Sorafenib plus intensive chemotherapy improves survival in patients with newly diagnosed, FLT3-internal tandem duplication mutation-positive acute myeloid leukemia

BACKGROUND

The addition of midostaurin to induction chemotherapy improves survival in younger patients with newly diagnosed, FLT3-mutated acute myeloid leukemia (AML). Sorafenib is a potent multikinase inhibitor with efficacy when given as monotherapy. The authors investigated whether the addition of sorafenib to intensive induction chemotherapy improves outcomes in patients with FLT3-internal tandem duplication (ITD)-mutated AML.

METHODS

In total, 183 patients who were newly diagnosed with FLT3-ITD-mutated AML between February 2001 and December 2017 were identified. Of these, 79 patients (43%) underwent intensive chemotherapy with the addition of sorafenib, and 104 (57%) received intensive chemotherapy alone. Propensity score matching identified 42 patients in each cohort.

RESULTS

The overall response rate was 98% in the sorafenib cohort and 83% in the intensive chemotherapy cohort (P = .057). The median follow-up was 54 months. The median event-free survival was 35 months in the sorafenib cohort and 8 months in the intensive chemotherapy cohort (P = .019), and the median overall survival was 42 and 13 months, respectively (P = .026). With censoring at the time of allogeneic stem cell transplantation, the median event-free survival was 31 and 8 months in the sorafenib and intensive therapy cohorts, respectively (P = .031), and the median overall survival was not reached and 10 months, respectively (P = .001). Multivariate Cox proportional hazards models confirmed that treatment with sorafenib was a favorable prognostic factor (P = .009; hazard ratio, 0.558; 95% CI, 0.360-0.865).

CONCLUSIONS

The addition of sorafenib improves survival in patients with FLT3-ITD-mutated AML regardless of whether they undergo allogeneic stem cell transplantation.

A phase 2 study of pracinostat combined with ruxolitinib in patients with myelofibrosis

Although ruxolitinib improves symptoms and splenomegaly in patients with advanced myelofibrosis, whether this agent is truly disease-modifying remains unclear. Histone deacetylase inhibitors (HDACi) downregulate JAK2 via interference with chaperone function. Pracinostat, a pan-HDACi, has modest single-agent activity in myelofibrosis. We conducted a single-institution, phase 2, investigator-initiated trial of ruxolitinib plus pracinostat (begun after 12 weeks of ruxolitinib) in 25 patients with myelofibrosis, of whom 20 received both agents. Sixteen (80%) patients had objective responses (all 'clinical improvement'). The rate of spleen response (by palpation) was 74%, and that of symptom response 80%. Most responses occurred prior to pracinostat initiation. Three patients experienced improvement in bone marrow fibrosis, and one a near-complete molecular response after two years on study treatment. All patients discontinued pracinostat and are currently off-study. Pracinostat interruptions and dose reductions were frequent, often due to worsening anemia. These findings do not support continued development of pracinostat in myelofibrosis.

Early T precursor acute lymphoblastic leukaemia/lymphoma shows differential immunophenotypic characteristics including frequent CD33 expression and in vitro response to targeted CD33 therapy

The differential immunophenotypic characteristics of early T precursor (ETP) acute lymphoblastic leukaemia/lymphoma (ALL) remain incompletely characterized. The study group (n = 142) included 106 (74·7%) men and 36 (25·3%) women with a median age of 34·9 years (range, 2-79) at diagnosis. Patients were subtyped by flow cytometry immunophenotyping as follows: 33 (23·2%) ETP; 32 (22·5%) early non-ETP; 60 (42·2%) thymic; and 17 (12·1%) mature. Excepting definitional markers, there was a significant differential expression of the markers CD2, CD10, CD33 and TdT between ETP-ALL and non-ETP-ALL. Positive CD33 expression (≥20% of leukaemic blasts) was detected in 21/33 (63%) ETP-ALL compared with 17/95 (17·9%) non-ETP-ALL (P < 0·001). Notably, targeted anti-CD33 therapy with IMGN779 resulted in significant growth inhibition and increased apoptosis in ETP-ALL cells in vitro. An 11-marker T-ALL immunophenotype score discriminated reliably between ETP and non-ETP ALL. Longitudinal analysis of ETP-ALL cases in this study demonstrated that the immunophenotype may be occasionally dynamic but is largely stable over the disease course. In summary, identification of ETP-ALL might be enhanced by using an 11-marker T-ALL immunophenotype score. CD33 expression is frequent in ETP-ALL, and in vitro data suggest that exploring anti-CD33 therapy in ETP-ALL is warranted.

