Loss of CD22 expression and expansion of a CD22dim subpopulation in adults with relapsed/refractory B-lymphoblastic leukaemia after treatment with Inotuzumab-Ozogamicin.

Treatment options for relapsed or refractory B-lymphoblastic leukaemia (r/r B-ALL) are limited and the prognosis of these patients remains dismal, but novel immunotherapeutic options such as the anti-CD22 antibody-drug-conjugate Inotuzumab-Ozogamicin (InO) have improved outcomes in these patients. Flow cytometry is essential to assess antigen-expression prior to treatment initiation of antigen-directed immunotherapies. Here, we present flow cytometric and clinical data of three adult patients with r/r B-ALL who failed treatment with InO associated with reduced or lost antigen-expression. In addition, we present comparative data on two different diagnostic CD22-specific antibody clones that exhibit significant differences in staining intensities.

Myocardial calcification in a patient with B-lymphoblastic leukemia accompanied by tumor lysis syndrome.

Myocardial calcification, a rare disease that leads to chronic or acute heart failure and with a poor prognosis, occurs in patients with abnormal calcium-phosphorus metabolism. The association between myocardial calcification and tumor lysis syndrome has not been reported to date. A 50-year-old man with hyperthermia and general malaise presented to our hospital and was clinically diagnosed with B-lymphoblastic leukemia (B-ALL) and febrile neutropenia accompanied by septic shock. Prednisolone was administered for tumor reduction. Two to three hours later, electrocardiography demonstrated ST elevation in V4-6, and blood tests showed elevated levels of cardiac enzymes. Transthoracic echocardiogram revealed diffuse severe hypokinesis with decreased left ventricular ejection fraction. Additionally, blood tests showed that serum phosphorus level increased to 8.0 mg/dl, which was likely due to tumor lysis syndrome. Circulatory and respiratory failure due to left heart failure progressed, and he died 3 days after administration of prednisolone. Pathological autopsy revealed diffuse proliferation of atypical B-lymphoblasts in the bone marrow, which led to the pathological diagnosis of B-ALL, accompanied by necrosis. On the cut surface of the heart, the left ventricle was dilated, and patchy yellowish-brown areas were present in the epicardial-side of the myocardium and spread through the circumferential wall of the left ventricle and interventricular septum. Microscopically, myocardial fibers were granularly basophilic in that area and were revealed as calcium deposits by Von Kossa staining. He was diagnosed with myocardial calcification. The drastic increase in the serum phosphorus level caused by tumor lysis syndrome seemed to be associated with myocardial calcification.

Inotuzumab: from preclinical development to success in B-cell acute lymphoblastic leukemia.

Inotuzumab ozogamicin (InO) is a recently US Food and Drug Administration-approved antibody-drug conjugate for the treatment of relapsed/refractory B-cell acute lymphoblastic leukemia (ALL). InO consists of a CD22-targeting immunoglobulin G4 humanized monoclonal antibody conjugated to calicheamicin. Although initially developed for the treatment of non-Hodgkin lymphoma (NHL) because of activity in preclinical models and high response rates in indolent lymphomas, a phase 3 trial was negative and further development focused on CD22+ ALL. Although results in NHL were disappointing, parallel testing in early-phase trials of CD22+ ALL demonstrated feasibility and efficacy. Subsequently, the randomized phase 3 Study Of Inotuzumab Ozogamicin Versus Investigator's Choice Of Chemotherapy In Patients With Relapsed Or Refractory Acute Lymphoblastic Leukemia trial showed that InO was superior to standard of care regimens with a significantly improved complete remission (CR) rate in patients with relapsed/refractory disease (80.7% vs 29.4%, P < .001). Patients achieving CR with InO also had a significantly higher rate of undetectable minimal residual disease compared with chemotherapy (78.4% vs 28.1%, P < .001). InO-specific side effects, including veno-occlusive disease, have been an ongoing area of concern, and consensus guidelines for minimizing toxicities are now available. Ongoing trials are investigating the combination of InO with other agents in the relapse setting and the addition of InO to frontline therapy. This review details the preclinical and clinical development of InO, focusing on how best to use it and future directions for further development.

