Gemtuzumab Ozogamicin for Relapsed and Refractory Acute Myeloid Leukemia and Myeloid Sarcomas

Extramedullary infiltration in pediatric acute myeloid leukemia: Results from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative

BACKGROUND

The outcome of extramedullary infiltration (EMI) in pediatric acute myeloid leukemia (AML) is controversial, and little is known about the implications of stem cell transplantation (SCT) and gemtuzumab ozogamicin (GO) treatment on patients with EMI.

METHODS

We retrieved the clinical data of 713 pediatric patients with AML from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset, and analyzed the clinical and prognostic characteristics of patients with EMI at diagnosis and relapse.

RESULTS

A total of 123 patients were identified to have EMI at diagnosis and 64 presented with EMI at relapse. The presence of EMI was associated with age ≤2 years, M5 morphology, abnormal karyotype, and KMT2A rearrangements. Hyperleukocytosis and complex karyotype were more prevalent in patients with EMI at relapse. Additionally, patients with EMI at diagnosis had a reduced incidence of FLT3 ITD-/NPM1+, whereas those with EMI at relapse displayed a lower frequency of FLT3 ITD+. Patients with EMI at diagnosis exhibited a lower complete remission (CR) rate at the end of Induction Course 1 and higher relapse incidence. Importantly, EMI at diagnosis independently predicted both shorter event-free survival (EFS) and overall survival (OS). Regarding relapse patients, the occurrence of EMI at relapse showed no impact on OS. However, relapse patients with myeloid sarcoma (MS)/no central nervous system (CNS) exhibited poorer OS compared to those with CNS/no MS. Furthermore, regarding patients with EMI at diagnosis, SCT failed to improve the survival, whereas GO treatment potentially enhanced OS.

CONCLUSION

EMI at diagnosis is an independent adverse prognostic risk factor for pediatric AML, and GO treatment potentially improves survival for patients with EMI at diagnosis.

Extramedullary Myeloid Leukemia in the Setting of a Myeloproliferative Neoplasm

Extramedullary acute myeloid leukemia (EML), also known as myeloid sarcoma (MS), is an extramedullary solid mass derived from the proliferation of myeloblasts outside of the bone marrow. EML can present independently or concurrently with intramedullary acute myeloid leukemia (iAML). It can happen de novo or secondary to iAML, myeloproliferative neoplasm (MPN), chronic myelomonocytic leukemia (CMML), or myelodysplastic syndrome (MDS). We present a 57-year-old female with a history of Janus kinase 2 (JAK-2)-positive essential thrombocythemia (ET) evolving into EML in the setting of a persistent TP53 mutation. We discuss the essential diagnostic studies including tissue biopsy and fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) imaging. We also investigate the significance of cytogenetics and next-generation sequencing (NGS) along with the unique pathogenesis, treatment and prognostic implications.

Granulocytic sarcoma causing long spinal cord compression: Case report and literature review

Context: Granulocytic sarcoma (GS) is an extramedullary form of proliferating myeloblasts. It is frequently reported in patients with acute myeloid leukemia (AML) but rarely in patients with chronic myeloid leukemia (CML). Spinal cord compression caused by CML-associated GS is exceedingly rare, with only few cases reported in the literature. To our knowledge, this is the first reported case in which GS caused such extensive compression.Findings: A 37-year-old man with CML suffered from back pain for 2 months. Notably, he had already achieved molecular remission (MR) after receiving imatinib mesylate for CML; bone marrow aspiration results were consistent with CML in chronic phase. Image examination revealed that developed GS occupied nearly the entire thoracic spinal canal, thereby causing extensive spinal cord compression. The tumor completely diminished after his treatment regimen was upgraded. He showed no signs of recurrence after 1-year follow-up.Conclusion: Extramedullary infiltration of CML should be taken into consideration when a mass lesion develops and compresses the spinal cord in a CML patient who has been receiving routine and standard treatment modalities; thus, a sudden and unexpected progression mandates a refinement and upgrade of treatment modality.

Use of gemtuzumab ozogamicin in relapsed refractory acute myeloid leukemia: Multi-center real life data from Turkey

We retrospectively evaluated the use of gemtuzumab ozogamicin (GO) in relapsed refractory (R/R) acute myeloid leukemia (AML) patients. Twenty-one CD33 positive R/R AML patients who received GO as a single agent in 4 hematology centers were included in this study. The median age was 59, and the median ECOG performance score was 2. According to cytogenetic analysis, 1 patient had favorable risk, 12 patients with intermediate, and 8 patients with adverse risk. The overall response rate was 52.3%. Partial response was achieved in 3 of 8 patients with adverse risk. 33.3% of patients developed grade 3 anemia. Grade 4 neutropenia and thrombocytopenia were observed in 80% of the patients. One of the patients died due to sinusoidal obstruction syndrome / veno-occlusive disease (SOS / VOD) due to GO side effects. GO may be considered as a good option for salvage therapy in R/R AML patients.