Novel monoclonal antibody-based treatment strategies in adults with acute lymphoblastic leukemia

Adult acute lymphoblastic leukemia (ALL) has a poor overall survival compared with pediatric ALL where cure rates are observed in more than 90% of patients. The recent development of novel monoclonal antibodies targeting CD20, CD19, and CD22 has changed the long-term outcome of this disease, both in the frontline setting (e.g. rituximab) and for patients with relapsed/refractory disease (e.g. inotuzumab ozogamicin and blinatumomab). The CD3-CD19 bispecific T-cell-engaging antibody blinatumomab is also the first drug approved in ALL for patients with persistent or recurrent measurable residual disease, providing a new treatment paradigm for these patients. Several new agents are also in development that use novel constructs or target alternative surface epitopes such as CD123, CD25, and CD38. Herein, we review the role of monoclonal antibodies in adult ALL and summarize the current and future approaches in ALL, including novel combination therapies and the possibility of early incorporation of these agents into treatment regimens.

Phase 1/2 study of DFP-10917 administered by continuous intravenous infusion in patients with recurrent or refractory acute myeloid leukemia

BACKGROUND

DFP-10917, a deoxycytidine nucleoside analogue, has a unique mechanism of action resulting in leukemic cell death when administered for prolonged periods at low doses. The current phase 1/2 study investigated the safety, maximum tolerated dose, and evidence of antileukemic activity for DFP-10917 administered by 7-day or 14-day continuous intravenous infusion in patients with recurrent or refractory acute myeloid leukemia (AML).

METHODS

In the phase 1 dose escalation portion of the study, patients were administered DFP-10917 by 7-day continuous intravenous infusion plus 21-day rest (stage 1) or 14-day continuous intravenous infusion plus 14-day rest (stage 2). The primary objectives of phase 1 were to determine the maximum tolerated dose, the phase 2 dose, and the dose-limiting toxicities (DLTs) of DFP-10917. The primary objectives of phase 2 were to evaluate the overall response rate of DFP-10917 using complete response (CR), CR without platelet recovery (CRp), CR with incomplete blood count recovery (CRi) or partial response.

RESULTS

In stage 1 of phase 1 (4-35 mg/m² /day as a 7-day continuous intravenous infusion), a DLT of grade 3 diarrhea occurred at a dose of 35 mg/m² /day. In stage 2 of phase 1, a dose of 10 mg/m² /day as a 14-day continuous intravenous infusion resulted in DLTs of prolonged hypocellularity, abdominal pain, diarrhea, and vomiting. The dose of 6 mg/m² /day as a 14-day continuous intravenous infusion was found to be well tolerated and was selected for phase 2. Response rates in patients in phase 2 (N = 29) were 20.7% CR, 3.4% CRp, and 24.1% CRi. The overall response rate was 48.3% (95% confidence interval, 29.4%-67.5%).

CONCLUSIONS

DFP-10917 as a 14-day continuous intravenous infusion at a dose of 6 mg/m² /day can be administered safely and appears to be effective in patients with recurrent or refractory AML. A phase 3 investigation comparing DFP-10917 monotherapy versus standard of care in an early recurrent or refractory AML setting is warranted.

Treatment of relapsed/refractory acute lymphoblastic leukemia

Patients with relapsed or refractory acute lymphoblastic leukemia (R/R ALL) have dismal outcomes, with survival of less than 6 months, and treatment options in the salvage setting have been limited to conventional cytotoxic chemotherapy with minimal activity. Advances in the development of novel targeted therapies have significantly improved outcomes in R/R ALL. Blinatumomab, inotuzumab ozogamicin, and chimeric antigen receptor (CAR) T-cell therapy constitute new treatment modalities that are challenging the historical regimens and paving a new path for treating patients with R/R ALL.