Cost comparison by treatment arm and center-level variations in cost and inpatient days on the phase III high-risk B acute lymphoblastic leukemia trial AALL0232.

The Children's Oncology Group (COG) develops and implements multi-institutional clinical trials with the primary goal of assessing the efficacy and safety profile of treatment regimens for various pediatric cancers. However, the monetary costs of treatment regimens are not measured. AALL0232 was a COG randomized phase III trial for children with acute lymphoblastic leukemia that found that dexamethasone (DEX) was a more effective glucocorticoid than prednisone (PRED) in patients younger than 10 years, but PRED was equally effective and less toxic in older patients. In addition, high-dose methotrexate (HD-MTX) led to better survival than escalating doses of methotrexate (C-MTX). Cost data from the Pediatric Health Information System database were merged with clinical data from the COG AALL0232 trial. Total and component costs were compared between treatment arms and across hospitals. Inpatient costs were higher in the HD-MTX and DEX arms when compared to the C-MTX and PRED arms at the end of therapy. There was no difference in cost between these arms at last follow-up. Considerable variation in total costs existed across centers to deliver the same therapy that was driven by differences in inpatient days and pharmacy costs. The more effective regimens were found to be more expensive during therapy but were ultimately cost-neutral in longer term follow-up. The variations in cost across centers suggest an opportunity to standardize resource utilization for patients receiving similar therapies, which could translate into reduced healthcare expenditures.

Multimodal Treatment of Rhinocerebral Mucormycosis in a Pediatric Patient With Relapsed Pre-B Acute Lymphoblastic Leukemia.

A 17-year-old girl developed invasive rhinocerebral mucormycosis during intensive re-induction chemotherapy for relapsed pre-B acute lymphoblastic leukemia. Due to the high case fatality rate for invasive mucormycosis in profoundly immunosuppressed patients, an aggressive treatment regimen was pursued. In addition to the standard of care treatments with intravenous amphotericin and aggressive surgical debridements, she received intraventricular amphotericin to the brain via an Ommaya reservoir, hyperbaric oxygen treatments, filgrastim, intravenous immunoglobulin and antifungal in vitro synergy testing to allow for more targeted antifungal therapy with the addition of micafungin. After a 3-month treatment course, it was determined that her mucormycosis was under appropriate control, allowing her to continue treatment for her leukemia with hematopoietic stem cell transplant with a plan for continued intravenous antifungal therapy through engraftment.

Evaluation and Management of Acute-Onset Hemiparesis in an Adolescent With Leukemia.

Emergency departments (EDs) are alert to the possibility of stroke and the need for early interventions to improve long-term clinical outcomes. However, new-onset hemiparesis in pediatric patients with leukemia may be due to a number of different etiologies, including most common side effects from chemotherapeutic agents. We present a case of a 15-year-old boy with pre-B acute lymphoblastic leukemia on chemotherapy, having recently received a high-dose methotrexate infusion in addition to intrathecal methotrexate therapy, who presented to our ED with acute right-sided hemiparesis. He was initially suspected as having a possible ischemic stroke. Magnetic resonance imaging (diffusion-weighted and fluid-attenuated inversion recovery sequence) demonstrated focal areas of diffusion restriction, an early sign of delayed-onset methotrexate neurotoxicity. Our patient received appropriate supportive care and leucovorin rescue with gradual clinical recovery, after a prolonged hospitalization and acute care rehabilitation over the course of several months. Our case illustrates the need for ED providers to consider methotrexate neurotoxicity in pediatric oncology patients presenting with acute neurologic changes.

