Long-term outcomes of corticosteroid graft versus host disease prophylaxis in peripheral blood allogeneic haemopoietic stem cell transplant: a comparative cohort analysis.

BACKGROUND: Corticosteroids (CSs) have previously been incorporated into graft versus host disease (GVHD) prophylaxis regimens for bone marrow (BM) and haemopoietic stem cell transplant (HSCT). AIMS: To assess the impact of prophylactic CS in HSCT using peripheral blood (PB) stem cells. METHODS: Patients were identified from three HSCT centres receiving a first PB-HSCT between January 2011 and December 2015 from a fully human leukocyte antigen (HLA)-matched sibling or unrelated donor for acute myeloid leukaemia or acute lymphoblastic leukaemia. To enable meaningful comparison, patients were divided into two cohorts. RESULTS: Cohort 1 included only myeloablative-matched sibling HSCT, where the only variation in GVHD prophylaxis was the addition of CS. In these 48 patients, there were no differences in GVHD, relapse, non-relapse mortality, overall survival or GVHD-relapse-free-survival (GRFS) at 4 years after transplant. Cohort 2 included the remaining HSCT recipients, where one group received CS-prophylaxis and the non-CS group received an antimetabolite, ciclosporin and anti-T-lymphocyte globulin. In these 147 patients, those receiving CS-prophylaxis experienced higher rates of chronic GVHD (71% vs 18.1%, P < 0.001) and lower rates of relapse (14.9% vs 33.9%, P = 0.02). Those receiving CS-prophylaxis had a lower 4-year GRFS (15.7% vs 40.3%, P = 0.002). CONCLUSIONS: There does not appear to be a role for adding CS to standard GVHD prophylaxis regimens in PB-HSCT.

Targeting MCL-1 and BCL-2 with polatuzumab vedotin and venetoclax overcomes treatment resistance in R/R non-Hodgkin lymphoma: Results from preclinical models and a Phase Ib study.

The treatment of patients with relapsed or refractory lymphoid neoplasms represents a significant clinical challenge. Here, we identify the pro-survival BCL-2 protein family member MCL-1 as a resistance factor for the BCL-2 inhibitor venetoclax in non-Hodgkin lymphoma (NHL) cell lines and primary NHL samples. Mechanistically, we show that the antibody-drug conjugate polatuzumab vedotin promotes MCL-1 degradation via the ubiquitin/proteasome system. This targeted MCL-1 antagonism, when combined with venetoclax and the anti-CD20 antibodies obinutuzumab or rituximab, results in tumor regressions in preclinical NHL models, which are sustained even off-treatment. In a Phase Ib clinical trial (NCT02611323) of heavily pre-treated patients with relapsed or refractory NHL, 25/33 (76%) patients with follicular lymphoma and 5/17 (29%) patients with diffuse large B-cell lymphoma achieved complete or partial responses with an acceptable safety profile when treated with the recommended Phase II dose of polatuzumab vedotin in combination with venetoclax and an anti-CD20 antibody.

Dynamics of Epstein-Barr virus on post-transplant lymphoproliferative disorders after antithymocyte globulin-conditioned allogeneic hematopoietic cell transplant.

