Update From BYOND Trial of Bosutinib in Chronic-Phase CML
Posted: Wednesday, July 29, 2020
An update from the current phase IV BYOND trial confirmed the use of bosutinib for patients who have chronic-phase chronic myeloid leukemia (CML) that is resistant or intolerant to prior tyrosine kinase inhibitors across all treatment lines. Andreas Hocchaus, MD, of the Universitätsklinikum Jena, Germany, and colleagues reported high rates of both cytogenetic and molecular response, with many patients achieving a deep molecular response, while maintaining health-related quality of life. These results were published in the journal Leukemia.
“Despite a high incidence of diarrhea, which is usually transient and often improves with dietary changes and the administration of supportive care, bosutinib discontinuation due to this adverse event was low,” the investigators noted.
In this clinical trial, 163 patients with resistant or intolerant CML received bosutinib at 500 mg once daily (starting dose). Most of these patients (n = 156) had Philadelphia chromosome–positive (Ph+) chronic-phase CML. The median treatment duration was 23.7 months.
The cumulative confirmed rate of major cytogenetic response by 1 year—the primary endpoint—was 75.8% in the 144 evaluable patients with Ph+ chronic-phase CML after one or two prior tyrosine kinase inhibitors and 62.2% in those after three prior tyrosine kinase inhibitors. As for the rates of cumulative complete cytogenetic response and major molecular response by 1 year in patients with Ph+ chronic-phase CML, they were 80.6% and 70.5%, respectively. Of note, no treated patient with chronic-phase disease was reported to have experienced disease progression to accelerated or blast phase.
In terms of toxicity, diarrhea (87.7%), nausea (39.9%), and vomiting (32.5%) were the most common treatment-emergent adverse events across all study patients. However, two, three, and two patients discontinued treatment due to the respective toxicity. As for patient-reported outcomes, health-related quality of life was found to be maintained from baseline following 12 months of bosutinib treatment in patients with chronic-phase CML.
Disclosure: For full disclosures of the study authors, visit nature.com.