Lower TNF Inhibitor Persistence in Spondylitis Save

A claims data analysis shows that only one-third of ankylosing spondylitis (AS) treated with tumor necrosis factor inhibitors (TNFi) therapy remain on their initial drug in the 2 years post initiation.

The long-term objectives in managing AS are to improve quality of life, prevent structural damage, and preserve function. Deodhar and colleagues sought to analyze the efficacy of TNFi as measured by persistence, discontinuations, and switching over 2 years of follow up.

This retrospective analysis of adult AS patient data was gathered from the IBM MarketScan Commercial Claims database, specifically looking at patients initiating a TNFi from 01/01/2009 to 12/31/2013. AS patients with other inflammatory diagnoses were excluded. Discontinuation was defined as a ≥ 90-day gap in therapy without starting a new TNFi.  Persistence was defined a no gaps in therapy (≥ 90 days) during the 2-year follow-up.

Analysis of 1372 AS patients (846 males/526 females) found that the most common TNFi started was adalimumab (~44%), followed by etanercept (~41%), infliximab (~10%), golimumab (~4%), and certolizumab (1%).  The main points of the study included: 

• Over 2 years only 33% of AS patients (n = 454) persisted on their index TNFi
• 41% discontinued their index TNFi and did not restart a TNFi
• 26% stopped their index TNFi and switched to a second TNFi
• Patients also taking cDMARDs were more likely to persist with their index TNFi  
• Less likely to persist were females and opioid users 

These retrospective results suggest a higher than expected discontinuation and switching rate amongst AS patients starting a TNFi.