PALACE 4: Apremilast safe, effective in DMARD-naïve psoriatic arthritis
Use of apremilast monotherapy in the treatment of disease-modifying antirheumatic drugs (DMARDs)-naïve psoriatic arthritis (PsA) patients is well-tolerated and helps improve signs/symptoms over 52 weeks, according to the results of the PALACE 4 trial.
The trial randomized 527 patients with active PsA (mean disease duration, 3.4 years) to treatment with placebo (n=176), apremilast 20 mg twice a day (BID; n=175) or apremilast 30 mg BID (n=176). Those who were assigned to the placebo arm were randomly reassigned to apremilast at week 16 or 24. Apremilast treatment continued to week 52 and extended up to 4 years.
At week 16, the primary endpoint of the proportion of patients achieving ≥20 percent improvement in ACR response criteria (ACR20) was significantly greater in either apremilast arm than in the placebo arm (28.0 percent with 20 mg vs 15.9 percent; p=0.0062; 30.7 percent with 30 mg vs 15.9 percent; p=0.0010).
Both apremilast doses proved superior to placebo in terms of the mean change in the HAQ Disability Index (HAQ-DI) score at week 16 (−0.17 with 20 mg vs 0.03; p=0.0008; −0.21 with 30 mg vs 0.03; p<0.0001). A similar pattern of results was observed for ACR responses at week 16, swollen/tender joint counts and psoriasis assessments. The observed improvements were sustained through week 52.
Common adverse events (AEs) over 52 weeks included diarrhoea, nausea, headache and upper respiratory tract infection. Most events were mild or moderate in severity. Serious AEs and AEs leading to discontinuation were similar across the three treatment arms. Laboratory abnormalities were infrequent and transient.
In light of the favourable benefit–risk profile of apremilast observed in PALACE 4, researchers pointed out that apremilast represents a potential treatment option for DMARD-naive patients with active PsA.