High-dose imatinib mesylate therapy in newly diagnosed Philadelphia chromosome-positive chronic phase chronic myeloid leukemia

Imatinib mesylate (STI571) is effective in chronic phase chronic myelogenous leukemia (CML). However, most patients treated with 400 mg imatinib daily have variable levels of residual molecular disease. We treated 114 patients with newly diagnosed chronic phase CML with 400 mg imatinib twice daily. Overall, 109 patients (96%) had a major cytogenetic response (Philadelphia chromosome [Ph] < 35%), and 103 (90%) had a complete response (Ph 0%). With a median follow-up of 15 months, no patient has progressed to accelerated or blastic phase. The estimated 2-year survival rate was 94%. By quantitative polymerase chain reaction (QPCR) studies, 71 (63%) of 112 patients showed BCR-ABL/ABL percentage ratios decrease to less than 0.05%, and 31 (28%) to undetectable levels. Compared with standard-dose imatinib, high-dose imatinib was associated with significantly better complete cytogenetic response (P =.0005), major molecular response (QPRC < 0.05%; P =.00001), and complete molecular response (undetectable BCR-ABL; P =.001). High-dose imatinib was well tolerated but resulted in more frequent myelosuppression; 82% of patients continue to receive 600 mg or more of imatinib daily. In conclusion, high-dose imatinib induced higher rates of complete cytogenetic response and of molecular response in patients with newly diagnosed chronic phase CML.     

Plasma exposure of imatinib and its correlation with clinical response in the Tyrosine Kinase Inhibitor Optimization and Selectivity Trial

Background

This study evaluates the correlation between imatinib trough plasma concentrations (C_min) and clinical response and safety in patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase in the Tyrosine Kinase Inhibitor OPtimization and Selectivity (TOPS) trial.

Design and Methods

Patients were randomized 1:2 to 400 mg/day or 800 mg/day imatinib. Imatinib C_min levels were collected at pre-dose before treatment, and at the end of months 1 (day 29), 6, 9, and 12.

Results

Imatinib C_min were stable over time in the 400 mg/day dose arm, but showed a slight decrease in the 800 mg/day arm due to dose adjustments between months 1–6. The overall median imatinib C_min levels were 1040, 1200, 1935, and 2690 ng/mL for the actual 300, 400, 600, and 800 mg/day doses, respectively. The rates of major molecular response (MMR) at 3, 6, 9, and 12 months, and complete cytogenetic response (CCyR) at 6 and 12 months were significantly lower among patients with the lowest imatinib C_min levels at Day 29 (<1165 ng/mL, 25^th percentile). There was an apparent association between high imatinib C_min and the occurrence of grade 3/4 neutropenia and all-grade rash, diarrhea, arthralgia/myalgia, and all-cause edema.

Conclusions

Imatinib C_min levels were relatively stable over time and proportional to the dose administered. Patients with an imatinib C_min above 1165 ng/mL on Day 29 achieved MMR faster and had higher MMR and CCyR rates at 12 months. There appeared to be an association between imatinib C_min and the frequency of some adverse events. This trial was registered at http://www.clinicaltrials.gov as {"type":"clinical-trial","attrs":{"text":"NCT00124748","term_id":"NCT00124748"}}NCT00124748.     

Result of high-dose imatinib mesylate in patients with Philadelphia chromosome-positive chronic myeloid leukemia after failure of interferon-alpha

Imatinib at 400 mg daily is effective in chronic-phase chronic myeloid leukemia (CML) after interferon failure, although only a few patients achieve a molecular remission. We investigated whether higher doses of imatinib may be more effective. Thirty-six patients with chronic-phase CML after failure on interferon-alpha were treated with 400 mg imatinib twice daily. Median time from diagnosis was 25 months (range, 10-135 months); 4 patients (11%) had clonal evolution. All 11 patients with active disease achieved complete hematologic response. Excluding patients with fewer than 35% Ph-positive metaphases before the start of therapy, 19 (90%) of 21 evaluable patients achieved a major cytogenetic response. Of 27 evaluable patients, 24 (89%) achieved a complete cytogenetic response. Quantitative polymerase chain reaction was performed in bone marrow every 3 months. Of 32 evaluable patients, 18 (56%) showed BCR-ABL/ABL percentage ratios lower than 0.045%, including 13 (41%) with undetectable levels. With a median follow-up of 15 months, all patients were alive in chronic phase. Toxicities were similar to those reported with standard dose; 71% of patients continue to receive 600 mg or more of imatinib daily. In conclusion, high-dose imatinib induces complete cytogenetic responses in most patients with chronic-phase CML after interferon failure. This is accompanied by a high rate of molecular remission.     