BACKGROUND: The use of antithymocyte globulin (ATG) in allogeneic hematopoietic cell transplant (HCT) is associated with an increased risk of Epstein-Barr virus (EBV) reactivation and post-transplant lymphoproliferative disorders (PTLD). The dynamics and outcomes of EBV-DNAemia are not well described in this population. METHODS: We retrospectively assessed the kinetics of EBV-DNAemia after ATG conditioning of HCT recipients. Receiver operating characteristic (ROC) curves were used to assess EBV-DNAemia to predict EBV-PTLD in this group. RESULTS: A total of 174/405 (43%) consecutive HCT recipients from two centers met inclusion criteria of ATG conditioned, non-B-cell lymphoma patients. Of these with EBV-DNA measured using standardized IU/ml, 78.6% (92/117) developed EBV-DNAemia: 62% spontaneously resolved; 19% cleared after preemptive rituximab, and 13% developed EBV-PTLD. ROC curve analysis using maximum pre-EBV-PTLD EBV-DNAemia, demonstrated an AUC of 0.912 with EBV-DNAemia of 9782 IU/ml, associated with 82.6% sensitivity and 94.4% specificity for development of EBV-PTLD. Median time for EBV-DNAemia to increase from initial detection to >1000 IU/ml was 7 days; to >10 000 IU/ml, 12 days; and to >100 000 IU/ml, 18 days. Median EBV-DNAemia level prior to administration of rituximab was significantly lower in patients with successful preemptive treatment, compared with those who developed EBV-PTLD (3.41 log10  IU/ml [3.30-3.67] vs. 4.34 log10  IU/ml [3.85-5.13], p = .002; i.e., 2628 IU/ml vs. 21 965 IU/ml, respectively). CONCLUSIONS: EBV-DNAemia >10 000 IU/ml was the strongest predictor of the development of EBV-PTLD, and progression to this level was rapid in ATG-conditioned HCT recipients. This information may guide EBV-PTLD management strategies in these high-risk patients.

SUBA-Itraconazole for Primary Antifungal Prophylaxis After Allogeneic Hematopoietic Cell Transplantation.

Background: Itraconazole (ITZ) is an effective agent when used as primary invasive fungal disease (IFD) prophylaxis, but is limited by drug tolerability and variability in serum concentrations. A new formulation, SUBA-itraconazole (for "super bioavailability"; S-ITZ), addresses the limitations of conventional ITZ formulations. Methods: We conducted a retrospective cohort study at 2 Australian centers to evaluate the safety, tolerability, and effectiveness of S-ITZ as primary antifungal prophylaxis in hematopoietic cell transplant (HCT) recipients without grade II-IV acute graft-vs-host disease, from day 1 until approximately day 100 (cohort A) or day 1 until neutrophil engraftment (cohort B). A total of 204 patients and 1410 trough plasma ITZ concentrations were assessed. Results: The incidence of breakthrough proven/probable IFD at day 180 was 1.0% (95% confidence interval [CI], .2%-3.2%), with 1.6% in cohort A and 0% in cohort B, and overall fungal-free survival of proven/probable IFD was 82.9% (95% CI, 76.8%-87.4%). Preengraftment early permanent S-ITZ discontinuation was 3.4% overall, with no significant difference between cohorts. No patients required cessation due to gastrointestinal intolerance attributed to S-ITZ. The geometric mean trough plasma ITZ concentration was 1130ng/mL (interquartile range, 566-1801ng/mL; coefficient of variation, 56.57%) and the median time to achieve therapeutic levels was 10 days. Conclusions: S-ITZ is a safe and well-tolerated oral formulation and is a novel alternative for primary IFD prophylaxis after HCT.

Cytomegalovirus (CMV) management in allogeneic hematopoietic cell transplantation: Pre-transplant predictors of survival, reactivation, and spontaneous clearance.

BACKGROUND: Cytomegalovirus (CMV) reactivation is a frequent complication after allogeneic hematopoietic cell transplant (alloHCT). METHOD: We analyzed 159 alloHCT recipients with 4409 quantitative CMV viral loads to determine pre-transplant predictors of CMV reactivation, clinically significant CMV infection (cs-CMVi, defined as CMV viral load >1000 IU/mL), CMV disease, kinetics of spontaneous clearance of CMV, and survival using a standardized pre-emptive therapy approach to identify at-risk groups to target prevention strategies. RESULTS: Cs-CMVi was most common in D-/R+ unrelated donor transplants (URD). Spontaneous CMV clearance occurred in 26% of patients who reached a viral load of 56-137 IU/mL, 6% at 138-250 IU/mL and in one patient >250 IU/mL. Median time between the first CMV reactivation (>56 IU/mL) and a viral load >250 IU/mL was 13 days, whereas the time from the first viral load >250 IU/mL to reach a vial load >1000 IU/mL was 4 days. Cs-CMVi was associated with a significant increase in non-relapse mortality (NRM) on multivariate analysis. CONCLUSIONS: Overall, this study indicates that D-/R+ URD recipients are at high-risk for cs-CMVi- and CMV-related mortality, and are potential candidates for targeted CMV prophylaxis. Spontaneous clearance of CMV beyond a viral load of 250 IU/mL is uncommon, suggesting that this could be used as an appropriate threshold to initiate pre-emptive therapy.

