Incidence of second malignancies in patients with chronic myeloid leukemia in the era of tyrosine kinase inhibitors.

Patients with chronic myeloid leukemia (CML) treated with tyrosine kinase inhibitors (TKIs) have near-normal life expectancies. With this comes the possibility of developing second cancers; we aimed to evaluate the incidence of second malignancies in patients with CML using Surveillance, Epidemiology, and End Results Program data. We identified 13,276 patients with CML newly diagnosed in 2001-2014. Patients who had prior history of cancer, a concurrent diagnosis of other malignancies in the same diagnostic year, or a second leukemia after CML diagnosis were excluded. Second malignancies were observed in 597 patients (4%) with a median follow-up of 69 months. The 5- and 10-year cumulative incidences of death for all patients were 30.5% and 41.8%. The 5- and 10-year cumulative incidences of second malignancies were 4.4% and 7.2%, respectively. The overall standardized incidence ratio (SIR) was 1.204. Increased SIRs compared to the general population were observed for the male genital system, 1.593; digestive system, 1.291; skin, 1.588; and urinary system, 1.366. Overall excess absolute risk was 1.714 per 1000 person-years at risk. Our results suggest that relative incidence of overall second malignancies in CML is slightly higher than that of the general population, with minimal increase in the excess absolute risk.

Tyrosine kinase inhibitor discontinuation in patients with chronic myeloid leukemia: a single-institution experience.

BACKGROUND: Patients with CML treated with TKI can have a life expectancy comparable to that of the general population. Due to the extended duration of TKI administration, treatment discontinuation has been increasingly sought. METHODS: Medical records of 100 patients with CML who were in MR4.5 and discontinued their TKI outside clinical trials were reviewed. RESULTS: After a median follow-up of 30 months (range, 5-112 months) after discontinuation, 35% and 17% lost MR4.5 and major molecular response (MMR), respectively. Only six patients lost MMR 12 months or more after discontinuation. Loss of MR4.5 was observed in 29% and 7% of patients with sustained MR4.5 duration of more than 2 and 6 years before discontinuation, respectively. By univariate analysis, there was a higher risk of loss of MR4.5 for patients who were treated for less than 87 months, received second or subsequent line TKI, never received interferon, or those with sustained MR4.5 for less than 6 years. By multivariate analysis, sustained MR4.5 for 6 years or more was the only significant predictor for durable response. Overall, 30% of patients who discontinued while in MR4.5 were retreated with 93% regaining MR4.5 at a median of 5 months. CONCLUSION: These results demonstrate that under proper conditions, treatment discontinuation is feasible outside of clinical trial setting. MR4.5 duration of 6 years or more before discontinuation is associated with very low risk of loss of MR4.5.

Characteristics and outcome of chronic myeloid leukemia patients with E255K/V BCR-ABL kinase domain mutations.

Kinase domain (KD) mutations of ABL1 represent the most common resistance mechanism to tyrosine kinase inhibitors (TKI) in CML. Besides T315I, mutations in codon 255 are highly resistant mutations in vitro to all TKI. We aimed to study the incidence, prognosis, and response to treatment in patients with E255K/V. We evaluated 976 patients by sequencing of BCR-ABL1 fusion transcript for ABL1 KD mutations. We identified KD mutations in 381 (39%) patients, including E255K/V in 48 (13% of all mutations). At mutation detection, 14 patients (29%) were in chronic phase (CP), 12 (25%) in accelerated phase (AP), and 22 (46%) in blast phase (BP). 9/14 CP patients responded to treatment (best response complete hematologic response-CHR-4; complete cytogenetic response-CCyR-1; major molecular response-MMR-4); only 4/12 AP patients (CHR 3; MMR 1) and 7/22 BP patients responded (CCyR 2; MMR 2; partial cytogenetic response-PCyR-3). After a median follow-up of 65 months from mutation detection, 36 patients (75%) died: 9/14 (64%) in CP, 9/12 (75%) in AP, and 18/22 (82%) in BP (p = 0.003); median overall survival was 12 months. Patients with E255K/V mutation have a poor prognosis, regardless of the stage of the disease at detection.

