Bosutinib for Patients with Previously Treated Chronic Myeloid Leukemia: Results from the French Observational Boseval Study

• Published in: Blood 2024-11, Vol.144 (Supplement 1), p.3150-3150
• Main Authors: Rousselot, Philippe, Ianotto, Jean-Christophe, Quittet, Philippe, Hacini, Maya, Roth-Guepin, Gabrielle, Meunier, Mathieu, Maloisel, Frederic, Coiteux, Valérie, Etienne, Gabriel
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2024-200145

Background: Bosutinib (BOS) is approved in France for the treatment of newly diagnosed Philadelphia chromosome-positive (Ph+) chronic phase chronic myeloid leukemia (CML), and for patients (pts) with Ph+ CML previously treated with ≥1 tyrosine kinase inhibitor (TKI) and for whom imatinib, nilotinib and dasatinib are not considered appropriate treatment options. Aims: This study aimed to characterize the safety and effectiveness of BOS in pts with previously treated CML receiving treatment in a real-world clinical setting in France. Methods: BOSEVAL is a non-interventional, observational, prospective study conducted at 23 centers in Metropolitan France. Eligible pts, aged ≥18 yr, had a diagnosis of Ph+ and/or BCR::ABL1+ CML and were resistant/intolerant to prior treatment with ≥1 TKI. Primary outcomes measures were treatment-related adverse events (TRAEs) and permanent BOS discontinuation due to TRAEs, as determined by the investigator. Results: This study included 142 pts who commenced BOS treatment between Oct 22, 2015, and Dec 19, 2019, with a follow-up period of 3 yr from BOS initiation. Among the 139 pts evaluable for effectiveness, the median age at BOS initiation was 65.0 (range, 23.0−88.0) yr, 56.1% were male; 46.0%, 30.2% and 23.7% of pts received BOS as 2nd, 3rd, and ≥4th line treatment, respectively. Median time from CML diagnosis to the initiation of BOS treatment was 3.9 (range, 0.2−29.2) yr. In all, 64.7% of pts switched to BOS due to intolerance to their last TKI therapy; most common (≥20%) TKI therapies prior to BOS initiation were imatinib (46.8%) and dasatinib (33.1%). At study completion (median follow-up, 3.1 yr), 55.6% of pts were still receiving BOS; median duration of treatment was 2.8 (range, 0−3.4) yr. Median dose at treatment initiation was 200 (range, 100−500) mg/day, and the average dose during treatment was 300 (range, 57−500) mg/day. Dose escalations were reported in 76.1% of pts. Dose reductions and dose interruptions occurred in 50.0% and 43.7% of pts, respectively. Most common primary reasons for permanent BOS discontinuation were intolerance (27.5%) and loss of response/suboptimal response (11.3%). Adverse events (AEs) were reported in 99.3% of pts; 60.6% of patients experienced at least one serious AE and 88.0% of patients experienced TRAEs. Most common (≥10%) any grade TRAEs were diarrhea (53.5%), hepatocellular injury (14.8%), nausea (14.1%) and abdominal pain (10.6%). TRAEs led to permanent treatment discontinuation in