Uptake of Rituximab Biosimilars in Medicare and Medicaid in 2019-2022

ABSTRACT

Objectives: This study evaluated the uptake and costs of 3 biosimilars among Medicare and Medicaid populations for 2019 to 2022: rituximab-abbs (Truxima), rituximab-pvvr (Ruxience), and rituximab-arrx (Riabni).

Study Design: A retrospective, descriptive study.

Methods: Using the annually aggregated, product-level utilization and cost data of biologic and biosimilar rituximab products from CMS drug spending data, total claims and costs (reimbursement and out of pocket) for all rituximab products were identified and extracted from Medicare Part B, Medicare Part D, and Medicaid. Average spending per dosage unit (ASPDU) of individual rituximab products was also extracted, and their annual growth rates in 2022 (vs 2021) were calculated. Descriptive data analyses were performed using Microsoft Excel 2016.

Results: Four years after entering the US market, rituximab biosimilar use increased from between 0% and 7% in 2019 to 60%, 41%, and 61% of all rituximab claims paid by Medicare Part B, Medicare Part D, and Medicaid, respectively, in 2022. Corresponding total costs for rituximab biosimilars also reached 45%, 32%, and 47% of all rituximab products. The ASPDU of biologic rituximab increased 2% in Medicare Part B in 2022 (vs 2021) but decreased by 2% in Medicaid. The ASPDU of rituximab biosimilars (rituximab-abbs and rituximab-pvvr) decreased between 15% and 26% in 2022 in Medicare Part B and Medicaid, while their ASPDU slightly increased between 1% and 2% in Medicare Part D.

Conclusions: Significant uptake of rituximab biosimilars in Medicare and Medicaid occurred within the first 4 years of marketing in the US.

Am J Manag Care. 2024;30(12):In Press

Takeaway Points

• Significant uptake of rituximab biosimilars in Medicare and Medicaid occurred within the first 4 years of marketing in the US.
• Significant increases in the market share of rituximab biosimilars in Medicare and Medicaid spending were observed.
• Total savings of $728 million from all rituximab products in Medicare and Medicaid were observed for 2022 vs 2019—$506 million if adjusting for decreased number of total claims.

Biologics are medications made from living organisms through highly complex manufacturing processes. They are used to prevent, treat, or cure a variety of diseases that include cancer, chronic kidney disease, diabetes, cystic fibrosis, and autoimmune disorders.¹ Data show that biologic expenditure exceeds 50% of total medicine spending in the US, based on the 2024 IQVIA report.² Approved through an abbreviated licensure pathway at the FDA, biosimilars are highly similar to existing biological reference products and have no clinically meaningful differences in safety, purity, and potency from their reference biologics.³ They usually cost 15% to 45% less than their reference products.⁴ As of October 18, 2024, the FDA had approved 61 biosimilars.⁵

Rituximab (Rituxan) is a monoclonal antibody medication used to treat rheumatoid arthritis, chronic lymphocytic leukemia, and non-Hodgkin lymphoma, among its many other indications. Biological rituximab was among the top 10 drugs by global sales in 2019, hitting $6.54 billion.⁶ Three rituximab biosimilars have been approved by the FDA since November 2018: rituximab-abbs (Truxima, approved in November 2018), rituximab-pvvr (Ruxience, approved in July 2019), and rituximab-arrx (Riabni, approved in December 2020).⁵ These biosimilars are approved for indications similar to those for biological rituximab in adults, except for a rare autoimmune condition called pemphigus vulgaris.⁵ Findings from several studies that used clinical trial and real-world data demonstrate similar efficacy, effectiveness, and safety between biosimilar and reference rituximab.^7-10 A recent study assessed the utilization of 3 rituximab biosimilars dispensed from 340B-eligible entities or health systems for 2019 through 2021.¹¹ This study found an increase in rituximab biosimilar adoption from 0% to 60%, with higher adoption for oncology vs nononcology indications and in nonacademic settings.¹¹ But real-word evaluations in the uptake and cost savings of rituximab biosimilars in nationally representative populations remain limited. This study analyzed the most up-to-date Medicare and Medicaid drug spending data to evaluate the uptake and cost of 3 rituximab biosimilars, relative to their originator rituximab, among Medicare and Medicaid populations for 2019 through 2022.