甲磺酸伊马替尼治疗慢性粒细胞白血病附加异常Ph阳性克隆的预后意义

目的探讨甲磺酸伊马替尼（伊马替尼）治疗后慢性粒细胞白血病（CML）具有附加异常的Ph阳性克隆的演变及其预后意义。方法收集37例CML加速期和急变期患者的骨髓标本培养24h,G显带进行核型分析。结果伊马替尼治疗前患者的附加染色体种类主要有双Ph、＋8、i（17q）等,其次还有-Y、除i（17q）外17号的异常、inv（3q）等,以及少见的易位和其他异常。伊马替尼治疗后具有附加异常的Ph阳性克隆比例发生扩增、基本不变、比例下降、完全消失等4种形式的演变。24例加速期患者中有2例获得完全细胞遗传学缓解（CCyR）,13例急变期患者中2例获CCyR。附加异常克隆扩增／不变组的中位生存时间和无疾病进展时间显著短于比例下降／完全消失组（P〈0．05）。结论有附加染色体异常的Ph阳性CML患者伊马替尼治疗后附加异常克隆比例可以下降甚至完全消失,获得CCyR,并伴生存期延长。     

Late response to low-dose imatinib in patients with chronic phase chronic myeloid leukemia

Imatinib was the first BCR-ABL tyrosine kinase inhibitor to become clinically available. In this study, we retrospectively evaluated the long-term efficacy of low-dose imatinib (final maintenance dose <300?mg per day) due to intolerance, in comparison to optimal-dose imatinib (≥300?mg per day) in patients with Philadelphia chromosome-positive chronic myeloid leukemia in the chronic phase. The Kaplan-Meier estimates of the median time to complete cytogenetic response, major molecular response, and complete molecular response were longer for 31 patients receiving low-dose imatinib (360, 1360, and 1420?days, respectively) than 74 patients receiving optimal-dose imatinib (170, 420, and 720?days, respectively). However, the differences in response shrank over time and progression-free survival were comparable between the two groups. These findings suggest that long-term treatment with low-dose imatinib is an acceptable alternative for patients with intolerance to the optimal dose.     

Safety and efficacy of bosutinib (SKI-606) in chronic phase Philadelphia chromosome-positive chronic myeloid leukemia patients with resistance or intolerance to imatinib

Bosutinib, a dual Src/Abl kinase inhibitor, has shown potent activity against chronic myeloid leukemia (CML). In this phase 1/2 study we evaluated bosutinib in patients with chronic phase imatinib-resistant or imatinib-intolerant CML. Part 1 was a dose-escalation study to determine the recommended starting dose for part 2; part 2 evaluated the efficacy and safety of bosutinib 500 mg once-daily dosing. The study enrolled 288 patients with imatinib-resistant (n = 200) or imatinib-intolerant (n = 88) CML and no other previous kinase inhibitor exposure. At 24 weeks, 31% of patients achieved major cytogenetic response (primary end point). After a median follow-up of 24.2 months, 86% of patients achieved complete hematologic remission, 53% had a major cytogenetic response (41% had a complete cytogenetic response), and 64% of those achieving complete cytogenetic response had a major molecular response. At 2 years, progression-free survival was 79%; overall survival at 2 years was 92%. Responses were seen across Bcr-Abl mutants, except T315I. Bosutinib exhibited an acceptable safety profile; the most common treatment-emergent adverse event was mild/moderate, typically self-limiting diarrhea. Grade 3/4 nonhematologic adverse events (> 2% of patients) included diarrhea (9%), rash (9%), and vomiting (3%). These data suggest bosutinib is effective and tolerable in patients with chronic phase imatinib-resistant or imatinib-intolerant CML. This trial was registered at http://www.clinicaltrials.gov as NCT00261846.     

