Pfizer announced that the FDA has approved Bosulif (bosutinib) for the treatment of adult patients with chronic, accelerated, or blast phase Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) with resistance, or intolerance to prior therapy.
The registrational trial (Study 200) was a global, single-arm, open-label, multi-cohort, Phase 1/2 study of >500 patients with imatinib (Gleevec; Novartis)-resistant or –intolerant Ph+ CML with separate cohorts for chronic, accelerated and blast phase disease previously treated with one prior TKI (imatinib) or more than one TKI (imatinib followed by dasatinib [Sprycel; Bristol-Myers Squibb] and/or nilotinib [Tasigna; Novartis]).
The major cytogenetic response (MCyR) at 24 weeks for patients with chronic phase CML who had been previously treated with imatinib only (n=266) was 33.8% (95% CI: 28.2, 39.9). With a minimum follow-up of 23 months, 53.4% of patients achieved a MCyR. Of patients who achieved MCyR, 52.8% had a MCyR lasting at least 18 months. The median duration of MCyR was not reached for these patients.
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The MCyR by 24 weeks for patients with chronic phase CML who had been treated with imatinib and at least one other TKI (n=108) was 26.9% (95% CI: 18.8, 36.2). With a minimum follow-up of 13 months, 32.4% of patients achieved a MCyR. Of patients who achieved MCyR, 51.4% had a MCyR lasting at least nine months. The median duration of MCyR was not reached for these patients.
A low rate of transformation (4%, n=16) from the chronic phase to the advanced or blast phase was also observed in patients treated with Bosulif.
Bosulif is a kinase inhibitor that limits cancer cell growth by inhibiting the Abl and Src signaling pathways. Bosulif is expected to be available mid-September. It will be available as 100mg and 500mg tablets.
For more information, call (800) 438-1985 or visit www.pfizer.com.
This article originally appeared on MPR
