Cost-effectiveness of rituximab strategies in rheumatoid arthritis

Cost-Utility Analysis of Rituximab vs Mycophenolate Mofetil for the Treatment of Pemphigus Vulgaris

Importance

There is an increasing body of literature that supports the use of rituximab as a first-line steroid-sparing agent in pemphigus vulgaris. However, the cost of rituximab is substantial compared with conventional agents, and there are limited health economic data to justify its use.

Objective

To evaluate the cost-effectiveness of rituximab biosimilars relative to mycophenolate mofetil as a first-line steroid-sparing agent for moderate to severe pemphigus vulgaris.

Design, Setting, and Participants

A cost-utility analysis over a 24-month time horizon was conducted from the perspective of the Australian health care sector using a modeled cohort of treatment-naive adult patients with moderate to severe pemphigus vulgaris. A Markov cohort model was constructed to simulate disease progression following first-line treatment with rituximab biosimilars or mycophenolate mofetil. The simulated cohort transitioned between controlled disease, uncontrolled disease, and death. Efficacy and utility data were obtained from available published literature. Cost data were primarily obtained from published government data. One-way and probabilistic sensitivity analyses were performed to assess uncertainty. Primary outcomes were the changes in cost and quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) over the 24 months.

Interventions

Rituximab biosimilars and mycophenolate mofetil.

Results

The simulated cohort of treatment-naive patients had a mean age of 50.8 years, a female-to-male ratio of 1.24, and moderate to severe disease as classified by the Harman criteria. First-line rituximab biosimilars were associated with a cost reduction of AU$639 and an improvement of 0.07 QALYs compared with mycophenolate mofetil, resulting in an ICER of -AU$8818/QALY. Rituximab biosimilars were therefore more effective and less costly compared with mycophenolate mofetil. Sensitivity analyses demonstrated that rituximab biosimilars remained cost-effective across a range of values for cost, utility, and transition probability input parameters and willingness-to-pay thresholds.

Conclusions and Relevance

In this cost-utility analysis, rituximab biosimilars were cost-effective compared with mycophenolate mofetil for moderate to severe pemphigus vulgaris. Further investigation into its cost-effectiveness over a longer time horizon is necessary, but the favorable results of this study suggest that the high acquisition costs of rituximab biosimilars may be offset by its effectiveness and provide economic evidence in support of its listing on the Pharmaceutical Benefits Scheme for pemphigus vulgaris.

Low-dose rituximab protocol in rheumatoid arthritis-outcome and economic impact

OBJECTIVES

A significant proportion of RA patients, particularly those associated with poor prognostic factors, fail on conventional DMARDs (cDMARDs). Although rituximab (RTX) has been effective in these patients, the cost of therapy makes it unaffordable, particularly in poor and developing countries. Numerous, albeit small, studies using lower doses have shown contradictory results. We aimed to analyse the effectiveness of a low-dose RTX protocol based on clinical outcomes in RA patients.

METHODS

Seropositive RA patients with moderate to high disease activity (DAS28-ESR > 3.2) despite combination cDMARDs, treated with RTX, were included in retrospective analysis. All patients were treated according to a predefined protocol, using 500 mg RTX with ongoing cDMARDs at baseline and repeat dosing at 6 weeks or beyond, on lack of moderate to good EULAR response. The B cell count was assessed at baseline, 2 and 24 weeks.

RESULTS

At 12 weeks, 93% of 166 patients [mean (s.d.) age, 51.5 (11.96) years, 25 men and 141 women, with a disease duration of 10.4 (6.29) years] achieved moderate to good EULAR response. At 24 weeks, 90.8% of patients achieved moderate to good EULAR response, 19.8% achieved low disease activity and 29.5% achieved remission, with a mean change in DAS28-ESR from baseline of 2.9 (1.3). RTX failure and relapse were seen in 5.4% and 3.6%, respectively. The response was maintained for 12.3 (7.2) months with a mean RTX dose 521.1 (100.8) mg. Adverse events were seen in 9.6%. When compared with the standard dosing regimen with the originator molecule, a cost reduction of 90% was achieved.

CONCLUSION

A low-dose RTX regimen achieved reasonably good clinical outcomes at the end of 6 months, with a significantly lower cost.

Experience With the Use of Rituximab for the Treatment of Rheumatoid Arthritis in a Tertiary Hospital in Spain: RITAR Study

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There is evidence supporting that there are no relevant clinical differences between dosing rituximab 1000 mg or 2000 mg per cycle in rheumatoid arthritis (RA) patients in clinical trials, and low-dose cycles seem to have a better safety profile. Our objective was to describe the pattern of use of rituximab in real-life practice conditions.

Doses of rituximab for retreatment in rheumatoid arthritis: influence on maintenance and risk of serious infection

Objective

To investigate maintenance of rituximab (RTX) in RA patients re-treated with reduced doses compared with standard dose in a real life setting.

Methods

The Autoimmunity and Rituximab (AIR) registry is a nationwide prospective observational cohort investigating the long-term safety and efficacy of RTX in RA. The present study included patients from the AIR registry that have been re-treated with RTX after a first course of RTX standard dose (1000 mg × 2). Two groups were defined according to dose of RTX of the first retreatment course (i.e. second course): standard dose group and reduced dose group. Five years' maintenance and rate of serious infections of the retreatment period were compared between standard dose and reduced dose groups. Analyses used the inverse probability of treatment weighting propensity score adjusted method.

Results

Among the 1986 patients from the AIR registry, 1278 were included, 1093 (85.5%) treated with standard dose and 185 (14.5%) with reduced doses. Maintenance of RTX at 5 years in the standard and reduced groups was 55.5 and 53.8%, respectively, and did not significantly differ between groups in adjusted analyses (hazard ratio = 1.03; 95% CI: 0.81, 1.30), but the cumulative RTX dose received for retreatment [1.4 (0.6) vs 2.3 (1.0) g/year, P < 0.001] and the rate of serious infections were significantly lower in the reduced dose group (adjusted hazard ratio = 0.50; 95% CI: 0.27, 0.92; P = 0.02).

Conclusion

Use of reduced doses of RTX for retreatment did not alter the maintenance of RTX at 5 years in RA patients, but allowed a 39% total dose reduction and a lower rate of serious infections.