A study to assess the efficacy of enasidenib and risk-adapted addition of azacitidine in newly diagnosed IDH2-mutant AML

ABSTRACT

Enasidenib (ENA) is an inhibitor of isocitrate dehydrogenase 2 (IDH2) approved for the treatment of patients with IDH2-mutant relapsed/refractory acute myeloid leukemia (AML). In this phase 2/1b Beat AML substudy, we applied a risk-adapted approach to assess the efficacy of ENA monotherapy for patients aged ≥60 years with newly diagnosed IDH2-mutant AML in whom genomic profiling demonstrated that mutant IDH2 was in the dominant leukemic clone. Patients for whom ENA monotherapy did not induce a complete remission (CR) or CR with incomplete blood count recovery (CRi) enrolled in a phase 1b cohort with the addition of azacitidine. The phase 2 portion assessing the overall response to ENA alone demonstrated efficacy, with a composite complete response (cCR) rate (CR/CRi) of 46% in 60 evaluable patients. Seventeen patients subsequently transitioned to phase 1b combination therapy, with a cCR rate of 41% and 1 dose-limiting toxicity. Correlative studies highlight mechanisms of clonal elimination with differentiation therapy as well as therapeutic resistance. This study demonstrates both efficacy of ENA monotherapy in the upfront setting and feasibility and applicability of a risk-adapted approach to the upfront treatment of IDH2-mutant AML. This trial is registered at www.clinicaltrials.gov as #NCT03013998.

A multicenter phase Ib trial of the histone deacetylase inhibitor entinostat in combination with pembrolizumab in patients with myelodysplastic syndromes/neoplasms or acute myeloid leukemia refractory to hypomethylating agents

Patients with myelodysplastic syndromes/neoplasms (MDS) or acute myeloid leukemia (AML) with hypomethylating agent failure have a poor prognosis. Myeloid-derived suppressor cells (MDSCs) can contribute to MDS progression and mediate resistance to anti-PD1 therapy. As histone deacetylase inhibitors (HDACi) decrease MDSCs in preclinical models, we conducted an investigator-initiated, NCI-Cancer Therapy Evaluation Program-sponsored, multicenter, dose escalation, and expansion phase Ib trial (NCT02936752) of the HDACi entinostat and the anti-PD1 antibody pembrolizumab. Twenty-eight patients (25 MDS and 3 AML) were enrolled. During dose escalation (n=13 patients), there was one dose-limiting toxicity (DLT) on dose level (DL) 1 (G5 pneumonia/bronchoalveolar hemorrhage) and two DLTs at DL 2 (G3 pharyngeal mucositis and G3 anorexia). Per the 3 + 3 dose escalation design, DL 1 (entinostat 8 mg PO days 1 and 15 + pembrolizumab 200 mg IV day 1 every 21 days) was expanded and another 15 patients were enrolled. Hematologic adverse events (AEs) were common. The most common non-hematologic ≥G3 AEs were infection (32%), hypoxia/respiratory failure (11%), and dyspnea (11%). There were no protocol-defined responses among the 28 patients enrolled. Two patients achieved a marrow complete remission (mCR). Using a systems immunology approach with mass cytometry and machine learning analysis, mCR patients had increased classical monocytes and macrophages but there was no significant change of MDSCs. In conclusion, combining entinostat with pembrolizumab in patients with advanced MDS and AML was associated with limited clinical efficacy and substantial toxicity. Absence of an effect on MDSCs could be a potential explanation for the limited efficacy of this combination. ClinicalTrial.gov Identifier: NCT02936752.

Efficacy and toxicity of midostaurin with idarubicin and cytarabine induction in <i>FLT3</I>-mutated acute myeloid leukemia

Not available.

Samples from patients with AML show high concordance in detection of mutations by NGS at local institutions vs central laboratories

Next-generation sequencing (NGS) to identify pathogenic mutations is an integral part of acute myeloid leukemia (AML) therapeutic decision-making. The concordance in identifying pathogenic mutations among different NGS platforms at different diagnostic laboratories has been studied in solid tumors but not in myeloid malignancies to date. To determine this interlaboratory concordance, we collected a total of 194 AML bone marrow or peripheral blood samples from newly diagnosed patients with AML enrolled in the Beat AML Master Trial (BAMT) at 2 academic institutions. We analyzed the diagnostic samples from patients with AML for the detection of pathogenic myeloid mutations in 8 genes (DNMT3A, FLT3, IDH1, IDH2, NPM1, TET2, TP53, and WT1) locally using the Hematologic Neoplasm Mutation Panel (50-gene myeloid indication filter) (site 1) or the GeneTrails Comprehensive Heme Panel (site 2) at the 2 institutions and compared them with the central results from the diagnostic laboratory for the BAMT, Foundation Medicine, Inc. The overall percent agreement was over 95% each in all 8 genes, with almost perfect agreement (κ > 0.906) in all but WT1, which had substantial agreement (κ = 0.848) when controlling for site. The minimal discrepancies were due to reporting variants of unknown significance (VUS) for the WT1 and TP53 genes. These results indicate that the various NGS methods used to analyze samples from patients with AML enrolled in the BAMT show high concordance, a reassuring finding given the wide use of NGS for therapeutic decision-making in AML.

Entospletinib with decitabine in acute myeloid leukemia with mutant TP53 or complex karyotype: A phase 2 substudy of the Beat AML Master Trial

BACKGROUND

Patients with acute myeloid leukemia (AML) who have tumor protein p53 (TP53) mutations or a complex karyotype have a poor prognosis, and hypomethylating agents are often used. The authors evaluated the efficacy of entospletinib, an oral inhibitor of spleen tyrosine kinase, combined with decitabine in this patient population.

METHODS

This was a multicenter, open-label, phase 2 substudy of the Beat AML Master Trial (ClinicalTrials.gov identifier NCT03013998) using a Simon two-stage design. Eligible patients aged 60 years or older who had newly diagnosed AML with mutations in TP53 with or without a complex karyotype (cohort A; n = 45) or had a complex karyotype without TP53 mutation (cohort B; n = 13) received entospletinib 400 mg twice daily with decitabine 20 mg/m² on days 1-10 every 28 days for up to three induction cycles, followed by up to 11 consolidation cycles, in which decitabine was reduced to days 1-5. Entospletinib maintenance was given for up to 2 years. The primary end point was complete remission (CR) and CR with hematologic improvement by up to six cycles of therapy.

RESULTS

The composite CR rates for cohorts A and B were 13.3% (95% confidence interval, 5.1%-26.8%) and 30.8% (95% confidence interval, 9.1%-61.4%), respectively. The median duration of response was 7.6 and 8.2 months, respectively, and the median overall survival was 6.5 and 11.5 months, respectively. The study was stopped because the futility boundary was crossed in both cohorts.

