Salvage therapy for refractory or relapsed acute lymphocytic leukemia

Burden of hospitalization in acute lymphoblastic leukemia patients treated with Inotuzumab Ozogamicin versus standard chemotherapy treatment

Background

Inotuzumab Ozogamicin (INO), has demonstrated an improvement in overall survival, high rate of complete remission, favorable patient‐reported outcomes, and manageable safety profile vs standard of care (SoC; intensive chemotherapy) for relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) in the phase 3 INO‐VATE trial. With a one‐hour weekly dosing schedule, INO might be associated with lower healthcare system burden. This study analyses hospitalizations for INO vs SoC.

Methods

All patients receiving study treatment in the INO‐VATE trial were included. The days hospitalized during study treatment was calculated. Due to different treatment durations for INO and SoC (median of 3 vs 1 cycles), number of hospital days was mainly reported per observed patient month. Hospital days per patient month were analyzed for different treatment cycles, subgroups, and main reasons for hospitalization. Differences between treatments were analyzed by the incidence rate ratio (IRR).

Results

Overall, 82.9% and 94.4% INO and SoC patients experienced at least one hospitalization. The mean hospitalization days per patient month was 7.6 and 18.4 days for INO and SoC (IRR = 0.413, P < .001), which corresponds to patients spending 25.0% and 60.5% of their treatment time in a hospital. Main hospitalization reasons were R/R ALL treatment (5.2 (INO) vs 14.0 (SoC) days, IRR = 0.368, P < .001), treatment toxicities (1.4 vs 2.8 days, IRR = 0.516, P < .001) or other reasons (1.0 vs 1.6 days, IRR 0.629, P < .001).

Conclusions

Inotuzumab Ozogamicin treatment in R/R ALL is associated with a lower hospitalization burden compared with SoC. It is likely this lower burden has a favorable impact on healthcare budgets and cost‐effectiveness considerations.

Treatment of Relapsed/Refractory Acute Lymphoblastic Leukemia in Adults

Patients with relapsed and refractory acute lymphoblastic leukemia (ALL) have a dismal prognosis with less than 10 % of patients surviving 5 years. Most such patients cannot be rescued with currently available therapies, whatever the initial treatment they receive. Therefore, there is an urgent need for novel treatment options. Fortunately, over the past several years, an improved understanding of the biology of the disease has allowed the identification of rational molecular targets for therapeutic endeavors and the emergence of novel therapies has sparked great interest. This review will discuss the current treatment landscape for adult patients with relapsed and/or refractory ALL.

Refining the Role of Hematopoietic Cell Transplantation for Acute Lymphoblastic Leukemia as Novel Therapies Emerge

Acute lymphoblastic leukemia (ALL) is a rare adult neoplasm. The disorder consists of precursor B or T phenotypes. In the pediatric population, ALL was a success story in that 80% of children with ALL enjoy long-term survival. In adults, similar complete remission rates are achieved with current induction regimens; however, less than 50% of patients are alive at 5 years, with most deaths due to relapsed disease. Accordingly, optimizing post remission consolidation therapy might improve in outcomes. Such strategies may include chemotherapy and autologous or allogeneic transplant. Moreover, the ability to modify such therapy based on better disease risk stratification while taking into account patient characteristics such as performance status and presence of comorbidities is necessary to tailor treatment accordingly. Here, we review available medical literature on the use of hematopoietic cell transplantation as a consolidation modality in the treatment of adult ALL.

Blinatumomab-induced donor T-cell activation for post-stem cell transplant-relapsed acute CD19-positive biphenotypic leukemia

Post-stem cell transplantation (SCT) relapsed acute lymphoblastic leukemia (ALL) has extremely poor prognosis with median survival of less than 1 year. Donor lymphocyte infusion, second transplantation, chemotherapy or cytokine treatment have been tried as a salvage regimen without significant clinical benefit. Recently, blinatumomab, a bispecific monoclonal antibody targeting CD3-expressing T cells and CD19-expressing B-cell lineage malignant cells demonstrated promising outcomes in relapsed/refractory ALL patients. Literature on blinatumomab use in biphenotypic ALL along with Philadelphia chromosome positive (Ph+) ALL is limited. We report a case of post-SCT relapsed CD19 expressing biphenotypic lymphoblastic leukemia patient who achieved complete remission after blinatumomab treatment and has lasting remission for 1 year.

Clofarabine for the treatment of adult acute lymphoid leukemia: the Group for Research on Adult Acute Lymphoblastic Leukemia intergroup

Clofarabine, a second-generation purine analog displaying potent inhibition of DNA synthesis and favorable pharmacologic profile, is approved for the treatment of acute lymphoblastic leukemia (ALL) after failure of at least two previous regimens in patients up to 21 years of age at diagnosis. Good neurologic tolerance, synergy with alkylating agents, management guidelines defined through pediatric ALL and adult acute myeloid leukemia, have also prompted its administration in more than 100 adults with Philadelphia chromosome-positive and negative B lineage and T lineage ALL, as single agent (40 mg/m(2)/ day for 5 days), or in combination. In a Group for Research on Adult Acute Lympho- blastic Leukemia (GRAALL) retrospective study of two regimens (clofarabine ± cyclophosphamide + / - etoposide (ENDEVOL) ± mitoxantrone ± asparaginase ± dexamethasone (VANDEVOL)), remission was achieved in 50% of 55 relapsed/refractory patients, and 17-35% could proceed to allogeneic stem cell. Clofarabine warrants further exploration in advanced ALL treatment and bridge-to-transplant.

Efficacy of CPX-351, (cytarabine:daunorubicin) liposome injection, against acute lymphoblastic leukemia (ALL) xenograft models of the Pediatric Preclinical Testing Program

BACKGROUND

CPX-351, a liposomal formulation of cytarabine and daunorubicin co-encapsulated at an optimized synergistic 5:1 molar ratio, has demonstrated improved clinical outcomes over conventional cytarabine/daunorubicin treatment in a randomized phase 2 trial in patients with AML as well as superior efficacy against preclinical leukemia models when compared to the free drugs in combination.

