Rituximab versus cyclophosphamide for anca- associated vasculitis: a cost analysis

Background Cyclophosphamide (CYC) and Rituximab (RTX) have been found to be of equivalent effectiveness in remission induction of severe ANCA-associated vasculitis (AAV) (1); [2]. American College of Rheumatology in 2019, and more recently EULAR guidance on treatment of AAV, has recommended the use of RTX first-line due to a more favorable side-effect profile [3]. In the UK, in the absence of contraindications, our current guidance still advocates the use of CYC first-line. While RTX biosimilars are available at reduced cost compared to the originator molecule, the drug cost of RTX is far greater than CYC. A change in UK guidance could have significant cost-implications to healthcare services. Objectives The objective of this study was to compare the cost RTX and CYC induction regimens for patients with AAV and calculate the cost difference to our department of the two regimens. Methods Drug costs for CYC and the current preferred (cheapest) RTX biosimilar was provided by our pharmacy team. Exact drug costs are considered commercially sensitive and are hence not reported here. The Hospital Business Intelligence Unit provided total visit cost data and an average total visit cost for both RTX and CYC was calculated using worked examples. This accounts for cost differences due to in drug administration and the need for medical review. Data was available on the number of patients with AAV who started induction treatment with CYC from January 2022 and December 2022. We were able to calculate a total cost for this and an equivalent cost if these patients had all received RTX induction. Results As expected, drug costs for RTX were significantly greater than for CYC. Total visit costs were however similar. The increased total costs for CYC likely largely due to our policy of consultant and multidisciplinary team review prior to each infusion. The total visit cost approximations for cyclophosphamide for patients with AAV treated with CYC between January 2022 to December 2022 was £44,000. When RTX total visit costs were considered, the annual costs for RTX induction for these patients would have been approximately £14,000. Furthermore, as a standard CYC induction is administered as 6 cycles, while RTX is administered as two 1g infusions, if patients treated with CYC had received RTX this would have created an additional 143 hours of availability on our biologics day unit. Other potential time and cost savings we did not measure would include nadir monitoring bloods for CYC done prior to each infusion and pharmacy time in preparing the drugs and associated other medications such as anti-emetics. Conclusion The annual net saving if our hospital trust had treated the patients with AAV who received CYC induction with RTX instead, would have equated to £30,000. While this does not take into account subsequent maintenance treatment choices, we can be reassured that a shift towards RTX induction first-line in AAV, is likely to lead to significant cost-savings and would not place an additional financial burden on healthcare resources. References [1]Jones RB, Tervaert JW, Hauser T, Luqmani R, Morgan MD, Peh CA, et al. Rituximab versus cyclophosphamide in ANCA-associated renal vasculitis. N Engl J Med. 2010;363(3):211-20. [2]Stone JH, Merkel PA, Spiera R, Seo P, Langford CA, Hoffman GS, et al. Rituximab versus cyclophosphamide for ANCA-associated vasculitis. N Engl J Med. 2010;363(3):221-32. [3] Chung SA, Langford CA, Maz M, Abril A, Gorelik M, Guyatt G, et al. 2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis. Arthritis Rheumatol. 2021;73(8):1366-83. Acknowledgements Joy Craine and Megan Rowe within the Pharmacy at Royal United Hospitals for providing all drug cost data. Business Intelligence Unit within the Royal United Hospitals for providing all cost data. Disclosure of Interests Ella Amor: None declared, Ben Mulhearn: None declared, William Tillett Speakers bureau: Abbvie, Amgen, Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB. Consultant of: Abbvie, Amgen, Eli Lilly, GSK, Janssen, Novartis, Ono Pharma, Pfizer, UCB, Grant/research support from: Janssen, UCB, Pfizer, Eli-Lilly, Charlotte Cavill: None declared, Sarah Tansley: None declared.