By Phoebe Starr
Madrid, Spain—Apremilast, a novel oral inhibitor of phosphodiesterase 4, achieved sustained improvement in the signs and symptoms of psoriatic arthritis, physical function, and skin improvement in the longer-term follow-up of 52 weeks in the PALACE 1 trial, according to results reported for the first time at the 2013 European League Against Rheumatism (EULAR) annual meeting.
Of patients who failed methotrexate, 63% showed 20% improvement by the American College of Rheumatology 20% criteria for improvement (ACR20) at week 52, and no new safety signals were reported. Few laboratory abnormalities were found, suggesting that frequent monitoring may not be necessary with this agent.
For patients with psoriatic arthritis, “Longer-term follow-up of PALACE 1 shows that apremilast maintains its efficacy and safety for over a year in patients previously treated with DMARDs [disease-modifying antirheumatic drugs] and/or biologic agents. The longer the data we have, the better,” said lead investigator Arthur F. Kavanaugh, MD, Director of the Center for Innovative Therapy, Division of Rheumatology, Allergy and Immunology, University of California, San Diego.
“We are very happy with these data. We still need to see where its role will be, and perhaps apremilast will be useful for patients who are not refractory to other treatments,” Dr Kavanaugh added.
PALACE 1 is a phase 3, multicenter, double-blind, placebo-controlled, parallel-group study of 504 patients with active psoriatic arthritis despite receiving DMARDs and/or biologics for the previous 4 months. Patients were allowed to continue using background DMARD therapy during the trial.
Patients were randomized to apremilast 20 mg or 30 mg twice daily or to placebo for 24 weeks. At week 24, all patients in the placebo arm were rerandomized to 1 of the 2 apremilast arms.
In 2012, results from week 16 demonstrated the superiority of apremilast versus placebo on ACR20 in 31.3% of the apremilast 20-mg group and in 40% of the apremilast 30-mg group (P <.001 vs placebo) versus 19.4% in the placebo group.
The 52-week results were presented for the first time at EULAR 2013: ACR20 was reached by 63% of the apremilast 20-mg group and by 54.8% of the apremilast 30-mg group. Up to 20% of the patients reached ACR50 and ACR70 (ie, at least a 50% or 70% response in the signs and symptoms of psoriatic arthritis).
Skin improvement was also seen. Apremilast achieved a 75% improvement on the Psoriasis Area Severity Index in 37% of those receiving the 30-mg dose and in 25% of patients receiving the 20-mg dose.
Treatment-related adverse events were few and comparable between groups. Diarrhea or nausea were the most common adverse events, but were manageable with anticipation and medication.
Most notable is that few laboratory abnormalities were reported for patients who were taking apremilast up to 1 year. “We may not need to monitor patients on apremilast as carefully as those on anti-TNF inhibitors,” Dr Kavanaugh commented.