A single-patient case report published in Blood Research describes a 56-year-old woman with paroxysmal nocturnal hemoglobinuria (PNH) whose persistent anemia improved after danicopan was added to ravulizumab therapy. The correspondence, published open access on 26 October 2026, reports that the addition of the factor D inhibitor reduced residual extravascular hemolysis that had continued despite C5 inhibitor treatment.
PNH is characterized by complement-mediated hemolysis. Although C5 inhibitors effectively control intravascular hemolysis, some patients develop clinically significant extravascular hemolysis because of upstream C3 deposition, the authors note. This residual hemolysis can keep hemoglobin levels low even when intravascular hemolysis markers appear controlled.
The patient was diagnosed with PNH in 2019 and managed with intermittent transfusions. In October 2024, she developed progressive renal dysfunction, and testing showed a PNH clone size of 95.72 percent. Ravulizumab, a C5 inhibitor, was initiated in March 2025.
After ravulizumab began, her lactate dehydrogenase level normalized, indicating control of intravascular hemolysis. However, her hemoglobin level remained below 10 g/dL, with marked reticulocytosis and continued transfusion requirements after more than six months of treatment, a pattern consistent with ongoing extravascular hemolysis driven by C3-tagged red cells.
Danicopan, a factor D inhibitor acting upstream of C5 in the complement cascade, was added in November 2025. According to the report, her hemoglobin level subsequently exceeded 10 g/dL, reticulocyte counts gradually decreased, and her transfusion dependence declined.
The authors state that this case demonstrates that adding danicopan to ravulizumab can reduce residual extravascular hemolysis and improve anemia in patients with PNH receiving C5 inhibitor therapy. As a single-patient correspondence, the report documents one clinical course and does not establish efficacy for broader populations; controlled studies would be needed to confirm the observed benefit.
Subject of Research: A case report of danicopan add-on therapy for extravascular hemolysis in a patient with paroxysmal nocturnal hemoglobinuria treated with ravulizumab.
Article Title: Danicopan add-on therapy for extravascular hemolysis in a patient with paroxysmal nocturnal hemoglobinuria receiving ravulizumab
Article References: Park, Y., & Lee, H. (2026). Danicopan add-on therapy for extravascular hemolysis in a patient with paroxysmal nocturnal hemoglobinuria receiving ravulizumab. Blood Research, 61(1), Article 69. https://doi.org/10.1007/s44313-026-00186-7
Image Credits: AI Generated
DOI: 10.1007/s44313-026-00186-7
Keywords: paroxysmal nocturnal hemoglobinuria, danicopan, ravulizumab, extravascular hemolysis, complement inhibitor, factor D inhibitor, anemia, case report, hematology, C5 inhibitor, add-on, therapy
News Source: Ophelia Keating. (October 28, 2026). Danicopan added to ravulizumab eased anemia in a PNH case report. Scienmag.