Prediction for sustained deep molecular response of BCR-ABL1 levels in patients with chronic myeloid leukemia in chronic phase.

BACKGROUND: The achievement of a sustained deep molecular response is a goal of increasing relevance because it opens the possibility of treatment discontinuation. The objective of this analysis was to develop a prediction model for a sustained molecular response with BCR-ABL1 level <0.0032% on the international scale (MR4.5 ) for at least 2 years according to BCR-ABL1 levels achieved within the first 12 months of therapy. METHODS: Data for 603 patients with newly diagnosed chronic myeloid leukemia in chronic phase in consecutive prospective clinical trials were analyzed. The best fit average molecular response was defined by robust linear regression models, with which the average molecular levels were defined. The minimum acceptable molecular response was defined by quantile regression for the 95th percentile, with which the worst 5% BCR-ABL1 levels were identified. RESULTS: In 603 patients with a median follow-up of 103 months, 2002 BCR-ABL1-level data points within 1 year of tyrosine kinase inhibitors were identified. The regression equation for the best fit average levels for a sustained MR4.5 was Log10 (PCR) = -0.1424 × (Months) - 0.8668, and the regression equation for minimum acceptable levels was Log10 (PCR) = -0.1403 × (Months) + 0.6142 (where PCR indicates polymerase chain reaction). To achieve a sustained MR4.5 , the best fit average levels were 0.051%, 0.019%, 0.007%, and 0.003% at 3, 6, 9, and 12 months, respectively; the minimum acceptable levels were 1.561%, 0.592%, 0.225%, and 0.085% at 3, 6, 9, and 12 months, respectively. CONCLUSIONS: This model proposes optimal values that predict the highest probability of reaching such a goal. These values can be used to guide therapy when a sustained MR4.5 is the objective. Cancer 2018;124:1160-8. © 2017 American Cancer Society.

Clonal chromosomal abnormalities appearing in Philadelphia chromosome-negative metaphases during CML treatment.

Clonal chromosomal abnormalities in Philadelphia chromosome-negative (CCA/Ph-) metaphases emerge as patients with chronic phase chronic myeloid leukemia (CP-CML) are treated with tyrosine kinase inhibitors (TKIs). We assessed the characteristics and prognostic impact of 598 patients with CP-CML treated on clinical trials with various TKIs. CCA/Ph- occurred in 58 patients (10%); the most common were -Y in 25 (43%) and trisomy 8 in 7 patients (12%). Response to TKI therapy was similar for patients with CCA/Ph- and those without additional chromosomal abnormalities (ACAs). We further categorized CCA/Ph- into those in which -Y was the only clonal abnormality, and all others. We found that patients with non -Y CCA/Ph- had worse failure-free survival (FFS), event-free survival (EFS), transformation-free survival (TFS), and overall survival (OS) compared with those without ACAs with the following 5-year rates: FFS (52% vs 70%, P = .02), EFS (68% vs 86%, P = .02), TFS (76% vs 94%, P < .01), and OS (79% vs 94%, P = .03). In a multivariate analysis, non -Y CCA/Ph- increased the risk of transformation or death when baseline characteristics were considered with a hazard ratio of 2.81 (95% confidence interval, 1.15-6.89; P = .02). However, this prognostic impact was not statistically significant when achieving BCR-ABL <10% at 3 months was included in the analysis. In conclusion, non -Y CCA/Ph- are associated with decreased survival when emerging in patients with chronic-phase CML across various TKIs. This trial was registered at www.clinicaltrials.gov as #NCT00048672, #NCT00038649, and #NCT00050531 (imatinib); #NCT00254423 (dasatinib); #NCT00129740 (nilotinib); and NCT01570868 (ponatinib).

Patient-driven discontinuation of tyrosine kinase inhibitors: single institution experience.