CONCLUSIONS

The combination of entospletinib and decitabine demonstrated activity and was acceptably tolerated in this patient population; however, the CR rates were low, and overall survival was short. Novel treatment strategies for older patients with TP53 mutations and complex karyotype remain an urgent need.

GABA-A Receptor Encephalitis After Autologous Hematopoietic Stem Cell Transplant forMultiple Myeloma

Background and Objectives

The relationship between autologous hematopoietic stem cell transplant (aHSCT) for multiple myeloma (MM) and anti-GABA_A receptor (GABA_AR) encephalitis is unknown. We aimed to describe the clinical features, diagnostic process, and outcome of 3 cases of anti-GABA_AR encephalitis in patients with a history of prior aHSCT for MM.

Methods

A case series of 3 patients. Anti-GABA_AR antibody was tested at the University of Pennsylvania Laboratory.

Results

The patients were all male, aged 52 (case 1), 61 (case 2), and 62 (case 3) years at encephalitis symptom onset. The duration between completion of aHSCT and the onset of encephalitis was 43, 18, and 9 months, respectively. All 3 patients presented with new seizures and altered cognitive function. Other symptoms included headache and visual obscurations in cases 1 and 2 and intractable vertigo and mania in case 3. Brain MRI demonstrated nonenhancing multifocal T2-weighted/fluid-attenuated inversion recovery cortical and subcortical hyperintensities in all 3 patients. Cases 2 and 3 underwent brain biopsy before initiating immunomodulatory therapy, which demonstrated nonspecific encephalitis with astrogliosis in the white matter; these 2 patients were started on immunotherapy for the treatment of anti-GABA_AR encephalitis after 22 days and 3 months, respectively, from the first presentation. Case 1 was started on empiric immunotherapy within 8 days of presentation without requiring brain biopsy, given characteristic MRI imaging. CSF analysis demonstrated the presence of anti-GABA_AR antibodies in all 3 cases. Cases 1 and 3 also tested positive for anti-GABA_AR antibodies in the serum (serum test was not performed in case 2). Cases 1 and 2 recovered to work full-time within 1 year. Case 3 reported occasional myoclonic-like movement.

Discussion

We highlight the importance of considering anti-GABA_AR encephalitis in patients with seizures, multifocal nonenhancing brain lesions, and a history of aHSCT for MM. Awareness in recovered post-aHSCT patients with MM may be crucial because prompt recognition can avoid brain biopsy and delays in treatment. The rapid initiation of immunotherapy while awaiting autoantibody results will likely improve functional outcomes.

The genetic landscape of germline DDX41 variants predisposing to myeloid neoplasms

Germline DDX41 variants are the most common mutations predisposing to acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) in adults, but the causal variant (CV) landscape and clinical spectrum of hematologic malignancies (HMs) remain unexplored. Here, we analyzed the genomic profiles of 176 patients with HM carrying 82 distinct presumably germline DDX41 variants among a group of 9821 unrelated patients. Using our proposed DDX41-specific variant classification, we identified features distinguishing 116 patients with HM with CV from 60 patients with HM with variant of uncertain significance (VUS): an older age (median 69 years), male predominance (74% in CV vs 60% in VUS, P = .03), frequent concurrent somatic DDX41 variants (79% in CV vs 5% in VUS, P < .0001), a lower somatic mutation burden (1.4 ± 0.1 in CV vs 2.9 ± 0.04 in VUS, P = .012), near exclusion of canonical recurrent genetic abnormalities including mutations in NPM1, CEBPA, and FLT3 in AML, and favorable overall survival (OS) in patients with AML/MDS. This superior OS was determined independent of blast count, abnormal karyotypes, and concurrent variants, including TP53 in patients with AML/MDS, regardless of patient's sex, age, or specific germline CV, suggesting that germline DDX41 variants define a distinct clinical entity. Furthermore, unrelated patients with myeloproliferative neoplasm and B-cell lymphoma were linked by DDX41 CV, thus expanding the known disease spectrum. This study outlines the CV landscape, expands the phenotypic spectrum in unrelated DDX41-mutated patients, and underscores the urgent need for gene-specific diagnostic and clinical management guidelines.

A phase 1b study of glasdegib + azacitidine in patients with untreated acute myeloid leukemia and higher-risk myelodysplastic syndromes

This phase 1b study evaluated glasdegib (100 mg once daily) + azacitidine in adults with newly diagnosed acute myeloid leukemia (AML), higher-risk myelodysplastic syndromes (MDS), or chronic myelomonocytic leukemia (CMML) who were ineligible for intensive chemotherapy. Of 72 patients enrolled, 12 were in a lead-in safety cohort (LIC) and 60 were in the AML and MDS (including CMML) expansion cohorts. In the LIC, the safety profile of glasdegib + azacitidine was determined to be consistent with those of glasdegib or azacitidine alone, with no evidence of drug-drug interaction. In the expansion cohort, the most frequently (≥ 10%) reported non-hematologic Grade ≥ 3 treatment-emergent adverse events were decreased appetite, electrocardiogram QT prolongation, and hypertension in the AML cohort and sepsis, diarrhea, hypotension, pneumonia, and hyperglycemia in the MDS cohort. Overall response rates in the AML and MDS cohorts were 30.0% and 33.3%, respectively; 47.4% and 46.7% of patients who were transfusion dependent at baseline achieved independence. Median overall survival (95% confidence interval) was 9.2 (6.2-14.0) months and 15.8 (9.3-21.9) months, respectively, and response was associated with molecular mutation clearance. Glasdegib + azacitidine in patients with newly diagnosed AML or MDS demonstrated an acceptable safety profile and preliminary evidence of clinical benefits.Trial registration: ClinicalTrials.gov NCT02367456.

A phase 1b/2 study of TP-0903 and decitabine targeting mutant TP53 and/or complex karyotype in patients with untreated acute myeloid leukemia ≥ age 60 years: Phase 1b interim results

