This study assessed the relevance of 2013 European LeukaemiaNet (ELN) response categories on patients treated with common frontline tyrosine kinase inhibitors (TKI) in chronic myeloid leukaemia in chronic phase (CML-CP). Four hundred and eighty-seven patients treated with imatinib (400 mg; IM 400, n = 70; 800 mg; IM800, n = 201), dasatinib (n = 107) or nilotinib (n = 109) were analysed. Intention to treat (ITT) analysis indicated that the proportion of patients falling into optimal, warning and failure ELN categories were 89%, 6%, 6% at 3 months, 78%, 17% and 6% at 6 months, and 75%, 13% and 13% at 12 months, respectively. Rates of optimal response at 3 months were 75% for IM400, 90% for IM800, 89% for dasatinib and 97% for nilotinib; 41%, 80%, 86% and 89% at 6 months; and 47%, 77%, 76% and 87% at 12 months, respectively. Patients achieving optimal response had longer eventfree (EFS), failurefree (FFS), transformationfree (TFS) and overall survival (OS) compared to warning and failure responses at all-time points. Treatment with imatinib 800, dasatinib or nilotinib predicted for achieving an optimal response. Optimal response predicted for significantly longer EFS, FFS, TFS and OS at 3, 6 and 12 months, irrespective of the TKI modality used. ELN response categories reliably predicted outcomes in CML patients receiving commonly used TKIs.

Background

Several tyrosine kinase inhibitors (TKIs) are available for treatment of patients with chronic myeloid leukaemia in chronic phase (CML-CP). We analysed long-term molecular and cytogenetic response and survival outcomes for four TKI modalities used as frontline therapy for CML-CP.

Methods

In a retrospective cohort analysis, we included data from patients with CML-CP treated in prospective clinical trials with frontline TKI modalities at a single institution between July 31, 2000, and Sept 10, 2013. The main aim of the study was to determine whether achievement of complete cytogenetic response or major molecular response had similar prognostic implications irrespective of the frontline TKI modality used. We analysed each TKI modality for response assessment and analysed survival endpoints (event-free, failure-free, transformation-free, and overall survival) with the Kaplan-Meier method. Univariate and multivariate analyses were done with Cox proportional hazard regression.

Findings

Our analysis included 482 patients who were treated with imatinib 400 mg daily (n=68), imatinib 800 mg daily (n=200), dasatinib 50 mg twice daily or 100 mg daily (n=106), or nilotinib 400 mg twice daily (n=108). More patients receiving imatinib 800 mg or second-generation TKIs (ie, dasatinib or nilotinib) achieved complete cytogenetic response (58 [87%] of 67 for imatinib 400 mg vs 180 [90%] of 199 for imatinib 800 mg, vs 100 [96%] of 104 for dasatinib vs 99 [93%] of 107 for nilotinib), major molecular response (51 [76%] vs 171 [86%] vs 93 [90%] vs 97 [91%]), and 4·5 log or higher reduction in BCR-ABL transcripts (MR(4·5) response 38 [57%] vs 148 [74%] vs 76 [71%] vs 76 [71%]). This finding was consistent over time (3-60 months). 5-year event free survival significantly differed between the imatinib 400 mg group and the other TKI groups (imatinib 800 mg p=0·029, dasatinib p=0·003, nilotinib p=0·031). There was no significant difference in 5-year failure-free survival (p=0·32, p=0·075, p=0·332), transformation-free survival (p=0·053, p=0·038, p=0·493), or overall survival (p=0·563, p=0·162, p=0·981). Multivariate analysis showed that therapy with imatinib 800 mg (HR 0·51, 95% CI 0·29-0·88, p=0·016), dasatinib (0·28, 0·12-0·66, p=0·004), or nilotinib (0·42, 0·20-0·89, p=0·024) predicted for better event-free survival compared with imatinib 400 mg, but that failure-free, transformation-free, and overall survival were similar irrespective of the TKI used. 28 (41%) patients receiving imatinib 400 mg, 85 (43%) receiving imatinib 800 mg, 23 (21%) receiving dasatinib, and 27 (25%) receiving nilotinib discontinued treatment for any reason.

Interpretation

Treatment with imatinib 800 mg or the second-generation TKIs dasatinib or nilotinib resulted in superior and deeper responses than did standard-dose imatinib, which were maintained after 5 years of follow-up. Results with imatinib 800 mg were similar to those with second-generation TKIs, although more patients discontinued therapy.

Funding

MD Anderson Cancer Center, National Cancer Institute.