Unrelated Donor Transplant Recipients Given Thymoglobuline Have Superior GRFS When Compared to Matched Related Donor Recipients Undergoing Transplantation without ATG.

Recipients of allogeneic hematopoietic stem cell transplantation (HSCT) from unrelated donors (URDs) and mismatched related donors (MMRDs) typically have a higher incidence of acute and chronic graft-versus-host disease (GVHD) compared with matched related donors (MRDs). Anti-T-cell globulins (ATGs) are often used to reduce GVHD in these recipients. We report the outcomes of 211 adult peripheral blood stem cell transplant recipients with myeloid malignancies who received a standardized transplant protocol, in which ATG (Thymoglobuline 4.5 mg/kg) was administered to recipients of URD and MMRD (n = 147) but not MRD (n = 64) transplant. For all patients, incidence of acute GVHD grades 2 to 4 was 21.4%, and chronic GVHD was 35.0%. Two-year overall survival was 63.2% (95% confidence interval, 55.8% to 71.5%), relapse-free survival was 55.3% (47.4% to 64.6%), and GVHD-free, relapse-free survival (GRFS) was 30.7% (23.2% to 40.8%). There were no differences between recipients of MRDs and other donors in relapse, nonrelapse mortality, and overall and relapse-free survival. However, compared with MRD, recipients from URDs and MMRDs had reduced moderate to severe chronic GVHD (10.4% versus 30.1%, P= .002), less chronic GVHD requiring systemic therapy (19.4% versus 38.9%, P = .006), and superior 2-year GRFS (35.5% versus 20.0%, P = .003). In this retrospective review of nonrandomized transplant groups, outcomes of HSCT performed using an URD with ATG during conditioning were superior to transplant from an MRD without ATG. The addition of Thymoglobuline to conditioning in HSCT from MRD should be further examined in prospective trials.

Chronic myeloid leukaemia and tyrosine kinase inhibitor therapy: assessment and management of cardiovascular risk factors.

Several BCR-ABL1 tyrosine kinase inhibitors (TKIs) are approved for the first-line treatment of chronic phase chronic myeloid leukaemia (CML). Disease control is achieved in the vast majority of patients and disease-specific survival is excellent. Consequently, there is now emphasis on managing comorbidities and minimising treatment-related toxicity. Second-generation TKIs have cardiovascular risks that are greater than with imatinib treatment, but these risks must be balanced against the superior CML responses encountered with more potent TKIs. Cardiovascular risk should be assessed at baseline using a locally validated model based on the Framingham risk equation. Clinicians involved in the care of CML patients should be aware of the vascular complications of TKIs and manage cardiovascular risk factors early to mitigate treatment-related risks. Reversible risk factors, such as dyslipidaemia, smoking, diabetes and hypertension, should be addressed. We summarise the available data on cardiovascular complications in CML patients treated with TKIs. Using the latest evidence and collective expert opinion, we provide practical advice for clinicians to assess, stratify and manage cardiovascular risk in people with CML receiving TKI therapy.

Serum levels, safety and tolerability of new formulation SUBA-itraconazole prophylaxis in patients with haematological malignancy or undergoing allogeneic stem cell transplantation.

