new research suggests.
Dr. Philip J. Mease
A paper published in Arthritis Care & Research presents a pooled analysis of the PALACE 1-3 studies that included a total of 1,493 patients with active psoriatic arthritis whose disease had resisted treatment with tumor necrosis factor inhibitors or conventional disease-modifying antirheumatic drugs. Participants were randomized either to the oral phosphodiesterase 4 inhibitor apremilast (Otezla) 30 mg twice daily, 20 mg twice daily, or placebo for 24 weeks, after which all patients on placebo were rerandomized to one of the two apremilast doses until 52 weeks.
The analysis focused on 494 patients who were randomized to apremilast 30 mg twice daily at baseline.
At week 16, 40% patients with low disease activity at baseline had achieved remission on their clinical Disease Activity Index for Psoriatic Arthritis (cDAPSA) score, compared with 7% of patients with moderate disease activity and 2.1% of patients with high disease activity. The cDAPSA score is calculated as a composite score including swollen and tender joint counts, patient’s assessment of pain, and patient’s global assessment of disease activity, with possible scores from 0 to 154. Based on patients’ cDAPSA score, the researchers defined remission as a score of 4 or less, low disease activity as more than 4 and up to 13, moderate disease activity as more than 13 and up to 27, and high disease activity as greater than 27.
Among patients with moderate disease activity, 29.8% achieved low disease activity by week 16; among patients with high disease activity at baseline, 11.5% achieved low disease activity, and 38.1% achieved moderate disease activity.
The study found that patients who had moderate disease activity at baseline and achieved either low disease activity or remission by week 16 had a 58.9%-88.5% probability of remaining at those treatment targets by week 52. Patients with high disease activity at baseline who achieved low disease activity or remission by week 16 had a 64.3%-77.4% probability of achieving treatment targets by week 52.
Overall, nearly twice as many patients who had moderate disease activity at baseline achieved their treatment targets when compared with those who began with high disease activity (46.9% vs. 24.9%).
Any patient who achieved at least a 30% improvement in cDAPSA score by week 16 had a 63% probability of achieving treatment targets by week 52.
First author Philip J. Mease, MD, from the Swedish Medical Center and the University of Washington, Seattle, and coauthors noted that the absence of treatment response by week 16 should point to the need for a treatment adjustment. “Taken together, these findings provide a framework of reference for the selection and monitoring of patients with the highest likelihood of achieving optimal treatment responses with apremilast in clinical practice,” they wrote.
The authors also commented that their study provided support for the use of clinical Disease Activity Index for Psoriatic Arthritis score to monitor patients treated with apremilast.
The study was sponsored by Celgene. Three authors were employees of Celgene at the time of the study, and nine authors declared a range of consultancies, grants, research, and other support from the pharmaceutical sector, including from Celgene.
SOURCE: Mease P et al. Arthritis Care Res. 2019 Jan 7. doi: 10.1002/acr.24134