High Adherence Noted Among Infliximab Biosimilar Users

In a study of use of infliximab biosimilars among patients with gastrointestinal and rheumatologic conditions, investigators found high adherence.

The retrospective study, presented at the American College of Rheumatology (ACR) annual meeting, involved 533 patients in the IBM MarketScan commercial insurance database who were treated with infliximab from 2014 to 2018. Investigators characterized those who initiated use of infliximab biosimilars after treatment with the reference product or no prior infliximab treatment.

Patients were divided according to never having used infliximab reference product, early switchers with less than 2 years of reference product use, and late switchers with greater than 2 years of reference product use.

Investigators said 41.6% to 47.4% of patients had inflammatory bowel disease and 34.2% to 48.7% had rheumatoid arthritis. Psoriasis patients accounted for 8.8% to 14.2% of the population.

Roughly half of patients were highly adherent to infliximab biosimilars at 12 months of treatment with these alternative agents. Among those with ≥ 12 months of follow-up care, 53.6% of naïve users, 44.3% of early switchers, and 56.1% of late switchers remained highly adherent at 12 months.

High adherence among patients with at least 18 months of follow-up amounted to 59.3% for naïve infliximab biosimilar users, 50% for early switchers, and 40.7% for late switchers.

Investigators found that there was no significant difference in adherence among those who initiated biosimilar infliximab.

Investigators divided comorbidity rates according to patient type. Among infliximab naïve users, 14.3% had diabetes; 42.9%, hypertension; 17.3%, depression; chronic obstructive pulmonary disease, 19.4%; and cancer, 11.2%.

The respective percentages for early switchers were 17.5%, 37.7%, 21.1%, 7%, and 3.5%; and for late switchers, 15.9%, 38.1%, 10.6%, 15.9%, and 11.5%.

The adjusted odds ratio for high adherence among naïve infliximab biosimilar users was 1.68 (P = .26); and for early switchers, 0.70 (P = .35), meaning the former group was far more likely to adhere to infliximab biosimilar than the latter group.

Reference

Sarvesh S, Alanaeme JC, Curtis JR, Yun H. Utilization and adherence among infliximab biosimilar initiators in a U.S. national commercial insurance database. Presented at: ACR Convergence 2020; November 5-9, 2020. Poster 0555.