Neurocognitive Functioning of Children Treated for High-Risk B-Acute Lymphoblastic Leukemia Randomly Assigned to Different Methotrexate and Corticosteroid Treatment Strategies: A Report From the Children's Oncology Group.

Purpose Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for neurocognitive deficits that are associated with treatment, individual, and environmental factors. This study examined the impact of different methotrexate (MTX) and corticosteroid treatment strategies on neurocognitive functioning in children with high-risk B-lineage ALL. Methods Participants were randomly assigned to receive high-dose MTX with leucovorin rescue or escalating dose MTX with PEG asparaginase without leucovorin rescue. Patients were also randomly assigned to corticosteroid therapy that included either dexamethasone or prednisone. A neurocognitive evaluation of intellectual functioning (IQ), working memory, and processing speed (PS) was conducted 8 to 24 months after treatment completion (n = 192). Results The method of MTX delivery and corticosteroid assignment were unrelated to differences in neurocognitive outcomes after controlling for ethnicity, race, age, gender, insurance status, and time off treatment; however, survivors who were age < 10 years at diagnosis (n = 89) had significantly lower estimated IQ ( P < .001) and PS scores ( P = .02) compared with participants age ≥ 10 years. In addition, participants who were covered by US public health insurance had estimated IQs that were significantly lower ( P < .001) than those with US private or military insurance. Conclusion Children with high-risk B-lineage ALL who were age < 10 years at diagnosis are at risk for deficits in IQ and PS in the absence of cranial radiation, regardless of MTX delivery or corticosteroid type. These data may serve as a basis for developing screening protocols to identify children who are at high risk for deficits so that early intervention can be initiated to mitigate the impact of therapy on neurocognitive outcomes.

Inotuzumab ozogamicin in relapsed B-cell acute lymphoblastic leukemia.

Despite an improved understanding of disease biology and the use of multi-agent chemotherapy, the long-term survival of adults with B-cell acute lymphoblastic leukemia (B-ALL) ranges from 35% to 50%. Management of patients with relapsed B-ALL, a group characterized by dismal outcomes, poses a clinical challenge. To address this unmet need, novel therapeutics are being investigated in the setting of relapsed B-ALL with encouraging results. CD22 is an important B-cell antigen expressed in 80-90% of B-ALL cases. CD22 undergoes constitutive endocytosis with antibody ligation, making it an attractive biologic target for immunoconjugates. Inotuzumab ozogamicin (IO), a CD22-targeted antibody-drug conjugate demonstrated impressive single agent activity even among heavily pretreated relapsed B-ALL patients. A recent randomized phase III clinical trial demonstrates superiority of IO over standard of care chemotherapy as first- or second-line salvage therapy for relapsed B-ALL. In this review, we summarize the preclinical and clinical data available to date using IO in relapsed B-ALL.

Further drimane sesquiterpenes from Drimys brasiliensis stem barks with cytotoxic potential.

Drimys brasiliensis Miers (Winteraceae) is used in folk medicine for the treatment of cancer. Its anti-tumor activity has been demonstrated in vitro models using extracts and isolated compounds. This study investigates the cytotoxic effects of stem bark extracts of D. brasiliensis as well as isolated compounds that may be responsible for the activitys and evaluates them in leukemia cells. The stem bark extract were subjected to column chromatography, and the structures of compounds were elucidated based on spectroscopic methods by using NMR and infrared spectroscopy and GC/MS. The cytotoxicity of the isolated compounds was evaluated in chronic myeloid (K562) and acute B lymphoblastic (Nalm6) leukemia cells using tetrazolium assay (MTT). Two new compounds were isolated 1ß-O-p-methoxy-E-cinnamoyl-5α-keto-11α-enol-albicanol (1a) and the isomer 1ß-O-p-methoxy-E-cinnamoyl-5α-keto-11ß-enol-albicanol (1b) and 1ß-O-p-methoxy-E-cinnamoyl-isodrimeninol (2). The known compounds polygonal acid (3a) and the isomer isopolygonal acid (3b), fuegin (4a) and the isomer epifuegin (4b), the mixture drimanial (5) and 1ß-O-(p-methoxy-E-cinnamoyl)-6α-hydroxypolygodial (6) were also isolated. The drimanes (1-4) and drimanial (5), 1ß-(p-coumaroyloxy)-polygodial (7), 1ß-(p-methoxycinnamoyl)-polygodial (8), and polygodial (9) isolated previously were assessed in tumor cells. The IC50 values were between 3.56 and 128.91 µM. 1-ß-(p-cumaroiloxi)-polygodial showed the best result with IC50 8.18 and 3.56 µM by K562 and Nalm6, respectively. The chloroform extract of the stem bark of D. brasiliensis is a great source of drimane sesquiterpenes. Our experimental data suggest that drimanes are responsible for cytotoxicity activity demonstrated by this species, especially those with the aldehyde group linked to carbons C-11 and C-12.

