Apremilast (Otezla(®)), an oral small molecule inhibitor of type-4 cyclic nucleotide phosphodiesterase (PDE-4), is under development with Celgene Corporation for the treatment of psoriatic arthritis, psoriasis, ankylosing spondylitis, Behçet's syndrome, atopic dermatitis, and rheumatoid arthritis. Apremilast is indicated for the treatment of active psoriatic arthritis in adults. Apremilast has received its first global approval for this indication in the USA. Regulatory submissions for approval in this indication are under review in Canada and Europe. Regulatory filings have also been submitted for apremilast in the treatment of plaque psoriasis in the USA and Europe. This article summarizes the milestones in the development of apremilast leading to its first approval for the treatment of psoriatic arthritis.