Effectiveness and healthcare costs among stabilised rheumatoid arthritis patients with dose reduction of adalimumab or etanercept in real world

OBJECTIVES:

We assessed the level of maintained effectiveness and associated healthcare costs in stabilised rheumatoid arthritis (RA) patients who reduced doses of adalimumab or etanercept.

METHODS:

Eligible patients were identified from a US commercial insurance database using the following criteria: adults with ≥2 RA diagnoses; effectively treated on standard dose of adalimumab or etanercept for a 6-month baseline period; and ≥3 months of dose reductionwithin a 6-month assessment period following the index date (date of the first reduced dose). Effectiveness was estimated using a validated claims-based algorithm. Multivariate regression models were used to assess maintained effectiveness and healthcare costs in the short-term (months 7-12) and long-term (months 13-24) following the index date, while adjusting for baseline characteristics. Cost per patient maintaining effective treatment (CPME) was calculated as the average total healthcare costs divided by the proportion of patients with maintained effectiveness.

RESULTS:

Both groups (etanercept=375; adalimumab=610) had 70% females and a mean age of 48 years. Adjusted rates of maintained effectiveness for etanercept vs. adalimumab were 57.5% vs. 64.7% (p=0.028) in the short-term and 44.3% vs. 51.9% (p=0.047) in the long-term. Adjusted healthcare costs were similar for etanercept- and adalimumab-treated patients (short-term: $15,043 vs. $15,041; long-term: $31,461 vs. $30,449). The CPME was $2,915 higher with etanercept-treated patients in short-term and $12,349 higher in long-term compared with adalimumab-treated patients.

CONCLUSIONS:

Among stabilised RA patients who reduced biologic dosing, a greater proportion of adalimumab-treated patients maintained effectiveness than etanercept-treated patients. Adalimumab was associated with a lower total CPME than etanercept.