METHODS

Data Sources and Study Population

This analysis used the new publicly available CMS drug spending data, which include annually aggregated, product-level Medicare Part B, Medicare Part D, and Medicaid drug spending data for individual drugs for 2019 to 2022.¹² Medicare Part B drugs include drugs administered in doctors’ offices and other outpatient settings and paid for through the Medicare Part B program, which includes all Part B fee-for-service Medicare beneficiaries but excludes any beneficiaries in the Medicare Advantage program. Medicare Part D drugs include drugs that patients generally administer themselves and that are paid for through the Medicare Part D program, which covers approximately 70% of Medicare beneficiaries.¹² The Medicaid drug data represent national-level drug utilization data for covered outpatient drugs paid for by state Medicaid agencies. In summary, the CMS drug spending data represent drug payments reimbursed for about 70% of Medicare beneficiaries and nationwide Medicaid population.¹² Data files are publicly available and can be downloaded.¹²

Measurements and Statistical Analysis

Annually aggregated, product-level claims and costs for biological rituximab and all 3 rituximab biosimilar products were identified using Healthcare Common Procedure Coding System billing codes (J9312 for reference rituximab, Q5115 for rituximab-abbs, Q5119 for rituximab-pvvr, and Q5123 for rituximab-arrx) from Medicare Part B and their generic/branded drug names from Medicare Part D and Medicaid drug spending data. Annual total claims, total spending (representing the full value of the product, including the Medicare or Medicaid payment and beneficiary liability¹²), and average spending per dosage unit (ASPDU) for each biological and biosimilar rituximab product were extracted in each calendar year for Medicare Part B and D and Medicaid. The annual proportion of claims was calculated for each individual rituximab product, with the denominator representing total claims for all 4 rituximab products in the same year. Similarly, annual proportions of total spending were calculated for each individual rituximab product, with the denominator of total spending for all 4 rituximab products in the same year. Finally, their annual growth rates in ASPDU in 2022 (vs 2021) were calculated. Descriptive data analyses were performed using Microsoft Excel 2016.

RESULTS

Annual Total Beneficiaries Who Used Rituximab Products in Medicare Programs (Data Not Available for Medicaid)

In Medicare Part B, total Medicare beneficiaries who used reference rituximab decreased from 70,203 in 2019 to 27,486 in 2022, whereas the annual totals of Medicare beneficiaries who used rituximab-abbs (0 to 14,493 for 2019-2022), rituximab-pvvr (0 to 18,701 for 2019-2022), and rituximab-arrx (0 to 1949 for 2020-2022) all increased.

In Medicare Part D, annual total Medicare beneficiaries who used reference rituximab decreased from 1957 in 2019 to 1536 in 2022, whereas the annual totals of Medicare beneficiaries who used rituximab-abbs (0 to 494 for 2019-2022), rituximab-pvvr (0 to 364 for 2019-2022), and rituximab-arrx (0 to 50 for 2020-2022) all increased.

Annual Total Claims and Spending for All Rituximab Products

From 2019 to 2022, annual total Medicare Part B and Medicaid claims of all rituximab products decreased by 17% (from 243,181 to 201,081) and 8% (from 40,091 to 37,015), respectively, whereas annual Medicare Part D claims of rituximab products increased by 17% (from 5272 to 6178) (Figure 1). Medicare Part B was the dominant payment source for rituximab claims compared with Medicare Part D and Medicaid. Medicare Part D and Medicaid claims for rituximab products represented approximately 3% and 18% of Part B claims, respectively, in 2022.

