Apremilast monotherapy in DMARD-naive psoriatic arthritis patients: results of the randomized, placebo-controlled PALACE 4 trial.

objectivesThe PALACE 4 trial evaluated apremilast monotherapy in patients with active PsA who were DMARD-naive.

methodsEligible patients were randomized (1:1:1) to placebo, apremilast 20 mg twice a day or apremilast 30 mg twice a day. At week 16 or 24, placebo patients were rerandomized to apremilast. Double-blind apremilast treatment continued to week 52, with extension up to 4 years. The primary endpoint was the proportion of patients achieving ⩾20% improvement in ACR response criteria (ACR20) at week 16; secondary endpoints included the mean change in the HAQ Disability Index (HAQ-DI) score at week 16.

resultsA total of 527 patients with mean disease duration of 3.4 years and high disease activity were randomized and received treatment. More apremilast patients achieved ACR20 response at week 16 [placebo, 15.9%; 20 mg, 28.0% (P = 0.0062); 30 mg, 30.7% (P = 0.0010)]. The mean HAQ-DI improvements were -0.17 (20 mg; P = 0.0008) and -0.21 (30 mg; P < 0.0001) vs 0.03 (placebo). Both apremilast doses showed significant ACR50 responses vs placebo at week 16 and improvements in secondary efficacy measures (swollen/tender joint counts) and psoriasis assessments, with sustained improvements through week 52. Common adverse events (AEs) over 52 weeks were diarrhoea, nausea, headache and upper respiratory tract infection; most events were mild or moderate. Serious AEs and AEs leading to discontinuation were comparable between groups. Laboratory abnormalities were infrequent and transient.

conclusionsIn DMARD-naive patients, apremilast monotherapy improved PsA signs/symptoms over 52 weeks and was generally well tolerated.

trial registrationClinicalTrials.gov (http://clinicaltrials.gov), NCT01307423.