Bosutinib (BOS) for chronic phase (CP) chronic myeloid leukemia (CML) after imatinib (IMA) failure: $8-y update of a phase I/II study
Abstract No : 7549
Abstract Type : Poster Discussion Session
Indication : Chronic Myeloid Leukemia (CML)
Intervention : Bosutinib
Company : Pfizer Inc
Technology : Small molecule
54/284 (19%) CP2L pts were still on BOS after ≥9 y and 8/119 (7%) CP3L and 5/167 (3%) ADV pts after ≥8 y; 61 CP2L pts discontinued BOS since y 5 and 21 CP3L and 12 ADV pts since y 4. Overall, the most common reason for discontinuation was disease progression/lack of efficacy in CP2L (27%), CP3L (42%) and ADV (50%) pts; last dose before discontinuation was ≥500 mg/d in 59 (21%), 28 (24%) and 46 (28%) pts, respectively. In CP2L pts, median (range) of follow-up was 54 (1–155) mo, treatment duration 26 (<1–155) mo and dose intensity 438 (87–599) mg/d; responses were durable (Table) and overall survival (OS) at 9 y was 74% vs 84% at 5 y. OS at 8 y was 69% in CP3L, 54% in AP CML and 23% in BP CML pts vs 78%, 59% and 23% at 4 y. 55 CP2L, 29 CP3L and 98 ADV pts died on study (10, 3 and 2 since the 4/5-y reports); 15, 5 and 3 had on-treatment transformations to AP/BP. Most common new treatment-emergent adverse events since y 5 in CP2L pts were pleural effusion (n=13), arthralgia (n=12) and increased blood creatinine (n=11).
After ≥8 y, BOS continued to show durable efficacy and no new safety signals in pts with CP CML on long-term treatment, providing further support for BOS use after prior TKIs
Long term follow up establishes the earlier recorded safety and efficacy results, Increase confidence in Bosutinib usage post TKI therapy.