Novel EZH2 mutation in a patient with secondary B-cell acute lymphocytic leukemia after deletion 5q myelodysplastic syndrome treated with lenalidomide: A case report

RATIONALE

The gene deletion (5)(q22q35) is reported in 10-20% of myelodysplastic syndrome (MDS) cases and is associated with response to lenalidomide and favorable prognosis. The authors report here a clinical case of MDS transformation to B-cell acute lymphocytic leukemia (B-ALL) with an associated accrual of an additional mutation following treatment with lenalidomide.

PATIENT CONCERNS

A 69-year-old man presented with progressive anemia, normal white blood cell count, and thrombocytopenia consistent with MDS. He was administered lenalidomide for 27 months, then developed acute B-cell lymphocytic leukemia and acquired a previously unreported mutation in the gene enhancer of zeste homolog 2 (EZH2).

DIAGNOSES

After 27 months of therapy with lenalidomide, a surveillance bone marrow aspiration (BMA) revealed 90% cellularity with persistent multilineage dysplasia and a population of blasts comprising 54% of all bone marrow elements by morphology, consistent with B-ALL, even though the patient was asymptomatic. Conventional karyotype showed no signs of del(5)(q22q35) MDS, however bone marrow next-generation sequencing (NGS) demonstrated the accrual of a nonsense mutation (c.211del pL71*) in exon 3 of EZH2. A confirmatory BMA yielded 70% blasts and clinical features indicative of B-ALL.

INTERVENTIONS

Mini-hyper-CVD (cyclophosphamide and dexamethasone at 50% dose reduction, no anthracycline, methotrexate at 75% dose reduction, cytarabine at 0.5 g/m × 4 doses) was administered for 21 days.

OUTCOMES

A follow-up BMA was performed 2 months after mini-hyper-CVD therapy, showing dysplastic features with 25% ring sideroblasts, but no evidence of B-ALL. The patient is currently receiving monthly-low dose decitabine, ofatumumab, and dexamethasone, and is transfusion independent and asymptomatic after 7 cycles.

LESSONS

The present study shows an extremely rare progression of del(5)(q22q35) MDS to B-ALL with accompanying NGS data and a newly described acquisition of an EZH2 frameshift mutation. This case highlights the importance of NGS as a diagnostic and surveillance tool for MDS.

Validation of the 2017 European LeukemiaNet classification for acute myeloid leukemia with NPM1 and FLT3-internal tandem duplication genotypes

BACKGROUND

The revised 2017 European LeukemiaNet (ELN) classification (ELN-2017) of acute myeloid leukemia (AML) divides patients into 3 prognostic risk categories, with additional factors such as the fms-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) allele ratio (AR) considered for risk stratification. To the best of the authors' knowledge, the prognostic usefulness of ELN-2017 in comparison with ELN-2010 in younger patients with AML has not been validated to date.

METHODS

The authors performed a retrospective study on patients aged <60 years who received idarubicin plus cytarabine (IA)-based induction chemotherapy for newly diagnosed AML.

RESULTS

According to ELN-2017 criteria, the number of patients in the favorable (Fav), intermediate (Int), and adverse (Adv) risk categories was 192 patients (27%), 331 patients (46%), and 192 patients (27%), respectively. Overall survival probabilities at 5 years in the Fav, Int, and Adv groups were 57%, 37%, and 18%, respectively. In comparison, the 5-year overall survival probabilities in the Fav (169 patients), intermediate (IR)-1 (80 patients), IR-2 (306 patients), and Adv (160 patients) ELN-2010 categories were 59%, 32%, 40%, and 14%, respectively. Although ELN-2010 historically distinguishes prognosis into IR-1 and IR-2 categories in younger patients, this difference was nullified in the current study cohort. When comparing patients with a low FLT3-ITD AR with those with a high FLT3-ITD AR, no significant differences in survival were noted among patients with nucleophosmin 1 (NPM1)-mutated AML (P = .28) or wild-type NPM1 (P = .35), and in those treated with IA alone (P = .79) or those treated with IA and a FLT3 inhibitor (P = .10).

CONCLUSIONS

The ELN-2017 more accurately distinguishes prognosis in patients with newly diagnosed AML. The lack of prognostic significance for the FLT3-ITD AR needs further evaluation in different treatment settings.