Abstract With improved outcome for patients with chronic myeloid leukemia (CML) treated with tyrosine kinase inhibitors (TKIs), treatment discontinuation has become increasingly attractive to patients. We analyzed the outcomes of patients who chose to discontinue TKI therapy regardless of their ongoing response. Thirty-five patients with chronic phase CML discontinued TKI in complete cytogenetic response. Of them, 51% discontinued due to adverse effects, 23% due to long complete molecular response (CMR) (> 5 years), 9% due to pregnancy and 17% due to financial problems. After TKI discontinuation, patients were followed for a median of 16 months. Among 27 patients (77%) who discontinued TKIs in CMR, 11 (41%) had a molecular relapse after a median of 3.5 months. In univariate analysis we observed that patients with ≥ 64 months of CMR before TKI discontinuation had superior cumulative proportions of sustained CMR and major molecular response (MMR) at 12 months after discontinuation: 88.9% vs. 45.5% (p = 0.02) and 100% vs. 75% (p = 0.05), respectively. Patients treated with high dose imatinib or second generation TKIs had a higher cumulative proportion of sustained MMR at 12 months after discontinuation than patients treated with standard dose imatinib: 100% vs. 72.2% (p = 0.03), respectively. Of the five patients who stopped TKI in MR(4.5) (molecular response of 4.5-log reduction) one lost cytogenetic response. All three patients who discontinued TKIs in MMR lost cytogenetic response; one progressed to accelerated phase. Thirteen patients (37%) restarted TKIs after loss of response: 11 improved their response, and for two it is too early to assess. Treatment discontinuation can lead to sustained CMR in some patients, but risk of relapse is higher if patients discontinue TKIs when not in CMR.

Phase I-II study of bendamustine in patients with acute leukemia and high risk myelodysplastic syndrome.

UNLABELLED: A phase I-II study of bendamustine fractionated twice daily schedule for 4 days identified 75 mg/m(2) intravenously(IV) twice daily for 4 days as a phase II study schedule. BACKGROUND: Alkylating agents have shown activity in leukemia. Bendamustine, an active alkylating agent in lymphoma and chronic lymphocytic leukemia, was given in a fractionated twice daily schedule for 4 days to patients with acute leukemia and myelodysplastic syndrome (MDS) to define the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD). PATIENTS AND METHODS: Adults with refractory acute leukemia or high-risk MDS were treated with bendamustine at a starting dose of 50 mg/m(2) IV over 1-2 hours twice daily for 4 days. Dose escalations were by 25 mg/m(2) in the 1st 3 levels. The study used the 3 + 3 design. RESULTS: A total of 25 patients were treated. Their median age was 57 years; the median salvage number was 3. Grade 2 creatinine elevations were observed in 1 of 6 patients at the 50 mg/m(2) dose, in 2 of 13 patients at the 75 mg/m(2) dose, and in 3 of 6 patients at the 100 mg/m(2) dose. This was considered significant, even though DLT was not reached. One patient achieved marrow complete remission. Significant reductions of marrow blasts (50% or more) were observed in 6 of 25 patients (24%). CONCLUSION: Bendamustine fractionated dose level of 100 mg/m(2) IV twice daily for 4 days (800 mg/m(2) per course) was associated with Grade 2 renal toxicity. The proposed phase II schedule is 75 mg/m(2) IV twice daily for 4 days. Future studies should evaluate this schedule in less heavily treated patients.

Inotuzumab ozogamicin, an anti-CD22-calecheamicin conjugate, for refractory and relapsed acute lymphocytic leukaemia: a phase 2 study.

BACKGROUND: The outlook for patients with refractory and relapsed acute lymphocytic leukaemia (ALL) is poor. CD22 is highly expressed in patients with ALL. Inotuzumab ozogamicin is a CD22 monoclonal antibody conjugated to the toxin calecheamicin. We did a phase 2 study to assess the efficacy of this antibody. METHODS: We recruited patients at the MD Anderson Cancer Center, Houston, TX, USA, between June, 2010, and March, 2011. Adults and children with refractory and relapsed ALL were eligible. Ten adults were treated before enrolment of children started. Patients were given 1·8 mg/m(2) inotuzumab ozogamicin intravenously over 1 h every 3-4 weeks (the first three adults and three children received 1·3 mg/m(2) in the first course). The primary endpoint was overall response (complete response or marrow complete response with no recovery of platelet count or incomplete recovery of neutrophil and platelet counts). Analysis was done by intention to treat. This study is registered, number NCT01134575. FINDINGS: 49 patients were enrolled and treated. Median age was 36 years (range 6-80). CD22 was expressed in more than 50% of blasts in all patients. The median number of courses was two (range one to five) and the median time between courses was 3 weeks (range 3-6). Nine (18%) patients had complete response, 19 (39%) had marrow complete response, 19 (39%) had resistant disease, and two (4%) died within 4 weeks of starting treatment. The overall response rate was 57% (95% CI 42-71). The most frequent adverse events during course one of treatment were fever (grade 1-2 in 20 patients, grade 3-4 in nine), hypotension (grade 1-2 in 12 patients, grade 3 in one), and liver-related toxic effects (bilirubin: grade 1-2 in 12 patients, grade 3 in two; raised aminotransferase concentration: grade 1-2 in 27 patients, grade 3 in one). INTERPRETATION: Inotuzumab ozogamicin shows promise as a treatment for refractory and relapsed ALL. FUNDING: Pfizer.