PROCEDURES

Given the promising phase 2 data, limited toxicities observed, and the known clinical activities of cytarabine/daunorubicin, we assessed the efficacy of CPX-351 against a panel of childhood ALL xenograft models. Plasma pharmacokinetics of cytarabine and daunorubicin following CPX-351 treatment were determined by HPLC in order to correlate efficacy with drug exposure.

RESULTS

CPX-351, at a dose of 5 units/kg (corresponding to 5 mg/kg cytarabine and 2.2 mg/kg daunorubicin), was highly efficacious against all xenografts tested, inducing complete responses in four B-lineage xenografts and partial response in one T-lineage xenograft. These therapeutic responses were achieved with CPX-351 doses that provided drug exposures (based on Cmax and AUC) comparable to those observed in patients with AML.

CONCLUSIONS

These results suggest that CPX-351 may be a promising chemotherapeutic to be utilized in the treatment of ALL and support its testing in pediatric patients with leukemia.

Treating relapsed or refractory Philadelphia chromosome-negative acute lymphoblastic leukemia: liposome-encapsulated vincristine

Acute lymphoblastic leukemia (ALL) remains a disease with poor outcomes in adults. While induction chemotherapy achieves a complete remission in almost 90% of patients, the majority will relapse and die of their disease. Relapsed ALL is associated with a high reinduction mortality and chemotherapy resistance, with allogeneic hematopoietic stem cell transplantation offering the only therapy with curative potential. However, there is no efficacious and well tolerated standard regimen accepted as a “bridge” to allogeneic stem cell transplantation or as definitive treatment for patients who are not transplant candidates. Vincristine is an active drug in patients with ALL, but its dose intensity is limited by neurotoxicity, and its full potential as an anticancer drug is thus not realized. Encapsulation of vincristine into sphingomyelin and cholesterol nanoparticle liposomes facilitates dose-intensification and densification to enhanced target tissues with reduced potential for toxicity. Vincristine sulfate liposome injection (VSLI) is associated with significant responses in clinically advanced ALL, and has recently been approved by the US Food and Drug Administration for treatment of relapsed and clinically advanced Philadelphia chromosome-negative ALL. This review provides an overview of the preclinical and clinical studies leading to the approval of VSLI for the treatment of relapsed and refractory ALL, and suggests potential areas of future clinical development.

Chimeric antigen receptor-modified T cells for acute lymphoid leukemia

Chimeric antigen receptor-modified T cells with specificity for CD19 have shown promise in the treatment of chronic lymphocytic leukemia (CLL). It remains to be established whether chimeric antigen receptor T cells have clinical activity in acute lymphoblastic leukemia (ALL). Two children with relapsed and refractory pre-B-cell ALL received infusions of T cells transduced with anti-CD19 antibody and a T-cell signaling molecule (CTL019 chimeric antigen receptor T cells), at a dose of 1.4×10(6) to 1.2×10(7) CTL019 cells per kilogram of body weight. In both patients, CTL019 T cells expanded to a level that was more than 1000 times as high as the initial engraftment level, and the cells were identified in bone marrow. In addition, the chimeric antigen receptor T cells were observed in the cerebrospinal fluid (CSF), where they persisted at high levels for at least 6 months. Eight grade 3 or 4 adverse events were noted. The cytokine-release syndrome and B-cell aplasia developed in both patients. In one child, the cytokine-release syndrome was severe; cytokine blockade with etanercept and tocilizumab was effective in reversing the syndrome and did not prevent expansion of chimeric antigen receptor T cells or reduce antileukemic efficacy. Complete remission was observed in both patients and is ongoing in one patient at 11 months after treatment. The other patient had a relapse, with blast cells that no longer expressed CD19, approximately 2 months after treatment. Chimeric antigen receptor-modified T cells are capable of killing even aggressive, treatment-refractory acute leukemia cells in vivo. The emergence of tumor cells that no longer express the target indicates a need to target other molecules in addition to CD19 in some patients with ALL.

The role of allogeneic hematopoietic stem cell transplantation in the therapy of patients with acute lymphoblastic leukemia

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is an effective post-remission therapy in patients with acute lymphoblastic leukemia (ALL), but is associated with significant toxicity, so the optimal timing and use of this modality remains an issue of debate. Increased advances in reduced-intensity transplant preparative regimens and alternative donors has increased the accessibility of allogeneic transplantation. A risk adapted paradigm, using minimal residual disease analysis, may help in the selection of patients at highest risk for relapse, who may benefit most from alloHSCT. In this review, we summarize the indications for allogeneic transplantation within the risk-oriented paradigm, and also explore the latest literature on reduced intensity transplant regimens, as well as alternative donor transplantation for patients with ALL.

Defining the course and prognosis of adults with acute lymphocytic leukemia in first salvage after induction failure or short first remission duration

BACKGROUND

Results from salvage therapy in adult patients with acute lymphocytic leukemia (ALL) are wide-ranging and depend on several disease and patient characteristics. The objectives of this study were to define the prognosis for adult patients with ALL after first salvage through multivariate analyses of patient and disease characteristics.

METHODS

Adults with ALL who had primary resistance to frontline therapy or who had a disease recurrence after a first complete response (CR) duration <1 year were analyzed. Multivariate analyses for subsequent CR and survival were conducted.

RESULTS

Seventy-five of 245 patients (31%) achieved CR. The median CR duration was 5 months, the median survival was 4.7 months. In multivariate analysis, independent poor prognostic factors for not achieving CR were age >55 years, bone marrow blasts ≥20%, and platelet count <75 × 10(9) /L. Variables that were associated independently with shorter survival were age >55 years, bone marrow blasts ≥20%, platelet count <75 × 10(9) /L, albumin level <3 g/L, and lactic dehydrogenase level ≥1000 IU/L. Patients who had ≥3 of the 5 adverse factors (45%) had a median survival of 2 to 3 months and CR rates of 8% to 15%. Achieving CR was associated independently with improved survival in a landmark multivariate analysis (P < .0001; hazard ratio, 0.40; 95% confidence interval, 0.03-0.72).

CONCLUSIONS

The current analyses identified a subset of adults patients ALL in first salvage for whom standard therapies were associated with an extremely poor outcome. The results also confirmed the importance of achieving CR to attain improved survival.