The distribution of T-cell subsets and the expression of immune checkpoint receptors and ligands in patients with newly diagnosed and relapsed acute myeloid leukemia

Background

Phenotypic characterization of immune cells in the bone marrow (BM) of patients with acute myeloid leukemia (AML) is lacking.

Methods

T‐cell infiltration was quantified on BM biopsies from 13 patients with AML, and flow cytometry was performed on BM aspirates (BMAs) from 107 patients with AML who received treatment at The University of Texas MD Anderson Cancer Center. The authors evaluated the expression of inhibitory receptors (programmed cell death protein 1 [PD1], cytotoxic T‐lymphocyte antigen 4 [CTLA4], lymphocyte‐activation gene 3 [LAG3], T‐cell immunoglobulin and mucin‐domain containing‐3 [TIM3]) and stimulatory receptors (glucocorticoid‐induced tumor necrosis factor receptor‐related protein [GITR], OX40, 41BB [a type 2 transmembrane glycoprotein receptor], inducible T‐cell costimulatory [ICOS]) on T‐cell subsets and the expression of their ligands (41BBL, B7‐1, B7‐2, ICOSL, PD‐L1, PD‐L2, and OX40L) on AML blasts. Expression of these markers was correlated with patient age, karyotype, baseline next‐generation sequencing for 28 myeloid‐associated genes (including P53), and DNA methylation proteins (DNA methyltransferase 3α, isocitrate dehydrogenase 1[IDH1], IDH2, Tet methylcytosine dioxygenase 2 [TET2], and Fms‐related tyrosine kinase 3 [FLT3]).

Results

On histochemistry evaluation, the T‐cell population in BM appeared to be preserved in patients who had AML compared with healthy donors. The proportion of T‐regulatory cells (Tregs) in BMAs was higher in patients with AML than in healthy donors. PD1‐positive/OX40‐positive T cells were more frequent in AML BMAs, and a higher frequency of PD1‐positive/cluster of differentiation 8 (CD8)‐positive T cells coexpressed TIM3 or LAG3. PD1‐positive/CD8‐positive T cells were more frequent in BMAs from patients who had multiply relapsed AML than in BMAs from those who had first relapsed or newly diagnosed AML. Blasts in BMAs from patients who had TP53‐mutated AML were more frequently positive for PD‐L1.

Conclusions

The preserved T‐cell population, the increased frequency of regulatory T cells, and the expression of targetable immune receptors in AML BMAs suggest a role for T‐cell–harnessing therapies in AML.

T‐cell subsets are preserved in the bone marrow of patients with acute myeloid leukemia. The expression of targetable immune checkpoints by T cells suggests that therapies harnessing T cells may benefit these patients.

P53 protein overexpression in de novo acute myeloid leukemia patients with normal diploid karyotype correlates with FLT3 internal tandem duplication and worse relapse-free survival

Although ~50% of acute myeloid leukemia (AML) patients have a normal diploid karyotype by conventional cytogenetics at diagnosis, this patient subset has a variable disease course and outcome. Aberrant overexpression of the p53 protein is usually associated with TP53 alterations and a complex karyotype, but the prevalence and impact of p53 overexpression in AML with diploid cytogenetics is unknown. We examined 100 newly diagnosed AML patients to evaluate the impact of p53 expression status quantified in bone marrow core biopsy samples using immunohistochemistry and computer-assisted image analysis. A total of 24 patients had p53 overexpression defined as 3+ staining intensity in ≥5% of cells; this finding correlated with lower platelet counts (P = .002), absence of CD34 expression in blasts (P = .009), higher bone marrow blast counts (P = .04), and a higher frequency of FLT3 internal tandem duplication (P = .007). Overexpression of p53 independently predicted for shorter leukemia-free survival in patients who underwent allogeneic stem cell transplantation by univariate (P = .021) and multivariate analyses (P = .004). There was no correlation between MDM2 and p53 protein expression in this cohort. We conclude that p53 expression evaluated by immunohistochemistry in bone marrow biopsy specimens at the time of AML diagnosis may indicate distinct clinical characteristics in patients with normal diploid cytogenetics and is a potentially valuable tool that can enhance risk-stratification.