Blinatumomab for the Treatment of Philadelphia Chromosome-Negative, Precursor B-cell Acute Lymphoblastic Leukemia.

Blinatumomab is a CD19/CD3 bispescific antibody designed to redirect T cells toward malignant B cells and induce their lysis. It recently gained accelerated approval by the FDA for the treatment of relapsed or refractory Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia (RR-ALL). In the phase II trial that served as the basis for approval, blinatumomab demonstrated significant single-agent activity and induced remission [complete remission (CR) and CR with incomplete recovery of peripheral blood counts (CRh)] in 43% of 189 adult patients with RR-ALL; the majority of responders (82%) also attained negative minimal residual disease (MRD(-)) status that did not generally translate into long-term remissions in most cases. Additional studies show that blinatumomab can induce high response rates associated with lasting remissions in patients in first remission treated for MRD positivity, suggesting a role for blinatumomab in the upfront, MRD-positive setting. Blinatumomab infusion follows a predictable immunopharmacologic profile, including early cytokine release that can be associated with a clinical syndrome, T-cell expansion, and B-cell depletion. Neurologic toxicities represent a unique toxicity that shares similarities with adverse effects of other T-cell engaging therapies. Further studies are needed to clarify the optimal disease setting and timing for blinatumomab therapy. Additional insights into the pathogenesis, risk factors, and prevention of neurologic toxicities as well as a better understanding of the clinical consequences and biologic pathways that are associated with drug resistance are needed.

Prognostic significance of minimal residual disease in high risk B-ALL: a report from Children's Oncology Group study AALL0232.

Minimal residual disease (MRD) is highly prognostic in pediatric B-precursor acute lymphoblastic leukemia (B-ALL). In Children's Oncology Group high-risk B-ALL study AALL0232, we investigated MRD in subjects randomized in a 2 × 2 factorial design to receive either high-dose methotrexate (HD-MTX) or Capizzi methotrexate (C-MTX) during interim maintenance (IM) or prednisone or dexamethasone during induction. Subjects with end-induction MRD ≥0.1% or those with morphologic slow early response were nonrandomly assigned to receive a second IM and delayed intensification phase. MRD was measured by 6-color flow cytometry in 1 of 2 reference labs, with excellent agreement between the two. Subjects with end-induction MRD <0.01% had a 5-year event-free survival (EFS) of 87% ± 1% vs 74% ± 4% for those with MRD 0.01% to 0.1%; increasing MRD amounts was associated with progressively worse outcome. Subjects converting from MRD positive to negative by end consolidation had a relatively favorable 79% ± 5% 5-year disease-free survival vs 39% ± 7% for those with MRD ≥0.01%. Although HD-MTX was superior to C-MTX, MRD retained prognostic significance in both groups (86% ± 2% vs 58% ± 4% for MRD-negative vs positive C-MTX subjects; 88% ± 2% vs 68% ± 4% for HD-MTX subjects). Intensified therapy given to subjects with MRD >0.1% did not improve either 5-year EFS or overall survival (OS). However, these subjects showed an early relapse rate similar to that seen in MRD-negative ones, with EFS/OS curves for patients with 0.1% to 1% MRD crossing those with 0.01% to 0.1% MRD at 3 and 4 years, thus suggesting that the intensified therapy altered the disease course of MRD-positive subjects. Additional interventions targeted at the MRD-positive group may further improve outcome. This trial was registered at www.clinicaltrials.gov as #NCT00075725.