Gemtuzumab-ozogamicin and blinatumomab as treatment for refractory mixed-phenotype blast crisis in chronic myeloid leukaemia

In the tyrosine kinase inhibitor era, the blast phase of chronic myeloid leukaemia (BP-CML) renders an uncommon presentation and has a poor prognosis with an estimated overall survival below 20%. Mixed-phenotype blast phase is even more infrequent, presenting in 3.3% of these patients. Blast phase manifests along haematological sarcomas, with extramedullary activity in lymph nodes, skin and bone. We report the case of a patient with an ovarian sarcoma as an extramedullary presentation of mixed-phenotype BP-CML refractory to conventional treatment which responded to immunotherapy against CD33 and CD19.

The myeloid sarcoma treated by Venetoclax with hypomethylating agent followed by stem cell transplantation: rare case report

BACKGROUND

Myeloid sarcoma (MS) is a very rare condition, develops both in patients with other hematological neoplasms, and as isolated tumor. MS of the gynecologic tract is extremely rare. An available literature data about diagnosis and management of MS is summarized in the article. The role of chemotherapy, radiation therapy, surgery and bone marrow transplantation in the treatment is discussed. Polychemotherapy and allogeneic bone marrow transplantation were suggested to be the optimal treatment strategy of MS of the gynecological tract. The use of new targeted agents results in promising clinical data.

CASE PRESENTATION

We are presenting a rare clinical case of a MS of the uterine cervix with concomitant bone marrow involvement and describe all the peculiarities of the clinical course, diagnosis, and treatment. The patient received chemotherapy followed by allogeneic bone marrow transplantation. The pre-transplant therapy allowed us to perform allogeneic bone marrow transplantation with the deepest response possible: complete PET-negative and MRD-negative remission of the disease.

CONCLUSIONS

MS remains a subject of discussion regarding its diagnostic and therapeutic aspects. The use of novel targeting agents can be perspective option for patient with extramedullary disease.

Isolated Intracranial Myeloid Sarcoma Mimicking Malignant Lymphoma: A Diagnostic Challenge and Literature Reviews

Isolated intracranial myeloid sarcoma (MS) is an unusual variant tumor with few cases reported so far in the medical literature. A 29-year-old woman was admitted to our hospital presenting progressive visual loss in the right eye and weight loss (20 kg) without a previous history of hematological disease (HD). Radiologic evaluation showed the evidence of intracranial mass. Histologically, the resected tumor was composed of a uniform population of primitive cells and primarily misdiagnosed as a T-cell non-Hodgkin’s lymphoma (NHL). Chemotherapy with cyclophosphamide, doxorubicin, vinblastine, and prednisone (CHOP) was ineffective. A biopsy and histopathological evaluation were repeated, and immunohistochemical staining revealed the positivity of immature cells to an extensive panel of myeloid markers. These findings were consistent with a diagnosis of MS and bone marrow infiltration. Literature reviews of previous cases were also undertaken.

Lyon-University Hospital Experience with Gemtuzumab Ozogamicin Therapy in Acute Myeloid Leukemia: a 'Real-Life' Study

Ninety-four adults with newly diagnosed or relapsed/refractory acute myeloid leukemia (AML) were treated with fractionated doses of gemtuzumab ozogamicin (GO) at one-single French center over ten years. We attempted to define predictive factors for response and survival. The overall response rate was 70% (86% in newly diagnosed and 65% in relapsed/refractory AML). Mortality during induction was 6%. Disease-free survival (DFS) and overall survival at three years after GO treatment was 36% and 31%, respectively. Median DFS in relapsed/refractory patients was eight months with a 3-year DFS at 34%. Among remitters, allogeneic hematopoietic stem cell transplantation (HSCT) can be performed in 28 cases (42%), including two patients in first-line therapy and 26 in further line. In relapsed/refractory patients undergoing allogeneic HSCT after responding to GO therapy, the median DFS was not reached. Incidences of transplant-related mortality, grade ≥ 3 acute graft-versus-host (GvH) disease, and extensive chronic GvH disease were 11%, 14%, and 25%, respectively. No sinusoidal obstruction syndromes were reported among allografted patients as among the other patients in the studied cohort. GO-based chemotherapy is a viable option for the treatment of relapsed/refractory AML patients and is a feasible schedule as a bridge to allogeneic transplant.

New insights into sinusoidal obstruction syndrome

BACKGROUND

Entry criteria included patients who developed sinusoidal obstruction syndrome (SOS) at a single centre from January 2000 to December 2011. Patients who underwent haemopoietic stem cell transplantation or actinomicyn-based chemotherapy for nephroblastoma were selected. The study group comprised five patients with SOS who were compared with a control group of seven patients without SOS.

AIM

To study the relationships between endothelial extracellular vesicles (EV) and plasminogen-activator inhibitor type 1(PAI-1) to assess their modification in the early phase of SOS.

METHODS

Consecutive blood samples were tested for cell-derived EV, PAI-1 and coagulation parameters. Any statistically significant correlation between all datasets was searched.