Outcome after relapse of acute lymphoblastic leukemia in adult patients included in four consecutive risk-adapted trials by the PETHEMA Study Group

BACKGROUND

About one half of adults with acute lymphoblastic leukemia are not cured of the disease and ultimately die. The objective of this study was to explore the factors influencing the outcome of adult patients with relapsed acute lymphoblastic leukemia.

DESIGN AND METHODS

We analyzed the characteristics, the outcome and the prognostic factors for survival after first relapse in a series of 263 adult patients with acute lymphoblastic leukemia (excluding those with mature B-cell acute lymphoblastic leukemia) prospectively enrolled in four consecutive risk-adapted PETHEMA trials.

RESULTS

The median overall survival after relapse was 4.5 months (95% CI, 4-5 months) with a 5-year overall survival of 10% (95% CI, 8%-12%); 45% of patients receiving intensive second-line treatment achieved a second complete remission and 22% (95% CI, 14%-30%) of them remained disease free at 5 years. Factors predicting a good outcome after rescue therapy were age less than 30 years (2-year overall survival of 21% versus 10% for those over 30 years old; P<0.022) and a first remission lasting more than 2 years (2-year overall survival of 36% versus 17% among those with a shorter first remission; P<0.001). Patients under 30 years old whose first complete remission lasted longer than 2 years had a 5-year overall survival of 38% (95% CI, 23%-53%) and a 5-year disease-free survival of 53% (95% CI, 34%-72%).

CONCLUSIONS

The prognosis of adult patients with acute lymphoblastic leukemia who relapse is poor. Those aged less than 30 years with a first complete remission lasting longer than 2 years have reasonable possibilities of becoming long-term survivors while patients over this age or those who relapse early cannot be successfully rescued using the therapies currently available.

DNA methylation profiles of organic anion transporting polypeptide 1B3 in cancer cell lines

PURPOSE

Multispecific organic anion transporter, OATP1B3/SLCO1B3, is expressed in several cancer cell lines as well as tumor tissues, and its expression sensitizes the cells to some anti-cancer agents. The present study was aimed to characterize the DNA methylation profiles around the transcriptional start site (TSS) of OATP1B3 and correlate them with the mRNA expression in cancer and immortalized cell lines.

METHODS

The mRNA expression and DNA methylation profiles of OATP1B3 were determined by RT-PCR and bisulfite sequencing, respectively.

RESULTS

The expression of OATP1B3 mRNA was detected in DLD-1, TFK-1, PK-8, and PK-45P cells, but below the limit of detection in HepG2, Caco-2, and HEK293 cells. Bisulfite sequencing demonstrated that CpG dinucleotides around the TSS are differentially methylated among cell lines and partly associated with the mRNA expression profile of OATP1B3. Furthermore, treatment with 5-aza-2'-deoxycytidine, an inhibitor of DNA methyltransferase, significantly increased the mRNA expression of OATP1B3 in HepG2 and Caco-2 cells by 18- and 14-fold, respectively, but not in DLD-1 and TFK-1 cells.

CONCLUSION

DNA methylation-dependent gene silencing is at least partly involved in the regulation of OATP1B3 expression in cancer/immortalized cell lines.

Outcome of adults with acute lymphocytic leukemia in second or subsequent complete remission

The outcome of adults with acute lymphocytic leukemia (ALL) who achieve a complete response (CR) on salvage therapy is thought to be poor, but not previously analyzed. To define the course of adult ALL post CR on salvage therapy and the effects of pretreatment factors on prognosis. One hundred seventy-two adults with ALL who achieved a second or third CR on salvage therapy were reviewed. Prognostic factors affecting survival were analyzed by multivariate analysis. The median survival post achieving CR for the entire group was 10 months. The estimated 1-year survival rate was 42%. Forty-three patients underwent stem cell transplant in subsequent CR: their median survival was 12 months and the 3-year survival rate was 25%. Independent poor prognostic factors for survival were age  > 55 years, duration of first CR < 12 months, and lactate dehydrogenase levels > 1000 IU/L. This analysis defines the outcome of adult ALL in CR post salvage therapy and the prognostic factors influencing survival. These results could be used in assessing the efficacy of new treatments aimed at improving CR durations and survival post salvage therapy.

Philadelphia chromosome-positive acute lymphoblastic leukemia

The Philadelphia (Ph) chromosome, a short chromosome 22, is the most frequent cytogenetic abnormality in adult patients with acute lymphoblastic leukemia (ALL). It occurs in approximately 20% to 30% of adults and in about 5% of children with this disease. The incidence rises with age and occurs in approximately 50% of patients older than 50 years. This article reviews the treatment regimens for Ph+ ALL, including imatinib and second generation tyrosine kinase inhibitors (TKIs). The introduction of effective TKIs in the treatment of Ph+ ALL has introduced several avenues of research in a disease that was hitherto difficult to treat.

Anti-Leukemic and Anti-GVHD Effects of Campath-1H in Acute Lymphoblastic Leukemia Relapsed after Stem-Cell Transplantation

Despite aggressive approaches, including second transplant, donor lymphocyte infusion and several new agents, the prognosis of acute lymphoid leukemia (ALL) patients relapsing after stem-cell transplantation (SCT) remains poor. Monoclonal-antibodies (moAb) could provide a useful tool in this setting. In particular, anti-CD52 moAb is useful in lymphoid malignancies. We thus treated as compassionate with campath-1H 3 ALL patients relapsed after SCT. In 2 cases we observed a reduction of peripheral blood and/or bone marrow blasts. In 1 case a GVHD grade reduction was observed. Larger trials are required in order to define the role of campath-1H in ALL.

Successful second allogeneic stem cell transplantation in second remission induced by dasatinib in a child with Philadelphia chromosome positive acute lymphoblastic leukemia

We report on the use of dasatinib, a second-generation bcr-abl kinase inhibitor, in a child in early relapse of Philadelphia chromosome positive acute lymphoblastic leukemia after hematopoietic stem cell transplantation. This patient benefited from the use of dasatinib obtaining of a complete molecular response which allowed a second successful transplant. Moreover, dasatinib was well tolerated in this heavily pretreated patient.

