High curability via intensive reinduction chemotherapy and stem cell transplantation in young adults with relapsed acute lymphoblastic leukemia in Sweden 2003-2007

Bispecific T-cell engaging antibodies in B-cell precursor acute lymphoblastic leukemias: focus on blinatumomab

Bispecific T-cell engaging antibodies are constructs engineered to bind to two different antigens, one to a tumor-specific target and the other to CD3-positive T cells or natural killer (NK) cells. Blinatumomab engages CD19 and CD3, performing effective serial lysis. The clinical development program in acute lymphoblastic leukemia (ALL) includes clinical trials in relapsed or refractory (R/R) patients and in B-cell precursor (BCP) ALL patients with measurable residual disease. Several trials are currently being conducted in de novo BCP-ALL, either in induction, consolidation, or before or after hematopoietic stem cell transplant. Combination with other targeted therapies or with other immunotherapeutic approaches are also underway. Several strategies are aimed to optimize the use of blinatumomab either by overcoming the mechanisms of resistance (e.g. inhibition of PD-1/PD-L1) or by improvements in the route of application, among others.

Phase II trial with sequential clofarabine and cyclophosphamide for refractory and relapsed philadelphia-negative adult acute lymphoblastic leukemia. Results of the GIMEMA LAL 1610 protocol

Clofarabine (CLO) and cyclophosphamide (CY) combinations were tested in late stage refractory/relapsed (R/R) acute lymphoblastic leukemia (ALL) with disappointing results and high-grade toxicity. We designed a sequential 5-day combination of CLO 40 mg/m²/d plus CY 400 mg/m²/d as first salvage for Philadelphia-negative ALL patients refractory or relapsed until 24 months from complete remission (CR). Primary endpoint was an overall response rate (ORR) ≥ 40%. Among 26 study patients (median age 40.5 years) ORR was 57.6% (CR with complete [n = 8] or incomplete [n = 7] hematologic recovery). Despite severe myelotoxicity, no dose-limiting toxicity suggested de-intensification of CLO schedule. With a median follow-up of 17.0 months, median and 1-year overall and disease-free survival were 6.5 months and 28.6%, and 3.7 months and 28.1%, respectively. This association was tolerable and more effective in patients younger than 40 years with B-precursor ALL, longer first CR, not previously transplanted and achieving CR with full hematological recovery.

Survival in adult acute lymphoblastic leukaemia (ALL): A report from the Swedish ALL Registry

OBJECTIVES

As new, effective therapies emerge for acute lymphoblastic leukaemia (ALL), the results of clinical trials need to relate to standard of care.

METHODS

We used the population-based Swedish ALL Registry to evaluate characteristics, treatment and long-term outcome in 933 patients with diagnosis between 1997 and 2015.

RESULTS

The median age was 53 years. The frequency of Philadelphia (Ph)-positive leukaemia was 34% of examined B-ALL with a peak incidence at 50-59 years. Five-year overall survival (OS) improved between 1997-2006 and 2007-2015; in patients 18-45 years from 50% (95% CI 43-57) to 65% (95% CI 58-72), 46-65 years from 25% (95% CI 18-32) to 46% (95% CI 37-55) and >65 years from 7% (95% CI 2.6-11) to 11% (95% CI 5.9-16) (P < 0.05). Men with Ph-neg B-ALL 46-65 years had inferior OS compared with women (P < 0.01). Standardised mortality ratio was 5.7 (95% CI 5.0-6.3) for patients who survived 5 years from diagnosis. In multivariable analysis, Ph-positive disease was not associated with impaired prognosis but with lower risk of death in 2007-2015.

CONCLUSIONS

In a population-based cohort, OS has improved in adult ALL, especially for Ph-positive disease but for middle-aged men with Ph-negative B-ALL outcome was poor. Cure without late toxicity or relapse is still desired.

Re-induction chemotherapy using FLAG-mitoxantrone for adult patients with relapsed acute leukemia: a single-center experience from United Arab Emirates

