In a nutshell
This study aimed to investigate the effectiveness and safety of bosutinib as a second line therapy for patients with chronic phase chronic myeloid leukemia (CML).
This study concluded that bosutinib was effective and safe for these patients as a second line therapy.
Bosutinib (bosulif) is a tyrosine kinase inhibitor (TKI – a drug which blocks certain proteins involved in cancer cell growth) that can be used for adults with newly-diagnosed Philadelphia chromosome positive (abnormal gemes leading to uncontrolled cancer cell growth) chronic myeloid leukemia. It can also be used for patients whose CML is resistant or intolerant to imatinib (gleevec). Imatinib is a TKI used to treat CML. In this case bosutinib is used as a second line therapy.
It was unknown how effective and safe bosutinib would be as a second line therapy for these patients.
Methods & findings
This study involved 284 patients with chronic phase CML (CP-CML) who received bosutinib as a second-line treatment after imatinib failure. The average follow-up time was 54.8 months. The average treatment duration was 25.6 months.
54% of patients remained on bosutinib at year 2 and 40% of patients remained on bosutinib at year 5. Overall survival was 91% at year 2 and 84% at year 5. 15% of patients on treatment had disease progression/death at year 2 and 19% at year 5.
169 patients stopped bosutinib by year 5. Most side effects began to occur within two years of treatment. 86% of patients experienced diarrhea, 46% experienced nausea and 37% experienced vomiting. 25% of patients experienced thrombocytopenia (low platelet count which can stop clotting).
The major cytogenetic response (MCR – when levels of abnromal genes are reduced) was 58% by year 2 and 60% by year 5. The complete cytogenetic response (CCR – when no abnormal genes are found in the blood) rate was 46% by year 2 and 50% by year 5. There was a 76% chance of maintaining MCR at year 2 and 71% chance at year 5. There was a 78% chance of maintaining CCR at year 2 and 69% chance at year 5.
The bottom line
This study concluded that bosutinib is effective and safe for for CML patients with abnormal genes who are resistant or intolerant to imatinib.
Consult your physician about the use of bosutinib for CP-CML.
Published By :
May 17, 2018