The atopic dermatitis (AD) space is changing rapidly, but the availability of new therapies across the US and Europe has been affected by differences in regulatory policy. The European Medicines Agency (EMA) and US Food and Drug Administration (FDA) have taken very different stances on approving new therapies, especially the Janus kinase (JAK) inhibitors. This divergence stems from results of the ORAL Surveillance (NCT02092467) trial, a post-marketing rheumatoid arthritis safety study of Xeljanz (tofacitinib), which highlighted the potential risk of cardiovascular problems, cancer and other serious adverse events. This safety data put a magnifying glass on the oral JAK inhibitor drug class, resulting in a lengthy dialogue among regulators that has led to ongoing delays in the US and some cautious approvals in Europe.

GlobalData expects the FDA will make some key decisions regarding JAK inhibitor approvals for AD during the fourth quarter of this year. These impending decisions are for Lilly/Incyte’s JAK1/2 inhibitor Olumiant (baricitinib), AbbVie’s JAK 1 inhibitor Rinvoq (upadacitinib) and Pfizer’s JAK 1 inhibitor Cibinqo (abrocitinib). The EMA has not seen the same delay, having approved Olumiant last December and Rinvoq in August for the treatment of moderate to severe AD. The agency is also expected to approve Cibinqo soon, following a positive opinion in October from the Committee for Medicinal Products for Human Use (CHMP). The drug has already been approved by the UK Medicines and Healthcare products Regulatory Agency (MHRA) and is now available in the UK.

While the FDA has delayed JAK inhibitor approvals due to safety discussions, the EMA is allowing approvals to proceed but has issued clear safety warnings regarding the use of JAK inhibitors in at-risk patient groups. This includes patients aged older than 65 years, patients who are current or past smokers, patients with other cardiovascular risk factors, and patients with other malignancy risk factors. In September, the FDA announced that it will require updated safety warnings for Olumiant and Rinvoq, both of which are approved in rheumatoid arthritis, to reflect the potential health risks associated with Xeljanz. This has likely added to delays already experienced. Despite this, in their third-quarter earnings calls, all companies expressed that they are closely and actively liaising with the FDA to support their decision making. Management at AbbVie, in particular, mentioned that they believed they would receive a decision on Rinvoq by the end of the year. In this case, it is likely that approvals for Olumiant and Cibinqo will follow close behind.

While it is unknown whether the FDA will approve all JAK inhibitors by year end, it is clear that the whole JAK inhibitor class has been affected, and that these drugs are likely to be considered a last-line option for treatment-refractory patients.