RESULTS

Antithrombin level and platelet count were statistically significantly reduced in SOS patients, suggesting a consumption status. PAI-1:Ag and PAI-1:act showed an inverse relationship with platelet counts (coef. -0.034, SE = 0.016; P = 0.041 and -0.052, SE = 0.019; P = 0.011 respectively). During follow up, PAI-1:Ag was inversely related to EV CD144+ (coef. -0.261, SE = 0.094; P = 0.007) and antithrombin (coef -0.509, SE = 0.175; P = 0.005). PAI-1:act showed an inverse association with EV CD144+ (coef.-0.251, SE = 0.121; P = 0.043), EV CD31+/CD41+ (coef. -0.004, SE = 0.002; P = 0.026) and antithrombin (coef. -0.470, SE = 0.220; P = 0.038). EV generated by rupture of gap junctions (EV CD144+) were increased in SOS patients and also showed a change over time.

CONCLUSION

This study demonstrates the existence of an ongoing procoagulant and hypofibrinolytic status in SOS, indicating a possible role for anticoagulant therapy. Moreover, these findings suggest a role for EV CD 144+, either alone or in combination with PAI-1, as a new biomarker for SOS.

FDA Approval Summary: Mylotarg for Treatment of Patients with Relapsed or Refractory CD33-Positive Acute Myeloid Leukemia

On September 2, 2017, the U.S. Food and Drug Administration approved gemtuzumab ozogamicin (GO; Mylotarg; Pfizer, New York City, NY) for treatment of relapsed or refractory (R/R) CD33-positive acute myeloid leukemia (AML) in patients 2 years of age and older. GO is a CD33-directed antibody drug conjugate linked to the cytotoxic antibiotic calicheamicin. It originally received accelerated approval for treatment of older patients with relapsed CD33-positive AML in 2000, but it was withdrawn from the market in 2010 when the confirmatory trial failed to demonstrate clinical benefit among safety concerns, such as a higher rate of induction fatalities on the GO combination arm compared with chemotherapy alone. In addition, GO was associated with hepatic veno-occlusive disease (VOD), which has substantial morbidity and mortality. Pharmacokinetic analyses suggested a lower maximum concentration of GO would result in less VOD without affecting target saturation or efficacy. A meta-analysis across dose schedules of GO in patients with R/R AML showed that a lower-dose "fractionated" schedule of 3 mg/m² days 1, 4, and 7 was associated with less early mortality, hemorrhage, and VOD, without an apparent decrease in complete remission (CR) rate. MyloFrance 1 was a single-arm study evaluating response rates in patients with relapsed CD33-positive AML treated with the lower-dose fractionated GO regimen. The CR rate was 26% (95% confidence interval 16%-40%). Common adverse reactions were fever, infections, nausea, vomiting, constipation, bleeding, increased liver enzymes, and mucositis. There were no cases of VOD. These results supported the approval of GO as monotherapy for R/R CD33-positive AML using the lower-dose fractionated regimen.

IMPLICATIONS FOR PRACTICE

Gemtuzumab ozogamicin (GO) 3 mg/m² days 1, 4, and 7 is an active regimen for induction of remission when used to treat patients with relapsed or refractory CD33-positive acute myeloid leukemia without curative intent. The risks of hepatic veno-occlusive disease and early mortality with this regimen appear to be lower than reported previously for GO 9 mg/m² days 1 and 15. The data were not sufficient to enable conclusions about the safety of GO in children younger than 2 years of age.

Myeloid Sarcoma: Presentation, Diagnosis, and Treatment

Myeloid sarcoma is an extramedullary tumor of immature granulocytic cells. It is a rare condition, most often associated with acute myeloid leukemia (AML), although in some rare cases it may present in nonleukemic patients. It should therefore be considered as a differential diagnosis of any atypical cellular infiltrate. It may occur at any site, leading to very varied clinical presentations. Diagnosis is challenging and relies on a high index of suspicion as well as radiology, histology, immunophenotyping, and molecular analyses, which also are essential for risk stratification and treatment planning. Systemic chemotherapy using AML-like regimens should be commenced early, even in nonleukemic disease. Surgery and/or radiotherapy may be indicated for symptomatic lesions or tumors causing local organ dysfunction or obstruction. Allogeneic hematopoietic stem cell transplantation has demonstrated promising results, particularly in patients who achieved complete remission with AML-induction protocols, and recent advances in genetic profiling may enable the development of novel targeted therapies. Prospective multicenter controlled trials are required to further refine management decisions and investigate the role of novel targeted therapies.

Gemtuzumab ozogamicin in acute myeloid leukemia revisited

INTRODUCTION

Gemtuzumab ozogamicin (GO) is a combination of calicheamicin and a recombinant humanized IgG4 antibody directed against CD33. From 2000 to 2010, it was approved by the FDA for treatment of relapsed, older patients with CD33(+) acute myeloid leukemia (AML). After withdrawal from the market, several trials have provided new evidence on the safety and clinical efficacy of GO.

