Background: Tyrosine kinase inhibitors (TKI) treatment has transformed chronic myeloid leukemia (CML) from a fatal neoplasm to a chronic disease with normal life expectancies. Indeed, half of CML patients are able to discontinue TKI without relapse. However, it seems clearly demonstrated that exposure to TKI may result in fetal malformations. Regarding its effects on fertility, preclinical studies and clinical case reports provide inconclusive evidence. Furthermore, due to the risk of CML relapse after TKI discontinuation, the optimal time to stop TKI represents a real dilemma.
Case report: We describe a 23-year-old woman who, after more than 6 years with imatinib and 1 year in deep molecular response [(DMR), MR ≥ 4], interrupted treatment to become pregnant. After 2 failed artificial insemination cycles, she underwent one process of controlled ovarian stimulation, achieving 2 blastocyst-embryos. In the meantime, BCR-ABL1IS levels increased despite interferon-alpha therapy, she lost the mayor molecular response (MMR), and the 2 embryos had to be cryopreserved. A stable second MR ≥ 4.0 was again obtained with nilotinib, and after stopping it, the 2 blastocyst-embryo transfers were unsuccessfully performed. Under DMR, a second ovarian stimulation and in vitro fertilization (IVF) was performed and 1 blastocyst embryo was transferred. This time, she became pregnant and a healthy baby was born. After more than 3 years of follow-up, she remains in treatment-free remission (TFR).
Conclusion: Compared with imatinib, nilotinib achieves earlier and deeper MR that allows safe and timely pregnancies in infertile CML women through IVF process, while patients remain in TFR after delivery.
Keywords: Chronic myeloid leukemia; Fertility; Imatinib; In vitro fertilization; Pregnancy; TKI.