CD123 expression patterns and selective targeting with a CD123-targeted antibody-drug conjugate (IMGN632) in acute lymphoblastic leukemia

The potential of CD123-targeted therapies in acute lymphoblastic leukemia/lymphoma remains largely unexplored. We examined CD123 expression levels in a large cohort of patients with acute lymphoblastic leukemia/lymphoma and assessed the in vitro impact of IMGN632, a conjugate of CD123-binding antibody with a novel DNA-alkylating payload. CD123 expression on leukemic blasts was surveyed using multicolor/multiparameter flow cytometry. The in vitro effect of IMGN632 was evaluated on B acute lymphoblastic leukemia/lymphoma cell lines and primary B acute lymphoblastic leukemia/lymphoma blasts. The study cohort (n=213) included 183 patients with B acute lymphoblastic leukemia/lymphoma and 30 with T acute lymphoblastic leukemia/lymphoma. CD123 expression was more prevalent in B acute lymphoblastic leukemia/lymphoma than in T acute lymphoblastic leukemia/lymphoma (164/183, 89.6% versus 13/30, 43.3%; P<0.0001), and within B acute lymphoblastic leukemia/lymphoma CD123 expression was more prevalent in Philadelphia chromosome-positive patients than in Philadelphia chromosome-negative patients (96.6% versus 86.3%; P=0.033). In T acute lymphoblastic leukemia/lymphoma, 12/13 (92.3%) patients with CD123-positive blasts had either early T precursor (ETP) or early non-ETP immunophenotype. IMGN632 was highly cytotoxic to B acute lymphoblastic leukemia/lymphoma cell lines, with half maximal inhibitory concentrations (IC₅₀) between 0.6 and 20 pM. In five of eight patients' samples, low picomolar concentrations of IMGN632 eliminated more than 90% of the B acute lymphoblastic leukemia/lymphoma blast population, sparing normal lymphocytes. In conclusion, CD123 expression is prevalent across acute lymphoblastic leukemia/lymphoma subtypes, and the CD123-targeted antibody-drug conjugate IMGN632 demonstrates promising selective activity in preclinical models of B acute lymphoblastic leukemia/lymphoma.

Bone marrow core biopsy in 508 consecutive patients with chronic myeloid leukemia: Assessment of potential value

BACKGROUND

The diagnosis of chronic myeloid leukemia (CML) is based on characteristic clinical and laboratory findings and the presence of BCR/ABL1 in the blood and/or bone marrow (BM). The utility of BM core biopsy in the workup of patients with CML has been questioned.

METHODS

The potential added value of BM biopsy versus aspiration in the workup of a single-institution series of 508 patients with CML at their initial presentation was systematically assessed. BM biopsy was considered essential when it was needed to establish the disease phase, often because blast counts derived from aspirate smears were misleading because the biopsy specimen was more representative of the disease. BM biopsy was considered helpful if it was needed for other nonessential reasons.

RESULTS

In 127 patients (25%), BM biopsy was either essential (109 patients) or helpful (18 patients). Patients with accelerated-phase (AP) or blast-phase (BP) disease often required a biopsy related to essential reasons. High-grade myelofibrosis (MF) was more frequent in patients with AP/BP disease than patients with chronic-phase disease (P = .0005), and the identification of BP disease required a BM biopsy assessment in 75% of the patients (P = .001). A follow-up BM evaluation more often yielded inadequate aspirates in patients with inadequate BM aspirates at the time of their initial diagnosis.

CONCLUSIONS

BM core biopsy remains valuable in the workup of 25% of patients with CML because it facilitates identification of the disease phase or MF. The initial grade of MF is associated with the disease stage and outcome after therapy. BM biopsy is, therefore, indicated for patients with CML who have AP/BP disease or other findings suggestive of progressive disease.

Economic value of regular monitoring of response to treatment among US patients with chronic myeloid leukemia based on an economic model

BACKGROUND

Regular molecular monitoring with reverse-transcription quantitative PCR (RT-qPCR) analysis of BCR-ABL1 transcripts is associated with reduced disease progression among patients with chronic myeloid leukemia (CML). Molecular monitoring assists in the timely detection of primary or secondary resistance to tyrosine kinase inhibitor (TKI) therapy and is a recommended practice by the National Comprehensive Cancer Network guidelines. An economic model was developed to estimate the potential impact of CML monitoring vs lack of monitoring on patient healthcare costs.