OBJECTIVES: To assess therapeutic levels, safety and tolerability of a novel formulation SUBA-itraconazole (where SUBA stands for SUper BioAvailability) when compared with conventional itraconazole liquid when used as antifungal prophylaxis in patients undergoing allogeneic HSCT or in haematological malignancy patients with an intermediate/high risk of invasive fungal infection (IFI). METHODS: This was a single-institution, prospective cohort study using a historical control group as the comparator. RESULTS: A total of 57 patients were assessed: 27 in the SUBA-itraconazole cohort and 30 in the liquid itraconazole cohort. Therapeutic concentrations were achieved significantly more quickly in the SUBA-itraconazole group: median of 6 (95% CI 5-11) days versus 14 (95% CI 12-21) days in the liquid itraconazole group (P < 0.0001). At day 10, therapeutic concentrations were achieved in 69% (95% CI 44%-81%) of the SUBA-itraconazole group versus 21% (95% CI 7%-33%) of the liquid itraconazole group (P < 0.0001). The mean trough serum concentrations at steady-state of SUBA-itraconazole were significantly higher, with less interpatient variability [1577 ng/mL, coefficient of variation (CV) 35%] versus liquid itraconazole (1218 ng/mL, CV 60%) (P < 0.001). There were two (7.4%) treatment failures in the SUBA-itraconazole group, both due to cessation of therapy for mucositis, compared with seven (23.3%) treatment failures in the liquid itraconazole group, due to subtherapeutic levels (five), mucositis (one) and gastrointestinal intolerance (one) (P = 0.096). CONCLUSIONS: The use of the SUBA-itraconazole formulation was associated with more rapid attainment of therapeutic levels with less interpatient variability compared with conventional liquid itraconazole when used as IFI prophylaxis in allogeneic HSCT or intermediate-/high-IFI risk haematological malignancy patients.

Resolution of aquaporin-4 antibodies in a woman with neuromyelitis optica treated with human autologous stem cell transplant.

We report a 47-year-old woman with highly active neuromyelitis optica (NMO) and persistent high titre anti-aquaporin-4 antibodies (anti-AQP-4) who was resistant to multiple immune therapies until she underwent autologous hematopoietic stem cell transplant (auto-HSCT). NMO is the only demyelinating disease with a clinically useful serum biomarker, aquaporin-4, a water channel protein expressed on astrocytes. Anti-AQP-4 antibodies correlate with NMO disease activity and animal models strongly suggest the antibody is pathogenic. Auto-HSCT was associated with clinical and radiological remission, improved disability and resolution of AQP-4 antibodies which are still undetectable 12 months later. The utility of auto-HSCT for refractory NMO warrants further investigation, particularly with regards to pre-conditioning regimens and the utility of AQP-4 antibodies as a biomarker for immunological and clinical remission.

A multicenter phase 2 study of risk-adjusted salvage chemotherapy incorporating vinorelbine and gemcitabine for relapsed and refractory lymphoma.

BACKGROUND: Administration of salvage chemotherapy to patients with relapsed or refractory lymphoma is associated with significant toxicity. Vinorelbine and gemcitabine are novel chemotherapeutic agents with minimal overlapping toxicity. We present a phase 2 study of vinorelbine and gemcitabine with or without ifosfamide administered in an ambulatory care setting for relapsed or refractory lymphoma. METHODS: Ninety patients were enrolled. Group 1 comprised patients with "good" risk disease, Group 2 comprised patients with "high" risk disease, and Group 3 comprised patients relapsing after prior stem cell transplant. Patients in Group 1 and Group 3 received vinorelbine and gemcitabine with filgrastim support (VGF); those in Group 2 received the above regimen with ifosfamide (FGIV). We incorporated a standardized interim evaluation with dose escalation for patients with suboptimal response after 2 cycles. RESULTS: Toxicities were acceptable. Febrile neutropenia was uncommon: 7% after VGF (7 of 107 cycles) and 19% for FGIV (26 of 148 cycles). Unplanned admissions occurred in 23 of 107 cycles (21%) after VGF and 50 of 148 (34%) after FGIV. Overall response for Groups 1, 2 and 3, respectively was 76%, 39% and 50%, with median overall survival of 28, 9 and 30 months. CONCLUSIONS: Vinorelbine-based and gemcitabine-based chemotherapy is effective in the salvage setting against lymphoma and can be administered in an ambulatory setting.