Phase IV study evaluating efficacy of escalated dose of imatinib in chronic myeloid leukemia patients showing suboptimal response to standard dose imatinib

The aim of this phase IV study was to (1) to define efficacy of escalating dose imatinib in chronic myeloid leukemia (CML) patients showing suboptimal response to standard dose imatinib and (2) to find markers that predict the response to escalating doses of imatinib. CML patients in chronic phase (CP) who failed to achieve optimal response with 400 mg/day imatinib or patients in accelerated phase (AP) or blast crisis (BC) who failed to achieve complete hematologic response after 3 months of 400–600 mg/day imatinib were enrolled. CP patients received 600 mg/day, while AP/BC patients received 600–800 mg/day imatinib. Patients received imatinib for at least 12 months or until the disease progression or intolerable toxicity. Along with cytogenetic response (CyR), molecular response was assessed with BCR-ABL/ABL ratio. Baseline BCR-ABL gene mutation test was performed. Seventy-one patients (median age, 49.0 years, M:F?=?50:21) received escalated dose imatinib. Grade 3 edema in two patients was the only nonhematologic toxicities more than grade 2. For evaluable patients, 30.8% of patients achieved CCyR at 6 months, and median time to treatment failure (TTFx) was 18.0 months. TTFx was longer in patients who achieved greater than 50% reduction in BCR-ABL/ABL within 6 months (early molecular responder (EMR)) compared with those who did not (non-EMR; p?<?0.001). Of 31 patients who had mutational status data, three had mutation. All mutants failed to achieve CCyR. In conclusion, escalated dose imatinib shows considerable efficacy with tolerable toxicity in CML patients showing suboptimal response to standard dose imatinib. EMR is an early predictive marker for positive imatinib response.     

SHP-1 expression accounts for resistance to imatinib treatment in Philadelphia chromosome-positive cells derived from patients with chronic myeloid leukemia

We prove that the SH2-containing tyrosine phosphatase 1 (SHP-1) plays a prominent role as resistance determinant of imatinib (IMA) treatment response in chronic myelogenous leukemia cell lines (sensitive/KCL22-S and resistant/KCL22-R). Indeed, SHP-1 expression is significantly lower in resistant than in sensitive cell line, in which coimmunoprecipitation analysis shows the interaction between SHP-1 and a second tyrosine phosphatase SHP-2, a positive regulator of RAS/MAPK pathway. In KCL22-R SHP-1 ectopic expression restores both SHP-1/SHP-2 interaction and IMA responsiveness; it also decreases SHP-2 activity after IMA treatment. Consistently, SHP-2 knocking-down in KCL22-R reduces either STAT3 activation or cell viability after IMA exposure. Therefore, our data suggest that SHP-1 plays an important role in BCR-ABL-independent IMA resistance modulating the activation signals that SHP-2 receives from both BCR/ABL and membrane receptor tyrosine kinases. The role of SHP-1 as a determinant of IMA sensitivity has been further confirmed in 60 consecutive untreated patients with chronic myelogenous leukemia, whose SHP-1 mRNA levels were significantly lower in case of IMA treatment failure (P < .0001). In conclusion, we suggest that SHP-1 could be a new biologic indicator at baseline of IMA sensitivity in patients with chronic myelogenous leukemia.     

XPC genetic polymorphisms correlate with the response to imatinib treatment in patients with chronic phase chronic myeloid leukemia

Chronic myeloid leukemia (CML) is driven by the BCR‐ABL protein, which promotes the proliferation and viability of the leukemic cells. Moreover, BCR‐ABL induces genomic instability that can contribute to the emergence of resistant clones to the ABL kinase inhibitors. It is currently unknown whether the inherited individual capability to repair DNA damage could affect the treatment results. To address this, a comprehensive analysis of single nucleotide polimorfisms (SNPs) on the nucleotide excision repair (NER) genes (ERCC2‐ERCC8, RPA1‐RPA3, LIG1, RAD23B, XPA, XPC) was performed in 92 chronic phase CML patients treated with imatinib upfront. ERCC5 and XPC SNPs correlated with the response to imatinib. Haplotype analysis of XPC showed that the wild‐type haplotype (499C‐939A) was associated with a better response to imatinib. Moreover, the 5‐year failure free survival for CA carriers was significantly better than that of the non‐CA carriers (98% vs. 73%; P = 0.02). In the multivariate logistic model with genetic data and clinical covariates, the hemoglobin (Hb) level and the XPC haplotype were independently associated with the treatment response, with patients having a Hb ≤11 g/dl (Odds ratio [OR] = 5.0, 95% confidence interval [CI] = 1.5–16.1) or a non‐CA XPC haplotype (OR = 4.1, 95% CI = 1.6–10.6) being at higher risk of suboptimal response/treatment failure. Our findings suggest that genetic polymorphisms in the NER pathway may influence the results to imatinib treatment in CML. Am. J. Hematol., 2010. © 2010 Wiley‐Liss, Inc.     

