Apremilast as an Off-Label Therapeutic Agent: A Comprehensive Review of Safety and Efficacy Data in the Literature for Combination Therapy and Inflammatory Dermatoses

Objective: To review the literature regarding the efficacy and safety of off-label use of apremilast in combination therapies for psoriasis and psoriatic arthritis and for other currently off-label inflammatory dermatoses. Methods: The Medline database was queried for all relevant articles published between 2014 and 2021 using exploded MeSH terms and keywords pertaining to the following themes: off-label, combination therapy, biologics, biologic therapy, methotrexate, and systemic psoriasis therapy. The Boolean term “AND” was used to find the intersection of these themes with the term “apremilast.” Results: 8 case series and 6 case reports investigated the use of apremilast in combination therapy for psoriasis and psoriatic arthritis. Addition of apremilast improved PASI scores by 31.8-77.4% among case series and 80-100% among case reports with adverse effects primarily consisting of gastrointestinal symptoms. 5 randomized-control trials (RCT), 9 open-label trials, 18 case series, and 30 case reports investigated the use of apremilast for off-label dermatoses. In RCTs, apremilast showed potential efficacy for atopic dermatitis and hidradenitis suppurativa. Open-label trials found apremilast efficacious for atopic dermatitis, allergic contact dermatitis, chronic pruritus, cutaneous sarcoidosis, discoid lupus erythematosus, hidradenitis suppurativa, lichen planus, prurigo nodularis, rosacea, and vitiligo. Limitations: Small sample size and short follow up duration for available randomized-control and open-label trials. Current data from case series/reports potentially limits generalizability of findings. Conclusion: Apremilast's safety profile makes it a potential efficacious, non-biologic systemic agent for monotherapy and combination therapy for a wide range of inflammatory dermatoses.