Residual DNA methylation at remission is prognostic in adult Philadelphia chromosome-negative acute lymphocytic leukemia

Pretreatment aberrant DNA methylation patterns are stable at time of relapse in acute lymphocytic leukemia (ALL). We hypothesized that the detection of residual methylation alterations at the time of morphologic remission may predict for worse prognosis. We developed a real-time bisulfite polymerase chain reaction assay and analyzed the methylation levels of p73, p15, and p57(KIP2) at the time of initial remission in 199 patients with Philadelphia chromosome-negative and MLL(-) ALL. Residual p73 methylation was detected in 18 (9.5%) patients, p15 in 33 (17.4%), and p57(KIP2) in 7 (3.7%); 140 (74%) patients had methylation of 0 genes and 48 (25%) of more than or equal to 1 gene. In 123 (65%) patients, matched pretreatment samples were also studied and compared with remission ones: in 82 of those with initial aberrant methylation of at least one gene, 59 (72%) had no detectable methylation at remission and 23 (28%) had detectable residual methylation. By multivariate analysis, the presence of residual p73 methylation was associated with a significant shorter duration of first complete remission (hazard ratio=2.68, P= .003) and overall survival (hazard ratio=2.69, P= .002). In conclusion, detection of epigenetic alterations allows the identification of patients with ALL with standard risk but with poor prognosis.

Outcome of adults with acute lymphocytic leukemia after second salvage therapy

BACKGROUND

The outcome of adults with acute lymphocytic leukemia (ALL) who undergo second salvage therapy has been characterized poorly. This is important with regard to investigational approaches aimed at helping this subset of patients. The objectives of the current study were to predict outcomes and determine the prognostic factors associated with second salvage therapy in patients with ALL.

METHODS

In this study, 288 patients were analyzed who received second salvage therapy for ALL at the authors' institution.

RESULTS

Overall, 53 patients (18%) achieved a complete response (CR). The median remission duration was 7 months and the median survival was 3 months. In multivariate analysis, prognostic factors that were associated independently with achieving CR were duration of first CR and platelet count. Patients with a first CR <36 months and platelet counts <50 x 10(9)/L had an expected CR rate of 7%. In multivariate analysis, prognostic factors that were associated independently with survival were duration of first CR, percentage bone marrow blasts, platelet count, and albumin level. The expected 12-month survival rates for patients with 0 or 1, 2, 3, or 4 adverse factors were 33%, 14%, 8%, and 0%, respectively. A repeat multivariate analysis using landmark assessment at 6 weeks selected achievement of CR as adding significantly to the survival benefit (P = .0001; hazard ratio, 0.51). Only 22 patients (8%) were able to undergo allogeneic stem cell transplantation as second salvage therapy, and their 1-year survival rate was 18%.

CONCLUSIONS

The outcome of adults with ALL undergoing second salvage therapy is poor. Novel effective therapies against ALL are needed in this subset of patients.

Bone-marrow relapse in paediatric acute lymphoblastic leukaemia

Marrow relapse is the major obstacle to cure for 10-15% of young patients with acute lymphoblastic leukaemia (ALL). Recent investigations into the biology of minimal residual disease indicate that many early relapses derive from residual cells present at first diagnosis, but some late relapses might represent new mutations in leukaemic cells not eliminated by conventional therapy. Treatment of marrow relapse involves higher doses and more intensive schedules of the drugs used for initial therapy with or without haemopoietic stem cell transplantation. In most reports, transplantation is better than continuation chemotherapy in early marrow relapse, but its role in later relapse is less clear. Current therapy cures 10% of patients with early marrow relapses and 50% of those with late relapses, but outcomes have changed little in the past two decades. Understanding the molecular biology of ALL underlies development of improved risk stratification and new therapies. Although better drugs are needed, introduction of new agents into clinical trials in paediatric disease has been difficult. Innovative trial designs and use of valid surrogate endpoints may expedite this process.

Allogeneic SCT in refractory or relapsed adult ALL is effective without prior reinduction chemotherapy

We present 60 patients with refractory (n=8) or relapsed (n=52) adult ALL who received allogeneic hematopoietic SCT (HSCT) with (n=41) or without (n=19) prior reinduction chemotherapy. In our center, omission of reinduction is recommended if a suitable donor is promptly available, tumor burden is moderate and disease features suggest a highly aggressive course. Overall survival (OS) of the whole cohort at 1, 2 and 5 years was 42, 33 and 28%, respectively. Leukemia-free survival at 1, 2 and 5 years was 37, 33 and 24%. Deaths were due to relapse (n=25), acute or chronic GVHD (n=7), infections (n=8) or toxicity (n=4). Interestingly, patients who did not receive reinduction before HSCT had better outcomes than patients who received reinduction with OS at 1, 2 and 5 years being 58 vs 34%, 47 vs 25% and 47 vs 18%, respectively (P=0.039). Importantly, even achievement of a second CR after reinduction was not associated with improved survival compared to patients directly proceeding to HSCT. We conclude that patients who undergo HSCT for refractory or relapsed ALL can achieve long-term survival. In selected patients, reinduction chemotherapy can be omitted if immediate HSCT is feasible.

Transplant-finalized salvage of adult acute lymphoblastic leukemia: results of a mitoxantrone- and methotrexate-based regimen in 36 patients

Idarubicin-based induction programs in acute lymphoblastic leukemia (ALL) account for 75?-?85% of complete remission rate. A small amount of patients exhibit primary refractoriness, and approximately 60% of those achieving a remission eventually relapse. The present study aimed to review the outcome of patients relapsing after or resistant to an idarubicin-based, induction-consolidation regimen (with/without additional high dose cytarabine). The 'ABC' phase II trial consisted of mitoxantrone (50 mg/m(2) over 5 days) associated with high-dose methotrexate (1.5 g/m(2) over 24 h, followed by folinic acid rescue), high-dose methyl-prednisolone (125 mg b.i.d.) and vincristine, plus granulocyte colony-stimulating factor. Eligible patients were treated with two courses ('A' and 'B', the latter with reduced drug dosages), followed by allogeneic or autologous haematopoietic stem cell transplantation (HSCT, 'C'). Thirty-six patients (3 primary resistant, 33 at first marrow relapse) were evaluated. With 'A', 21 achieved a complete remission (CR), 10 were refractory and 5 died early. Eighteen patients received 'B' (with one more CR, for an overall CR rate of 61%) and, eventually, 12 patients had 'C' procedures (7 autologous, 5 allogeneic HSCT). WHO grade >or=3 treatment-related toxicity developed in 50% and 34% of 'A' and 'B' courses, respectively. The median duration of CR was 5.2 (range 0.5-19.7) months and median overall survival was 7.6 (range 0.5-20) months. In spite of 12 HSCTs, there was no long-term survivor. 'ABC' salvage proved feasible and comparable to reported rescue chemotherapic regimens, but the achievement of cure in refractory/relapsing ALL remains an outstanding clinical task.

