The data relating to men on tyrosine kinase inhibitors who wish to have children is relatively limited, and is better for imatinib, dasatinib and nilotinib than bosutinib and ponatinib
There are two issues, fertility (the ability to conceive) and the potential impact on the child
We do not think the TKI impact male fertility. These data come from animal experiments and the fact that many men have had children while taking TKI. You say that your patients fertility has been affected but do you know it was better at diagnosis?
There is, to date, no suggestion that the TKI taken by men, have any detrimental effect on the foetus or the infant in terms of congenital abnormalities or later development

Jane

I have a 31yo male who is on second line Nilotinib for accelerated phase CML (additional cytogenetic abnormality - derivative chromosome 22). He has now been on Nilotinib for 10 months, with a bcr-abl of 0.49%. Initial CML therapy with imatinib occurred in the Czech republic and was affected by poor compliance. No new mutations were detected at relapse in 2019.

He has been trying to conceive with his 38yo wife for the past 12 months. They are now seeking assisted fertility options. His sperm number and function are reduced by the TKI however it is possible that they will be able to conceive with assistance. Given his wife's age they so not wish to defer pregnancy until his CML is better controlled.

Given the short time he has been on treatment with Nilotinib and the accelerated nature of his disease I have recommended that he remain on therapy however I have been unable to quantify the risk conferred to pregnancy outcomes in this setting. Are you aware of any data on outcomes in children born to males on Nilotinib?