7027

Background: TP-0903 is a multi-kinase inhibitor designed to target AXL, a receptor tyrosine kinase, and also inhibits cell cycle regulators such as Chk1/2 and other AML associated kinases. TP-0903 has shown prior anti-tumor activity at a safe dose in solid tumors. In pre-clinical AML studies, TP-0903 shows potent cytotoxicity in TP53 mutant ( TP53m) AML cell lines, an adverse prognostic genomic sub-group of AML. TP-0903 also had synergistic activity with decitabine (dec) in TP53m AML and prolonged survival in xenograft and genetically engineered mouse models. We report here on the initial safety and clinical results from the Leukemia and Lymphoma Society’s ongoing Beat AML phase 1b/2 (Ph1b/2) trial of TP-0903 in combination with dec (ClinicalTrials.gov NCT03013998). Methods: Newly diagnosed AML pts ≥60 years with TP53m and/or complex karyotype (≥3 abnormalities) were selected for a Ph1b/2 dose escalation study of TP-0903 combined with dec. Seven Ph1b pts were given TP-0903 every 28-day cycle from days 1-21 (Dose level (DL) 1 = 37 mg/day) and dec IV days 1-10 (20 mg/m2). A standard 3+3 design was used to evaluate the safety and tolerability. Nine additional patients enrolled onto Ph2 at DL1, but further assessments of safety, pharmacokinetics (PK) and correlative data was used to update the final recommended Ph2 dose (RP2D) of TP-0903 to DL-1 (25 mg/day) with dec. Results: At data cutoff (10Jan2022), 16 total pts were accrued. Ph1b treated 7 pts at DL1, 6 were DLT evaluable, and no DLTs were observed. Ph2 enrolled and treated 9 pts at DL1 before concerns of delayed count recovery led to the reduction of the Ph2 dose of TP-0903 to DL-1 (25 mg/day). For all 16 pts treated at DL1, 1 pt achieved CR, 4 pts CRh, and 1 pt CRi, for a composite CR (CR/CRh/CRi) rate of 37.5% (95% CI, 15.2-64.6), with 4 pts achieving MRD negativity by central flow cytometry. For the remaining 10 pts, 1 pt achieved MLFS (6%), 6 pts had stable disease (37.5%), 1 pt had treatment failure (6%), and 2 pts were not evaluable (12.5%) due to withdrawal of consent and death from early disease progression. Two pts (1 CR and 1 CRh) proceeded to stem cell transplantation. The most common grade 3 and above treatment-related AEs include decreased neutrophil counts (37.5%), platelet counts (31.3%), and anemia (18.8%). Finally, PK and correlative data analysis looking at soluble Axl and Gas6 also supported reduction to DL-1. Conclusions: Initial results with DL1 suggest that TP-0903/dec shows preliminary clinical activity in the prognostically poor TP53m/complex karyotype AML sub-group, with 4 pts achieving MRD negative status out of 6 patients who achieved a CR/CRh/CRi (66%). After further patients were treated on DL1, the toxicity profile and correlative data supported the de-escalation to DL-1 as the RP2D. The Ph2 study is ongoing to determine the clinical activity of this new RP2D (DL-1). Clinical trial information: NCT03013998.

Treatments and outcomes for patients with myelodysplastic syndrome (MDS) by Revised International Prognostic Scoring System (IPSS-R) scores at the Huntsman Cancer Institute (HCI)

e19034

Background: IPSS-R is used to classify risk of disease progression and guide treatment decisions for patients with MDS. Recent data shows mutational profiling may improve the prognostic stratification of MDS. Minimal real-world evidence exists for this population. Methods: A retrospective cohort study assessed real-world, patient-level data from adults diagnosed with MDS between 2010-2019 at HCI. All data were obtained from electronic medical records via chart review. IPSS-R scores were manually calculated from lab and cytogenetic data within 30 days of diagnosis. Patients with an intermediate to very-high IPSS-R score comprised the higher risk (HR) cohort. Primary objectives were to assess treatment patterns & clinical outcomes in the HR cohort. Results: Of the 259 MDS patients at HCI, 90 had an available IPSS-R score at diagnosis (ANC results were missing for 64% of cohort). After excluding clinical trial participants, 65 patients were included. Distribution of IPSS-R scores was: 15% very low (n = 10), 28% low (n = 18), 22% intermediate (n = 14), 23% high (n = 15), & 12% very high (n = 8). The average age of HR subjects was 67 years. 57% of HR patients were female (n = 21), 92% were white (n = 34), 8% (n = 3) had autoimmune disorders, & 8% (n = 3) had cerebrovascular disease. 14% (n = 5) of NGS-tested HR patients had TP53 alterations, while the most frequently altered gene was DNMT3A at 17% (n = 6). In the HR cohort, HMA was used to treat 62% of patients (n = 23) (median 2 cycles), while 27% (n = 10) received no MDS-related medication, and 11% (n = 4) received other MDS-related medications (lenalidomide, ruxolitinib, hydroxyurea). Second-line treatment was received by 9% of HR patients (n = 3). 35% of HR patients (n = 13) underwent stem-cell transplantation. Complete or partial response was achieved by 21% of HR patients treated with a HMA (n = 5); the remaining patients had stable disease (39%, n = 9), disease progression (26%, n = 6), or died (4%, n = 1). Transfusion independence was achieved by 60% of HMA-treated HR patients (n = 3) (median duration = 151 days from treatment initiation). Disease progression or death occurred in 89% of HR patients (n = 33) during the study period with a median progression free survival (PFS) of 8.3 months. PFS was significantly shorter for HR patients with TP53 alterations compared to wild-type (HR: 5.75, 95% CI (1.34-24.64)), using cox regression. Median overall survival for HR patients was 18.8 months. Conclusions: These results show HR patients have a low likelihood of achieving & maintaining complete remission. In addition, limited treatment options for HR patients further reveals a large unmet need. Specific genetic profiles may indicate the need for more aggressive treatments and management of relevant comorbidities. Updated results will be presented, including LR patients & economic outcomes.

A phase 1b study of once-weekly carfilzomib combined with lenalidomide and dexamethasone in patients with newly diagnosed multiple myeloma

Twice‐weekly carfilzomib with lenalidomide‐dexamethasone (Rd) is an effective regimen for newly diagnosed multiple myeloma (NDMM). Here we evaluated once‐weekly carfilzomib with Rd (once‐weekly KRd) in NDMM patients. The NDMM patients were enrolled regardless of transplant eligibility. Patients received carfilzomib on days 1, 8, and 15; lenalidomide 25 mg on days 1‐21; and dexamethasone 40 mg on carfilzomib days (also day 22 for cycles 1‐8) for ≤18, 28‐day cycles. Enrollment initiated in a carfilzomib 20/70 mg/m² (20 mg/m² on cycle one, day 1; 70 mg/m² thereafter) NDMM dose‐expansion arm, which was suspended because of serious adverse events. After evaluation of dose‐limiting toxicities in a two‐step‐up dose‐evaluation cohort, an NDMM dose‐expansion arm (carfilzomib 20/56 mg/m²) was opened. Fifty‐one NDMM patients were enrolled in dose‐finding and dose‐expansion cohorts. Results are presented for the carfilzomib 56 mg/m² NDMM dose‐expansion arm (n = 33). The grade ≥ 3 treatment‐emergent AE (TEAE) rate was 63.6%. Twenty‐five patients underwent stem cell collection; 18 proceeded to auto stem cell transplant, and five resumed KRd on study after autoSCT. The overall response rate (ORR) based on best overall response by cycle four was 97.0% (≥very good partial response [VGPR], 69.7%) in the NDMM 20/56 mg/m² cohort. In patients who did not receive autoSCT (n = 15), the median number of cycles was 16.0; ORR was 93.3% (≥VGPR, 80.0%). At a median follow‐up of 8.1 months, median progression‐free survival was not reached. Once‐weekly KRd (carfilzomib 56 mg/m²) had a favorable safety profile and promising activity in NDMM, supporting the use of this regimen in this setting.