Manganese (III) meso-tetrakis N-ethylpyridinium-2-yl porphyrin acts as a pro-oxidant to inhibit electron transport chain proteins, modulate bioenergetics, and enhance the response to chemotherapy in lymphoma cells.

The manganese porphyrin, manganese (III) meso-tetrakis N-ethylpyridinium-2-yl porphyrin (MnTE-2-PyP(5+)), acts as a pro-oxidant in the presence of intracellular H2O2. Mitochondria are the most prominent source of intracellular ROS and important regulators of the intrinsic apoptotic pathway. Due to the increased oxidants near and within the mitochondria, we hypothesized that the mitochondria are a target of the pro-oxidative activity of MnTE-2-PyP(5+) and that we could exploit this effect to enhance the chemotherapeutic response in lymphoma. In this study, we demonstrate that MnTE-2-PyP(5+) modulates the mitochondrial redox environment and sensitizes lymphoma cells to antilymphoma chemotherapeutics. MnTE-2-PyP(5+) increased dexamethasone-induced mitochondrial ROS and oxidation of the mitochondrial glutathione pool in lymphoma cells. The combination treatment induced glutathionylation of Complexes I, III, and IV in the electron transport chain, and decreased the activity of Complexes I and III, but not the activity of Complex IV. Treatment with the porphyrin and dexamethasone also decreased cellular ATP levels. Rho(0) malignant T-cells with impaired mitochondrial electron transport chain function were less sensitive to the combination treatment than wild-type cells. These findings suggest that mitochondria are important for the porphyrin's ability to enhance cell death. MnTE-2-PyP(5+) also augmented the effects of 2-deoxy-D-glucose (2DG), an antiglycolytic agent. In combination with 2DG, MnTE-2-PyP(5+) increased protein glutathionylation, decreased ATP levels more than 2DG treatment alone, and enhanced 2DG-induced cell death in primary B-ALL cells. MnTE-2-PyP(5+) did not enhance dexamethasone- or 2DG-induced cell death in normal cells. Our findings suggest that MnTE-2-PyP(5+) has potential as an adjuvant for the treatment of hematologic malignancies.

Treatment of relapsed precursor-B acute lymphoblastic leukemia with intensive chemotherapy: POG (Pediatric Oncology Group) study 9411 (SIMAL 9).

Pediatric patients who experience a bone marrow relapse of precursor-B acute lymphoblastic leukemia are cured <50% of the time. This study was designed to determine if intensification of therapies with known activity in this disease would improve the cure rates for patients with relapsed acute lymphoblastic leukemia. Patients were treated with intensive asparaginase during induction followed by repeated cycles of ifosfamide/etoposide and cytarabine/idarubicin. Patients with well-matched related donors were encouraged to undergo hematopoietic stem cell transplant as consolidation. The results of this study demonstrate no significant difference in disease-free survival in patients who received chemotherapy alone (45%) or chemotherapy followed by allogeneic stem cell transplant (50%). Furthermore, results from this study show no significant difference in event-free survival (39.9%±6.2%) or overall survival (41.6%±6.1%) at 8 years when compared with previous studies using less intensive regimens. Our results suggest that alternative therapies are needed to improve cure rates for pediatric patients with relapsed leukemia.

Targeting JAK1/2 and mTOR in murine xenograft models of Ph-like acute lymphoblastic leukemia.