Annual total Medicare Part B spending for all rituximab products decreased from $1.7 billion in 2019 to $1.0 billion in 2022, which represented a 40% reduction within 4 years of biosimilar entry. Similarly, annual total Medicaid spending for all rituximab products fell from $200 million to $159 million (20.5% reduction) during the same period. However, annual total Medicare Part D spending for all rituximab products increased from $61 million to $67 million (10% increase) (Figure 2). Overall, rituximab products reimbursed through Medicare Part B, Medicare Part D, and Medicaid programs represented savings of $728 million in 2022 compared with 2019. The percentage of Medicare Part D and Medicaid spending for rituximab products was about 6% and 15%, respectively, of Part B spending in 2022.

Annual Total Claims and Spending for Individual Rituximab Products

From 2019 to 2022, annual claims for rituximab-abbs increased from 0% to 23% of all Medicare Part B rituximab claims, from 0% to 21% of Part D claims, and from 7% to 23% of Medicaid claims (Figure 3). From 2020 to 2022, annual claims for rituximab-pvvr increased from 6% to 33% of all Medicare Part B rituximab claims, from 1% to 17% of Part D claims, and from 5% to 35% of Medicaid claims (Figure 3). From 2021 to 2022, annual claims for rituximab-arrx increased from 1% to 3% of all Medicare Part B rituximab claims, from 0% to 3% of Part D claims, and from 1% to 3% of Medicaid claims (Figure 3). Consequently, the annual number of claims for reference rituximab declined from 100% to 40% in Part B, from 100% to 59% in Part D, and from 93% to 39% in Medicaid.

Correspondingly, for 2019 to 2022, annual total spending on rituximab-abbs increased from 0% to 19% of Medicare Part B spending on all rituximab products, from 0% to 19% of Part D spending, and from 0% to 21% of Medicaid spending (Figure 4). For 2020 to 2022, annual total spending on rituximab-pvvr increased from 5% to 23% of Medicare Part B spending on all rituximab products, from 1% to 11% of Part D spending, and from 4% to 24% of Medicaid spending (Figure 4). For 2021 to 2022, annual total spending on rituximab-arrx increased from 1% to 3% of Medicare Part B spending on all rituximab products, from 0% to 2% of Part D spending, and from 0% to 2% of Medicaid spending (Figure 4). Consequently, the annual total spending on reference rituximab declined from 100% to 55% in 2022 in Part B, from 100% to 68% in Part D, and from 100% to 53% in Medicaid.

Annual Growth Rates in ASPDU for Individual Rituximab Products

The ASPDU for individual rituximab products varied significantly across Medicare and Medicaid (Figure 5). In Medicare Part B in 2022, the ASPDU was highest for reference rituximab ($82), followed by rituximab-arrx ($54), rituximab-abbs ($52), and rituximab-pvvr ($47). It remained steady (2%) for reference rituximab in 2022 and 2021, whereas the annual growth rates for rituximab-abbs, rituximab-pvvr, and rituximab-arrx fell 16%, 26%, and 26%, respectively, in 2022 compared with 2021. In Medicare Part D in 2022, the ASPDU was highest for reference rituximab ($99), followed by rituximab-abbs ($89), rituximab-arrx ($78), and rituximab-pvvr ($75). It remained the same for reference rituximab in 2022 and 2021, whereas the annual growth rates for rituximab-abbs, rituximab-pvvr, and rituximab-arrx were 2%, 1%, and 6%, respectively, in 2022 compared with 2021. In Medicaid in 2022, the ASPDU was highest for reference rituximab ($78), followed by rituximab-arrx ($63), rituximab-abbs ($62), and rituximab-pvvr ($51). Annual growth rates in the ASPDU for 2022 (vs 2021) for all rituximab products were –2% (reference rituximab), –15% (rituximab-abbs), –18% (rituximab-pvvr), and 5% (rituximab-arrx).