Glasdegib in combination with azacitidine (AZA) in patients (pts) with untreated higher-risk myelodysplastic syndromes (MDS), acute myeloid leukemia (AML) and chronic myelomonocytic leukemia (CMML): Effects on marrow recovery and transfusion independence

7526

Background: Glasdegib, an oral inhibitor of the Hedgehog signaling pathway, is approved in the USA in combination with low-dose cytarabine to treat pts with newly diagnosed AML unable to receive intensive chemotherapy due to comorbidities or age (≥75 years). Glasdegib + AZA showed promising remission rates and overall survival with a generally well-tolerated and manageable safety profile in an analysis of BRIGHT MDS & AML 1012 in pts with MDS, AML and CMML. Here we evaluate early hematopoietic recovery and transfusion independence with glasdegib + AZA in this ongoing Phase Ib study. Methods: Untreated pts with MDS, AML and CMML ineligible for intensive chemotherapy received glasdegib (100 mg QD) + AZA (75 mg/m2/D on D1–7 q28D). Data cutoff: Sept 11, 2019. Results: Among pts with MDS (n=30; including 3 with CMML), median duration of treatment was 5.0 months (range, 0.4–15.5). Recovery of absolute neutrophil count (ANC), hemoglobin (Hb) and platelets at 2 thresholds started in cycle (Cyc) 1 (Table). Early platelet recovery correlated with response to treatment; 54% (7/13) of pts with platelets ≥100,000/µL at Cyc 2, D1 achieved complete or partial remission vs 0% (0/13) of pts with <100,000/µL, P=0.002. Start of Cyc 2 was delayed due to AEs in 8% (2/26) of pts. 54% (7/13) of evaluable pts transfusion dependent at baseline (BL) became transfusion independent. Among pts with AML (n=30), median duration of treatment was 5.0 months (range, 0.3–14.9). ANC, Hb and platelet recoveries started in Cyc 1 (Table). 9% (2/23) of pts had Cyc 2 dose delays due to AEs. 64% (9/14) of evaluable pts transfusion dependent at BL became transfusion independent. Clinical trial information: NCT02367456 . Conclusions: Glasdegib + AZA shows promising rates of survival with early marrow recovery in the up-front treatment of pts with MDS, AML and CMML ineligible for intensive chemotherapy. The association between early hematopoietic recovery and efficacy in the MDS cohort merits further study. [Table: see text]

Clinical and economic analysis of patients with acute myeloid leukemia by FLT3 status and midostaurin use at a Comprehensive Cancer Center

INTRODUCTION

Identification of cytogenetic and molecular abnormalities has become vital for the appropriate treatment of acute myeloid leukemia (AML). One of the most common molecular alterations in AML is the constitutive activation by internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3).

METHODS

This observational, retrospective, cohort study at the Huntsman Cancer Institute (HCI) had two time periods: 1) a historical pre-midostaurin time period which consisted of the FLT3 mutated (FLT3m) and FLT3 wild type (FLT3wt) cohorts from January 1, 2007, to December 31, 2016, and 2) a post-midostaurin cohort which consisted of the FLT3 mutated midostaurin-user cohort (early mido) from May 01, 2017 to December 31, 2018.

RESULTS

In total, 39 patients were included in the FLT3m cohort, 61 in the FLT3wt cohort, and seven in the early mido cohort. FLT3m patients spent fewer days in the hospital during the first consolidation regimen and received fewer consolidation cycles compared to FLT3wt patients. Overall survival (OS) was similar between FLT3m and FLT3wt patients. For patients without hematopoietic stem cell transplant, OS was significantly shorter for FLT3m patients compared to FLT3wt patients. Mean AML related inpatient charges and physician charges for FLT3m patients were significantly higher than FLT3wt patients.

CONCLUSION

The FLT3 mutation is historically associated with a shorter time to transplant and increased total health care charges. More information is needed to evaluate the real-world treatment strategies for FLT3-mutated patients in the presence of FLT3 inhibitors and the impact of these treatment strategies on clinical and economic outcomes.

Weekly carfilzomib, lenalidomide, and dexamethasone in relapsed or refractory multiple myeloma: A phase 1b study

Twice‐weekly carfilzomib (27 mg/m²) with lenalidomide‐dexamethasone (KRd) is a standard‐of‐care in relapsed or refractory multiple myeloma (RRMM). This phase 1b study evaluated KRd with once‐weekly carfilzomib in RRMM. Patients received carfilzomib (30‐minute infusion; 56 or 70mg/m²) on days 1, 8, and 15; lenalidomide 25 mg on days 1‐21; and dexamethasone 40 mg on days 1, 8, 15, and 22 (day 22 omitted for cycles 9+) of 28‐day cycles. Primary objective was safety/tolerability; efficacy was a secondary objective. Fifty‐six RRMM patients enrolled: 22 during dose evaluation (56‐mg/m², n = 10; 70‐mg/m², n = 12) and 34 during dose expansion (all initiated dosing at 70 mg/m²). After 2 fatal adverse events (AEs) during 70‐mg/m² dose expansion, dosage reduction to 56 mg/m² was permitted. Results are presented for carfilzomib 56‐mg/m² (n = 10) and 70‐mg/m² groups (dose evaluation/expansion; n = 46). Median carfilzomib dose was 53.2 mg/m² (56‐mg/m² group) and 62.4 mg/m² (70‐mg/m² group). Grade ≥3 AE rates were 70.0% (56 mg/m²) and 69.6% (70 mg/m²). Overall response rates were 90.0% (56 mg/m²) and 89.1% (70 mg/m²); ≥very good partial response rates were 50.0% (56 mg/m²) and 73.9% (70 mg/m²). Once‐weekly KRd was active with acceptable toxicity in RRMM, supporting further evaluation of this regimen.