Improved survival in chronic myeloid leukemia since the introduction of imatinib therapy: a single-institution historical experience.

A total of 1569 patients with chronic myeloid leukemia (CML) referred to our institution within 1 month of diagnosis since 1965 were reviewed: 1148 chronic phase (CP), 175 accelerated phase (AP), and 246 blastic phase (BP). The median survival was 8.9 years in CP, 4.8 years in AP, and 6 months in BP. In CP, the 8-year survival was ≤ 15% before 1983, 42%-65% from 1983-2000, and 87% since 2001. Survival was worse in older patients (P = .004), but this was less significant since 2001 (P = .07). Survival by Sokal risk was significantly different before 2001 (P < .001), but not since 2001 (P = .4). In AP, survival improved over time (P < .001); the 8-year survival in patients treated since 2001 was 75%. Survival by age was not different in years < 2001 (P = .09), but was better since 2001 in patients ≤ 70 years of age (P = .004). In BP, the median survival improved over time (P < .001), although it has been only 7 months since 2001. In summary, survival in CML has significantly improved since 2001, particularly so in CP-AML and AP-CML. Imatinib therapy minimized the impact of known prognostic factors and Sokal risk in CP-CML and accentuated the impact of age in AP- and BP-CML.

Identification of side effects associated with intolerance to BCR-ABL inhibitors in patients with chronic myeloid leukemia.

Clinical intolerance occurs when the toxicity of a medication outweighs its clinical benefit. Early recognition of clinical intolerance to BCR-ABL inhibitors used for chronic myeloid leukemia (CML) is important for maximizing patient benefit. In CML, most side effects associated with BCR-ABL inhibitor therapy are mild and easily managed, so recognizing, monitoring, and addressing serious side effects may ensure optimal outcome. However, a subset of patients will be intolerant to first-line imatinib. Patients who experience unresponsive grade 3 or any grade 4 nonhematologic side effects to imatinib may require discontinuation and switching to second-line therapies, such as dasatinib or nilotinib, after identification of intolerance. The most common side effects associated with dasatinib and nilotinib are hematologic and generally are reversible with dose adjustment. Pleural effusions are more common with dasatinib use and may be managed by dose interruption and reduction. Both drugs possess warnings regarding QT prolongation, but nilotinib carries a black box warning for QT prolongation and sudden death.

Front-line therapy with second-generation tyrosine kinase inhibitors in patients with early chronic phase chronic myeloid leukemia: what is the optimal response?