AREAS COVERED

In this review, we discuss pharmacological and clinical aspects of GO. GO was found to show benefit in AML patients as adjunct to intensive chemotherapy when it was given in parallel to induction therapy. The benefit was restricted to patients with a favorable- or an intermediate-risk cytogenetic profile. Higher doses of GO above 6 mg/m(2) per administration were associated with increased toxicity without survival benefit, whereas repetitive doses of 3 mg/m(2) resulting in cumulative doses of 9 mg/m(2) were well tolerated. Predictive markers for response to GO other than the cytogenetic profile and P-glycoprotein activity are still missing.

EXPERT OPINION

GO as adjunct and in parallel to intensive induction chemotherapy does significantly improve survival end points in AML patients with favorable/intermediate-risk cytogenetics. A dose of 3 mg/m(2) per administration appears safer compared with 6 mg/m(2) and even 9 mg/m(2).

Efficacy and resistance of gemtuzumab ozogamicin for acute myeloid leukemia

Seventy to 80 % of patients with acute myeloid leukemia (AML) achieve complete remission following intensive chemotherapy, but more than 50 % of patients in remission subsequently relapse, which is often associated with clinical drug resistance. Therapy based on monoclonal antibodies (mAbs) has been developed to increase the selectivity of cytotoxic agents by conjugating them with a mAb. Gemtuzumab ozogamicin (GO) is a conjugate of a cytotoxic agent, a calicheamicin derivative, linked to a recombinant humanized mAb directed against the CD33 antigen, which is expressed on leukemia cells from more than 90 % of patients with AML. This conjugated mAb was introduced following promising results from phase I and II studies. However, the initial phase III study did not confirm the efficacy of GO in combination with conventional chemotherapies. Several subsequent phase III studies have shown the efficacy of GO in favorable and intermediate risk AML. Several resistance mechanisms against GO have been reported. Multidrug resistant (MDR) P-glycoprotein (P-gp), a trans-membrane glycoprotein that pumps out many anti-leukemic agents from cells, also affects GO. For this reasons, GO has been used in combination with MDR modifiers, such as cyclosporine, and in cases without P-gp. Several investigators have reported successful results of the use of GO in acute promyelocytic leukemia (APL). GO has also been described as effective in cases relapsed after treatment with all-trans retinoic acid (ATRA), arsenic acid and conventional chemotherapeutic agents. The efficacy of GO will be studied mainly in a favorable risk of AML, such as core binding factor leukemia and APL. In addition, suitable combinations with other chemotherapies and administration schedules should be discussed.

New therapeutic approaches to acute myeloid leukemia

BACKGROUND

The heterogeneity of acute myeloid leukemia (AML) has been established by many new insights into the pathogenesis and treatment of patients with AML. Understanding the basic cellular and molecular pathogenesis of leukemic cells is vital to the development of new treatment approaches.

OBJECTIVE/METHODS

To review progress until now with agents that are showing promise in the treatment of AML, we summarize the published preclinical and clinical trials that have been completed.

RESULTS

Based on recent progress of investigations, more specifically targeted agents have been developed for the treatment of AML such as tyrosine kinase inhibitors, monoclonal antibodies, epigenetic agents, antiangiogenic agents, and farnesyl transferase inhibitors.

CONCLUSION

In the future, in addition to performing therapeutic trials of these agents, it will be important to identify other highly specific therapeutic agents based on our evolving understanding of the biology of AML.

Antibody-drug conjugates of calicheamicin derivative: gemtuzumab ozogamicin and inotuzumab ozogamicin

Antibody-drug conjugates (ADC) are an attractive approach for the treatment of acute myeloid leukemia and non-Hodgkin lymphomas, which in most cases, are inherently sensitive to cytotoxic agents. CD33 and CD22 are specific markers of myeloid leukemias and B-cell malignancies, respectively. These endocytic receptors are ideal for an ADC strategy because they can effectively carry the cytotoxic payload into the cell. Gemtuzumab ozogamicin (GO, Mylotarg) and inotuzumab ozogamicin consist of a derivative of calicheamicin (a potent DNA-binding cytotoxic antibiotic) linked to a humanized monoclonal IgG4 antibody directed against CD33 or CD22, respectively. Both of these ADCs have a target-mediated pharmacokinetic disposition. GO was the first drug to prove the ADC concept in the clinic, specifically in phase II studies that included substantial proportions of older patients with relapsed acute myeloid leukemia. In contrast, in phase III studies, it has thus far failed to show clinical benefit in first-line treatment in combination with standard chemotherapy. Inotuzumab ozogamicin has shown remarkable clinical activity in relapsed/refractory B-cell non-Hodgkin lymphoma, and it has started phase III evaluation. The safety profile of these ADCs includes reversible myelosuppression (especially neutropenia and thrombocytopenia), elevated hepatic transaminases, and hyperbilirubinemia. There have been postmarketing reports of hepatotoxicity, especially veno-occlusive disease, associated with GO. The incidence is ~2%, but patients who undergo hematopoietic stem cell transplantation have an increased risk. As we steadily move toward the goal of personalized medicine, these kinds of agents will provide a unique opportunity to treat selected patient subpopulations based on the expression of their specific tumor targets.

