On January 31, 2022, the European Commission (EC) withdrew the marketing authorization (MA) for Pfizer’s topical phosphodiesterase-4 (PDE4) Staquis/Eucrisa (crisaborole) in the EU. Per the EC press release, Pfizer requested the EC to withdraw the MA and has decided not to market the product in the EU for commercial reasons, rather than due to safety or efficacy concerns. Although Staquis was approved in March 2020, it never launched in Europe, exemplified by the lack of pricing information available for the product across the five major European markets (5EU) (France, Germany, Italy, Spain, and UK).

Eucrisa is not approved in Japan, but it has been widely used in the US following its approval in 2016 and is now used in patients as young as 3 months, which speaks volumes about its safety profile. However, Eucrisa is an expensive therapy, averaging at $3,000 per year for all mild to moderate age groups. This may explain the reluctance to reimburse the drug in the EU when assessing the cost/benefit ratio. While Staquis is losing traction in the EU and Japan, there are some new PDE4s being developed. These include Otsuka Pharmaceutical/Medimetriks’ Moizerto (difamilast), which was approved by the Pharmaceuticals and Medical Devices Agency in September 2021, and Arcutis Biotherapeutics’ roflumilast, which is in late-stage development and aiming to enter the atopic dermatitis (AD) market soon. Both PDE4 inhibitors have shown great efficacy profiles but have failed to completely address the onsite application pain experienced with Eucrisa. Moreover, Otsuka and Arcutis have yet to conduct an active comparator study against Eucrisa/Staquis, making it more difficult for them to claim a superior status and thus differentiate themselves further.

Given this level of competition in the market, key opinion leaders (KOLs) interviewed by GlobalData noted that the PDE4 mechanism of action (MOA) is outdated due to the limited class efficacy in this disease, adding it will be difficult for these agents to differentiate themselves from newer entrants. AD patients are more likely to appreciate newer MOAs, such as the highly efficacious topical Janus kinase (JAK) inhibitors, which are extremely efficacious and have a faster onset of action. GlobalData believes that the integration of these new PDE4s will be slow, and that they will have a modest impact on the AD market given the intensity of competition.