RA Study Finds Methotrexate and TNFi Regimen Produced Better Adherence Than Triple Therapy

Carolyn Colwell

VA study found overall adherence low, but better in MTX and TNFi group.

Rheumatoid arthritis (RA) patients may adhere more completely and more often with a newer regimen of medications for than with a more conventional regimen that required more frequent dosing, a recent study of US veterans found.

The importance of non-persistence and non-adherence to prescribed medications is that they could result in poorer clinical outcomes, the authors wrote.

“[A]dult patients with RA in the VA were significantly more likely to be persistent and adherent in taking a [tumor necrosis factor inhibitor (TNFi)] plus [methotrexate (MTX)] combination therapy than in using triple therapy with non-biologic DMARDs (disease-modifying anti-rheumatic drugs),” Brian C. Sauer, PhD (pictured), and his colleagues reported. Sauer is an associate professor in the University of Utah’s School of Medicine’s Department of Internal Medicine Division of Epidemiology and an investigator at the Salt Lake City Veterans Affairs (VA) IDEAS COIN Center.

The American College of Rheumatology recommends treatment with non-biologics or biologics as monotherapy or combination therapy, based on the duration and severity of the disease, the study said.

This research compared a combination of TNFi (a biologic) plus MTX (Methotrexate, a non-biologic) with a triple therapy of non-biologics (MTX plus hydroxychloroquine and sulfasalazine). The study noted that the triple therapy drugs demanded more attention to dosing. Taken daily, hydroxychloroquine and sulfasalazine, for example, could require up to six tables a day in divided doses, while MTX injections can be administered once a week, and the TNFi can be administered even less frequently.

Sauer and his group analyzed claims data derived from a group of 4,364 VA patients who started TNFi plus MTX or the triple therapy between January 2006 and December 2012. They found that the group that started the TNFi plus MTX treatment was proportionally more persistent and adherent at one year than the group that started the triple therapy. The TNFi plus MTX group at one year had 24.2% adherence to that combination compared with 17.3% adherence to all three medications for the triple therapy group for those in both groups who persisted in taking the medications for 80 or more days.

“The overall persistence and adherence rates were low, but those findings are consistent with other analyses conducted in the VA and commercial settings,” the authors wrote.

“The lower adherence and persistence in the triple therapy group may be due to the increase regimen complexity of multi-day dosing,” the authors wrote. However, they added, “Methods to improve adherence and persistence are needed for both treatment groups.

Amgen, which in partnership with Wyeth Pharmaceuticals markets entanercept (Enbrel), a TNFi, sponsored the above study. In a statement at the end of the study, the authors wrote that it was “an investigator initiated project” and that Amgen did not have a role in the “collection, analysis, or interpretation of the data,” and that publication was “not contingent upon the approval by Amgen.” In the disclosures section, four of the eight co-authors reported a financial tie with Amgen either in terms of stock ownership, receipt of honoraria or research funding. The study added that Amgen did have the power to review and approve all the authors.

The authors also reported that their study was supported by a Veteran Affairs Health Services Research and Development Award.

Persistence With Conventional Triple Therapy Versus a Tumor Necrosis Factor Inhibitor and Methotrexate in US Veterans With Rheumatoid Arthritis,” was published in the March 2017 issue of Arthritis Care and Research.

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