Myeloid sarcoma: current approach and therapeutic options

Myeloid sarcoma is a rare disease that can present as an isolated extramedullary leukemic tumor, concurrently with or at relapse of acute myeloid leukemia. Owing to the rarity of this disorder, most of the literature comprises small retrospective studies and case reports. The aim of this review is to summarize the current published data regarding the clinical presentation, morphological, cytogenetic and molecular features, prognosis and treatment of myeloid sarcoma.

Gemtuzumab ozogamicin in non-acute promyelocytic acute myeloid leukemia

INTRODUCTION

Gemtuzumab ozogamicin (GO) has been used in relapsed, refractory and newly diagnosed acute myeloid leukemia (AML) as a single agent and in combination with intensive chemotherapy. Results of recent Phase III trials have led to its withdrawal in the USA although a beneficial effect of GO in genetically defined AML subgroups was evident.

AREAS COVERED

This review examines the use of GO as a single agent or in combination with intensive chemotherapy in non-acute promyelocytic AML. The literature search was based on publications on GO indexed in the PubMed electronic database and selected meeting abstracts. GO has shown moderate activity as a single agent but promising activity in combination with intensive chemotherapy in refractory or relapsed AML. Relapsed AML defined molecularly by mutant nucleophosmin-1 without concurrent fms-related tyrosine kinase 3 (FLT3) internal tandem duplication seems to benefit most from GO. In newly diagnosed AML two up-front randomized Phase III trials evaluating GO in induction therapy failed to demonstrate an improvement in response and survival. Again, genetically defined subgroups may benefit.

EXPERT OPINION

Future challenges of personalized therapy in AML will be to integrate the signals from current subgroup analyses underlining the role of GO in genetically defined AML entities.

Use of gemtuzumab ozogamycin combined with conventional chemotherapy in patients with acute myeloid leukemia

Objective: To analyze the outcome of patients treated with gemtuzumab ozogamycin combined with conventional therapy treated at Hospital Israelita Albert Einstein. Methods: 14 patients who had high risk features (secondary leukemia, unfavorable cytogenetics, and refractory disease) were treated with gemtuzumab ozogamycin combined with conventional therapy and their outcome was analysed by reviewing their medical records. Results: Overall response rate was 58%, with 43% achieving complete response, with a median follow-up of 11 months, event-free survival was 3 months. Eleven patients died, 6 of them due to refractory acute myeloid leukemia. Only four patients presented with grade 3 to 4 toxicities and only one patient had sinusoidal obstruction syndrome after bone marrow transplant. Conclusion: gemtuzumab ozogamycin combined with chemotherapy is a feasible treatment regimen in acute myeloid leukemia patients. However, further studies are necessary to clarify which subgroup of patients may beneft from this treatment.

Phase I trial of gemtuzumab ozogamicin in intensive combination chemotherapy for relapsed or refractory adult acute myeloid leukemia (AML): Japan Adult Leukemia Study Group (JALSG)-AML206 study

In order to investigate better molecular-target therapy for acute myeloid leukemia (AML), we conducted a phase I trial of a combination of gemtuzumab ozogamicin (GO) with conventional chemotherapy. Between January 2007 and December 2009, a total of 19 adult Japanese patients with relapsed or refractory CD33-positive AML (excluding acute promyelocytic leukemia) were enrolled. All registered patients received a standard dose of cytarabine (Ara-C) (100 mg/m(2) × 7 days), combined with either idarubicin (IDR) (10-12 mg/m(2) × 3 days) or daunorubicin (DNR) (50 mg/m(2) × 3-5 days), and then GO (3-5 mg/m(2) ), which was administered 1 day after the last infusion of IDR (IAG regimen) or DNR (DAG regimen). While doses of both GO and IDR and the administration period of only DNR were increased, the dose-limiting toxicity (DLT) was assessed. Among 19 patients (nine in the IAG regimen, 10 in the DAG regimen), the median age was 59 years (range 33-64), and the relapsed/refractory ratio was 13/6. In the therapy using 3 mg/m(2) GO in the IAG or DAG regimen, grade 3/4 leukopenia and neutropenia were observed in all patients, but none had grade 3/4 non-hematological toxicities, except febrile neutropenia. Three patients in the IAG regimen who were administered 5 mg/m(2) GO showed DLT. No patients had veno-occlusive disease or sinusoidal obstructive syndrome. In conclusion, 3 mg/m(2) GO combined with Ara-C and IDR or DNR can be safely administered, and phase II trials should be conducted to investigate the clinical efficacy of the combination therapy.

Extramedullary relapse of AML with t(9;11)(p22;q23) associated with clonal evolution from trisomy 8 into tetrasomy 8

This report describes a patient with extramedullary relapse of acute myeloid leukemia (AML) without involving bone marrow. A 57-year-old man was diagnosed as having acute monoblastic leukemia with t(9;11)(p22;q23) and trisomy 8. Ten months after achieving complete response (CR) with chemotherapy, masses developed in his left forearm and in the back of his thigh, preceded by enigmatic peripheral neurological symptoms. Aspiration from the forearm showed leukemic relapse, and fluorescence in situ hybridization (FISH) revealed that the majority of the cells had 11q23 anomaly and tetrasomy 8. Bone marrow or meningeal relapse was not observed. To our knowledge, this is the first case report of clonal evolution associated with the development of myeloid sarcoma as a relapse in AML.

