Dasatinib vs. imatinib in patients with chronic myeloid leukemia in chronic phase (CML-CP) who have not achieved an optimal response to 3 months of imatinib therapy: the DASCERN randomized study.

Early molecular response is associated with improved probability of deep molecular response and superior survival in patients with CML-CP. However, ~1 in 3 patients on first-line imatinib do not achieve this threshold. The phase 2b DASCERN trial (NCT01593254) assessed the outcome of early switch to dasatinib in patients with suboptimal response to first-line imatinib. Adult patients with CML-CP were randomized (2:1) to receive 100 mg dasatinib (n = 174) or continue imatinib at ≥400 mg (n = 86). The primary endpoint was the rate of major molecular response (MMR) at 12 months, which was 29% (dasatinib) and 13% (imatinib; P = 0.005). After ≥2 years of follow-up, 45 patients (52%) randomized to continue imatinib had crossed over to dasatinib. Considering treatment crossover, the 2-year cumulative MMR rate was 64% with dasatinib and 41% with imatinib (66% and 67%, respectively by intent-to-treat). Adverse events were consistent with the established safety profiles of both drugs. The results of this first prospective study support early monitoring of patients treated with first-line imatinib, and suggest that switching to dasatinib in cases of suboptimal response may offer clinical benefit. Further follow-up is needed to assess the long-term clinical benefit of early switching.

Phase II study of the halichondrin B analog eribulin mesylate in patients with locally advanced or metastatic breast cancer previously treated with an anthracycline, a taxane, and capecitabine.

PURPOSE: The activity and safety of eribulin mesylate (E7389), a nontaxane microtubule dynamics inhibitor with a novel mechanism of action, were evaluated in patients with locally advanced or metastatic breast cancer previously treated with an anthracycline, taxane, and capecitabine. PATIENTS AND METHODS: Eligible patients in this single-arm, open-label phase II study received eribulin mesylate (1.4 mg/m(2)) administered as a 2- to 5-minute intravenous infusion on days 1 and 8 of a 21-day cycle. The primary end point was objective response rate (ORR) assessed by independent review. RESULTS: Of 299 enrolled patients who had received a median of four prior chemotherapy regimens, 291 received eribulin (for a median of four cycles). Of these, 269 patients met key inclusion criteria for the primary efficacy analysis. The primary end point of ORR by independent review was 9.3% (95% CI, 6.1% to 13.4%; all partial responses [PRs]), the stable disease (SD) rate was 46.5%, and clinical benefit rate (complete response + PR + SD > or = 6 months) was 17.1%. The investigator-reported ORR was 14.1% (95% CI, 10.2% to 18.9%). Median duration of response was 4.1 months, and progression-free survival was 2.6 months. Median overall survival was 10.4 months. The most common treatment-related grade 3 or 4 toxicities were neutropenia (54%; febrile neutropenia, 5.5%), leukopenia (14%), and asthenia/fatigue (10%; no grade 4); grade 3 neuropathy occurred in 6.9% of patients (no grade 4). CONCLUSION: Eribulin demonstrated antitumor activity in extensively pretreated patients who had previously received an anthracycline, taxane, and capecitabine, with a manageable tolerability profile.