Apremilast probably has an early but limited role to play in patients with psoriatic arthritis largely due to its safety and ease of use.
The PALACE 4 study of apremilast (20 or 30mg) versus placebo found the oral phosphodiesterase 4 inhibitor achieved response rates of about 30% in DMARD- and biologic-naive patients.
At week 16, an ACR20 response was achieved in 28.0% of patients at the lower dose and 30.7% at the higher dose compared to 15.9% in the control group. Improvements were largely maintained through to 52 weeks.
The study also found more patients treated with apremilast achieved an ACR50 response, they had improved functionality as measured by the HAQ-Disability Index scores, and significantly improved measures such as DAS28-CRP and Clinical Disease Activity Index.
Adverse events were similar in both treated and control groups with few discontinuations of treatment.
“PALACE 4 demonstrated therapeutic effects of apremilast monotherapy in DMARD-naive patients with active PsA, establishing statistically significant advantages of apremilast over placebo across various manifestations of PsA,” the study said.
“Apremilast demonstrated an acceptable safety profile and was generally well tolerated up to 52 weeks. Given the favourable benefit-risk profile, apremilast may be a treatment option for DMARD-naive patients with active PsA.”
Co-investigator and Sydney rheumatologist Associate Professor Paul Bird told the limbic the modest effect and safety of apremilast could be most useful early in the disease.
“Apremilast is not a very powerful drug. It seems to work in a proportion of patients and particularly in those who have not had any previous medications.”
“So it has a mid-range response of about 30% and TNF inhibitors usually get around 60-70%. That’s what we’re looking for and is one of the reasons apremilast hasn’t got a [PBS] listing in this country or in many countries.”
“The advantage of the drug is its safety so if the price dropped on the drug I am sure it would get a listing but it’s just too expensive to be using.”
He said there was some imaging data coming out soon which will also support the use of apremilast – particularly if it could come in at lower price and for the initial six-month phase before biologic treatment could be initiated.
“In that first six months, it would be ideal because it’s got a very low side effect profile, doesn’t need regular monitoring, and it’s going to get 30% of people better which is not bad at all.”
“I’d probably use it before methotrexate, mainly because most patients don’t like methotrexate. They don’t like the idea of it and they get a lot of nuisance side effects.”
He added the other advantage for apremilast was that it was oral.
“And for patients, one of the things they complain about, quite rightly, is having to do an injection.”
Disclosure: Associate Professor Bird has received honoraria from Celgene Corporation for advisory boards and has taken part in Celgene-sponsored clinical studies.