OBJECTIVES : Analyze costs among patients with paroxysmal nocturnal hemoglobinuria (PNH) switching from C5 inhibitors (C5i) to pegcetacoplan (investigational C3 inhibitor administered subcutaneously). We illustrate a C3 switch calculation of total costs from a US payer perspective with/without pegcetacoplan.

METHODS : Costs were modeled for scenarios in which commercially insured PNH patients: 1) were treated with standard-of-care (SOC) C5i: ravulizumab or eculizumab, administered intravenously and 2) switched to pegcetacoplan. Payer-relevant economic endpoints from the Phase 3 PEGASUS trial (NCT03500549) included average number of transfusions and probabilities for breakthrough hemolysis (BTH) for pegcetacoplan and eculizumab. Ravulizumab data were estimated based on a matched indirect comparison and real-world use studies. Costs of transfusions, BTH-related hospitalizations, drugs, and administration (subcutaneous vs. intravenous) were estimated using publications, the Healthcare Cost and Utilization Project, or Center of Medicaid and Medicare Services files. Average C5i drug costs, including C5i dose escalation costs, were estimated using Micromedex. Total cost-of-care (TCC) for current SOC and cost savings for the first year of pegcetacoplan treatment were calculated (2020 US dollars).

RESULTS : PNH prevalence was ~12.5 per million; approximately 36 adult PNH patients are treated each year per 10 million members. Direct costs for C5i treatment were estimated at $19.9 million per year ($0.17 member/month) including drug, administration, transfusion, and BTH hospitalization costs. Estimates for switching all C5i-treated patients to pegcetacoplan resulted in avoiding approximately 71 transfusions and 7 BTH hospitalizations in year 1 corresponding to savings of $217K for these health outcomes and total cost savings of $3.79 million.

CONCLUSIONS : Switching to pegcetacoplan reduced the TCC for PNH treatment. Pegcetacoplan-related cost savings may be attributed to its superior efficacy in hemoglobin improvement that translated to direct cost offsets, including reductions in high-cost services such as transfusions and BTH-related hospitalizations. Overall, these savings may provide important formulary considerations for US payers.