PURPOSE: The response definitions proposed by the European LeukemiaNet (ELN) are defined on the basis of imatinib front-line therapy. It is unknown whether these definitions apply to patients treated with second-generation tyrosine kinase inhibitors (TKIs). PATIENTS AND METHODS: One hundred sixty-seven patients with newly diagnosed chronic myelogenous leukemia (CML) in chronic phase were treated with second-generation TKIs in phase II trials (nilotinib, 81; dasatinib, 86). Median follow-up was 33 months. Event-free survival (EFS) was measured from the start of treatment to the date of loss of complete hematologic response, loss of complete or major cytogenetic response, discontinuation of therapy for toxicity or lack of efficacy, progression to accelerated or blastic phases, or death at any time. RESULTS: Overall, 155 patients (93%) achieved complete cytogenetic response (CCyR), including 146 (87%) with major molecular response (MMR; complete in 46 patients [28%]). According to the ELN definitions, the rates of suboptimal response were 0%, 2%, 1%, and 12% at 3, 6, 12, and 18 months of therapy, respectively. There was no difference in EFS and CCyR duration between patients who achieved CCyR with and without MMR across all the landmark times of 3, 6, 12, and 18 months. CONCLUSION: The use of second-generation TKIs as initial therapy in CML induces high rates of CCyR at early time points. The ELN definitions of response proposed for imatinib therapy are not applicable in this setting. We propose that achievement of CCyR and partial cytogenetic response at 3 months should be considered optimal and suboptimal responses, respectively. The achievement of MMR offered no advantage over CCyR in defining long-term outcome in patients with newly diagnosed CML treated with second-generation TKIs.

The achievement of an early complete cytogenetic response is a major determinant for outcome in patients with early chronic phase chronic myeloid leukemia treated with tyrosine kinase inhibitors.

We analyzed the association between achievement of early complete cytogenetic response (CCyR) and event-free survival (EFS) and overall survival (OS) in patients with newly diagnosed chronic myeloid leukemia in chronic phase treated with imatinib 400 mg (n = 73), or imatinib 800 mg daily (n = 208), or second- generation tyrosine kinase inhibitors (n = 154). The overall CCyR rates were 87%, 91%, and 96%, respectively (P = .06); and major molecular response (MMR) rates were 77%, 87%, and 89%, respectively (P = .05). Their 3-year EFS rates were 85%, 92%, and 97% (P = .01), and OS rates were 93%, 97%, and 100% (P = .18), respectively. By landmark analysis, patients with 3-, 6-, and 12-month CCyR had significantly better outcome: 3-year EFS rates of 98%, 97%, and 98% and OS rates of 99%, 99%, and 99%, respectively, compared with 83%, 72%, and 67% and 95%, 90%, and 94%, in patients who did not achieve a CCyR. Among patients achieving CCyR at 12 months, the depth of molecular response was not associated with differences in OS or EFS. In conclusion, second tyrosine kinase inhibitors induced higher rates of CCyR and MMR than imatinib. The achievement of early CCyR remains a major determinant of chronic myeloid leukemia outcome regardless of whether MMR is achieved or not.

Malignancies occurring during therapy with tyrosine kinase inhibitors (TKIs) for chronic myeloid leukemia (CML) and other hematologic malignancies.

Success of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML) has given patients hope for a long disease-free-survival. A longer survival raises the question of late effects, including development of another malignancy. Records of 1445 patients with CML/myeloproliferative neoplasm or other hematologic malignancies treated with TKIs were reviewed to investigate frequency and characteristics of second malignancies (other than acute myeloid leukemia, acute lymphocytic leukemia, or myelodysplastic syndrome). The number of second cancers was compared with the number expected from the Surveillance, Epidemiology, and End Results database. After a median follow-up of 107 months (range, 13-362 months) after CML/myeloproliferative neoplasm diagnosis, 66 patients (4.6%) developed 80 second cancers, including skin (31%), prostate (15%), melanoma (13%), digestive system (10%), kidney (4%), thyroid (4%), breast (3%), chronic lymphocytic leukemia (3%), hepatobiliary (3%), and other cancers (14%). Excluding nonmelanoma skin cancers, 55 second cancers were seen in 51 (3.5%) of all patients treated. The risk of second cancer was lower than expected (observed-to-expected ratio, 0.6; 95% confidence interval, 0.44-0.81). Second cancers occur in a small percentage of patients receiving therapy with TKIs for hematologic malignancies, mostly CML. No evidence at the moment suggests that exposure to TKIs increases the risk of developing second cancers.

Predictive factors for outcome and response in patients treated with second-generation tyrosine kinase inhibitors for chronic myeloid leukemia in chronic phase after imatinib failure.