The novel histone deacetylase inhibitor, LBH589, induces expression of DNA damage response genes and apoptosis in Ph- acute lymphoblastic leukemia cells

We investigated the mechanism of action of LBH589, a novel broad-spectrum HDAC inhibitor belonging to the hydroxamate class, in Philadelphia chromosome-negative (Ph(-)) acute lymphoblastic leukemia (ALL). Two model human Ph(-) ALL cell lines (T-cell MOLT-4 and pre-B-cell Reh) were treated with LBH589 and evaluated for biologic and gene expression responses. Low nanomolar concentrations (IC(50): 5-20 nM) of LBH589 induced cell-cycle arrest, apoptosis, and histone (H3K9 and H4K8) hyperacetylation. LBH589 treatment increased mRNA levels of proapoptosis, growth arrest, and DNA damage repair genes including FANCG, FOXO3A, GADD45A, GADD45B, and GADD45G. The most dramatically expressed gene (up to 45-fold induction) observed after treatment with LBH589 is GADD45G. LBH589 treatment was associated with increased histone acetylation at the GADD45G promoter and phosphorylation of histone H2A.X. Furthermore, treatment with LBH589 was active against cultured primary Ph(-) ALL cells, including those from a relapsed patient, inducing loss of cell viability (up to 70%) and induction of GADD45G mRNA expression (up to 35-fold). Thus, LBH589 possesses potent growth inhibitory activity against including Ph(-) ALL cells associated with up-regulation of genes critical for DNA damage response and growth arrest. These findings provide a rationale for exploring the clinical activity of LBH589 in the treatment of patients with Ph(-) ALL.

How I treat acute lymphocytic leukemia in adults

The treatment of newly diagnosed acute lymphocytic leukemia (ALL) in adults remains unsatisfactory. Not withstanding the outstanding progress in curing childhood ALL, only approximately one third of adults younger than 60 years can be cured, and the overall published survival curves have not changed significantly during the past 15 years. Recent therapeutic advances in allogeneic transplantation through the conduct of large collaborative studies, better understanding of the relevance of cytogenetics, improved molecular techniques for the detection of minimal residual disease, and clinical research into novel biologic and targeted therapies have all combined to offer potentially a better hope for an improved outcome in this disease. The current approach in 2007 to the management of this disease is presented by way of a discussion of illustrative cases. In this uncommon and difficult disease, well-structured intergroup studies will remain vital for future progress.

Outcome of treatment after first relapse in adults with acute lymphoblastic leukemia initially treated by the LALA-94 trial

Fifty-four percent of adults with acute lymphoblastic leukemia (ALL) who entered the LALA-94 trial experienced a first relapse. We examined the outcome of these 421 adult patients. One hundred and eighty-seven patients (44%) achieved a second complete remission (CR). The median disease-free survival (DFS) was 5.2 months with a 5-year DFS at 12%. Factors predicting a better outcome after relapse were any transplant performed in second CR (P<0.0001), a first CR duration >1 year (P=0.04) and platelet level >100 x 10(9)/l at relapse (P=0.04). Risk groups defined at diagnosis and treatment received in first CR did not influence the outcome after relapse. The best results were obtained in a subset of patients who were eligible for allogeneic stem cell transplantation (SCT). Geno-identical allogeneic SCT was performed in 55 patients, and 3 patients received donor lymphocyte infusions. Forty-four transplantations were performed from an unrelated donor (of which four were cord blood). We conclude that most adult patients with recurring ALL could not be rescued using current available therapies, although allogeneic SCT remains the best therapeutic option.

The cost-effectiveness of stem cell transplantations from unrelated donors in adult patients with acute leukemia

OBJECTIVE

Hematopoietic stem cell transplantation is an accepted treatment of hematological malignancies, but the cost-effectiveness of this technology has not been fully explored. This study aims to assess the cost-effectiveness of stem cell transplantation from either cord blood or bone marrow/peripheral blood compared with no transplantation in adult patients with acute leukemias not expected to be cured with chemotherapy.

METHODS

A systematic review was performed to estimate the efficacy of unrelated cord blood and bone marrow/peripheral blood stem cells (BM/PBSC) transplantations in adults with acute leukemia. A Markov decision analysis model using Monte Carlo simulations was used to calculate the incremental cost-effectiveness ratio (ICER) and 95% confidence intervals (CIs).

RESULTS

The estimated cumulative survival at 1 and 10 years were 27.9% and 14%, respectively, for cord blood recipients and 47% and 17.7%, respectively, for BM/PBSC recipients. Using conservative assumptions, the cost per life-year gained compared with no transplantation was US 16,346 dollars (95% CI 8695 dollars, 38,006 dollars) for BM/PBSC transplantation and US 34,360 dollars (95% CI 23,101 dollars, 89,417 dollars) for cord blood transplantation.

CONCLUSIONS

Although both types of stem cell transplantations are associated with a high short-term mortality and high cost, the cumulative gains in life-years of survivors can be substantial, resulting in ICERs compared with no transplantation that are usually considered acceptable. However there is less certainty about this conclusion with cord blood transplantation.

Risk assessment in haemotopoietic stem cell transplantation: disease and disease stage

This chapter addresses the impact of the disease and disease status on the outcome of stem-cell transplantation. In consideration of the other topics addressed within this volume we have elected to focus on allogeneic rather than autologous transplantation. Furthermore we have not tried to be comprehensive and discuss the role of disease status in all conditions amenable to allografting, but rather to review the evidence that exists for selected haematological malignancies. Where possible we have made some clear recommendations, but where evidence is less clear we have indicated the ongoing controversies.

