Is stopping nilotinib treatment safe in patients with chronic myelogenous leukemia that have achieved a stable response?

This study aimed to investigate the safety and effectiveness of stopping nilotinib treatment in patients with chronic-phase chronic myelogenous leukemia. 

This study concluded that stopping nilotinib after two years of consolidation treatment was safe and effective. 

Nilotinib (Tasigna) is a type of targeted therapy called a tyrosine kinase inhibitor (TKI). It is used for treating imatinib (Gleevec)-resistant chronic myelogenous leukemia (CML). Imatinib is another TKI commonly used to treat CML. It can also be used as a consolidation treatment. Consolidation treatment is used to kill any cancer cells remaining after the main treatment has been administered.   

It was not known if stopping nilotinib consolidation treatment was safe and effective for patients with chronic phase (CP) CML.  

This study involved 149 patients with CP-CML. All patients had achieved a molecular response (MR^4.5) after starting imatinib or nilotinib treatment. MR^4.5 is a sign of disease remission. 112 patients received consolidation therapy of nilotinib twice daily for up to 24 months. 90 patients maintained MR^4.5 at 24 months. 87 of these patients proceeded to stop nilotinib treatment. Patients were followed up for an average of 50.1 months after stopping nilotinib treatment. 

During follow-up, 53 patients had sustained MR^4.5. 34 patients had a relapse. The average time to relapse was 4 months. Nilotinib treatment was resumed in 33 patients. All 33 patients attained MR^4.5 at an average of 2.8 months.

The treatment-free remission (TFR) rate at 1 year after stopping nilotinib was 60.9%. TRF rate at 3 years after stopping nilotinib was also 60.9%. 

This study concluded that stopping nilotinib after two years of consolidation treatment was safe in patients with CP-CML.  

This study had a small number of participants. Also, the study was funded by Novartis, the manufacturer of nilotinib.