We assessed the predictive factors for outcome and response in 123 patients with chronic myeloid leukemia in chronic phase treated with second-generation tyrosine kinase inhibitors (TKIs) after imatinib failure. Better event-free survival rates with second-generation TKI therapy were associated with a previous cytogenetic response to imatinib (P < .001) and a performance status of 0 (P = .001). Patients with 0, 1, or 2 adverse factors had 2-year event-free survival rates of 78%, 49%, and 20% (P < .001), respectively; 2-year overall survival rates of 95%, 85%, and 40%, (P = .002), respectively; and a 12-month probability of achieving a major cytogenetic response of 64%, 36%, and 20% (P = .007), respectively. In conclusion, patients with poor performance status and no previous cytogenetic response to imatinib therapy have a low likelihood of responding to second-generation TKI with poor event-free survival and therefore should be offered additional treatment options. This scoring system could serve to advise patients of their prognosis and treatment options, as well as to evaluate the benefit of newer alternate options.

A phase I study of pemetrexed in patients with relapsed or refractory acute leukemia.

PURPOSE: To investigate the toxicity profile, activity, pharmacokinetics, and pharmacodynamics of pemetrexed in leukemia. PATIENTS AND METHODS: Patients with refractory or relapsed acute leukemia were eligible. A phase I 3+3 design was implemented. Pemetrexed was infused intravenously (IV) over 25 min with vitamin supplementation. Courses were repeated every 3 to 4 weeks according to toxicity and efficacy. The starting dose of 900 mg/m² was escalated by approximately 33% until the dose-limiting toxicity (DLT) was determined. RESULTS: Twenty patients with acute myeloid (AML) or lymphocytic (ALL) leukemia received therapy. The main non-hematologic adverse event was liver dysfunction at several dose levels, including 2 DLTs at 3,600 mg/m². One patient with ALL (3,600 mg/m² dose level) achieved a partial response. Pemetrexed pharmacokinetics were linear with escalated dosing. Elevated plasma deoxyuridine was observed in a subset of patients following pemetrexed infusion, but was not correlated with dose levels. Changes in the nucleotide pools of circulating mononuclear cells were observed, but were variable. CONCLUSIONS: The recommended phase II dose of pemetrexed for future leukemia studies is 2,700 mg/m(2) IV over 25 min every 3 to 4 weeks with vitamin supplementation. Deoxyuridine levels did not increase with increasing pemetrexed dose, suggesting pemetrexed inhibition of thymidylate synthase (TS) may be saturated by the 900 mg/m² dose level. However, no firm conclusion can be made regarding TS saturation in tumor cells. While tolerable, pemetrexed monotherapy had limited activity in this highly refractory population. Exploration of pemetrexed in combination with other active agents in leukemia is a reasonable future endeavor.

Imatinib front-line therapy is safe and effective in patients with chronic myelogenous leukemia with pre-existing liver and/or renal dysfunction.

BACKGROUND: Imatinib 400 mg daily is the standard treatment for patients with chronic myelogenous leukemia (CML). The safety and efficacy of imatinib in CML patients with pre-existing liver and/or renal dysfunction has not been analyzed. METHODS: The authors analyzed the outcome of 259 patients with early chronic phase CML treated with imatinib (starting dose 400 mg in 50, 800 mg in 209). Pre-existing liver and/or renal dysfunction was seen in 38 (15%) and 11 (4%) patients, respectively. RESULTS: Dose reductions were required in 91 (43%) of 210 patients with normal organ function, compared with 8 (73%) of 11 (P = .065) with renal dysfunction, and 19 (50%) of 38 (P = .271) with liver dysfunction. Grade 3-4 hematologic toxicities including anemia (29%, 10%, and 7% of patients with renal dysfunction, liver dysfunction, and normal organ function, respectively), neutropenia (57%, 30%, and 30%), and thrombocytopenia (43%, 30%, and 26%) were more frequent in patients with pre-existing renal dysfunction treated with high-dose imatinib. Grade 3-4 nonhematologic toxicities were observed at similar frequencies. Complete cytogenetic response rates, event-free survival, and overall survival were similar in all groups. CONCLUSIONS: Although patients with pre-existing liver and/or renal dysfunction might have a higher rate of hematologic toxicity and require more frequent dose reductions, most patients can be adequately managed, resulting in response rates and survival similar to those without pre-existing organ dysfunction.

