Costs of Switching TNF Agents versus Dose Escalation

Minneapolis—As patients and physicians seek improved disease control, switching among anti–tumor necrosis factor (TNF) agents has become common practice, according to the authors of a recent study. Study results were presented at an AMCP poster presentation; the poster was titled Healthcare Costs of Patients Switching or Dose Escalating Anti-Tumor Necrosis Factor Therapy. The authors noted that dose escalation may offer an alternative to switching among agents and that approved labeling for infliximab (IFX) and adalimumab (ADA) allows for dose escalation. Because there are limited data for understanding the cost implications of switching to a second anti-TNF agent compared with dose escalation, the researchers designed a study to examine all-cause healthcare costs (ACCs) and rheumatoid arthritis (RA)-specific healthcare costs (RASCs) of switching versus dose escalation. The study enrolled 2587 patients treated with ADA, etanercept (ETA), or IFX who were ≥18 years of age, diagnosed with RA, had no biologic claims for 6 months prior to the index date, had continuous plan enrollment for 6 months prior to the index date and for 12 months post-event, received ≥3 doses of IFX and ≥1 fill of ADA and ETA, and had no other selected inflammatory disorders. The study defined switch as a claim for a non-index anti-TNF agent during follow-up. Dose escalation in IFX was defined as a ≥33% increase in the number of vials in a claim or the decrease in intervals between infusions; for ADA and ETA, dose escalation was defined as a refill <28 days, increase in days supply per claim, or decrease in number of days ≥7 between refills. Cost measures included medication costs, inpatient services, and outpatient services. Of the 2587 patients in the study, 23.5% (n=608) were insured by Medicare and 76.5% (n=1979) by commercial health plans. Overall, 1229 patients switched therapy and 1358 escalated the dose. Of those who switched, 449 switched from ADA, 629 switched from ETA, and 151 switched from IFX. Of those who escalated the dose, 89% (n=1208) were undergoing treatment with IFX, 7% (n=92) with ADA, and 4% (n=58) with ETA. Following adjustment for age and comorbidity, ACCs were comparable for all patients ($32,493 vs $31,885; P=.484). In the adjusted RASC sample, dose escalation was significantly less costly compared with switching ($17,667 vs $20,341; P<.001). Results in the commercial sample were similar to the overall results, whereas in the Medicare sample, there were no significant differences between ACC/RASC costs of switching versus dose escalation in the unadjusted sample. Dose escalation was significantly less costly in the adjusted RASC sample compared with switching ($15,488 vs $17,971; P=.008). In conclusion, the authors said that the ACCs of switching agents versus escalating the dose are similar when comparable patient samples are evaluated. The RASC-specific costs of dose escalation are significantly lower than the costs of switching, they added. This study was supported by Centocor Ortho Biotech, Inc.