Results from a multi-center trial suggest that patients with rheumatoid arthritis (RA) who have had stable, low disease activity while on the biologic drug etanercept (Enbrel) may be able to cut their dose in half without relapsing. The results of the PRESERVE trial, published recently in The Lancet, are promising for patients.

“If you cut the dose of etanercept in half, the patients’ responses were about the same as on a full dose. That has incredible implications for cost savings and for taking less medication,” says Eric Ruderman, MD, professor of medicine in the division of rheumatology, Northwestern University Feinberg School of Medicine in Chicago. Dr. Ruderman was not involved in the study.

A 2012 study by Thomson Reuters Healthcare in Cambridge, Mass., found that the average annual payment for etanercept is $15,345. Etanercept is a tumor necrosis factor inhibitor (anti-TNF), meaning it blocks TNF, a protein involved in inflammation. Other anti-TNFs currently approved for RA include infliximab (Remicade), adalimumab (Humira), certolizumab pegol (Cimzia) and golimumbab (Simponi).

For the PRESERVE trial, a total of 834 patients who continued to have moderately active RA despite using methotrexate – a traditional disease-modifying antirheumatic drug (DMARD) – were enrolled at 80 centers in Europe, Latin America, Asia and Australia. Each week for 36 weeks, they received full doses of etanercept (50 mg) plus methotrexate. At the end of that time period, 604 had achieved low disease activity and sustained it until the end of the 36 weeks. Those patients were then divided into three groups: For the next 52 weeks, a third continued taking the full dose of etanercept, a third were given 25 mg of etanercept, and a third got placebo. All patients continued taking methotrexate. Neither doctor nor patient knew which patients were assigned to which group.  

Low disease activity was defined as having a disease activity score (DAS28) ≤ 3.2; remission was defined as having DAS28 < 2.6. The DAS28 is calculated using the scores of certain blood tests and counting tender and swollen joints in 28 places.

At the end of the 52 weeks, the researchers found that 82.6 percent of those who took the full dose of etanercept continued to have low disease activity, compared with 79.1 percent of the half-dose group, and 42.6 percent of the placebo group.