Rate of deep molecular response in chronic myeloid leukemia treated with nilotinib

This study aimed to investigate the rate of deep molecular response in patients with newly diagnosed chronic myeloid leukemia who were treated with nilotinib.

This study concluded that good molecular response rates are seen in these patients.

Molecular response (MR) is a measure of the levels of BCR-ABL1 gene in leukemia cells. The BCR-ABL1 gene is found in abundance in cancer cells. Polymerase chain reaction (PCR) is the technique used to detect and measure DNA levels. The DNA of BCR-ABL1 genes can be measured with this technique. There are conventional and digital methods of PCR. The digital method is more sensitive and can detect lower levels.   

Nilotinib (Tasigna) is a targeted therapy drug used to treat chronic myeloid leukemia (CML) who are resistant to other therapies. The rate of deep MR in patients with newly diagnosed CML treated with nilotinib is still unknown.

This study involved 128 patients with newly diagnosed chronic phase (CP) CML. Patients were treated with 300mg nilotinib twice a day. The main outcome measured was the rate of deep molecular response after 2 years.

73.4% of patients achieved a major MR by 2 years. This is where the level of BCR-ABL1 is less than or equal to 0.1% on the International Scale. 27% of patients achieved a confirmed MR4.5 by 2 years. This is where the level of BCR-ABL1 is less than or equal to 0.0032%. Three-month BCR-ABL1 levels were predictive of later responses.

Digital PCR detected BCR-ABL1 in 39.4% of samples from patients with confirmed MR4.5. It also identified further decreases in BCR-ABL1 with continued nilotinib use.

Safety results, including cardiovascular events (heart-related), were similar to those from other nilotinib trials.

This study concluded that good MR rates are seen in CML patients treated with nilotinib. The study also proved that low BCR-ABL1 levels can be monitored with digital PCR.

Studies involving larger groups of patients and of a longer duration should be carried out.