Salvage therapy for acute myeloid leukemia with fludarabine, cytarabine, and idarubicin with or without gemtuzumab ozogamicin and with concurrent or sequential G-CSF

The current salvage therapies for relapsed/refractory acute myeloid leukemia (AML) are unsatisfactory. Over the past 7 years, we have used two salvage regimens: fludarabine, cytarabine, and idarubicin with (FLAG-IM) or without gemtuzumab ozogamicin (GO) (9 mg/m(2) on Day 8) (FLAG-I) in relapsed/refractory AML. Three-quarters of patients also received concurrent G-CSF. Seventy-one patients were treated, 23 with FLAG-I and 48 with FLAG-IM. The median duration of follow-up was 30.6 months. The treatment groups were well balanced with median ages of 48 years (range 18-70) and 47 years (range 20-68), unfavorable cytogenetics in 57% and 35%, prior allogeneic stem cell transplant in 43% and 42%, and CR1 duration <1 year in 60% and 67%, respectively, for FLAG-I and FLAG-IM. The complete remission (CR) rate in the FLAG-I group was 39% with an additional 13% achieving a CRp [overall response rate (ORR) 52%]; the CR rate in the FLAG-IM group was 29% with an additional 27% achieving a CRp (ORR 56%). The median duration of response (DOR; 16.8 vs. 8.3 months), event-free survival (EFS; 7.4 vs. 4.1 months), and overall survival (OS; 8.8 vs. 5.0 months) trended to favor FLAG-I over FLAG-IM. The patients who received G-CSF concurrent with chemotherapy had superior overall response rate (ORR; 62% vs. 29%, P = 0.026), median EFS (6.2 vs. 3.4 months, P = 0.010), and OS (8.8 vs. 3.9 months, P = 0.004) when compared with those who sequentially received G-CSF and chemotherapy, regardless of chemotherapy regimen. The addition of GO, at this dose and schedule, to FLAG-I failed to improve the outcomes in patients with relapsed/refractory AML. The patients who received G-CSF concurrently with chemotherapy had improved outcomes. Am. J. Hematol., 2009. (c) 2009 Wiley-Liss, Inc.

Targeted treatment of acute myeloid leukemia in older adults: role of gemtuzumab ozogamicin

As the overall prognosis and treatment response rate to standard chemotherapy for acute myeloid leukemia (AML) remains poor in the older adult population, there is a need for more effective therapeutic agents with lower toxicity profiles that can be offered to these patients. Gemtuzumab ozogamicin (GO) is an anti-CD33 monoclonal antibody that was approved by the US Food and Drug Administration for use as monotherapy in patients 60 years of age and older with relapsed AML. GO consists of a humanized anti-CD33 antibody (hP67.6) which is linked to N-acetyl-gamma calicheamicin 1,2-dimethyl hydrazine dichloride. Once the antibody attaches to the surface antigen, it is rapidly internalized. Calicheamicin, a potent enediyne, is subsequently released and acts as a cytotoxic anti-tumor agent. In this population, GO has an acceptable toxicity and yields response rates approaching 30%. The efficacy of GO as monotherapy and in combination therapy for treatment of both de novo and relapsed AML continues to be investigated.

Gemtuzumab ozogamicin in the treatment of acute myeloid leukemia

Gemtuzumab ozogamicin (GO) is a chemotherapeutic agent that consists of a humanized anti-CD33 antibody (hP67.6) linked to N-acetyl-calicheamicin 1,2-dimethyl hydrazine dichloride, a potent enediyne antitumor antibiotic. GO was approved conditionally by the Federal Drug Administration in May 2000 as single-agent therapy for first recurrence of acute myeloid leukemia (AML) in patients over the age of 60 years who are unfit for conventional cytotoxic therapy. In this setting, it produces a complete response (CR) rate of 13%, with another 13% achieving CR with inadequate platelet recovery (CRp). The most common adverse effects associated with GO are infusion-related reactions and myelosuppression. GO monotherapy at the dose of 9 mg/m(2) is complicated with hepatic veno-occlusive disease in approximately 5% of cases, particularly prior to or following stem cell transplantation. Attenuated doses of GO or fractionated doses appear to be equally effective and better tolerated. GO has shown remarkable activity in acute promyelocytic leukemia, particularly for the elimination of minimal residual disease. Combinations of GO with chemotherapy as induction or post-remission therapy are promising, and phase III trials are ongoing.