METHODS

An Excel-based decision-analytic economic model was developed from a US payer perspective. The model was used to estimate the expected healthcare cost differences between regular molecular monitoring of CML patients and lack of monitoring. CML progression rates among patients with vs without monitoring, the annual cost of CML progression, the average number of monitoring tests per year, and the average cost per RT-qPCR monitoring test were incorporated into the model. Univariate and multivariable sensitivity analyses were conducted.

RESULTS

Based on estimates in published literature, disease progression to the accelerated/blast phase occurs among 0.35% of patients with monitoring and 5.12% of patients without monitoring, and the annual cost of CML progression is $136,308 per patient year. The analysis found that total healthcare costs, including the costs associated with CML progression and RT-qPCR monitoring tests (three tests per year), were $1,142 for patients with monitoring and $6,982 for patients without monitoring (difference = $5,840). In a hypothetical cohort of 100 patients with CML, achieving a 100% monitoring rate was associated with a total cost-savings of $584,005 compared to a 0% monitoring rate. This cost-savings remained consistent under both univariate and multivariable sensitivity analyses.

CONCLUSION

Regular CML monitoring was associated with improved outcomes among CML patients and, consequently, reduced healthcare costs.

Abstract 1875: Oxidative metabolism as a novel therapeutic target to eradicate T-ALL with mitochondrial complex I inhibitor IACS-010759

Adult T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy with limited treatment options, largely driven by the activating Notch1 mutations. Oncogenic Notch1 facilitates c-Myc signaling and glutamine oxidation, induces metabolic stress and increased reliance on oxidative metabolism maintained by AMPK and modulates metabolism under energy stress by mTOR (Kishton, Cell Metabolism 2016; Chan, Blood 2007).

In this study, we report pre-clinical activity of the novel OXPHOS inhibitor (OXPHOSi) IACS-010759 in NOTCH-mutated T-ALL, and characterize the cellular and metabolic responses to OxPhos inhibition. Exposure to IACS-010759 (0-370 nM) in vitro for 5 days drastically reduced T-ALL viability, with EC50 ranging from 0.001-10 nM for T-ALL cell lines and 13-45 nM for T-ALL PDX models (n=5). Oral administration of IACS-010759 at 7.5 mg/kg daily was tolerable in both, aggressive T-ALL PDX and in Notch-1 mutated murine T-ALL model, significantly reduced leukemia burden and extended survival. Functional metabolic characterization of T-ALL confirmed that IACS-010759 effectively inhibited mitochondrial respiration and caused striking dose-dependent decrease in basal and maximal OCR, ATP and NADH production. Pharmacological inhibition of Complex I with IACS-010759, similar to knockout of Complex I subunit NDUSF4 using CRISPR-CAS9, induced catastrophic changes in mitochondria, with induction of ROS, DNA damage and compensatory mTOR pathway activation. Further, OXPHOSi led to downregulation of mitochondrial Complex I, II, III and IV, decrease of wide range of TCA cycle enzymes and proteins involved in the mitochondrial transport. This translated into decrease of TCA cycle intermediates and reduction in ATP and NADH content by metabolomic analysis. Using stable isotope-resolved metabolomics (SIRM) flux analysis, IACS-010759 (30 nM at 24 hr) significantly decreased flux of glucose through the TCA cycle and redirected it towards glycolysis, additionally increased utilization of glutamine for fueling the TCA cycle, in particular through reductive metabolism, uncovering reliance on glutaminolysis as an additional therapeutic target. Consistent with this hypothesis, combined therapy of OXPHOSi with Glutaminase (GLS-i) or mTOR inhibitors caused additive or synergistic reduction of viability of T-ALL cells, and elicited anti-leukemia activity in T-ALL resistant to Complex I inhibitor alone. Ongoing in vivo studies will address the impact of Complex I Inhibition in the context of genetic GLS knockout utilizing Notch1-mutated GLS fl/fl murine model (Herranz, Nat Med 2016). Taken together, our findings indicate that OXPHOSi, alone and more so in combination with GLS inhibition, constitutes an novel therapeutic modality that targets unique metabolic vulnerability of Notch1- mutated T-ALL cells.

