Xiaolin Fan

Early molecular response predicts outcomes in patients with chronic myeloid leukemia in chronic phase treated with frontline nilotinib or imatinib

We explored the impact of early molecular response (EMR; BCR-ABL ≤10% on the international scale [BCR-ABL(IS)] at 3 or 6 months) on outcomes in patients with newly diagnosed chronic myeloid leukemia in chronic phase treated with nilotinib or imatinib based on 4 years of follow up in Evaluating Nilotinib Efficacy and Safety in Clinical Trials-Newly Diagnosed Patients. Patients (n = 846) received nilotinib 300 mg twice daily, nilotinib 400 mg twice daily, or imatinib 400 mg once daily. At 3 months, more patients had EMR failure (ie, BCR-ABL(IS) >10%) on imatinib (33%) than on nilotinib (9%-11%); similarly at 6 months, 16% of patients in the imatinib arm vs 3% and 7% in the nilotinib arms had EMR failure. In all arms, EMR failure was associated with lower rates of molecular response, an increased risk of progression, and lower overall survival compared with EMR achievement. We also analyzed patient and treatment characteristics associated with EMR and found distinct patterns in the nilotinib arms vs the imatinib arm. High Sokal risk score was associated with a high rate of EMR failure on imatinib, but not on nilotinib. In contrast, reduced dose intensity and dose interruptions were strongly associated with EMR failure in nilotinib-treated, but not imatinib-treated, patients. This study is registered at www.clinicaltrials.gov as #NCT00471497.

Nilotinib in imatinib-resistant or imatinib-intolerant patients with chronic myeloid leukemia in chronic phase: 48-month follow-up results of a phase II study

Nilotinib (Tasigna) is a BCR–ABL1 tyrosine kinase inhibitor approved for the treatment of patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (CML-CP) who are newly diagnosed or intolerant of or resistant to imatinib. The 48-month follow-up data for patients with CML-CP treated with nilotinib after imatinib resistance or intolerance on an international phase II study were analyzed. Overall, 59% of patients achieved major cytogenetic response; 45% achieved complete cytogenetic response while on study. The estimated rate of overall survival (OS) and progression-free survival (PFS) at 48 months was 78% and 57%, respectively. Deeper levels of molecular responses at 3 and 6 months were highly positively correlated with long-term outcomes, including PFS and OS at 48 months. Of the 321 patients initially enrolled in the study, 98 (31%) were treated for at least 48 months. Discontinuations were primarily due to disease progression (30%) or adverse events (21%). Nilotinib is safe and effective for long-term use in responding patients with CML-CP who are intolerant of or resistant to imatinib. Further significant improvements in therapy are required for patients who are resistant or intolerant to imatinib.

Nilotinib is associated with a reduced incidence of BCR-ABL mutations vs imatinib in patients with newly diagnosed chronic myeloid leukemia in chronic phase

In patients with chronic myeloid leukemia, BCR-ABL mutations contribute to resistance to tyrosine kinase inhibitor therapy. We examined the occurrence of treatment-emergent mutations and their impact on response in patients from the ENESTnd phase 3 trial. At the 3-year data cutoff, mutations were detected in approximately twice as many patients (21) on imatinib 400 mg once daily as on nilotinib (11 patients each on nilotinib 300 mg twice daily and nilotinib 400 mg twice daily). The majority of mutations occurred in patients with intermediate or high Sokal scores. Most mutations (14 [66.7%]) emerging during imatinib treatment were imatinib-resistant and nilotinib-sensitive. Incidence of the T315I mutation was low (found in 3, 2, and 3 patients on nilotinib 300 mg twice daily, nilotinib 400 mg twice daily, and imatinib, respectively) and mostly occurred in patients with high Sokal scores. Of the patients with emergent mutations, 1 of 11, 2 of 11, and 7 of 21 patients on nilotinib 300 mg twice daily, nilotinib 400 mg twice daily, and imatinib, respectively, progressed to accelerated phase/blast crisis (AP/BC) on treatment. Overall, nilotinib led to fewer treatment-emergent BCR-ABL mutations than imatinib and reduced rates of progression to AP/BC in patients with these mutations. (Clinicaltrials.gov NCT00471497).

Safety and efficacy of switching to nilotinib 400 mg twice daily for patients with chronic myeloid leukemia in chronic phase with suboptimal response or failure on front-line imatinib or nilotinib 300 mg twice daily

In a randomized, phase III trial of nilotinib versus imatinib in patients with newly diagnosed Philadelphia chromosome positive chronic myeloid leukemia in chronic phase, more patients had suboptimal response or treatment failure on front-line imatinib than on nilotinib. Patients with suboptimal response/treatment failure on imatinib 400 mg once or twice daily or nilotinib 300 mg twice daily could enter an extension study to receive nilotinib 400 mg twice daily. After a 19-month median follow up, the safety profile of nilotinib 400 mg twice daily in patients switching from imatinib (n=35) was consistent with previous reports, and few new adverse events occurred in patients escalating from nilotinib 300 mg twice daily (n=19). Of patients previously treated with imatinib or nilotinib 300 mg twice daily, respectively, 15 of 26 (58%) and 2 of 6 (33%) without complete cytogenetic response at extension study entry, and 11 of 34 (32%) and 7 of 18 (39%) without major molecular response at extension study entry, achieved these responses at any time on nilotinib 400 mg twice daily. Estimated 18-month rates of freedom from progression and overall survival after entering the extension study were lower for patients switched from imatinib (85% and 87%, respectively) versus nilotinib 300 mg twice daily (95% and 94%, respectively). Nilotinib dose escalation was generally well tolerated and improved responses in about one-third of patients with suboptimal response/treatment failure. Switch to nilotinib improved responses in some patients with suboptimal response/treatment failure on imatinib, but many did not achieve complete cytogenetic response (clinicaltrials.gov identifiers:00718263, 00471497 - extension).

Phase II study of nilotinib in patients with relapsed or refractory Philadelphia chromosome—positive acute lymphoblastic leukemia

Phase II study of nilotinib in patients with relapsed or refractory Philadelphia chromosome—positive acute lymphoblastic leukemia