Finnish Study Finds Anti-TNF Agents More Cost-Effective Than Rituximab in RA

A patient-level simulation model using real-world data from Finland evaluated the cost-effectiveness of abatacept, tocilizumab, and anti—tumor necrosis factor (anti-TNF) therapies as compared with rituximab in patients with rheumatoid arthritis (RA) who received previous treatment with an anti-TNF agent.

In the model, the patients were switched to another biological drug after lack of efficacy or an adverse event until all 4 biologic options were exhausted. After that, the patients were assumed to receive a sixth line treatment until death.

The model simulated 4 treatment regimens: abatacept, tocilizumab, rituximab, and a second anti-TNF; anti-TNF agents were considered together as a single group.

Different routes of administration for abatacept and tocilizumab, which can be given either subcutaneously or intravenously, were also pooled as single groups.

Patients were assumed to remain on any given treatment for at least 6 months, the average time interval for routine care visits to rheumatologists in Finland.

The model included each patients’ characteristics, history of drug use, and past treatment responses, and were used as predictors for future outcomes and costs. The analysis was conducted from a societal perspective as the study included both direct and indirect costs.

Data came from the National Register for Biological Treatments in Finland. Direct costs comprised drug costs, administration costs, costs of switching, and outpatient and inpatient care, while indirect costs included disability pension and sick leaves due to rheumatoid arthritis.

The median age of patients was 56 and most were female; more than half had a treatment response to the first TNF inhibitor. Median Health Assessment Score (HAQ) score was 1.1; median Disease Activity Score in a count of 28 joints (DAS28) was 4.6.

While a commonly referred threshold for cost-effectiveness has not been published in Finland, researchers used the willingness to pay threshold of €40,600 (US $45,207).

Based on the Finnish recommendations for health economic evaluations, all costs and benefits were discounted at 3.0% annually. Primary outcome of the simulation was incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) including only direct costs.

The study found that rituximab was associated with the lowest drug costs, but when administration costs and costs of switching were included, anti-TNF agents had the lowest drug costs as well as the highest number of QALYs gained, and as such were deemed the most cost-effective treatment option.

Abatacept was associated with the highest drug costs, and tocilizumab was associated with the lowest effectiveness.

The amount of QALY gained ranged from 9.405 for rituximab to 9.661 for anti-TNF drugs.

A sensitivity analysis showed that the self-administration of abatacept and tocilizumab decrease the administration costs, but the route of administration had no effect on other costs.

Rituximab had the highest costs and lowest QALYs when they were discounted at 0%, but when 6% were used, tocilizumab had the lowest number of QALYs gained.

When the time horizon of 10 years was used, rituximab had the lowest drug costs, including the costs of switching and administration costs, while tocilizumab was associated with the lowest QALYs.

Rituximab as a second-line treatment option had the highest direct costs even when the price discount of 30% for a biosimilar of the reference product Rituxan was used, owing to the highest outpatient and inpatient costs for rituximab.

As compared with patients with no response to the first anti-TNF agent, primary responders had slightly higher costs and QALYs gained.

The QALYs gained ranged from 11.960 to 12.370 for patients with negative rheumatoid factor (RF) status, while QALYs gained ranged from 9.159 to 9.415 for patients with positive RF status.

In addition, costs were higher among patients with negative RF status, compared with RF-positive patients. Furthermore, concomitant use of methotrexate or other non-biologic therapies lead to increased QALYs in comparison to nonuse of methotrexate or biologic monotherapy, respectively.

Reference

Huoponen S, Aaltonen KJ, Viikinkoski J, et al. Cost-effectiveness of abatacept, tocilizumab and TNF-inhibitors compared with rituximab as second-line biologic drug in rheumatoid arthritis [published online July 24, 2019]. PlOS One. doi.org/10.1371/journal.pone.0220142