Impact of early dose intensity on cytogenetic and molecular responses in chronic- phase CML patients receiving 600 mg/day of imatinib as initial therapy.

We conducted a trial in 103 patients with newly diagnosed chronic phase chronic myeloid leukemia (CP-CML) using imatinib 600 mg/day, with dose escalation to 800 mg/day for suboptimal response. The estimated cumulative incidences of complete cytogenetic response (CCR) by 12 and 24 months were 88% and 90%, and major molecular responses (MMRs) were 47% and 73%. In patients who maintained a daily average of 600 mg of imatinib for the first 6 months (n = 60), MMR rates by 12 and 24 months were 55% and 77% compared with 32% and 53% in patients averaging less than 600 mg (P = .037 and .016, respectively). Dose escalation was indicated for 17 patients before 12 months for failure to achieve, or maintain, major cytogenetic response at 6 months or CCR at 9 months but was only possible in 8 patients (47%). Dose escalation was indicated for 73 patients after 12 months because their BCR-ABL level remained more than 0.01% (international scale) and was possible in 45 of 73 (62%). Superior responses achieved in patients able to tolerate imatinib at 600 mg suggests that early dose intensity may be critical to optimize response in CP-CML. The trial was registered at www.ANZCTR.org.au as #ACTRN12607000614493.

A phase II study of liposomal daunorubicin, in combination with cyclophosphamide, vincristine and prednisolone, in elderly patients with previously untreated aggressive non-Hodgkin lymphoma.

Liposomal daunorubicin (DaunoXome) was substituted for doxorubicin in the CHOP regimen, aiming to reduce toxicity and maintain or improve efficacy in elderly patients. Eligibility criteria included: age >or=60 years; previously untreated aggressive non-Hodgkin Lymphoma (NHL) and performance status (PS) 0-2. Treatment was cyclophosphamide 750 mg/m(2), vincristine 1.4 mg/m(2) (maximum 2 mg), and DaunoXome 100 mg/m(2) i.v. on day 1, prednisolone 100 mg po on days 1-5 and G-CSF 5 microg/kg/day sc, for 6-8 cycles. For the 51 patients, median age was 70 years (range 60-88), 94% had diffuse large B-cell lymphoma (DLBCL) and 55% were high-intermediate or high-risk according to the age-adjusted international prognostic index. A mean of 6 cycles was delivered, with dose reductions of DaunoXome in 8.3% of cycles. The combined CR and CRu rate was 65.2%, survival was 566 days and 5-year survival 35%. Three deaths occurred during treatment and may have been related to COP-X. Only 4 (7.8%) of the remaining patients had >or=10% reduction in LVEF. However, 35% of patients were hospitalised during treatment, mostly for febrile neutropenia. The response rate to COP-X was similar to that expected with CHOP, with low cardiac toxicity. The high rate of infectious complications suggests that the DaunoXome dose used may be too high for this patient group. These results support further investigation of this regimen in patients with aggressive NHL.

BCR-ABL messenger RNA levels continue to decline in patients with chronic phase chronic myeloid leukemia treated with imatinib for more than 5 years and approximately half of all first-line treated patients have stable undetectable BCR-ABL using strict sensitivity criteria.