A randomized phase II trial of CX-01 with standard therapy in elderly patients with acute myeloid leukemia (AML)

7001

Background: Elderly AML patients have poor outcomes irrespective of therapy. CX-01 is a low anticoagulant heparin derivative that retains heparin’s ability to alter the activity of the CXCL12/CXCR4 axis, P-selectin, extracellular histones, and Platelet Factor 4. A pilot study of CX-01 combined with standard therapy for AML led to a complete remission (CR) rate of 92% ( Blood Adv 2:381, 2018). We conducted a randomized, dose-finding study of the same combination in newly diagnosed elderly AML patients. Methods: 76 fit patients older than 59 were randomized to induction with idarubicin and cytarabine on a 7+3 schedule only (Group 1); 7+3 with a lower dose of CX-01 (0.125 mg/kg/hour) (Group 2); or 7+3 with a higher dose of CX-01 (0.25 mg/kg/hour) (Group 3). Patients in CR received consolidation therapy consisting of up to 3 cycles of intermediate dose cytarabine (1000 mg/m2 every 12 hours on Days 1, 3, 5) without or with the same dose of CX-01 for Groups 1, 2, and 3, respectively. CX-01 was given as a continuous infusion after a 4 mg/kg bolus until completion of chemotherapy. Results: 66 of 75 treated patients were evaluable for response. Ten patients were not evaluable due to withdrawal of consent (6 patients), introduction of midostaurin after its approval (3 patients), or death due to hepatic sinusoidal obstructive disease at Day 21 (1 patient in Group 2). We present results for evaluable patients and not on an intent to treat basis. Baseline characteristics were similar across groups. The composite CR rate (CR + CRi) was highest for patients in Group 3 with 89% patients achieving a composite CR as compared to 58% and 50% in Groups 1 and 2, respectively. Kaplan-Meier curves indicated a statistically significant improvement in event free survival (EFS) (P = 0.019) and a non-significant trend (P = 0.10) to improvement in OS in Group 3 as compared to Group 1. Groups 1 and 2 were comparable for EFS and OS. CX-01 was well tolerated without increased incidence of bleeding in Groups 2 and 3. Conclusions: The encouraging CR rate and EFS in elderly fit patients with newly diagnosed AML suggests that CX-01 may potentiate the efficacy of standard AML induction therapy. A randomized study to confirm these findings with the higher dose of CX-01 is warranted. Clinical trial information: NCT02873338.

Quizartinib, an FLT3 inhibitor, as monotherapy in patients with relapsed or refractory acute myeloid leukaemia: an open-label, multicentre, single-arm, phase 2 trial

BACKGROUND

Old age and FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutations in patients with acute myeloid leukaemia are associated with early relapse and poor survival. Quizartinib is an oral, highly potent, and selective next-generation FLT3 inhibitor with clinical antileukaemic activity in relapsed or refractory acute myeloid leukaemia. We aimed to assess the efficacy and safety of single-agent quizartinib in patients with relapsed or refractory acute myeloid leukaemia.

METHODS

We did an open-label, multicentre, single-arm, phase 2 trial at 76 hospitals and cancer centres in the USA, Europe, and Canada. We enrolled patients with morphologically documented primary acute myeloid leukaemia or acute myeloid leukaemia secondary to myelodysplastic syndromes and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 into two predefined, independent cohorts: patients who were aged 60 years or older with relapsed or refractory acute myeloid leukaemia within 1 year after first-line therapy (cohort 1), and those who were 18 years or older with relapsed or refractory disease following salvage chemotherapy or haemopoietic stem cell transplantation (cohort 2). Patients with an FLT3-ITD allelic frequency of more than 10% were considered as FLT3-ITD positive, whereas all other patients were considered as FLT3-ITD negative. Patients received quizartinib once daily as an oral solution; the initial 17 patients received 200 mg per day but the QTcF interval was prolonged for more than 60 ms above baseline in some of these patients. Subsequently, doses were amended for all patients to 135 mg per day for men and 90 mg per day for women. The co-primary endpoints were the proportion of patients who achieved a composite complete remission (defined as complete remission + complete remission with incomplete platelet recovery + complete remission with incomplete haematological recovery) and the proportion of patients who achieved a complete remission. Efficacy and safety analyses included all patients who received at least one dose of quizartinib (ie, the intention-to-treat population). Patients with a locally assessed post-treatment bone marrow aspirate or biopsy were included in efficacy analyses by response; all other patients were considered to have an unknown response. This study is registered with ClinicalTrials.gov, number NCT00989261, and with the European Clinical Trials Database, EudraCT 2009-013093-41, and is completed.

FINDINGS

Between Nov 19, 2009, and Oct 31, 2011, a total of 333 patients were enrolled (157 in cohort 1 and 176 in cohort 2). In cohort 1, 63 (56%) of 112 FLT3-ITD-positive patients and 16 (36%) of 44 FLT3-ITD-negative patients achieved composite complete remission, with three (3%) FLT3-ITD-positive patients and two (5%) FLT3-ITD-negative patients achieving complete remission. In cohort 2, 62 (46%) of 136 FLT3-ITD-positive patients achieved composite complete remission with five (4%) achieving complete remission, whereas 12 (30%) of 40 FLT3-ITD-negative patients achieved composite complete remission with one (3%) achieving complete remission. Across both cohorts (ie, the intention-to-treat population of 333 patients), grade 3 or worse treatment-related treatment-emergent adverse events in 5% or more of patients were febrile neutropenia (76 [23%] of 333), anaemia (75 [23%]), thrombocytopenia (39 [12%]), QT interval corrected using Fridericia's formula (QTcF) prolongation (33 [10%]), neutropenia (31 [9%]), leucopenia (22 [7%]), decreased platelet count (20 [6%]), and pneumonia (17 [5%]). Serious adverse events occurring in 5% or more of patients were febrile neutropenia (126 [38%] of 333; 76 treatment related), acute myeloid leukaemia progression (73 [22%]), pneumonia (40 [12%]; 14 treatment related), QTcF prolongation (33 [10%]; 32 treatment related), sepsis (25 [8%]; eight treatment related), and pyrexia (18 [5%]; nine treatment related). Notable serious adverse events occurring in less than 5% of patients were torsades de pointes (one [<1%]) and hepatic failure (two [1%]). In total, 125 (38%) of 333 patients died within the study treatment period, including the 30-day follow-up. 18 (5%) patients died because of an adverse event considered by the investigator to be treatment related (ten [6%] of 157 patients in cohort 1 and eight [5%] of 176 in cohort 2.

INTERPRETATION

Single-agent quizartinib was shown to be highly active and generally well tolerated in patients with relapsed or refractory acute myeloid leukaemia, particularly those with FLT3-ITD mutations. These findings confirm that targeting the FLT3-ITD driver mutation with a highly potent and selective FLT3 inhibitor is a promising clinical strategy to help improve clinical outcomes in patients with very few options. Phase 3 studies (NCT02039726; NCT02668653) will examine quizartinib at lower starting doses.

FUNDING

Ambit Biosciences/Daiichi Sankyo.

CPX-351 exhibits potent and direct ex vivo cytotoxicity against AML blasts with enhanced efficacy for cells harboring the FLT3-ITD mutation

PURPOSE

Identify AML patients most likely to respond to CPX-351, a nano-scale liposome formulation containing cytarabine and daunorubicin co-encapsulated at a 5:1 molar ratio.