DISCUSSION

Significant uptake of rituximab biosimilars in both Medicare and Medicaid populations has been observed since their introductions in 2019. Specifically, 4 years after entering the US market, use of rituximab biosimilars increased from between 0% and 7% in 2019 to 60%, 41%, and 61% of all rituximab claims paid by Medicare Part B, Medicare Part D, and Medicaid, respectively, in 2022. The significant uptake of rituximab biosimilars in Medicare and Medicaid is encouraging and was likely led by the increased discount in the ASPDU of rituximab-abbs and rituximab-pvvr in Medicare Part B (–16% and –26%, respectively) and Medicaid (–15% and –18%) compared with the originator rituximab (2% in Medicare Part B and –2% in Medicaid) in 2022. The utilization of rituximab biosimilars is about 70% in Europe at 3 years after biosimilar launch, where 5 biosimilars were approved.¹³ In this study, the adoption of rituximab biosimilars was slower in Medicare Part D than in Medicare Part B and Medicaid, which was likely driven by the smaller price discounts of the rituximab biosimilars compared with the biologics. The ASPDU of rituximab biosimilars in Medicare Part D was between 76% and 90% of the ASPDU of reference rituximab, whereas it was 57% to 66% in Medicare Part B and 65% to 81% in Medicaid. A more aggressive discount in rituximab biosimilar pricing compared with biologics could lead to further improvement of the uptake of rituximab biosimilars in the US market.

Like the significant uptake in utilization, notable reductions in total spending for all rituximab products were simultaneously reached for Medicare Parts B and D and Medicaid. Compared with 2019, annual total spending for all rituximab products decreased by 40% for Medicare Part B, 10% for Medicare Part D, and 20% for Medicaid in 2022, reflecting a total savings of $728 million for these 3 programs. Bourbeau et al assessed biosimilar use among 38 American Society of Clinical Oncology PracticeNET practices for 2019 to 2021, and they reported that rituximab biosimilar use reached 70% by the last quarter of 2021.¹⁴ In addition, they found that public health care payers, including Medicare, Medicaid, and Medicare Advantage, were associated with a lower likelihood of biosimilar use compared with commercial health care payers.¹⁴ Therefore, the marketing of rituximab biosimilars might have generated significant savings for patients and payers in commercial health care settings in the US market. In addition, the cost savings and efficiency of administration of rituximab could be further improved through partial transition from intravenous to subcutaneous administration of rituximab to increase provider capacity and free patient time.¹⁵

Limitations

Study limitations included the use of annually aggregated product-level data instead of patient-level data, which could support only descriptive analysis instead of covariate- controlled, multivariable analysis. This study lacked access to data that may have affected biosimilar rituximab use and cost, such as patient/provider perceptions and acceptance, payer policies, and manufacturer rebates. In addition, Medicare Parts B and D drug use spending data were not adjusted for the consumer price index, and the data did not include beneficiaries enrolled in the Medicare Advantage program. Some of the data assessed in this study were from the COVID-19 pandemic, which may have had an impact on the use of rituximab treatments as a group. However, these findings provide new national-level evidence on utilization rates and costs of biological and biosimilar rituximab products in Medicare and Medicaid.

CONCLUSIONS

This study found that significant uptake of rituximab biosimilars in Medicare and Medicaid occurred within the first 4 years of their marketing in the US. Researchers should evaluate postmarketing use, switching, and safety of biosimilar products and urge policy makers and the pharmaceutical industry to introduce new biosimilars for improving competition and health care savings in the US market. 

Author Affiliation: Department of Health Outcomes Research and Policy, Auburn University Harrison College of Pharmacy, Auburn, AL.

Source of Funding: None.

Author Disclosures: The author reports no relationship or financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Authorship Information: Concept and design; acquisition of data; analysis and interpretation of data; drafting of the manuscript; statistical analysis; administrative, technical, or logistic support; and supervision.