Dasatinib induces rapid hematologic and cytogenetic responses in adult patients with Philadelphia chromosome positive acute lymphoblastic leukemia with resistance or intolerance to imatinib: interim results of a phase 2 study

Patients with Philadelphia (Ph) chromosome-positive acute lymphoblastic leukemia (ALL) have a rapid disease course and a poor prognosis. Dasatinib, a novel, oral, multitargeted kinase inhibitor of BCR-ABL and SRC family kinases, has previously induced responses in patients with imatinib-resistant or -intolerant Ph-positive ALL. We present the interim results of a phase 2 study designed to further assess the efficacy, safety, and tolerability of dasatinib 140 mg in this patient population (n = 36). With a minimum follow-up of 8 months, treatment with dasatinib resulted in substantial hematologic and cytogenetic response rates. Major hematologic responses were achieved in 42% (15/36) of patients, 67% of whom remained progression-free. Complete cytogenetic responses were attained by 58% (21/36) of patients. The presence of BCR-ABL mutations conferring imatinib resistance did not preclude a response to dasatinib. Dasatinib was also tolerable, with 6% (2/36) of patients discontinuing therapy as a result of study-drug toxicity. Most adverse events (AEs) were grade 1 or 2; febrile neutropenia was the most frequent severe AE, but this and other cytopenias were manageable with dose reduction. Dasatinib represents a safe and effective treatment option and an important therapeutic advance for patients with Ph-positive ALL. This trial was registered at www.clinicaltrials.gov as #CA180015.

Emerging therapeutic options for Philadelphia-positive acute lymphocytic leukemia

Acute lymphocytic leukemia (ALL) is a heterogeneous group of disorders that are associated with a cure rate of > 80% in children. The prognosis in adults is considerably inferior, with age, disease bulk, leukemia karyotype and immune phenotype being prognostically relevant. Adult ALL treatment programs include induction, intensified consolidation and maintenance phases with CNS prophylaxis. The addition of imatinib in patients with BCR-ABL-positive ALL has improved the prognosis of this subgroup, but their survival is still poor. Initial data on the second-generation BCR-ABL inhibitors, dasatinib and nilotinib, indicate a potentially greater efficacy than imatinib, but the improvement is likely to be modest. The overall efforts in terms of developmental therapeutics in ALL are very modest and not in keeping with the urgent need for improvement. Most agents being investigated have mechanisms of action similar to those of existing agents for ALL therapy and thus represent modest opportunities to improve results. Of such agents, data on BCR-ABL inhibitors, sphingosomal vincristine, pemetrexed, talotrexin, annamycin and ABT-751 are reviewed.

High-dose idarubicin in combination with Ara-C in patients with relapsed or refractory acute lymphoblastic leukemia: a pharmacokinetic and clinical study

OBJECTIVE

High dose (HD) Ara-C combined with a single HD idarubicin dose (IDA) is an efficient and safe salvage regimen for patients with refractory or relapsed acute lymphoblastic leukemia as indicated by phase II studies. No data are available on the pharmacokinetics of IDA after a rapid HD intravenous infusion. An open phase II pharmacokinetic and clinical study was performed to evaluate antileukemic efficacy, IDA pharmacokinetics and to investigate the presence of IDA and its reduced metabolite idarubicinol (IDAol) in cerebrospinal fluid (CSF) of patients treated with HD-IDA.

PATIENTS AND METHODS

Twenty-five patients with refractory or relapsed acute lymphoblastic leukemia received Ara-C 3 g/m2 from days 1-5, idarubicin (HD-IDA) 40 mg/m2 as rapid intravenous (i.v.) infusion on day 3 and subcutaneous G-CSF 5 microg/kg from day 7 until PMN recovery. Pharmacokinetics of IDA was evaluated after HD idarubicin administration in nine of these patients. CSF samples were collected in 15 patients at different times. IDA and IDAol concentrations were quantified by a validated HPLC assay described in detail elsewhere.

RESULTS

Eleven patients (44%, 95% CI: 23-65%) achieved complete remission with median disease free survival for 6 months. After administration of HD-IDA i.v. bolus of 40 mg/m2, plasma level profiles of unchanged drug and IDAol were similar to those previously described after standard dose and measured with the same analytical method. The mean terminal half-life measured for IDA in this group of patients (14.9 h) was not significantly different from the mean value observed after standard dose (13.9 h, P=0.72). IDAol t1/2 was also similar after HD-IDA (46.2 h) and standard dose (39.4 h, P=0.79). Pharmacokinetic data reveal that in our series of patients IDA and IDAol clearances are significantly higher than those observed in patients treated with 12 mg/m2 of IDA but, although the administered dose (mg/m2) of the drug is 3.3 times higher, IDA exposure (measured in terms of AUC) is only 2.3 times and IDAol exposition 2.1 times greater. Furthermore, HD infusion resulted in a ratio between the AUC of parent drug and idarubicinol not different from the value observed with the standard-dose. IDA and IDAol were measurable only in 3 of the 15 cerebrospinal fluid samples collected.

CONCLUSION

Responses observed in our series are comparable to those reported with other salvage regimens. The IDA exposure lower than expected may explain the safety of the single i.v. administration of 40 mg/m2 of IDA, combined with HD Ara-C, with a degree of myelosuppression equivalent to that reported with this agent administered in standard doses. Our data do not allow us to clearly attribute this behavior to a pharmacokinetic non-linearity since the baseline creatinine clearance, even within normal values, and patient age are significantly different in the two groups. Cerebrospinal fluid penetration was poor, reaching levels not considered as cytotoxic.

Outcome of 609 adults after relapse of acute lymphoblastic leukemia (ALL); an MRC UKALL12/ECOG 2993 study

Most adults with acute lymphoblastic leukemia (ALL) who achieve complete remission (CR) will relapse. We examined the outcome of 609 adults with recurring ALL, all of whom were previously treated on the Medical Research Council (MRC) UKALL12/ECOG2993 study, where the overall survival (OS) of newly diagnosed patients is 38% (95% confidence interval [CI]=36%-41%) at 5 years. By contrast, OS at 5 years after relapse was 7% (95% CI=4%-9%). Factors predicting a good outcome after salvage therapy were young age (OS of 12% in patients younger than 20 years vs OS of 3% in patients older than 50 years; 2P<.001) and short duration of first remission (CR1) (OS of 11% in those with a CR1 of more than 2 years versus OS of 5% in those with a CR1 of less than 2 years; 2P<.001). Treatment received in CR1 did not influence outcome after relapse. In a very highly selected subgroup of patients who were able to receive HSCT after relapse, some were long-term survivors. We conclude from a large, unselected series with mature follow-up that most adults with recurring ALL, whatever their prior treatment, cannot be rescued using currently available therapies. Prevention of recurrence is the best strategy for long-term survival in this disease.

