Study Finds High Rates of Switching, Discontinuation of Biologics Among Patients With AS

Patients with ankylosing spondylitis (AS), a rheumatic disease involving inflammation of the vertebrae that results in structural changes to the axial skeleton, are typically given non-steroidal anti-inflammatory drugs (NSAIDs) as the first-line treatment. However, patients who do not respond adequately to NSAIDs may benefit from biologic therapies, including anti—tumor necrosis factor (anti-TNF) treatments including adalimumab (Humira), certolizumab pegol (Cimzia), etanercept (Enbrel), golimumab (Simponi), and infliximab (Remicade or its biosimiars, Inflectra and Renflexis). Real-world data on the use of biologics in patients with AS, especially in the United States, have been limited, however; a new study, published in Future Medicine, seeks to add to the body of knowledge concerning biologic treatment patterns and therapy modifications among US patients with active AS.

The US-based, retrospective, observational study used pharmacy and medical claims data from the Optum Research Database (which includes commercial and Medicare Advantage health plan enrollees and comprises data for approximately 13.5 million individuals). Adult patients with AS were included if they had 1 or more approvals for a pharmacy fill or medical infusion of a biologic between January 2013 and January 201

A total of 426 patients met inclusion criteria, and initiated the following therapies:

• Etanercept (45.1%)
• Adalimumab (28.6%)
• Golimumab (11.7%)
• Infliximab (11.7%)
• Certolizumab pegol (2.8%)

The researchers found that patients who initiated adalimumab had the longest mean duration of treatment persistence (243 days). Those who initiated etanercept had the shortest mean duration of persistence (192 days). Furthermore, only 40.6% of patients overall persisted for 12 or more months with the therapy that they had initiated. Golimumab had the highest rate of 12-month persistence at 50.0%, and certolizumab pegol had the lowest rate at only 33.3%.

Among those who discontinued therapy with the treatment that they had initiated during the study, 31.0% did not switch to a different anti-TNF treatment, 7.0% discontinued their therapy and then restarted the same treatment later, and 21.4% switched to a different anti-TNF agent. Among those who switched treatments, most switched to either adalimumab (56.0%) or infliximab (17.6%).

Among those who persisted on their anti-TNF therapy for 90 days or more, 45% received additional treatments:

• Corticosteroids (16.8%)
• Opioids (12.9%)
• NSAIDs (10.2%)
• Antidepressants (7.2%)

A low proportion of patients (7.2%) received a dose escalation of their anti-TNF therapy, but dose escalation was notably higher in those who had a treatment that required intravenous administration (38.5%) than subcutaneous administration (2.7%).

The study’s authors posit that the high rates of use of etanercept and adalimumab may be due to formulary availability and insurance contracts in the United States. They note that, while reasons for discontinuation of anti-TNF therapy were not investigated in this study, previous studies have shown that approximately 30% to 60% of patients with AS who discontinued or switched anti-TNF agents did so because of adverse events or lack of efficacy.

The authors concluded that a large proportion of patients with AS either switched or discontinued their therapy during 12 months of follow-up, and that many required additional therapies for their AS. These findings, they say, point to the need to better understand optimal therapy strategies to improve symptom control and patient outcomes.