The FDA has updated the product label for the cancer drug nilotinib (Tasigna, Novartis) to incorporate data for providers about how to discontinue the medication in certain patients.
The FDA first approved Nilotinib in 2007, is shown for the treatment of patients with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML).
With these updated dosing suggestions, patients with early (chronic) phase CML who have been taking nilotinib for a long time or more, and whose leukemia has responded to treatment as per particular criteria as detected by a test that has received FDA marketing authorization, might be eligible to stop taking the medication.
CML is a cancer of the bone marrow and causes the body making too many white blood cells. Patients with CML have an abnormality is called as the Philadelphia chromosome, which produces a protein called BCR-ABL. The National Cancer Institute estimates approximately 8,950 patients will be diagnosed to have CML this year, and 1,080 will die of the disease.
Nilotinib is a kinase inhibitor update that works in CML by blocking BCR-ABL, which promotes abnormal cell growth. This FDA update adds data to the product label for patients and health care providers with respect to the conditions under which patients might be eligible to discontinue treatment and notes that if drug therapy is stopped patients must be regularly monitored for disease recurrence.
In the first trial, among the 190 newly diagnosed patients to have CML who stopped nilotinib after taking it for at least three years and meeting other specified criteria, 51.6% were still in the TFR phase after around one year (48 weeks) and 48.9% were still in the TFR phase after approximately two years (96 weeks).
In the second trial, among the 126 patients who had stopped nilotinib after taking it for at least three years after switching from the cancer drug imatinib, 57.9% were still in the TFR phase after approximately one year (48 weeks) and 53.2% were still in the TFR phase after around two years (96 weeks). An important part of both trials was regular and frequent monitoring of specific genetic (RNA) data that determines the BCR-ABL protein level in the blood with a diagnostic test that has received FDA marketing approval.
Monitoring with a test able to detect decreases of particular RNA data with high accuracy and precision is critical to the safe cessation of nilotinib, as this monitoring provides the first signs of relapse.
Most common side effects in patients who discontinued nilotinib include musculoskeletal symptoms such as body pains, bone pain, and pain in extremities. Some patients experienced prolonged musculoskeletal symptoms. The long-term results of patients discontinuing versus to continuing with treatment are unknown at this time.