Advances and potential treatment for Philadelphia chromosome-positive adult acute lymphoid leukaemia

Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL) is the most common subtype of ALL in adults. Conventional chemotherapy-based approaches that are effective in other precursor B cell ALL cases have a poor chances of cure in patients with a Ph+ diagnosis. Therefore, allogeneic stem cell transplantation performed during the first remission is the recommended therapy. Recently, the availability of imatinib mesylate and other tyrosine kinase inhibitors and small molecules that affect the BCR/ABL signalling pathways has introduced a new therapeutic opportunity, and could change the treatment paradigm and prognosis for these patients. In this article, the results from clinical trials using imatinib in relapsed/refractory patients and as front-line therapy are described. In addition, preliminary experiences with novel tyrosine kinase inhibitors in imatinib-resistant Ph+ ALL are discussed.

Emerging drugs for adult acute lymphoblastic leukaemia

Although most patients with adult acute lymphoblastic leukaemia (ALL) can achieve a remission when treated with conventional, DNA-damaging chemotherapy, in more than half of all cases the disease relapses and ultimately results in death. Therefore, there is a substantial need for new antileukaemic drugs. Recent advances in the understanding of the molecular alterations in ALL have lead to the identification of new targets and the arrival of molecular-targeted therapies in the clinical setting. The prototype for this approach is the treatment of Philadelphia chromosome-positive ALL with imatinib mesylate. Here, the targeting of a molecular abnormality--inhibition of BCR-ABL tyrosine kinase--has turned a very poor-prognosis disease into one in which promising results are achieved. Promising new therapies are under development that target various goals, including the NOTCH signalling pathway, purine nucleoside phosphorylase activity, mammalian target of rapamycin and tyrosine kinase. This review outlines recent advances in the development of emerging drugs for the treatment of adult ALL. The recent advances in the understanding of the biology and pathogenesis of ALL have helped to determine prognosis and to plan the therapy of adult patients with ALL. Still, despite improved complete remission rates of 65-90% with current therapy, only 20-40% of patients can be considered cured. New therapeutic alternatives are needed to improve these results. With a better understanding of the disease, more target-specific therapies could be designed. The aim of this review is to highlight new pharmacotherapies and those emerging drug treatments for patients with adult ALL.

Phase II study of sphingosomal vincristine in patients with recurrent or refractory adult acute lymphocytic leukemia

BACKGROUND

Outcomes with salvage therapy for patients with recurrent or refractory acute lymphocytic leukemia (ALL) are poor, with complete response (CR) rates reported to be 20-30% and a median survival ranging from 2-6 months. New agents are needed to reduce the recurrence rate after frontline chemotherapy. Vincristine is an important component of ALL therapy. In animal models, the encapsulation of vincristine into sphingomyelin liposomes or "sphingosomes" for injection (SV) has improved efficacy compared with conventional vincristine.

METHODS

A Phase II clinical trial of single-agent SV given at a dose of 2.0 mg/m2 every 2 weeks was conducted in patients with recurrent or refractory ALL. Approximately half of the 16 patients who received SV had a first CR duration of less than 1 year, 19% had failed standard induction chemotherapy, and 50% had Philadelphia chromosome-positive disease. SV was the first salvage attempt in 69% of the patients.

RESULTS

The overall response rate in the 14 evaluable patients was 14% (1 CR and 1 partial response). Five patients (36%) had transient reductions in bone marrow leukemia infiltrate with subsequent regrowth of the leukemia between SV infusions. Toxicity with limited treatment (median number of doses was two; range, one to five doses) was minimal with expected peripheral neuropathy.

CONCLUSIONS

Further study of SV in patients with ALL is warranted. A Phase I-II clinical trial of weekly SV with pulse dexamethasone currently is ongoing.

Clofarabine: in pediatric patients with acute lymphoblastic leukemia

Clofarabine is a purine nucleoside analog that inhibits DNA synthesis and repair. Its effects are mediated via the inhibition of ribonucleotide reductase and DNA polymerase. Clofarabine also disrupts the integrity of mitochondrial membranes, resulting in programmed cell death. In 61 pediatric patients with relapsed or refractory acute lymphoblastic leukemia treated with clofarabine 52 mg/m2 infused intravenously over 2 hours once daily for 5 days every 2-6 weeks, rates of complete remission, complete remission without platelet recovery, and partial remission were 12%, 8%, and 10%, respectively. Data are from two non-comparative, multicenter, phase II studies. The most common adverse events associated with clofarabine 52 mg/m2 once daily for 5 days every 2-6 weeks in 96 patients with acute myelogenous or lymphoblastic leukemia (combined analysis of phase I/II trials) were hematologic events (including anemia, leukopenia, thrombocytopenia, neutropenia, and febrile neutro-penia), gastrointestinal events (including vomiting, nausea, and diarrhea), infections, and transient elevations in liver enzymes. Capillary leak syndrome or systemic inflammatory response syndrome was reported in four patients.

Adult acute lymphoblastic leukemia

Much progress has been made in understanding the biology of and therapy for acute lymphoblastic leukemia (ALL). This progress has translated into the recognition of several subgroups of ALL and the institution of risk-adapted therapies. New therapies are emerging based on the definition of specific cytogenetic-molecular abnormalities. Changes in the pathologic classification of ALL have led to therapeutic consequences. Adaptation of successful treatment strategies in children with ALL has resulted in similar complete remission rates in adults. Prognosis has Improved especially in mature B-cell ALL and T-cell lineage ALL. However, regardless of ALL subgroup, long-term survival in adults is still inferior to that in children. Development of new drugs and agents tailored to subset-specific cytogenetic-molecular characteristics is vital to the therapeutic success in adult ALL.

