More Evidence of Low Rates of Adherence and Persistence for Biologics for Inflammatory Diseases

A recent review confirms that, despite evidence that biologic therapies treating rheumatoid arthritis (RA), psoriasis (PsO), and psoriatic arthritis (PsO) improve health-related quality of life (QOL), relieve symptoms, slow disease progression, and produce greater clearance of PsO, adherence and persistence rates for these drugs are still low in the United States, leading to suboptimal patient outcomes and putting a substantial burden on the healthcare system.

The study, published August 21, 2018, in Patient Preference and Adherence, by Mwangi J. Murage, PhD, and colleagues, concludes that there is a significant opportunity for improvement in rates of adherence and persistence, and the authors suggest using a targeted approach, including better patient education about drug effectiveness, safety and tolerability; lower out-of-pocket costs; refilling at specialty pharmacies; and reducing comorbidities.

The review included 43 primary studies spanning 2000 to 2015; studies lasted 1 to 5 years, and a majority were considered of moderate to high quality. The sample sizes of the included studies varied widely, ranging from 45 patients to 15,834 patients, with most including more than 100 patients.

Using the medication possession ratio (MPR) or the percentage of days covered (PDC) over 80%, adherence rates in patients with RA and PsO ranged as follows:

• for etanercept (Enbrel), 16% to 73%
• for adalimumab (Humira), 21% to 70%
• and infliximab (Remicade), 38% to 82%

Using the criteria of a 45-day or larger gap, persistence rates in RA ranged from the following:

• 46% to 89% for etanercept,
• 42% to 94% for adalimumab
• and 41% to 76% for infliximab.

For patients with PsO, persistence rates for etanercept and adalimumab ranged from 34% to 50% and from 50% to 62%, respectively. Ustekinumab (Stelara) was the most commonly studied biologic in the PsO literature. Similar persistence rates were seen for PsA.

Many factors were associated with nonadherence or nonpersistence—some demographic or socioeconomic, others related to patients’ choices or understanding of treatment pathways, the study authors said.

Younger age, female gender, non-white race, higher out-of-pocket costs, greater disease severity, and more comorbidities were associated with lower adherence and persistence rates. The study also suggests that better adherence and persistence was observed among experienced users of biologic medications. The authors note that qualitative surveys revealed that nonpersistence was partly due to patients’ perceptions of ineffectiveness and safety or tolerability concerns.

The authors note that the present study adds to the available literature by evaluating the consistency in the rates of adherence and persistence across patients with RA, PsO, or PsA, which has not been previously reported.

The study was funded by Eli Lilly and Company.

Reference

Murage MJ, Tongbram V, Feldman SR, et al. Medication adherence and persistence in patients with rheumatic arthritis, psoriasis, and psoriatic arthritis: a systematic literature review. Patient Prefer Adherence. 2018;12:1483-1503. Doi: 10.2147/PPA.S167508.