Address Correspondence to: Jingjing Qian, PhD, Department of Health Outcomes Research and Policy, Auburn University Harrison College of Pharmacy, 4306D Walker Building, Auburn University, Auburn, AL 36849-5506. Email: jzq0004@auburn.edu

REFERENCES

1. Research & development: biologics & biosimilars. PhRMA Foundation. Accessed May 3, 2019. https://www.phrma.org/advocacy/research-development/biologics-biosimilars

2. The use of medicines in the U.S. 2024: usage and spending trends and outlook to 2028. IQVIA. May 7, 2024. Accessed July 9, 2024. https://www.iqvia.com/insights/the-iqvia-institute/reports-and-publications/reports/the-use-of-medicines-in-the-us-2024

3. What are “biologics” questions and answers. FDA. Updated February 6, 2018. Accessed March 8, 2019. https://www.fda.gov/about-fda/center-biologics-evaluation-and-research-cber/what-are-biologics-questions-and-answers

4. Carl DL, Laube Y, Serra-Burriel M, Naci H, Ludwig WD, Vokinger KN. Comparison of uptake and prices of biosimilars in the US, Germany, and Switzerland. JAMA Netw Open. 2022;5(12):e2244670. doi:10.1001/jamanetworkopen.2022.44670

5. FDA-approved biosimilar products. FDA. October 18, 2024. Accessed November 11, 2024. https://www.fda.gov/drugs/biosimilars/biosimilar-product-information

6. The top 20 drugs by global sales in 2019. Fierce Pharma. July 27, 2020. Accessed April 20, 2024. https://www.fiercepharma.com/special-report/top-20-drugs-by-global-sales-2019

7. McBride A, Daniel S, Driessen MT, et al. Assessment of rituximab-abbs, a biosimilar, and rituximab outcomes in patients with CLL or NHL: a real-world UK study. Leuk Res. 2021;111:106671. doi:10.1016/j.leukres.2021.106671

8. Jourdain H, Hoisnard L, Sbidian E, Zureik M. Severe hypersensitivity reactions at biosimilar versus originator rituximab treatment initiation, switch and over time: a cohort study on the French National Health Data System. BioDrugs. 2023;37(3):397-407. doi:10.1007/s40259-023-00584-8

9. Luo X, Du X, Li Z, et al. Clinical benefit, price, and uptake for cancer biosimilars vs reference drugs in China: a systematic review and meta-analysis. JAMA Netw Open. 2023;6(10):e2337348. doi:10.1001/jamanetworkopen.2023.37348

10. Shim SC, Božic´-Majstorovic´ L, Berrocal Kasay A, et al. Efficacy and safety of switching from rituximab to biosimilar CT-P10 in rheumatoid arthritis: 72-week data from a randomized phase 3 trial. Rheumatology (Oxford). 2019;58(12):2193-2202. doi:10.1093/rheumatology/kez152

11. Labdi BA, Elbeshbeshy RA, Winkler M, Johnson SG, Attridge RL. Rituximab reference vs biosimilar utilization for oncology vs nononcology indications. Am J Manag Care. 2023;29(11):e353-e356. doi:10.37765/ajmc.2023.89461

12. CMS drug spending. CMS. Updated September 10, 2024. Accessed October 15, 2024. https://www.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/Information-on-Prescription-Drugs/index.html

13. The impact of biosimilar competition in Europe: December 2021. IQVIA. Accessed April 25, 2024. https://www.iqvia.com/-/media/iqvia/pdfs/library/white-papers/the-impact-of-biosimilar-competition-in-europe-2021.pdf

14. Bourbeau B, Lyman GH, Lei XJ, et al. Biosimilar use among 38 ASCO PracticeNET practices, 2019-2021. JCO Oncol Pract. 2023;19(7):516-522. doi:10.1200/OP.22.00618

15. Harvey MJ, Zhong Y, Morris E, Beverage JN, Epstein RS, Chawla AJ. Assessing the transition from intravenous to subcutaneous delivery of rituximab: benefits for payers, health care professionals, and patients with lymphoma. PLoS One. 2022;17(1):e0261336. doi:10.1371/journal.pone.0261336