Significance of increasing levels of minimal residual disease in patients with Philadelphia chromosome-positive chronic myelogenous leukemia in complete cytogenetic response.

PURPOSE: The aim of this study was to evaluate the clinical relevance of increases in quantitative polymerase chain reaction (QPCR) levels in patients with chronic myelogenous leukemia (CML) who are in complete cytogenetic response (CGCR) on therapy. Patients with Philadelphia chromosome (Ph)-positive CML receiving tyrosine kinase inhibitors (TKIs) are frequently monitored for response by QPCR studies for minimal molecular disease. The clinical significance of increasing levels of QPCR in patients in CGCR is uncertain. PATIENTS AND METHODS: One hundred sixteen patients in durable CGCR, and on imatinib therapy for at least 18 months, had increases in QPCR levels (documented at least twice consecutively) as defined by literature reports. These were further analyzed by the achievement of major molecular response (MMR) defined as QPCR < or = 0.05%, as well as by the degree of increase in QPCR. RESULTS: Only 11 (9.5%) of 116 patients with increases in QPCR had CML progression; 10 of them were among 44 patients (23%) who either lost a MMR or never had a MMR, and had more than 1 log increase of QPCR. CONCLUSION: Most patients with increases in QPCR remain in CGCR. Patients who lose a MMR or never achieve a MMR, and have more than 1 log increase of QPCR, should be monitored more closely, and may be evaluated for mutations of BCR-ABL kinase domain and considered for investigational therapeutic interventions.

Chronic myeloid leukemia (CML) with P190 BCR-ABL: analysis of characteristics, outcomes, and prognostic significance.

The most common BCR-ABL transcripts in chronic myeloid leukemia (CML) are e13a2(b2a2) and e14a2(b3a2). Other transcripts such as e1a2 are rare and their outcome with tyrosine kinase inhibitors (TKI) therapy is undefined. We analyzed 1292 CML patients and identified 14 with only e1a2 transcripts, 9 in chronic phase (CP), 1 in accelerated phase (AP), and 4 in blast phase (BP). Of the CP, 4 achieved complete hematologic response (CHR); 2, complete cytogenetic response (CCyR); 2, partial cytogenetic response (PCyR), and 1 did not respond to imatinib. Five patients progressed to myeloid BP (3), lymphoid BP (1), or AP (1). The AP patient received various TKIs sequentially and achieved only CHR. BP patients received hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, adriamycin, dexamethasone) plus imatinib/dasatinib or idarubicin plus cytarabine (Ara-C); 2 did not respond, 1 had CCyR, and 1 short-lasting complete molecular response (CMR). Overall, cytogenetic responses lasted 3 to 18 months; only 2 achieved major molecular response (MMR) on TKI. P190(BCR-ABL) CML is rare and is associated with an inferior outcome to therapy with TKI. These patients need to be identified as high-risk patients.

Failure to achieve a complete hematologic response at the time of a major cytogenetic response with second-generation tyrosine kinase inhibitors is associated with a poor prognosis among patients with chronic myeloid leukemia in accelerated or blast phase.

Second-generation tyrosine kinase inhibitors are effective in Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia (CML). Occasionally, patients with Ph(+) ALL, or accelerated phase (AP) or blast phase (BP) CML achieve a major cytogenetic response (MCyR) but not a complete hematologic response (CHR). We analyzed 126 patients with CML in AP or BP, or with Ph(+) ALL treated with dasatinib or nilotinib after imatinib failure. Twenty patients received sequential treatment with both dasatinib and nilotinib for a total of 146 instances. CHR and MCyR rates were 54% and 37%, respectively in AP, 17% and 39% in BP, and 33% and 50% in Ph+ ALL. Failure to achieve a CHR at the time of achievement of a MCyR was associated with an inferior outcome, similar to that of patients without a MCyR (2-year survival rate, 37% and 35%, respectively). In contrast, patients with MCyR and concomitant CHR had a 77% 2-year survival rate. Twelve of 29 patients with MCyR without concomitant CHR later achieved a CHR; the 2-year survival rate for these patients was 55% compared with 22% for those who never achieved a CHR. These results suggest that achievement of a MCyR without concomitant CHR is associated with poor outcome.