PURPOSE: In the first years of imatinib treatment, BCR-ABL remained detectable in all but a small minority of patients with chronic myeloid leukemia. We determined whether BCR-ABL continues to decline with longer imatinib exposure and the incidence and consequence of undetectable BCR-ABL. EXPERIMENTAL DESIGN: BCR-ABL levels were measured in a subset of 53 imatinib-treated IRIS trial patients for up to 7 years (29 first-line, 24 second-line). Levels were deemed undetectable using strict PCR sensitivity criteria. RESULTS: By 18 months, the majority achieved a 3-log reduction [major molecular response (MMR)]. BCR-ABL continued to decline but at a slower rate (median time to 4-log reduction and undetectable BCR-ABL of 45 and 66 months for first-line). The probability of undetectable BCR-ABL increased considerably from 36 to 81 months of first-line imatinib {7% [95% confidence interval (95% CI), 0-17%] versus 52% (95% CI, 32-72%)}. Undetectable BCR-ABL was achieved in 18 of 53 patients and none of these 18 lost MMR after a median follow-up of 33 months. Conversely, MMR was lost in 6 of 22 (27%) patients with sustained detectable BCR-ABL and was associated with BCR-ABL mutations in 3 of 6. Loss of MMR was recently defined as suboptimal imatinib response. There was no difference in the probability of achieving molecular responses between first- and second-line patients but first-line had a significantly higher probability of maintaining MMR [P = 0.03; 96% (95% CI, 88-100%) versus 71% (95% CI, 48-93%)]. CONCLUSIONS: With prolonged therapy, BCR-ABL continued to decline in most patients and undetectable BCR-ABL was no longer a rare event. Loss of MMR was only observed in patients with sustained detectable BCR-ABL.

Measurement of in vivo BCR-ABL kinase inhibition to monitor imatinib-induced target blockade and predict response in chronic myeloid leukemia.

PURPOSE: Intrinsic sensitivity to imatinib, based on measurement of inhibitory concentration 50% for imatinib, is variable in untreated patients with chronic myeloid leukemia (CML). This suggests that patient-tailored dosing may be more rational than a fixed dose for all. Dose optimization potentially could be based on accurate measurement of the level of BCR-ABL kinase inhibition achieved in vivo. PATIENTS AND METHODS: In vivo kinase inhibition was measured by calculating the reduction in protein (p)--Crkl level in mononuclear blood cells taken from 49 CML patients at weekly intervals after imatinib therapy was commenced. RESULTS: Greater than 50% inhibition (> 50% reduction in p-Crkl from baseline) was achieved by 21% of patients by days 7 to 14 (and maintained in all patients on days 21 to 28) and an additional 24% of patients achieved more than 50% inhibition by days 21 to 28. Thus, overall 45% of patients achieved more than 50% inhibition. All of these patients achieved major molecular responses by 24 months compared with 56% of the patients who failed to achieve 50% kinase inhibition (P < .001). Patients with less than 50% kinase inhibition were also more likely to have suboptimal responses. CONCLUSION: In vivo BCR-ABL kinase inhibition can be assessed in the first month of imatinib therapy and may provide a valuable guide to optimization of dosage. The extent of BCR-ABL kinase inhibition is an excellent predictor of cytogenetic and molecular response. These observations suggest that dose adjustment based on in vivo measurements of drug-induced target inhibition could be applied in settings beyond imatinib and may be a more effective approach than using one dose for all patients in targeted anticancer therapy.

Efficacy and safety of imatinib in patients with chronic myeloid leukemia and complete or near-complete cytogenetic response to interferon-alpha.