METHODS

We examined the ex vivo cytotoxic activity of CPX-351 against leukemic cells isolated from 53 AML patients and an additional 127 samples including acute lymphoblastic leukemia, myelodysplastic syndrome/myeloproliferative neoplasms, or chronic lymphocytic leukemia/lymphoma. We assessed activity with respect to common molecular lesions and used flow cytometry to assess CPX-351 cellular uptake.

RESULTS

AML specimen sensitivity to CPX-351 was similar across conventional risk groups. FLT3-ITD cases were five-fold more sensitive to CPX-351. CPX-351 was active across other indications with nearly all cases exhibiting IC₅₀ values markedly lower than reported 72-h plasma drug concentration in patients receiving CPX-351. The range and distribution of CPX-351 IC₅₀ values were comparable for AML, CLL, and ALL, whereas MDS/MPN cases were less sensitive. CPX-351 uptake analysis revealed a correlation between uptake of CPX-351 and cytotoxic potency.

CONCLUSIONS

Our findings are consistent with clinical data, in which CPX-351 activity is retained in high-risk AML patients. Ex vivo analysis of cytotoxic potency may provide a means to identify specific AML subsets, such as FLT3-ITD, that benefit most from CPX-351 and warrant additional clinical evaluation.

FGF2 from Marrow Microenvironment Promotes Resistance to FLT3 Inhibitors in Acute Myeloid Leukemia

Potent FLT3 inhibitors, such as quizartinib (AC220), have shown promise in treating acute myeloid leukemia (AML) containing FLT3 internal tandem duplication (ITD) mutations. However, responses are not durable and resistance develops within months. In this study, we outline a two-step model of resistance whereby extrinsic microenvironmental proteins FLT3 ligand (FL) and fibroblast growth factor 2 (FGF2) protect FLT3-ITD+ MOLM14 cells from AC220, providing time for subsequent accumulation of ligand-independent resistance mechanisms. FL directly attenuated AC220 inhibition of FLT3, consistent with previous reports. Conversely, FGF2 promoted resistance through activation of FGFR1 and downstream MAPK effectors; these resistant cells responded synergistically to combinatorial inhibition of FGFR1 and FLT3. Removing FL or FGF2 from ligand-dependent resistant cultures transiently restored sensitivity to AC220, but accelerated acquisition of secondary resistance via reactivation of FLT3 and RAS/MAPK signaling. FLT3-ITD AML patients treated with AC220 developed increased FGF2 expression in marrow stromal cells, which peaked prior to overt clinical relapse and detection of resistance mutations. Overall, these results support a strategy of early combination therapy to target early survival signals from the bone marrow microenvironment, in particular FGF2, to improve the depth of response in FLT3-ITD AML. Cancer Res; 76(22); 6471-82. ©2016 AACR.

CD229 is expressed on the surface of plasma cells carrying an aberrant phenotype and chemotherapy-resistant precursor cells in multiple myeloma

Multiple Myeloma (MM) is a plasma cell (PC) malignancy, which despite significant therapeutic advances, is still considered incurable. This is due to the persistence of chemotherapy-resistant minimal residual disease in the patients' bone marrow (BM) after an effective induction therapy. Immunotherapies targeting surface molecules expressed on the bulk of tumor cells and the chemotherapy-resistant, myeloma-propagating cells could play a central role in this clinical setting. We recently described surface molecule CD229 as a potential therapeutic target for MM. In our current study we assessed the expression of CD229 on different PC subtypes and on cells with a myeloma-propagating phenotype in a total of 77 patients with PC dyscrasias independently at 2 different cancer centers. We found that CD229 was strongly and homogeneously overexpressed on the PC of patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering myeloma, MM, and PC leukemia. CD229 was particularly overexpressed on those PC showing an abnormal phenotype such as expression of CD56. Most importantly, CD229 was also highly expressed on those cells in the patients' BM displaying the phenotype of chemotherapy-resistant and myeloma-propagating cells. In conclusion, our combined findings suggest that immunotherapies targeting CD229 will not only be effective for the bulk of tumor cells but will also help to eradicate chemotherapy-resistant cells remaining in the patients' BM after induction treatment. Hopefully, the design of CD229-specific monoclonal antibodies or chimeric antigen receptor-transduced T cells will help to achieve prolonged remissions or even cures in MM patients.

Abstract 984: FGF2 from the bone marrow promotes resistance to FLT3 inhibitors in AML

Introduction: Activating mutations in the FLT3 kinase are present in ∼25% of newly diagnosed acute myeloid leukemia (FLT3+ AML) patients and confer a poor prognosis. Treatment with FLT3 inhibitors is initially effective, but residual leukemia cells survive in the bone marrow microenvironment and clinical resistance develops within months. We tested proteins from the bone marrow microenvironment for their ability to protect FLT3-ITD+ MOLM14 cells from AC220, and found that FLT3 ligand (FL) and fibroblast growth factor 2 (FGF2) were among the most protective.

Results: Consistent with previous reports, FL restored downstream FLT3 phosphorylation and signaling in the presence of the FLT3 inhibitor quizartinib (AC220). In contrast, FGF2 activated FGFR1 and the MAPK pathway, circumventing the effects of AC220 on MOLM14 cells and increasing cell survival. To model the effect of prolonged contact with the bone marrow microenvironment, MOLM14 cells were cultured continuously in FGF2 and AC220. Under these conditions, 4/4 cultures developed AC220 resistance and resumed exponential growth after 7 weeks. Development of FGF2-mediated resistance was accelerated compared to MOLM14 cultured continuously in AC220 alone (only 2/4 resistant cultures,12 weeks). Long-term resistant cultures grown in FGF2 were protected from AC220 across a wide range of concentrations, but concurrent treatment with the FGFR inhibitor PD173074 synergistically overcame FGF2-mediated protection.

Serial bone marrow biopsies of patients on the AC220 phase II clinical trial were analyzed by immunohistochemistry. Quantification of FGF2 revealed a significant increase in AC220 during treatment (34% to 51% after one month, p&lt;0.01) and FGF2 expression peaked at 61% after 4 months (p&lt;0.01), indicating that residual leukemia cells exist in a microenvironment abundant in FGF2. To test if FGFR inhibition could overcome FGF2-mediated protection from bone marrow stroma, we grew MOLM14 cells in co-culture with an FGF2-expressing stromal cell line (HS-5). HS-5 co-culture increased viability in MOLM14 in AC220 treatment, however concurrent PD173074 treatment abrogated stromal cell protection suggesting that combination of FLT3 and FGFR inhibitors may overcome resistance mediated by the microenvironment.

Conclusions: FGF2 ligand-induced activation of the FGFR1/MAPK pathway leads to protection from AC220 in vitro and eventual development of resistance. FGF2-mediated resistance can be overcome by concurrent FLT3 and FGFR inhibition. Consistent with our in vitro model, patients treated with AC220 had increasing FGF2 in their bone marrow, which peaked prior to resistance and relapse, suggesting that combined FLT3 and FGFR inhibitors may improve the durability of response. Our results provide an approach to develop rational inhibitor combinations that cirucumvent ligand-mediated pathways of resistance.

