Oocyte cryopreservation during blinatumomab treatment for acute lymphoblastic leukemia: A case report.

Fertility preservation (FP) in female patients with B-cell acute lymphoblastic leukemia (B-ALL) is challenging because the urgent initiation of chemotherapy often limits the time available for FP. Oocyte cryopreservation (OC) is the most established method for female FP; however, it requires ovarian stimulation, which may not be feasible in this clinical context. We report successful OC during blinatumomab treatment in a 19-year-old woman with newly diagnosed Philadelphia chromosome-negative B-ALL. She received one course of conventional chemotherapy with a gonadotropin-releasing hormone agonist, followed by one course of blinatumomab as induction therapy before allogeneic hematopoietic cell transplantation. Immediately after completion of blinatumomab, ovarian stimulation was initiated. After 13 days of stimulation, 22 oocytes were retrieved, of which 16 mature oocytes were cryopreserved. This case suggests that OC during blinatumomab treatment may represent a feasible FP strategy while maintaining intensive oncologic therapy.