OBJECTIVES: Until 2022, only one laboratory had a market authorization for a C5 inhibitor (C5i), eculizumab. With the patent expiring and biosimilars entering the market, this laboratory released a new form of its drug, ravulizumab that is administered less frequently, thus providing costly anti-biosimilar competition for the national health insurance. This study examines the consequences of the launch of this new drug on consumption at the University hospitals of Paris (AP-HP) and the impact of the COMED (Committee for the Evaluation of Drugs in AP-HP) recommendations on the use of the new C5i and the promotion of biosimilars.

METHODS: The data for this study was collected between Q4 2022 and Q1 2023 through a survey distributed to hospital pharmacists and by accessing AP-HP databases (consumptions/expenditures).

RESULTS: The data from 12 hospitals has been categorized by indication: paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic-uremic syndrome (aHUS), myasthenia gravis (MG), neuromyelitis optica spectrum disorder, and other indications, for eculizumab and ravulizumab. Between Q4 2022 and Q1 2023, 15 patients were initiated on treatment with eculizumab (PNH: 4, MG: 2, aHUS: 2, Other: 7), and 62 patients with ravulizumab (PNH: 32, MG: 30). There were 151 patients on maintenance treatment with eculizumab (PNH: 45, MG: 29, aHUS: 60, other: 16), and 139 patients with ravulizumab (PNH: 108, MG: 31). The overall expenses on C5i increased by 70.84% for Q4 2022 - Q1 2023 compared to Q4 2021 - Q1 2022 and ravulizumab accounted for 67% of the total C5i expenses during Q4 2022 – Q1 2023.

CONCLUSIONS: Ravulizumab's launch increased treatment initiation and expenses, indicating its significant impact on consumption patterns and costs. Hospitals adhered to COMED's PNH recommendations, but Mag exhibited center-dependent overconsumption despite available alternatives. The launch of eculizumab biosimilars is expected in 2023 for PNH and in 2024 for aHUS, which will determine their market share.