Citation Format: Natalia Baran, Alessia Lodi, Shannon Sweeney, Vinitha Mary Kuruvilla, Antonio Cavazos, Anna Skwarska, Sriram Shanmuga Velandy, Karine Harutyunyan, Ningping Feng, Jason Gay, Marcin Kaminski, Elias J. Jabbour, Adolfo Ferrando, M. Emilia Di Francesco, Joseph R. Marszalek, Stefano Tiziani, Marina Konopleva. Oxidative metabolism as a novel therapeutic target to eradicate T-ALL with mitochondrial complex I inhibitor IACS-010759 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1875.

Chronic lymphoproliferative disorder of NK-cells: A single-institution review with emphasis on relative utility of multimodality diagnostic tools

BACKGROUND

Chronic lymphoproliferative disorder of NK-cells (CLPD-NK) manifests as a persistent increase (≥2 × 10⁹ /L, for > 6 months) of mature NK-cells in peripheral blood with an indolent clinical course. The disease is rare, and only limited case series have been published.

METHODS

We retrospectively studied 11 patients with CLPD-NK diagnosed at our institution between 2005 and 2017.

RESULTS

Patients included 7 men and 4 women with a median age of 60 years (range, 25-89 years). Ten patients (91%) had cytopenias. Bone marrow involvement by CLPD-NK ranged from 5-15%. The most commonly detected antigenic aberrancies by  low cytometry immunophenotyping were as follows: CD7^{decreased/dim} (30%), CD8^uniform+ (36%), CD56^-/partial (73%), CD94^bright (55%), and KIR restriction (100%). JAK/STAT pathway mutations were detected in 8 of 10 (80%) patients and involved STAT3 (n = 7) and JAK3 (n = 1). The presence of mutations tended to correlate with the occurrence of other cytopenias (anemia/thrombocytopenia) and requirement for treatment. Seven patients received single-agent therapy, with amelioration of symptoms; 4 patients were observed. There were no disease-associated deaths or progression to more aggressive disease during the follow-up interval (median, 17 months).

CONCLUSIONS

Patients with CLPD-NK have an indolent clinical course and frequent hematologic manifestations that are responsive to single-agent therapy. Mutations in STAT3 are common and portend more pronounced clinical manifestations.

Patient-reported outcomes from a phase 3 randomized controlled trial of inotuzumab ozogamicin versus standard therapy for relapsed/refractory acute lymphoblastic leukemia

BACKGROUND

Inotuzumab ozogamicin (InO), an anti-CD22 antibody-calicheamicin conjugate, demonstrated superior clinical activity versus standard-of-care (SOC) chemotherapies for relapsed/refractory B-cell acute lymphoblastic leukemia in the phase 3 randomized controlled INO-VATE trial. The authors assessed patient-reported outcomes (PROs) from that study.

METHODS

Patients were randomized to receive either InO (1.8 mg/m² per cycle for ≤6 cycles) or SOC (fludarabine/cytarabine [ara-C]/granulocyte colony-stimulating factor, or ara-C plus mitoxantrone, or high-dose ara-C for ≤4 cycles) and completed the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and the EuroQoL 5 Dimensions Questionnaires at baseline, on day 1 of each cycle, and at the end of treatment. Treatment differences in PROs were assessed using longitudinal mixed-effects models with random intercepts and slopes.

RESULTS

Questionnaire completion rates in the InO (n = 164) and SOC (n = 162) arms were 85% and 65%, respectively. Baseline scores were similar between arms. Patients who received InO reported better quality of life (QoL), functioning, and symptom scores (except for constipation and emotional functioning). Least-squares mean (95% confidence interval [CI]) differences in physical, role, and social functioning and in appetite loss were significant (6.9 [95% CI, 1.4-12.3], 11.4 [95% CI, 3.2-19.5], 8.4 [95% CI, 0.7-16.1], and -8.7 [95% CI, -16.0 to -1.4], respectively; all P < .05) and had exceeded the minimally important difference of 5. Mean treatment differences in favor of InO on the EuroQoL visual analog scale and the global health status/QoL, dyspnea, and fatigue scales reached or approached the minimally important difference of 5, although without statistical significance. No dimensions were significantly worse with InO versus SOC.