BACKGROUND: Nilotinib is a potent, second-generation inhibitor of BCR-ABL1 tyrosine kinase and has been approved as frontline and salvage therapy for patients with chronic-phase chronic myeloid leukemia (CP-CML). METHODS: In this single-institution, phase 2 study, 122 patients with newly diagnosed CP-CML received nilotinib 400 mg twice daily. The median follow-up on study was 78.3 months (interquartile range, 58.4-96.5 months). RESULTS: Fifty-six percent of patients remained on therapy at the last follow-up. Both the complete cytogenetic response rate and the major molecular response (MR) rate were 91%. Seventy-five percent and 59% of patients achieved a ≥4.5-log reduction in BCR-ABL1 transcripts (MR4.5) and a sustained MR4.5 beyond 2 years, respectively. The estimated event-free survival and overall survival rates at 5 years were 89% and 93%, respectively, and the corresponding rates at 10 years were 85% and 88%, respectively. Treatment discontinuation due to toxicity occurred in 19% of patients, mostly because of cardiovascular events (10%) and biochemical abnormalities (6%). The top 3 nonhematologic toxicities were rash (55%), elevated bilirubin (57%), and elevated aminotransferases (48%). Hematologic toxicity was transient and mild. Ischemic cardiovascular adverse events occurred in 8% of patients. Four patients (3%) progressed to accelerated or blast phase while on therapy, and 7 patients (6%) died on study. CONCLUSIONS: The current data confirm the long-term efficacy of nilotinib 400 mg twice daily in patients with CP-CML. A majority of patients can achieve sustained MR4.5.

Background

Outcomes in patients with chronic myeloid leukemia in blast phase (CML-BP) are historically dismal. Herein, the authors sought to analyze the characteristics, prognostic factors, and survival outcomes in patients with CML-BP in the tyrosine kinase inhibitor (TKI) era.

Methods

A total of 477 patients with CML-BP were treated with a TKI at some point during the course of their CML. Cox proportional hazard models identified characteristics that were predictive of survival. Overall survival and failure-free survival were assessed. Optimal cutoff points for specific parameters were identified using classification and regression tree (CART) analysis.

Results

The median age of the patients was 53 years (range, 16-84 years) and 64% were male. Approximately 80% of patients initially were diagnosed in the chronic phase of CML at a median of 41 months (range, 0.7-298 months) before transformation to CML-BP. De novo CML-BP occurred in 71 patients. Approximately 72% of patients received TKI therapy before CML-BP. The initial therapy for CML-BP included a TKI alone (35%), a TKI with chemotherapy (46%), and non-TKI therapies (19%). The median overall survival was 12 months and the median failure-free survival was 5 months. In multivariate analysis, myeloid immunophenotype, prior TKI, age ≥58 years, lactate dehydrogenase level ≥1227 IU/L, platelet count < 102 K/μL, no history of stem cell transplantation, transition to BP from chronic phase/accelerated phase, and the presence of chromosome 15 aberrations predicted for a significantly increased risk of death. Achievement of major hematologic response and/or complete cytogenetic response to first-line treatment was found to be predictive of better survival. The combination of a TKI with intensive chemotherapy followed by stem cell transplantation appeared to confer the best outcome.

Conclusions

Patients with CML-BP continue to pose a therapeutic challenge, have dismal outcomes, and require newer treatment approaches. Cancer 2017;123:4391-402. © 2017 American Cancer Society.

Background

Outcomes in patients with chronic myeloid leukemia in blast phase (CML-BP) are historically dismal. Herein, the authors sought to analyze the characteristics, prognostic factors, and survival outcomes in patients with CML-BP in the tyrosine kinase inhibitor (TKI) era.

Methods

A total of 477 patients with CML-BP were treated with a TKI at some point during the course of their CML. Cox proportional hazard models identified characteristics that were predictive of survival. Overall survival and failure-free survival were assessed. Optimal cutoff points for specific parameters were identified using classification and regression tree (CART) analysis.

Results

The median age of the patients was 53 years (range, 16-84 years) and 64% were male. Approximately 80% of patients initially were diagnosed in the chronic phase of CML at a median of 41 months (range, 0.7-298 months) before transformation to CML-BP. De novo CML-BP occurred in 71 patients. Approximately 72% of patients received TKI therapy before CML-BP. The initial therapy for CML-BP included a TKI alone (35%), a TKI with chemotherapy (46%), and non-TKI therapies (19%). The median overall survival was 12 months and the median failure-free survival was 5 months. In multivariate analysis, myeloid immunophenotype, prior TKI, age ≥58 years, lactate dehydrogenase level ≥1227 IU/L, platelet count < 102 K/μL, no history of stem cell transplantation, transition to BP from chronic phase/accelerated phase, and the presence of chromosome 15 aberrations predicted for a significantly increased risk of death. Achievement of major hematologic response and/or complete cytogenetic response to first-line treatment was found to be predictive of better survival. The combination of a TKI with intensive chemotherapy followed by stem cell transplantation appeared to confer the best outcome.

Conclusions

Patients with CML-BP continue to pose a therapeutic challenge, have dismal outcomes, and require newer treatment approaches. Cancer 2017;123:4391-402. © 2017 American Cancer Society.