OBJECTIVES: Progression of PsA can lead to irreversible damage, functional impairment, and associated healthcare costs. Anti-TNF biologics have been shown to delay PsA progression and seem to have better efficacy compared with apremilast, a phosphodiesterase-4 inhibitor recently approved for PsA. The impact of using apremilast prior to anti-TNF has not been fully understood. This study evaluated the economic impacts of timely versus delayed use of anti-TNF among patients with moderately-to-severely active PsA from a US payer perspective. METHODS: A Markov model was developed to evaluate the costs and outcomes of two treatment sequences over a one-year time horizon. PsA patients received either adalimumab (timely use of anti-TNF) or apremilast (delayed use) as initial treatment. Those who did not achieve ACR20 response in the first 12 weeks of treatment or who lost ACR20 response would use subsequent treatments, which included a mixture of anti-TNF biologics, followed by palliative care. Efficacy was based on ACR20 response, changes in the Health Assessment Questionnaire (HAQ), and reduction in skin lesions measured by the Psoriasis Area and Severity Index (PASI). Direct costs, including treatment-related costs and other medical costs, and incremental costs per responder were calculated. Subgroup analyses among patients with moderate-to-severe psoriasis were performed. RESULTS: After one year, patients starting with adalimumab had higher ACR20 response rates and higher costs than apremilast (70.4% vs. 59.6%, $37,732 vs. $31,173). The one-year incremental cost per ACR20 responder was $60,766 for timely vs. delayed use of anti-TNF. Among the subgroup with psoriasis, starting with adalimumab lead to higher response rates in both ACR20 and PASI75 and higher costs compared with apremilast (43.2% vs. 30.0%, $39,329 vs. $33,143). The incremental cost per ACR20+PASI75 responder was $46,949. CONCLUSIONS: Timely use of anti-TNF is a cost-effective strategy for the management of PsA due to improvements in joint and skin condition.