Phase 1/2 clinical study of dasatinib in Japanese patients with chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia

A phase 1/2 study was conducted to assess the safety and efficacy of dasatinib in Japanese patients with chronic myelogenous leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL) resistant or intolerant to imatinib. In phase 1, 18 patients with chronic phase (CP) CML were treated with dasatinib 50, 70, or 90 mg twice daily to evaluate safety. Dasatinib ≤ 90 mg twice daily was well tolerated. In phase 2, dasatinib 70 mg was given twice daily to CP-CML patients for 24 weeks and to CML patients in accelerated phase (AP)/blast crisis (BC) or Ph⁺ ALL for 12 weeks. In the CP-CML group (n = 30) complete hematologic response was 90% and major cytogenetic response (MCyR) 53%. In the AP/BC-CML group (n = 11) major hematologic response (MaHR) was 64% and MCyR 27%, whereas in the Ph⁺ ALL group (n = 13) MaHR was 38% and MCyR 54%. Dasatinib was well tolerated and most of the nonhematologic toxicities were mild or moderate. Dasatinib therapy resulted in high rates of hematologic and cytogenetic response, suggesting that dasatinib is promising as a new treatment for Japanese CML and Ph⁺ ALL patients resistant or intolerant to imatinib.     

A scoring system to predict molecular responses in patients with chronic myeloid leukemia in the chronic phase receiving initial imatinib therapy

<正>Objective To develop a scoring system to predict molecular responses in patients with chronic myeloid leukemia in the chronic phase(CML-CP) receiving initial imatinib therapy.Methods Data from consecutive adults with newly diagnosed CML-CP treated by initial imatinib was interrogated and subjects were distributed randomly into training and validation cohort,in a ratio of2:1.Fine-gray models were applied in the training cohort to identify co-variates of predictive value for major molecul...     

Seven-year response to imatinib as initial treatment versus re-treatment in Chinese patients with chronic myelogenous leukemia in the chronic phase

The purpose of our study is to compare the 7-year response to imatinib monotherapy as an initial treatment and re-treatment in Chinese patients with chronic myelogenous leukemia-chronic phase (CML-CP) patients in a single center in Beijing. A retrospective study of 171 CML-CP patients receiving imatinib monotherapy was done with 73 in the initial treatment group (disease course ??6?months) and 98 in the re-treatment group (disease course >6?months). Cumulative rates of complete cytogenetic response (CCyR) at 6, 12, and 36?months after imatinib treatment in the initial and re-treatment groups were 75%, 89%, and 96%, and 48%, 77% and 84% (p?=?0.0002), respectively. The median time to CCyR in the initial and re-treatment groups was 6?months (95% CI, 3.3?C8.3) and 9?months (95% CI, 6.4?C11.6), respectively (p?=?0.0002). Cumulative rates of major molecular responses at 9, 12, and 18?months after imatinib treatment in the initial and re-treatment groups were 31%, 48%, and 60%, and 15%, 25% and 37% (p?=?0.017), respectively. The median time to the major molecular response in the initial and re-treatment groups was 15?months (95% CI, 12.3?C17.7) and 36?months (95% CI, 25.9?C46.0), respectively (p?=?0.017). Progression-free survival at 84?months in the initial and re-treatment groups was 97% and 85%, respectively (p?=?0.09). Event-free survival at 84?months in the initial and re-treatment groups was 92% and 70%, respectively (p?=?0.049). Only two of the 171 patients discontinued imatinib therapy for grade 3/4 adverse events. Our study revealed that CML-CP patients would benefit from early treatment with imatinib.     

