Rituximab Biosimilars May Be Cost-Effective Treatment for Pemphigus Vulgaris

Rituximab biosimilars may be cost effective as a first-line steroid-sparing agent for patients with pemphigus vulgaris (PV), according data from a study published in JAMA Dermatology.

The cost-utility analysis (CUA) sought to assess the cost effectiveness of rituximab biosimilars compared with mycophenolate mofetil (MMF) as a first-line steroid-sparing agent for the treatment of adult patients with moderate to severe PV.

Researchers conducted the CUA from the perspective of the Australian health care sector. The primary outcomes were incremental costs and quality-adjusted life-years (QALYs), which were used to calculate the incremental cost-effectiveness ratio (ICER).

A Markov cohort model was created to simulate disease progression after first-line adjuvant therapy with rituximab biosimilars or MMF. A hypothetical cohort of treatment-naive patients with moderate to severe PV were included in the model.

The simulated patients had a mean age of 50.8 years with a female-to-male ratio of 1.24. The participants transitioned among 3 health states: controlled disease, uncontrolled disease, and death.

The patients who had disease control while receiving treatment with MMF were maintained with MMF until relapse, death, or termination of the model, whichever occurred first. The model estimated the expected costs and QALYs during a 24-month period using 4 separate 6-month cycles.

First-line adjuvant therapy with rituximab biosimilars was the dominant treatment option with an ICER of -AU$8818/QALY in the base-case analysis. First-line MMF was associated with an average total cost of AU$6866 per patient, compared with AU$6227 per patient with rituximab biosimilars during the 24 months. A total of 0.88 QALYs were accrued in the MMF arm, and 0.95 QALYs were accrued in the rituximab arm.

The rituximab cohort had higher total costs in the first 12 months of treatment. The difference in total costs was +AU$1975 in the rituximab arm compared with the MMF arm in the first 6 months of treatment, +AU$466 during the first 12 months, -AU$522 for the first 18 months, and -AU$639 at the end of treatment. The cumulative accrued QALYs was favorable to the rituximab group during the 24 months.

In the 1-way sensitivity analyses, ICER values were less than the standard willingness-to-pay threshold of AU$50,000/QALY (range, -AU$24,365/QALY to $4865/QALY). An increase in the cost of rituximab induction was associated with a less cost-effective result for first-line treatment with rituximab biosimilars and a more cost-effective result for first-line MMF. First-line treatment with rituximab biosimilars continued to be the dominant strategy when their medication cost varied between the upper and lower adjustment values.

The investigators noted that their analysis compared treatment sequences to better reflect clinical practice for chronic diseases, although the specificity of the sequences limits the applicability of the results, as other interventions may be used depending on physician and patient preference. In addition, the 24-month timeframe precludes definitive conclusions on the long-term cost-effectiveness of first-line rituximab. Also, the study is limited by the use of model inputs derived from other countries in the absence of Australian data.

“Rituximab biosimilars proved to be more effective as well as cost saving compared with MMF,” stated the researchers. “This suggests that the use of rituximab biosimilars as first-line steroid-sparing agents for PV may be associated with a reduction in health care expenditure. However, assessment of their extent of use in clinical practice will be required for an accurate prediction of their financial effect on the health system budget and taxpayers.”

Disclosure: Several of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.

Reference

Chen MKY, Vissapragada R, Bulamu N, et al. Cost-utility analysis of rituximab vs mycophenolate mofetil for the treatment of pemphigus vulgaris. JAMA Dermatology. Published online July 27, 2022. doi:10.1001/jamadermatol.2022.2878