CRLF2 rearrangements, JAK1/2 point mutations, and JAK2 fusion genes have been identified in Philadelphia chromosome (Ph)-like acute lymphoblastic leukemia (ALL), a recently described subtype of pediatric high-risk B-precursor ALL (B-ALL) which exhibits a gene expression profile similar to Ph-positive ALL and has a poor prognosis. Hyperactive JAK/STAT and PI3K/mammalian target of rapamycin (mTOR) signaling is common in this high-risk subset. We, therefore, investigated the efficacy of the JAK inhibitor ruxolitinib and the mTOR inhibitor rapamycin in xenograft models of 8 pediatric B-ALL cases with and without CRLF2 and JAK genomic lesions. Ruxolitinib treatment yielded significantly lower peripheral blast counts compared with vehicle (P < .05) in 6 of 8 human leukemia xenografts and lower splenic blast counts (P < .05) in 8 of 8 samples. Enhanced responses to ruxolitinib were observed in samples harboring JAK-activating lesions and higher levels of STAT5 phosphorylation. Rapamycin controlled leukemia burden in all 8 B-ALL samples. Survival analysis of 2 representative B-ALL xenografts demonstrated prolonged survival with rapamycin treatment compared with vehicle (P < .01). These data demonstrate preclinical in vivo efficacy of ruxolitinib and rapamycin in this high-risk B-ALL subtype, for which novel treatments are urgently needed, and highlight the therapeutic potential of targeted kinase inhibition in Ph-like ALL.

Inotuzumab ozogamicin in the treatment of B-cell acute lymphoblastic leukemia.

INTRODUCTION: Inotuzumab ozogamicin (CMC-544) is a humanized anti-CD22 monoclonal antibody conjugated with calicheamicin. Preclinical data indicate activity against B-cell tumors and early results from clinical trials indicate activity against B-cell lineage acute lymphoblastic leukemia (ALL). AREAS COVERED: This paper reviews the design, pharmacokinetic and pharmacodynamic characteristics, and preclinical and clinical experience of inotuzumab ozogamicin in adult ALL. EXPERT OPINION: Inotuzumab ozogamicin appears as an effective salvage therapy in patients with advanced ALL, allowing more patients to receive stem cell transplant (SCT) with encouraging response rates. This agent should provide a unique opportunity to treat selected ALL patient subpopulations.

Intra-abdominal Rhizopus microsporus infection successfully treated by combined aggressive surgical, antifungal, and iron chelating therapy.

SUMMARY: Zygomycetes are widely distributed in the environment as inhabitants of soil and decaying matter. On rare occasions, these organisms can cause invasive infections in immunocompromised hosts. As zygomycetes are resistant to most conventional antifungal agents, its infection is often fatal. We report 2 cases of unusual intra-abdominal Rhizopus microsporus infection in children with acute leukemia as a result of an unprecedented outbreak due to oral intake of contaminated allopurinol tablets and ready-to-eat food items. Among the 2 patients, one of them survived after aggressive combined surgical, antifungal (AmBisome, Caspofungin, and Posaconazole) and iron chelation therapy.

Delayed recognition of intrathecal methotrexate overdose.

A 10-year-old girl who presented to our hospital was diagnosed as having B-precursor cell acute lymphoblastic leukemia. St Jude's Total XIII protocol was started. In the second block of the consolidation phase, 10 hours after triple intrathecal treatment, we realized that instead of 12 mg, 120 mg of methotrexate had accidentally been given. Although the patient had no symptoms 10 hours after intrathecal treatment, to prevent the possible neurotoxic effects of methotrexate, a cerebrospinal fluid exchange was performed. Simultaneously, systemic dexamethasone and calcium folinic acid were given. At the time of this writing (2 y), the patient has had no symptoms and has continued on the chemotherapy protocol as planned. Administration of high-dose intrathecal methotrexate may not lead to symptoms, as was the case in our patient. This may be related to individual variations in cerebrospinal fluid dynamics and drug metabolism.