Citation Format: Jacqueline Martinez, Elie Traer, Nathalie Javidi-Sharifi, Anupriya Agarwal, Jennifer Dunlap, Isabel English, Tibor Kovacsovics, Jeffrey Tyner, Melissa Wong, Brian Druker. FGF2 from the bone marrow promotes resistance to FLT3 inhibitors in AML. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 984. doi:10.1158/1538-7445.AM2015-984

Multivariate analysis of factors affecting overall survival, event free survival, and 60-day mortality among AML patients treated with CPX-351 or intensive chemotherapy

7100

Background: CPX-351 encapsulates cytarabine (CYT) and daunorubicin (DNR) at a 5:1 molar ratio within liposomes, enabling preferential drug uptake within leukemic blasts and intracellular release, potentially enhancing efficacy in AML. A pair of randomized Phase IIb studies in newly diagnosed older patients (pts) and younger 1st relapse AML pts reported improved rates of morphologic leukemia-free state, CR + CRi, and significant improvements in survival among previously untreated high risk (secondary) pts and among poor-risk 1st relapse pts. This report presents the results of the multivariate analyses performed on all pts treated in both studies. Methods: Patients 60-75 yo with newly diagnosed AML and ≤ 65 yo with 1st relapse AML and ECOG PS= 0-2, SCR < 2.0 mg/dL, total bilirubin < 2.0 mg/dL, ALT/AST <3x ULN, and LVEF ≥ 50% were eligible. Pts with APL, DNR exposure >368 mg/m2, active CNS leukemia, and uncontrolled infections were excluded. Pts were randomized 2:1 to receive up to 2 inductions and 2 consolidations with CPX-351 (100 u/m2; D 1, 3, 5) or CYT + DNR (7+3) for newly diagnosed pts or investigator’s choice of salvage chemotherapy for relapsed pts. Allogeneic transplantation was permitted. Univariate and multivariate Cox and logistic regression were used to assess associations between baseline characteristics and overall (OS) and event-free survival (EFS) and 60-day mortality for all pts. The multivariate employed stepwise selection to identify statistically significant prognostic factors after accounting for potential treatment effects. Results: Patient characteristics including cytogenetics were well balanced. Significant negative prognostic factors affecting OS, EFS, and 60-day mortality included relapsed disease (Study 205 participation, HR=2.13, p<0.001), adverse cytogenetics (HR=1.52, p=0.024), and low (<3g/dL) serum albumin (HR=1.82, p=0.005). CPX-351 treatment was a significant positive factor in EFS (HR=0.62, p=0.006). Conclusions: This analysis identified and quantitated disease specific (adverse cytogenetics) and patient specific (albumin<3gm/dL) factors that can be used to better design future studies. Clinical trial information: NCT00788892 and NCT00822094.

Kinase pathway dependence in primary human leukemias determined by rapid inhibitor screening

Kinases are dysregulated in most cancers, but the frequency of specific kinase mutations is low, indicating a complex etiology in kinase dysregulation. Here, we report a strategy to rapidly identify functionally important kinase targets, irrespective of the etiology of kinase pathway dysregulation, ultimately enabling a correlation of patient genetic profiles to clinically effective kinase inhibitors. Our methodology assessed the sensitivity of primary leukemia patient samples to a panel of 66 small-molecule kinase inhibitors over 3 days. Screening of 151 leukemia patient samples revealed a wide diversity of drug sensitivities, with 70% of the clinical specimens exhibiting hypersensitivity to one or more drugs. From this data set, we developed an algorithm to predict kinase pathway dependence based on analysis of inhibitor sensitivity patterns. Applying this algorithm correctly identified pathway dependence in proof-of-principle specimens with known oncogenes, including a rare FLT3 mutation outside regions covered by standard molecular diagnostic tests. Interrogation of all 151 patient specimens with this algorithm identified a diversity of kinase targets and signaling pathways that could aid prioritization of deep sequencing data sets, permitting a cumulative analysis to understand kinase pathway dependence within leukemia subsets. In a proof-of-principle case, we showed that in vitro drug sensitivity could predict both a clinical response and the development of drug resistance. Taken together, our results suggested that drug target scores derived from a comprehensive kinase inhibitor panel could predict pathway dependence in cancer cells while simultaneously identifying potential therapeutic options.

A comparison of CR versus CRi response following CPX-351 treatment of newly diagnosed AML in elderly patients (pts)

6601

Background: A Phase 2b study randomized untreated elderly AML pts to CPX-351 or 7+3. CPX-351 improved leukemia clearance (88% v 71%, <5% marrow blasts), CR+CRi rate (67% v 51%), and was particularly effective in pts with adverse karyotype and antecedent hematologic disorders (sAML). Survival following CRi is usually inferior compared to CR. CPX-351 markedly prolongs plasma drug levels and maintains the 5:1 molar ratio for optimal leukemic cell killing potentially delaying hematologic recovery among CRi patients. Consequently, we compared the characteristics and outcomes of pts achieving CR v CRi. Methods: Untreated AML pts, aged 60-75, PS= 0-2, SCr < 2.0 mg/dL, total bilirubin <2.0 mg/dL, ALT/AST <3 x ULN, and LVEF ≥50% were eligible. Pts were randomized 2:1 to receive up to 2 inductions and 2 consolidations with CPX-351 (100 u/m2; D 1, 3, 5; 90 min infusion) or 7+3 (cytarabine=100 mg/m2 and daunorubicin=60 mg/m2). Consolidation with stem cell transplantation (SCT) was permitted. The 1o endpoint was CR+CRi rate. The 7+3 control arm had only a single CRi among 21 responders. The CPX-351 arm had 15 CRi (27%) and 41 CR (73%) allowing a CR v CRi comparison to be made. Results: CR and CRi pts were balanced by age, race, and PS. The CRi group had more males (87% v 51%), more baseline WBC>20K (27% v 15%), and more adverse karyotype (40% v 27%) and sAML (47% v 29%). A smaller proportion of CRi pts received post-remission chemotherapy (47% v 73%) but had similar rates of SCT (13% v 20%). Most CRi pts had delayed platelet recovery (80%). By 1-year more CRi pts had relapsed (54% v 39%) and more had died (54% v 34%). Contributing causes included: relapsed AML (7 CRi v 10 CR pts), complications post SCT (1 CRi v 1 CR pt), chemotherapy complications (0 CRi v 2 CR pts) and unknown causes (0 CRi v 1 CR pt). The survival curves were not significantly different (p=0.39). Conclusions: More CRi patients had adverse karyotype and sAML and most (53%) received no post remission chemotherapy. Survival was not significantly different compared to CR patients but was markedly better than that of non-responders. These data suggest that CRi following CPX-351 provides clinically meaningful benefit, a finding that needs to be confirmed in a larger randomized study.