BACKGROUND: Interferon-alpha (IFN-alpha) confers a survival advantage for the minority of patients with chronic myeloid leukemia (CML) who achieve a complete cytogenetic response. The question of whether IFN-alpha-responsive patients can experience further improvements with imatinib has not been answered. Imatinib offers clear quality of life advantages. Furthermore, patients who achieve a major molecular response (MMR) while receiving imatinib are likely to remain progression free. METHODS: A total of 23 patients treated for a median of 4.5 years with IFN-alpha (range, 1.6-14.3 years) who had achieved a complete (Philadelphia chromosome [Ph] negative, n = 15 patients) or near-complete (1-10% Ph, n = 8 patients) cytogenetic response were studied. The primary objective was to determine whether ceasing therapy with IFN-alpha and switching to 12 months of imatinib treatment at a dose of 400 mg/day could improve the molecular response as assessed by real-time quantitative polymerase chain reaction of BCR-ABL transcript levels. Safety was also assessed. RESULTS: Every patient who had not achieved an MMR while receiving IFN-alpha (n = 16 patients) achieved an MMR after a median of 3 months of imatinib treatment. Significant BCR-ABL reductions (median, 63-fold; range, 18-425-fold) occurred in 15 of these patients. Every patient who had already achieved an MMR while receiving IFN-alpha (n = 7 patients) maintained an MMR while receiving imatinib. No patients discontinued imatinib due to toxicity, but 1 patient withdrew consent. CONCLUSIONS: These data suggest that switching IFN-alpha-responsive patients to imatinib leads to a rapid improvement in achieving an MMR, a response with established prognostic value, and is well tolerated. The study should help patients and their physicians make evidence-based decisions regarding the potential benefits and risks of switching to imatinib.

Pegfilgrastim to support CHOP-14 in elderly patients with non-Hodgkin's lymphoma.

This study investigated whether pegfilgrastim support would enable on-schedule delivery of dose-dense cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP-14) to elderly patients with non-Hodgkin's lymphoma (NHL). Thirty patients 60 years of age and older with aggressive NHL were evaluated after receiving up to six cycles of CHOP-14 supported with pegfilgrastim. The median age was 68 years (range 61 - 74). Forty-seven per cent of patients received full dose chemotherapy on schedule for all cycles (range 65 - 93). Chemotherapy was delayed in 10 patients and dose reduced in 15 patients. Hematological toxicity was the most common reason for delays and dose reduction. Six of nine patients (67%) achieved a peripheral blood CD34+ count of at least 20 cellsx106 L-1 on day 12 of cycle one. The delivery on schedule of dose-dense CHOP-14 to elderly patients with previously untreated aggressive NHL is safe and efficacious with once per cycle pegfilgrastim support.

Decitabine. MGI Pharma Inc/SuperGen Inc.

Decitabine is a DNA methyltransferase inhibitor under development by SuperGen Inc and MGI Pharma Inc for the potential treatment of a range of hematological malignancies, including myelodysplastic syndrome, solid tumors and sickle cell disease.

Real-time quantitative PCR analysis can be used as a primary screen to identify patients with CML treated with imatinib who have BCR-ABL kinase domain mutations.

Mutations within the BCR-ABL kinase domain in imatinib-treated chronic myeloid leukemia (CML) are the main mechanism of acquired resistance. The early detection of mutations should provide clinical benefit by allowing early intervention. Quantitative polymerase chain reaction (RQ-PCR) results of BCR-ABL mRNA were correlated with mutation analysis in 214 patients treated with imatinib. We determined whether there was a difference in the incidence of mutations between the patients with a more than 2-fold rise in BCR-ABL and patients with stable or decreasing levels. Of the 56 patients with a more than 2-fold rise, 34 (61%) had detectable mutations (median rise, 3.0-fold; 25th-75th percentiles, 2.3-5.2). In 31 (91%) of these 34 patients, the mutation was present at the time of the rise and became detectable within 3 months in the remaining patients. Only 1 (0.6%) of 158 patients with stable or decreasing BCR-ABL levels had a detectable mutation, P less than .0001. Thus, a more than 2-fold rise identified 34 (97%) of 35 patients with a mutation. We conclude that a rise in BCR-ABL of more than 2-fold can be used as a primary indicator to test patients for BCR-ABL kinase domain mutations.