Consolidation therapy for adult acute myeloid leukemia: a systematic analysis according to evidence based medicine

Post-remission therapy in acute myeloid leukemia (AML) remains problematic. It has been demonstrated that younger patients can maintain longer complete remissions (CR) with aggressive post-remission therapies after induction treatment: allogeneic (allo), autologous (auto) stem cell transplantation (SCT), or intensive chemotherapy (ICC). The purpose of our study was to identify the most important randomized and controlled studies comparing these three therapeutic options, in order to draw conclusions and possible suggestions for post-remission therapy of AML, according to the evidence based medicine (EBM) rules. We performed an exhaustive analysis of the literature, searching either in electronic databases or among the references of the identified articles (hand searching). We searched the MEDLINE computer database for reports from 1985 through January 2005 and selected for analysis the clinical trials conducted over adults affected by newly diagnosed AML aged less than 65 years. The study design had to satisfy strict methodological criteria and must consider global mortality and/or disease free survival as primary outcomes. Overall we found 7750 papers; by using the limits "clinical trial" as publication type, "all adults 19+ years", we were able to select 344 papers. Among these, a further selection was made, based on two main clinical queries: 1) is auto-SCT superior to ICC/no other therapy in improving DFS and/or OS in adult AML patients in first CR? 2) is allo-SCT superior to auto-SCT/other therapeutic options in improving DFS and/or OS in adult AML patients in first CR? Concerning the first query, a possible advantage of auto-SCT over ICC was not clearly supported by data from clinical trials; there is no evidence that auto-SCT is superior in terms of OS to chemotherapy. Nevertheless, the reported TRM has been significantly reduced within the past years. Thus, the percentage of patients suitable for auto-SCT in CR has increased. Moreover, the scarce data concerning the comparison between auto-SCT and chemotherapy in different subsets of patients are unable to suggest a differentiated approach in patients with high-risk, standard-risk or low-risk AML. Data from the literature show that patients with unfavorable risk disease are more often addressed to allo-SCT and patients with low-risk disease receive more often intensive consolidation chemotherapy. Concerning the second query, interpretation of data from the main prospective studies about the role of allo-SCT in previously untreated AML is not easy. The first problem is the lack of real randomized clinical trials; in fact, according to the reported studies, AML patients generally receive allo-SCT on the basis of donor availability (the so called "genetic randomization"). The second problem is the frequent absence of intention to treat analysis. Despite methodological limitations, it was possible to compare allo-SCT with auto-SCT on a donor versus no-donor analysis and within risk groups. No overall benefit of allo-grafting on survival was demonstrated by any trial. In conclusion, the EBM approach highlighted the limitations observed in the published studies concerning consolidation therapy in AML; some suggestions, emerging from non-randomized, as well as randomized studies, are adequate, but not conclusive. This point, coupled with the intrinsic complexity to study AML biological heterogeneity, is probably a major obstacle to draw conclusive evidences for consolidation therapy in AML. These observations should plan to address new randomized studies on AML therapy; however, due to the emergence of genetic subgroups and new drugs targeting specific abnormalities, these trials should probably be designed directly focusing on the single entities. In this way, the cure of AML could eventually become the cure of each specific AML subset with its peculiar biological, molecular and prognostic features.

Adding low-dose gemtuzumab ozogamicin to fludarabine, Ara-C and idarubicin (MY-FLAI) may improve disease-free and overall survival in elderly patients with non-M3 acute myeloid leukaemia: results of a prospective, pilot, multi-centre trial and comparison with a historical cohort of patients

We report the final results of a prospective multi-centre trial testing the combination of chemotherapy (fludarabine, cytosine arabinoside and idarubicin; FLAI) followed by low-dose gemtuzumab ozogamicin (GO), for induction treatment of patients with CD33+ acute myeloid leukaemia (AML). Forty-six consecutive patients were treated: the median age was 66 (range: 60-80) years; the karyotype was unfavourable in 12 patients (26%), intermediate in 33 (71%) and favourable in one (3%). Eleven major infectious complications were recorded. There was one early death. Of the 45 evaluable patients, 24 achieved a complete response (CR; 52%), 66% and 33% in good-intermediate/poor karyotype patients. Median duration of CR was 7 (3-24) months. The cumulative incidence of relapse was 37% with an actuarial 2-year survival of 54%. These results were compared with 47 patients matched for age and karyotype who received FLAI, without GO. The proportion of patients achieving CR was comparable. However, patients with de novo AML receiving GO (n = 26) had a significantly lower risk of relapse at 2 years when compared with patients not receiving GO (n = 35) (40% vs. 80%, P = 0.01) and significantly better overall 2-year survival (40% vs. 14%P = 0.02). Patients with secondary AML had comparable outcome whether or not they received GO. This GO-based induction chemotherapy has a good toxicity profile. In keeping with a recent prospective randomised trial, the addition of GO seems to prolong disease-free survival.

Gemtuzumab therapy for isolated extramedullary AML relapse following allogeneic stem-cell transplant

BACKGROUND

A 19-year-old male with primary refractory acute myeloid leukemia received salvage therapy with mitoxantrone and cytarabine combination. He received consolidation therapy 3 months later with a matched-unrelated-donor stem-cell transplant. The disease relapsed in the bone marrow (BM) 9 months after the initial stem-cell transplant, and was successfully treated by repeat transplant from the same donor. Ten months following repeat transplant, the patient presented with an increasing number of extramedullary sites of biopsy-proven disease relapse (i.e. cranial and peripheral nerves, tongue, abdominal wall and chest wall). Repeated biopsy of the BM and chimera study showed no morphologic evidence of leukemic infiltrate with 100% donor-cell population.