Clofarabine plus cytarabine compared with cytarabine alone in older patients with relapsed or refractory acute myelogenous leukemia: results from the CLASSIC I Trial

PURPOSE

To compare the receipt of clofarabine plus cytarabine (Clo+Ara-C arm) with cytarabine (Ara-C arm) in patients ≥ 55 years old with refractory or relapsed acute myelogenous leukemia (AML).

PATIENTS AND METHODS

Patients were randomly assigned to receive either clofarabine (Clo) 40 mg/m(2) or a placebo followed by Ara-C 1 g/m(2) for five consecutive days. The primary end point was overall survival (OS). Secondary end points included event-free survival (EFS), 4-month EFS, overall remission rate (ORR; complete remission [CR] plus CR with incomplete peripheral blood count recovery), disease-free survival (DFS), duration of remission (DOR), and safety.

RESULTS

Among 320 patients with confirmed AML (median age, 67 years), the median OS was 6.6 months in the Clo+Ara-C arm and 6.3 months in the Ara-C arm (hazard ratio [HR], 1.00; 95% CI, 0.78 to 1.28; P = 1.00). The ORR was 46.9% in the Clo+Ara-C arm (35.2% CR) versus 22.9% in the Ara-C arm (17.8% CR; P < .01). EFS (HR: 0.63; 95% CI, 0.49 to 0.80; P < .01) and 4-month EFS (37.7% v 16.6%; P < .01) favored the Clo+Ara-C arm compared with Ara-C arm, respectively. DFS and DOR were similar in both arms. Overall 30-day mortality was 16% and 5% for CLO+Ara-C and Ara-C arms, respectively. In the Clo+Ara-C and Ara-C arms, the most common grade 3 to 4 toxicities were febrile neutropenia (47% v 35%, respectively), hypokalemia (18% v 11%, respectively), thrombocytopenia (16% v 17%, respectively), pneumonia (14% v 10%, respectively), anemia (13% v 0%, respectively), neutropenia (11% v 9%, respectively), increased AST (11% v 2%, respectively), and increased ALT (10% v 3%, respectively).

CONCLUSION

Although the primary end point of OS did not differ between arms, Clo+Ara-C significantly improved response rates and EFS. Study follow-up continues, and the role of clofarabine in the treatment of adult patients with AML continues to be investigated.

Prevention and management of asparaginase/pegasparaginase-associated toxicities in adults and older adolescents: recommendations of an expert panel

The rapidly increasing use of pegasparaginase (pegASNase) in adults, after a half century of use of asparaginase (ASNase) in children, has prompted a need for guidelines in the management and prevention of toxicities of asparagine depletion in adults. Accordingly, an initial set of recommendations are provided herein. Major advantages of pegASNase are its 2-3-week duration of action, in contrast to less than 3 days with native ASNase, and the flexibility of intravenous or intramuscular administration of pegASNase and associated patient and physician convenience. The most frequent toxicities of both types of ASNase are hepatic and pancreatic, with pancreatitis being the most serious. Other toxicities are hypersensitivity reactions, thrombosis, nausea/vomiting, and fatigue. Whether or not the replacement of one dose of pegASNase for 6-9 doses of native ASNase can be achieved in adults with similar efficacy and acceptable toxicities to those achieved in children remains to be established.

Outpatient consolidation treatment with clofarabine in a phase 2 study of older adult patients with previously untreated acute myelogenous leukemia

This report describes outpatient (OP) administration of clofarabine in older patients (≥60 years) with untreated acute myelogenous leukemia (AML). Overall, 112 patients underwent clofarabine induction. Clofarabine was administered to 35 OPs for a total of 72 OP cycles, with 81% of these cycles representing consolidation treatment. Median length of hospital stay was 0-6 days and 5-25 days across OP and inpatient (IP) cycles, respectively. The most common adverse events (AEs) were nausea, vomiting, diarrhea, febrile neutropenia, edema, hypokalemia and pneumonia. The overall frequency of treatment-emergent grade ≥3 AEs and serious AEs was generally not different with IP or OP administration of clofarabine. No deaths were reported within 30 days following OP or IP consolidation cycles. In the appropriately selected older patient, OP administration of clofarabine consolidation appears feasible, is as well tolerated as IP administration and has potential to contribute to the quality of life in elderly patients with AML.

Value of allogeneic versus autologous stem cell transplantation and chemotherapy in patients with myelodysplastic syndromes and secondary acute myeloid leukemia. Final results of a prospective randomized European Intergroup Trial

BACKGROUND

Allogeneic stem cell transplantation is usually considered the only curative treatment option for patients with advanced or transformed myelodysplastic syndromes in complete remission, but post-remission chemotherapy and autologous stem cell transplantation are potential alternatives, especially in patients over 45 years old.

DESIGN AND METHODS

We evaluated, after intensive anti-leukemic remission-induction chemotherapy, the impact of the availability of an HLA-identical sibling donor on an intention-to treat basis. Additionally, all patients without a sibling donor in complete remission after the first consolidation course were randomized to either autologous peripheral blood stem cell transplantation or a second consolidation course consisting of high-dose cytarabine.

RESULTS

The 4-year survival of the 341 evaluable patients was 28%. After achieving complete remission, the 4-year survival rates of patients under 55 years old with or without a donor were 54% and 41%, respectively, with an adjusted hazard ratio of 0.81 (95% confidence interval [95% CI], 0.49-1.35) for survival and of 0.67 (95% CI, 0.42-1.06) for disease-free survival. In patients with intermediate/high risk cytogenetic abnormalities the hazard ratio in multivariate analysis was 0.58 (99% CI, 0.22-1.50) (P=0.14) for survival and 0.46 (99% CI, 0.22-1.50) for disease-free survival (P=0.03). In contrast, in patients with low risk cytogenetic characteristics the hazard ratio for survival was 1.17 (99% CI, 0.40-3.42) and that for disease-free survival was 1.02 (99% CI, 0.40-2.56). The 4-year survival of the 65 patients randomized to autologous peripheral blood stem cell transplantation or a second consolidation course of high-dose cytarabine was 37% and 27%, respectively. The hazard ratio in multivariate analysis was 1.22 (95% CI, 0.65-2.27) for survival and 1.02 (95% CI, 0.56-1.85) for disease-free survival.

CONCLUSIONS

Patients with a donor and candidates for allogeneic stem cell transplantation in first complete remission may have a better disease-free survival than those without a donor in case of myelodysplastic syndromes with intermediate/high-risk cytogenetics. Autologous peripheral blood stem cell transplantation does not provide longer survival than intensive chemotherapy.