Comparison of regulatory pathways for the approval of advanced therapies in the European Union and the United States

Background aims: Regulatory agencies in the European Union (EU) and in the United States of America (USA) have adapted and launched regulatory pathways to accelerate patient access to innovative therapies, such as advanced therapy medicinal products (ATMPs). The aim of this study is to analyze similarities and differences between regulatory pathways followed by the approved ATMPs in both regions.

Methods: A retrospective analysis of the ATMPs approved by EU and US regulatory agencies was carried out until May 31, 2020. Data were collected on the features and timing of orphan drug designation (ODD), scientific advice (SA), expedited program designation (EP), marketing authorization application (MAA) and marketing authorization (MA) for both regions.

Results: In the EU, a total of fifteen ATMPs were approved (eight gene therapies, three somatic cell therapies, three tissue-engineered products and one combined ATMP), whereas in the USA, a total of nine were approved (five gene therapies and four cell therapies); seven of these were authorized in both regions. No statistical differences were found in the mean time between having the ODD or EP granted and the start of the pivotal clinical trial or MAA in the EU and USA, although the USA required less time for MAA assessment than the EU (mean difference, 5.44, P = 0.012). The MAA assessment was shorter for those products with a PRIME or breakthrough designation.. No differences were found in the percentage of ATMPs with expedited MAA assessment between the EU and the USA (33.3% versus 55.5%, respectively, P = 0.285) or in the time required for the MAA expedited review (mean difference 4.41, P = 0.105). Approximately half of the products in both regions required an Advisory Committee during the MAA review, and 60% required an oral explanation in the EU. More than half of the approved ATMPs (67% and 55.55% in the EU and the USA, respectively) were granted an ODD, 70% by submitting preliminary clinical data in the EU. The mean number of SA and protocol assistance per product conducted by the European Medicines Agency was 1.71 and 3.75, respectively, and only 13% included parallel advice with health technology assessment bodies. A total of 53.33% of the products conducted the first SA after the pivotal clinical study had started, reporting more protocol amendments. Finally, of the seven ATMPs authorized in both regions, the type of MA differed for only two ATMPs (28.6%), and four out of eight products non-commercialized in the USA had a non-standard MA in the EU.

Conclusions: The current approved ATMPs mainly target orphan diseases. Although EU and US regulatory procedures may differ, the main regulatory milestones reached by the approved ATMPs are similar in both regions, with the exception of the time for MAA evaluation, the number of authorized products in the regions and the type of authorization for some products. More global regulatory convergence might further simplify and expedite current ATMP development in these regions.