Introduction: We would like to share the case of a 55-year-old male patient with ALK-positive lung cancer with a corpuscular hemolytic anemia following alectinib therapy.
Case presentation: Approximately 7 weeks after initiating alectinib therapy, this patient developed anemia. Laboratory tests revealed a new Coombs-negative hemolysis with adequate substrate levels, an increase in indirect bilirubin, reticulocytes, and undetectable haptoglobin levels. Cytomorphology primarily showed numerous acanthocytes. This presentation aligns with a case reported in Japan, describing severe hemolytic anemia with morphological changes in erythrocytes under alectinib treatment.
Conclusion: This is the first report describing a rapid increase in hemoglobin after pausing alectinib and no relapse of hemolysis after switching to lorlatinib, while the lung cancer remained stable (stable disease).
Keywords: ALK mutation; Alectinib; Hemolysis; Lorlatinib; Non-small cell lung cancer.
© 2025 The Author(s). Published by S. Karger AG, Basel.