The economic burden of switching targeted disease-modifying anti-rheumatic drugs among rheumatoid arthritis patients

Aims: To estimate real world healthcare costs and resource utilization of rheumatoid arthritis (RA) patients associated with targeted disease modifying anti-rheumatic drugs (tDMARD) switching in general and switching to abatacept specifically.

Materials and methods: RA patients initiating a tDMARD were identified in IMS PharMetrics Plus health insurance claims data (2010–2016), and outcomes measured included monthly healthcare costs per patient (all-cause, RA-related) and resource utilization (inpatient stays, outpatient visits, emergency department [ED] visits). Generalized linear models were used to assess (i) average monthly costs per patient associated with tDMARD switching, and (ii) among switchers only, costs of switching to abatacept vs tumor necrosis factor inhibitors (TNFi) or other non-TNFi. Negative binomial regressions were used to determine incident rate ratios of resource utilization associated with switching to abatacept.

Results: Among 11,856 RA patients who initiated a tDMARD, 2,708 switched tDMARDs once and 814 switched twice (to a third tDMARD). Adjusted average monthly costs were higher among patients who switched to a second tDMARD vs non-switchers (all-cause: $4,785 vs $3,491, p?p?p?p?=?.021), and numerically lower all-cause costs ($4,444 vs $4,741, p?=?0.188). Switchers to TNFi relative to abatacept had more frequent inpatient stays after switch (incidence rate ratio (IRR) = 1.85, p?=?.031), and numerically higher ED visits (IRR = 1.32, p?=?.093). Outpatient visits were less frequent for TNFi switchers (IRR = 0.83, p?Limitations and conclusions: Switching to another tDMARD was associated with higher healthcare costs. Switching to abatacept, however, was associated with lower RA-related costs, fewer inpatient stays, but more frequent outpatient visits compared to switching to a TNFi.     

National and regional dose escalation and cost of tumor necrosis factor blocker therapy in biologic-naïve rheumatoid arthritis patients in US health plans

Objective:

This study examined the proportion and magnitude of dose escalation nationally and regionally among rheumatoid arthritis (RA) patients treated with TNF-blockers and estimated the costs of TNF-blocker therapy.

Methods:

This retrospective cohort study used claims data from US commercially-insured adult RA patients who initiated adalimumab, etanercept, or infliximab therapy between 2005–2009. Biologic-naïve patients enrolled in the health plan for ≥6 months before and ≥12 months after therapy initiation were followed for 12 months. Dose escalation was assessed using three methods: (1) average weekly dose?>?recommended label dose, (2) average ending dispensed dose?>?maintenance dose, and (3) average dose after maintenance dose?>?maintenance dose. Annual cost of therapy included costs for mean dose and drug administration fees.

Results:

Overall, 1420 etanercept, 874 adalimumab, and 454 infliximab patients were included. A significantly lower proportion of etanercept-treated patients had dose escalation using the average weekly dose (3.9% vs 21.4% adalimumab and 69.6% infliximab; p?p?p?Limitations:

Exclusion of patients not on continuous TNF-blocker therapy limits the generalizability; however, ～50% of patients were persistent on therapy for 12 months. The study population comprised RA patients in commercial health plans, thus the results may not be generalizable to Medicare or uninsured populations.

Conclusions:

In this retrospective study, etanercept patients had the lowest proportions and magnitudes of dose escalation across all methods compared to adalimumab and infliximab patients nationally and regionally. Mean annual cost was lowest for etanercept-treated patients.     

Indirect cost-effectiveness analyses of abatacept and rituximab in patients with moderate-to-severe rheumatoid arthritis in the United States

Abstract

Objective: To estimate the incremental cost per quality-adjusted life-years (QALYs) for abatacept and rituximab, in combination with methotrexate, relative to methotrexate alone in patients with active rheumatoid arthritis (RA).

Methods: A patient-level simulation model was used to depict the progression of functional disability over the lifetimes of women aged 55–64 years with active RA and inadequate response to a tumor necrosis factor (TNF)-α antagonist therapy. Future health-state utilities and medical care costs were based on projected values of the Health Assessment Questionnaire Disability Index (HAQ-DI). Patients were assumed to receive abatacept or rituximab in combination with methotrexate until death or therapy discontinuation due to lack of efficacy or adverse events. HAQ-DI improvement at month 6, after adjustments for control drug (methotrexate) response, was derived from two clinical trials. Costs of medical care and biologic drugs, discounted at 3% annually, were from the perspective of a US third-party payer and expressed in 2007 US dollars.

Results: Relative to methotrexate alone, abatacept/methotrexate and rituximab/methotrexate therapies were estimated to yield an average of 1.25 and 1.10 additional QALYs per patient, at mean incremental costs of $58,989 and $60,380, respectively. The incremental cost-utility ratio relative to methotrexate was $47,191 (95% CI $44,810–49,920) per QALY gained for abatacept/methotrexate and $54,891 (95% CI $52,274–58,073) per QALY gained for rituximab/methotrexate. At an acceptability threshold of $50,000 per QALY, the probability of cost effectiveness was 90% for abatacept and 0.0% for rituximab.

Conclusion: Abatacept was estimated to be more cost effective than rituximab for use in RA from a US third-party payer perspective. However, head-to-head clinical trials and long-term observational data are needed to confirm these findings.     

Annual costs of tumor necrosis factor inhibitors using real-world data in a commercially insured population in the United States

Abstract

Objective:

To calculate annual cost per treated patient of tumor necrosis factor (TNF) inhibitors etanercept, adalimumab, and infliximab for common approved indications, based on actual TNF-inhibitor use in clinical practice.

Methods:

Adults with ≥1 claim for etanercept, adalimumab, or infliximab between January 2005 and March 2009 were identified from the IMS LifeLink? Health Plan Claims Database. Patients new to therapy or continuing therapy (i.e., a prior claim for a TNF-inhibitor) were analyzed separately. Included patients had been enrolled from 180 days before the first TNF-inhibitor claim (index date) through 360 days after the index date and had a diagnosis during the pre-index period for rheumatoid arthritis, psoriasis, psoriatic arthritis, or ankylosing spondylitis. Patients with Crohn’s disease, ulcerative colitis, or juvenile idiopathic arthritis were excluded. Annual costs were calculated using wholesale acquisition costs for the TNF-inhibitor and Medicare Physician Fee Schedule for drug administration. Costs from restarting or switching TNF-inhibitor therapy during the first year were included.

Results:

A total of 27,704 patients (11,528 new, 16,176 continuing) had claims for etanercept, adalimumab, or infliximab, most commonly (65%) for treatment of rheumatoid arthritis. The most commonly used agent was etanercept (14,777 patients; 53%), followed by adalimumab (6862 patients; 25%) and infliximab (6065 patients; 22%). Annual cost per treated patient was etanercept $14,873, adalimumab $17,766, and infliximab $21,256 across all indications. Annual cost per treated patient by disease was (etanercept/adalimumab/infliximab): rheumatoid arthritis ($14,314/$17,700/$20,390), psoriasis ($17,182/$17,682/$23,935), psoriatic arthritis ($15,030/$18,483/$24,974), and ankylosing spondylitis ($14,254/$16,925/$23,056). New and continuing patients showed similar results, with etanercept having the lowest costs.

Limitations:

This analysis is limited to three TNF-inhibitors and a US managed-care population.

Conclusions:

Based on this analysis of real-world use of TNF-inhibitors among patients in nationwide clinical practice settings, the annual TNF-inhibitor cost per treated patient was lowest for etanercept across all indications.