Adult acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia (ALL) in adults is a relatively rare neoplasm with a curability rate around 30% at 5 years. This consideration makes it imperative to dissect further the biological mechanisms of disease, in order to selectively implement an hitherto unsatisfactory success rate. The recognition of discrete ALL subtypes (some of which deserve specific therapeutic approaches, like T-lineage ALL (T-ALL) and mature B-lineage ALL (B-ALL)) is possible through an accurate combination of cytomorphology, immunophenotytpe and cytogenetic assays and has been a major result of clinical research studies conducted over the past 20 years. Two-three major prognostic groups are now easily identifiable, with a survival probability ranging from <10 to 20% (Philadelphia-positive ALL) to about 50-60% (low-risk T-ALL and selected patients with B-lineage ALL). These issues are extensively reviewed and form the basis of current knowledge. The second major point relates to the emerging importance of studies that reveal a dysregulated gene activity and its clinical counterpart. It is now clear that prognostication is a complex matter ranging from patient-related issues to cytogenetics to molecular biology, including the evaluation of minimal residual disease (MRD) and possibly gene array tests. On these bases, the role of a correct, highly personalised therapeutic choice will soon become fundamental. Therapeutic progress may be obtainable through a careful integration of chemotherapy, stem cell transplantation, and the new targeted treatments with highly specific metabolic inhibitors and humanised monoclonal antibodies.

Treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia

Philadelphia chromosome positive (Ph(+)) acute lymphoblastic leukemia (ALL) includes at least one-quarter of all adults with ALL. Until recently, conventional chemotherapy programs that have been effective in other precursor B-cell ALL cases have been unable to cure patients with this diagnosis. Allogeneic stem cell transplantation early in first remission has been the recommended therapy. The availability of imatinib mesylate and other tyrosine kinase inhibitors and small molecules that affect the BCR/ABL signaling pathways may be changing the treatment paradigm and the prognosis for these patients. The results from clinical trials using imatinib in the frontline setting and in relapsed patients as well as preliminary experience treating imatinib-resistant Ph(+) ALL will be described.

Early prediction of response in patients with relapsed or refractory Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ALL) treated with imatinib

Imatinib has pronounced but brief antileukemic activity in advanced Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ALL). We assessed the prognostic impact of pretreatment disease features and the early bone marrow (BM) response in 68 consecutive patients with Ph+ALL receiving imatinib salvage therapy. A complete hematologic or marrow response was achieved by 92% of patients with BM blasts below 5% on day 14, whereas 62.5% of patients with more than 5% BM blasts on day 14 were nonresponders. Similarly, time to progression (TTP) was superior in patients with a good day 14 response (5.2 versus 0.9 months; P &lt; .0001). Prior complete remission of less than 6 months, white blood cell count of more than 10 × 109/L, circulating peripheral blood blasts at diagnosis, additional Philadelphia chromosomes, or at least 2 Bcr-Abl fusion signals were associated with significantly inferior remission rate and response duration. In patients without poor prognostic features, single-agent imatinib may be appropriate before transplant salvage therapy. Conversely, patients with clinically or cytogenetically defined poor-risk features are candidates for trials of upfront imatinib in combination with other agents.

Efficacy and safety of imatinib mesylate (Glivec™) in combination with interferon-α (IFN-α) in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL)

Imatinib has marked antileukemic activity in advanced Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL), but secondary resistance develops rapidly, reflecting the limitations of single-agent therapy. Experimental data suggest that interferon-alpha (IFN-alpha) enhances the antileukemic activity of imatinib. We therefore examined combined imatinib and low-dose IFN-alpha in six patients with Ph+ALL who were ineligible for stem cell transplantation. All patients had received imatinib for 0.5-4.8 months prior to IFN-alpha, for relapsed (n=3) or refractory (n=1) Ph+ALL or as an alternative to chemotherapy following severe treatment-related toxicity (n=2). Five patients were in hematologic remission (CR) with minimal residual disease (MRD+), one patient was refractory to imatinib. Four of the five MRD+ patients are alive in CR after a median treatment duration of 20 (11-21) months. Two of these patients are in continuous CR 21 months after imatinib was initiated, while the other two patients experienced an isolated meningeal relapse that was successfully treated with additional intrathecal chemotherapy. Sustained molecular remissions were achieved in three patients and are ongoing 13 and 10.5 months after central nervous system (CNS) relapse and 6 months after starting concurrent IFN-alpha and imatinib, respectively. Marrow relapse occurred in one of the five MRD+ patients. Combination treatment was associated with a complete marrow response of 5 months duration in the imatinib-refractory patient. Imatinib combined with low-dose IFN-alpha may achieve prolonged hematologic and molecular remissions in a subset of patients with advanced Ph+ALL, who are not candidates for allogeneic SCT. CNS prophylaxis is necessary and may enhance the antileukemic activity of imatinib and IFN-alpha.

The biology and therapy of adult acute lymphoblastic leukemia

BACKGROUND

Much progress has been made in understanding the biology of acute lymphoblastic leukemia (ALL). This has translated into the recognition of several subgroups of ALL and the institution of risk-adapted therapies. New therapies are emerging based on the definition of specific cytogenetic-molecular abnormalities.

METHODS

A review from the English literature, including original articles and related reviews from Medline (Pubmed) and abstracts based on publication of meeting material, was performed.

RESULTS

Changes in the pathologic classification of ALL have led to therapeutic consequences. Adaptation of successful treatment strategies in children with ALL has resulted in similar complete response rates in adults. Prognosis has especially improved in mature-B-cell and T-lineage ALL. The role of tyrosine kinase inhibitors in Philadelphia chromosome-positive ALL was evaluated in the current study. However, regardless of the ALL subgroup, long-term survival of adults is still inferior to that in children.

CONCLUSIONS

Intense clinical and laboratory research is attempting to close the gap in outcome between children and adults with ALL. Investigations are focusing on 1) refinement of the basic treatment stratagem of induction, consolidation, and maintenance; 2) expansion of risk-based, subgroup-oriented therapies; 3) assessment of minimal residual disease, its impact on disease recurrence, and its practical implications in clinical practice; 4) salvage strategies; 5) the role of stem cell transplantation in ALL; and 6) the development of new drugs based on a better understanding of disease biology.