How would you treat a patient with chronic phase CML who could not tolerate nilotinib due to G4 thrombocytopenia despite sequential dose reductions?

It depends on various other factors such as the current response and the doses used. I generally work on trying to get the patients to tolerate treatment first and then focus on response. I have used doses of nilotinib as low as 50 mg daily in some patients; this may make the thrombocytopenia more manageable. I also allow for platelets in the 20-40 range in difficult patients with no increased risk of bleeding otherwise. A change in therapy is an option but thrombocytopenia tends to be seen across all TKIs. It is also worth assessing the bone marrow, including cytogenetics and NGS as these patients tend to have higher incidences of chromosomal abnormalities in Ph-negative metaphases and/or other molecular abnormalities aside from BCR::ABL1 ...