INVESTIGATIONS

Physical examination, complete blood count, BM biopsy, flow cytometry, cytogenetic analysis, chimera study, tongue biopsy, abdominal-wall biopsy, cytology and immunohistochemistry, CT scan of the chest, abdomen and pelvis, MRI of the brain, and cerebrospinal fluid analysis.

DIAGNOSIS

Isolated extramedullary relapse of acute myeloid leukemia after stem-cell transplant.

MANAGEMENT

Primary leukemia treatment with idarubicin, cytarabine, etoposide, dexamethasone, tioguanine on protocol and salvage therapy with mitoxantrone and cytarabine combination for primary refractory disease. A matched-unrelated-donor stem-cell transplant for consolidation and donor-lymphocyte infusions were performed, followed by repeat unrelated-donor transplant for leukemia relapse in the marrow, radiation therapy and gemtuzumab ozogamicin for multiple sites of extramedullary leukemia relapse.

The role of Gemtuzumab Ozogamicin in the treatment of acute myeloid leukemia patients

Gemtuzumab Ozogamicin (GO) is an antibody-targeted chemotherapy agent consisting of the humanized murine CD33 antibody (clone P67.6) to which the calicheamicin-g1 derivative is attached via a hydrolysable bifunctional linker. GO is able to induce apoptosis in vitro in CD33-expressing cells and it has been approved in USA and in Europe as monotherapy for the treatment of elderly patients (older than 60 years) with relapsed acute myeloid leukemia (AML). GO administered as a single agent has resulted in overall response rates of about 30% in previously relapsed adults AML patients (including also with incomplete platelet recovery). Preliminary data indicate a potential role for GO also as a component of induction or consolidation regimens in adults and children. As for adverse events, veno-occlusive syndrome characterizes its tolerability profile, but GO is comparatively well tolerated by most patients.

What role does gemtuzumab ozogamicin have in the treatment of acute myelogenous leukemia?

Gemtuzumab ozogamicin (GO) is a novel, targeted chemotherapy designed to treat acute myeloid leukemia (AML). GO consists of an antitumor antibiotic, calicheamicin, linked to a humanized monoclonal antibody against CD33. It has been approved in the United States since 2000 to treat CD33+ AML in first relapse in older adults who are not candidates for cytotoxic therapy. Beyond this indication, the role of GO is evolving. Single-agent GO has a limited role in de novo AML. Incorporation of GO into standard induction treatment in de novo and relapsed AML is feasible. Comparative phase III studies of such an approach are ongoing. GO is associated with serious toxicities, such as infusional reactions, transient liver function test abnormalities, and veno-occlusive disease of the liver, especially in patients who undergo hematopoietic stem cell transplantation.

Acute myeloid leukaemia presenting with mediastinal myeloid sarcoma: report of three cases and review of literature

Although myeloid sarcomas (MS) are frequently associated with acute myeloid leukaemia (AML), the occurrence of mediastinal MS is a much rarer event. The authors describe a distinct group of three AML patients with mediastinal MS and complex cytogenetics presenting at their centre over a 7-year period. Clinical features consistent with superior vena caval obstruction were noted at presentation in two of the three patients. Mediastinal mass was detected on routine chest radiography, and biopsies confirmed the diagnosis of MS. One patient relapsed after consolidation chemotherapy and died from progressive disease. Two patients underwent allogeneic haemopoietic stem cell transplant, but succumbed to transplant related complications. Review of mediastinal MS over the last 20 years shows that a significant proportion of patients have complex cytogenetic abnormalities and a poor long-term prognosis. Early and accurate diagnosis is essential and patients should be managed along the lines of high risk AML.

Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients

Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.

The role of gemtuzumab ozogamicin in acute leukaemia therapy

Gemtuzumab ozogamicin (GO) is an immunoconjugate that binds to CD33 on the surface of acute myeloid leukaemia (AML) blasts and, after internalisation, releases a cytotoxic drug, calicheamicin. GO is approved by the US Food and Drug Administration for the treatment of CD33-positive AML at first relapse in patients 60 years and older who are not candidates for other cytotoxic therapy. GO as a single agent has low antileukaemic activity. When given to patients meeting the criteria noted above, it produces a complete response (CR) rate of only 12%, with another 12% achieving CR with inadequate platelet recovery (CRp). The median survival of patients treated with GO monotherapy is 11.2 months. GO therapy at 9 mg/m(2) is complicated with hepatic veno-occlusive disease in 5-10% of patients, particularly prior to or following stem cell transplantation. GO at lower doses combined with chemotherapy as induction or postremission therapy is promising, however, and phase III trials are ongoing. GO is probably most active in acute promyelocytic leukaemia (APL). It is used for induction regimens in high-risk APL and for the elimination of minimal residual APL. Case reports suggest that GO also has activity in CD33-positive acute lymphoblastic leukaemia. In conclusion, single agent GO can induce responses in patients with CD33-positive AML in first recurrence. The future of GO is its use in combination with other cytotoxic agents. Ongoing clinical trials may better define the role of GO combinations, particularly in untreated AML.