Chromosomal abnormalities in Philadelphia chromosome negative metaphases appearing during imatinib mesylate therapy in patients with newly diagnosed chronic myeloid leukemia in chronic phase

The development of chromosomal abnormalities (CAs) in the Philadelphia chromosome (Ph)-negative metaphases during imatinib (IM) therapy in patients with newly diagnosed chronic myecloid leukemia (CML) has been reported only anecdotally. We assessed the frequency and significance of this phenomenon among 258 patients with newly diagnosed CML in chronic phase receiving IM. After a median follow-up of 37 months, 21 (9%) patients developed 23 CAs in Ph-negative cells; excluding -Y, this incidence was 5%. Sixteen (70%) of all CAs were observed in 2 or more metaphases. The median time from start of IM to the appearance of CAs was 18 months. The most common CAs were -Y and + 8 in 9 and 3 patients, respectively. CAs were less frequent in young patients (P = .02) and those treated with high-dose IM (P = .03). In all but 3 patients, CAs were transient and disappeared after a median of 5 months. One patient developed acute myeloid leukemia (associated with - 7). At last follow-up, 3 patients died from transplantation-related complications, myocardial infarction, and progressive disease and 2 lost cytogenetic response. CAs occur in Ph-negative cells in a small percentage of patients with newly diagnosed CML treated with IM. In rare instances, these could reflect the emergence of a new malignant clone.     

A phase I study of danusertib (PHA-739358) in adult patients with accelerated or blastic phase chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia resistant or intolerant to imatinib and/or other second generation c-ABL therapy

Danusertib is a pan-aurora kinase inhibitor with potent activity against Abl kinase including the gatekeeper T315I mutant. A phase 1 dose escalation study of danusertib was conducted in patients with accelerated or blastic phase chronic myeloid leukemia or Philadelphia chromosome-positive acute lymphoblastic leukemia. Two dosing schedules were studied: schedule A, in which danusertib was given by 3-hour intravenous infusion daily for 7 consecutive days (days 1–7) in a 14-day cycle, and schedule B, in which the danusertib was given by 3-hour intravenous infusion daily for 14 consecutive days (days 1–14) in a 21-day cycle. A total of 37 patients were treated, 29 with schedule A and eight with schedule B. The recommended phase 2 dose for schedule A was 180 mg/m². Enrollment to schedule B was stopped early because of logistical problems with the frequency of infusions. Febrile neutropenia and mucositis were dose-limiting toxicities in schedule A. Four patients with T315I ABL kinase mutation, all treated with schedule A, responded. Danusertib has an acceptable toxicity profile and is active in patients with Bcr-Abl-associated advanced hematologic malignancies. This study was registered with the European Clinical Trails Data Base (EudraCT number 2007-004070-18).     

Nilotinib (formerly AMN107), a highly selective BCR-ABL tyrosine kinase inhibitor, is effective in patients with Philadelphia chromosome-positive chronic myelogenous leukemia in chronic phase following imatinib resistance and intolerance

Nilotinib, an orally bioavailable, selective Bcr-Abl tyrosine kinase inhibitor, is 30-fold more potent than imatinib in pre-clinical models, and overcomes most imatinib resistant BCR-ABL mutations. In this phase 2 open-label study, 400 mg nilotinib was administered orally twice daily to 280 patients with Philadelphia chromosome-positive (Ph(+)) chronic myeloid leukemia in chronic phase (CML-CP) after imatinib failure or intolerance. Patients had at least 6 months of follow-up and were evaluated for hematologic and cytogenetic responses, as well as for safety and overall survival. At 6 months, the rate of major cytogenetic response (Ph < or = 35%) was 48%: complete (Ph = 0%) in 31%, and partial (Ph = 1%-35%) in 16%. The estimated survival at 12 months was 95%. Nilotinib was effective in patients harboring BCR-ABL mutations associated with imatinib resistance (except T315I), and also in patients with a resistance mechanism independent of BCR-ABL mutations. Adverse events were mostly mild to moderate, and there was minimal cross-intolerance with imatinib. Grades 3 to 4 neutropenia and thrombocytopenia were observed in 29% of patients; pleural or pericardial effusions were observed in 1% (none were severe). In summary, nilotinib is highly active and safe in patients with CML-CP after imatinib failure or intolerance. This clinical trial is registered at http://clinicaltrials.gov as ID no. NCT00109707.