, is that typically applications were submitted to the FDA first and the EMA second, along with more data from additional clinical trials or more data from the same clinical trial. As a result, the EMA was more likely to grant standard approval or a broader set of indications.

On the other hand, the EMA had a higher rate of first-cycle approvals than the FDA, which may also be due to the fact that applications were first submitted to the FDA and then to the EMA. This conclusion is based on the fact that the FDA’s second cycle approvals were based on data that were often submitted to the EMA in initial applications along with data previously submitted to the FDA.

The study authors note that the use of data from just two years is a limitation of the evaluation. They also comment that the two agencies are working more closely together today than they have in the past.