CONCLUSIONS

The current PRO data support the favorable benefit/risk ratio of InO for the treatment of relapsed/refractory acute lymphoblastic leukemia, with superior clinical efficacy and better QoL. Cancer 2018;124:2151-60. © 2018 American Cancer Society.

Updated Results of Rituximab Pre- and Post-BEAM with or without 90Yttrium Ibritumomab Tiuxetan during Autologous Transplant for Diffuse Large B-cell Lymphoma

Purpose: We evaluated the effect on long-term survival of adding rituximab (R) to BEAM (carmustine, etoposide, cytarabine, and melphalan) conditioning with or without yttrium-90 ibritumomab tiuxetan (⁹⁰YIT) in patients with relapsed diffuse large B-cell lymphoma (DLBCL) undergoing autologous stem cell transplant (ASCT).Experimental design: Patients were enrolled on three consecutive phase II clinical trials. Patients received two doses of rituximab (375 and 1,000 mg/m²) during mobilization of stem cells, followed by 1,000 mg/m² on days +1 and +8 after ASCT with R-BEAM or ⁹⁰YIT-R-BEAM (⁹⁰YIT dose of 0.4 mCi/kg) conditioning.Results: One hundred thirteen patients were enrolled, with 73 receiving R-BEAM and 40 receiving ⁹⁰YIT-R-BEAM. All patients had a prior exposure to rituximab. The median follow-up intervals for survivors were 11.8, 8.1, and 4.2 years in the three trials, respectively. The 5-year disease-free survival (DFS) rates were 62% for R-BEAM and 65% for ⁹⁰YIT-R-BEAM (P = 0.82). The 5-year overall survival rates were 73% and 77%, respectively (P = 0.65). In patients with de novo DLBCL, survival outcomes of the germinal center/activated b-cell histologic subtypes were similar with 5-year OS rates (P = 0.52) and DFS rates (P = 0.64), irrespective of their time of relapse (<1 vs. >1 year) after initial induction chemotherapy (P = 0.97).Conclusions: Administering ASCT with rituximab during stem cell collection and immediately after transplantation induces long-term disease remission and abolishes the negative prognostic impact of cell-of-origin in patients with relapsed DLBCL. The addition of ⁹⁰YIT does not confer a further survival benefit. Clin Cancer Res; 24(10); 2304-11. ©2018 AACR.

Efficacy and safety analysis by age cohort of inotuzumab ozogamicin in patients with relapsed or refractory acute lymphoblastic leukemia enrolled in INO-VATE

BACKGROUND

Inotuzumab ozogamicin (InO) has demonstrated efficacy and tolerability in patients aged 18 to 78 years with relapsed/refractory acute lymphoblastic leukemia (ALL) in the INO-VATE trial. This subset analysis compared the efficacy and safety of InO in younger and older patients.

METHODS

Intent-to-treat analyses of morphologic responses and overall survival (OS) included 326 randomized patients, and safety assessments included 307 patients receiving 1 or more doses of the study treatment. Of the 326 patients, 164 received InO at a starting dose of 1.8 mg/m² /cycle (0.8 mg/m² on day 1 and 0.5 mg/m² on days 8 and 15 of a 21- to 28-day cycle [≤6 cycles]); 60 patients were aged ≥55 years, and 104 were aged <55 years.

RESULTS

For older and younger patients, the median duration of InO therapy and the types and frequencies of adverse events of any grade were generally similar. Although the remission rates, median duration of remission (DOR), and progression-free survival were similar with InO for those aged <55 years and those aged ≥55 years, OS was longer for younger patients (median, 8.6 vs 5.6 months; hazard ratio, 0.610). Among patients proceeding to hematopoietic stem cell transplantation after InO treatment (28% of older patients and 58% of younger patients), the incidence of veno-occlusive disease was greater in older patients (41% vs 17%). The study database was not locked at the time of this analysis.

CONCLUSIONS

InO was tolerable in older patients with relapsed/refractory ALL. Although OS was longer for younger patients versus older patients, InO demonstrated high response rates with similar DOR in the 2 age groups. Cancer 2018;124:1722-32. © 2018 American Cancer Society.