We studied the outcome of 47 adult patients with relapsed acute leukaemia (AML = 25 and ALL = 22) treated with FLAG-mitoxantrone regimen. Median time to relapse was 10.7 months (range 1.9-27.7). Complete remission (CR2) was 60.1% which was significantly more frequent in ALL compared to AML (P = 0.049). WBC count < 100 × 10⁹/L at initial diagnosis and time to relapse > 1 year were significantly predictor for CR2 in AML (P = 0.005 for both). Induction death was significantly higher in ALL compared to AML (P = 0.039). Median follow-up was 4.0 months (0.9-119.8) for AML and 2.1 months (range 0.6-118.1) for ALL. Nine patients underwent allogeneic stem-cell transplantation (allo-SCT). Estimated overall survival (OS) at 12 and 18 months was 60.5 and 34.6%, respectively, for AML, and 39.9 and 29.9%, respectively, for ALL. For AML patients failure to achieve CR, WBC count at initial diagnosis > 5 × 10⁹/L and poor cytogenetic risk group was significant predictors of poor OS (P = 0.010, P = 0.025, and P = 0.015, respectively). For ALL patients failure to achieve of CR, WBC count at relapse < 5 × 10⁹/L (CR patients) and lack of any type of consolidation therapy were significant predictor of poor OS (P < 0.001, P = 0.008, P = 0.008, respectively).

Outcome of Reinduction Chemotherapy with a Modified Dose of Idarubicin for Children with Marrow-Relapsed Acute Lymphoblastic Leukemia: Results of the Childhood Acute Lymphoblastic Leukemia (CALL)-0603 Study

This multicenter, prospective trial was conducted to develop an effective and safe reinduction regimen for marrow-relapsed pediatric acute lymphoblastic leukemia (ALL) by modifying the dose of idarubicin. Between 2006 and 2009, the trial accrued 44 patients, 1 to 21 years old with first marrow-relapsed ALL. The reinduction regimen comprised prednisolone, vincristine, L-asparaginase, and idarubicin (10 mg/m²/week). The idarubicin dose was adjusted according to the degree of myelosuppression. The second complete remission (CR2) rate was 72.7%, obtained by 54.2% of patients with early relapse < 24 months after initial diagnosis and 95.0% of those with late relapse (P = 0.002). Five patients entered remission with extended treatment, resulting in a final CR2 rate of 84.1%. The CR2 rate was not significantly different according to the idarubicin dose. The induction death rate was 2.3% (1/44). The 5-year event-free and overall survival rates were 22.2% ± 6.4% and 27.3% ± 6.7% for all patients, 4.2% ± 4.1% and 8.3% ± 5.6% for early relapsers, and 43.8% ± 11.4% and 50.0% ± 11.2% for late relapsers, respectively. Early relapse and slow response to reinduction chemotherapy were predictors of poor outcomes. In conclusion, a modified dose of idarubicin was effectively incorporated into the reinduction regimen for late marrow-relapsed ALL with a low toxic death rate. However, the CR2 rate for early relapsers was suboptimal, and the second remission was not durable in most patients.

Isolated extramedullary cutaneous relapse despite concomitant severe graft-vs.-host disease and tissue chimerism analysis in a patient with acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation: A case report

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option for patients with acute lymphoblastic leukemia (ALL). The curative potential of allo-HSCT for ALL is, in part, due to the graft-vs.-leukemia (GVL) effect, in addition to the intensive conditioning chemo-radiotherapy. However, relapse remains the major cause of treatment failure following allo-HSCT for ALL. In the allo-HSCT setting, testing for genetic markers of hematopoietic chimerism has become a part of the routine diagnostic program. Routine chimerism analysis is usually performed in peripheral blood or bone marrow; in fact, little is known about the value of tissue chimerism in patients with extramedullary relapse (EMR) after the allo-HSCT setting. The present study reports on, a case of a patient with ALL who experienced isolated cutaneous EMR despite ongoing graft-vs.-host disease (GVHD), and the results of peripheral blood and skin tissue chimerism studies using multiplex polymerase chain reaction (PCR) of short tandem repeats (STR-PCR). The present case demonstrates that, although complete remission and/or chimerism may be achieved in the bone marrow, chimerism achieved at the tissue level, and the subsequent GVL effect, may be limited, despite concomitant severe GVHD following allo-HSCT. Our tissue chimerism analysis results provide a good example of how skin tissue may be a ‘sanctuary’ site for effector cells of GVL, despite active GVHD and complete hematopoetic chimerism.

FDA Approval: Blinatumomab

On December 3, 2014, the FDA granted accelerated approval of blinatumomab (Blincyto; Amgen, Inc.) for treatment of Philadelphia chromosome-negative relapsed or refractory precursor B-cell acute lymphoblastic leukemia (R/R ALL). Blinatumomab is a recombinant murine protein that acts as a bispecific CD19-directed CD3 T-cell engager. The basis for the approval was a single-arm trial with 185 evaluable adults with R/R ALL. The complete remission (CR) rate was 32% [95% confidence interval (CI), 26%-40%], and the median duration of response was 6.7 months. A minimal residual disease response was achieved by 31% (95% CI, 25%-39%) of all patients. Cytokine release syndrome and neurologic events were serious toxicities that occurred. Other common (>20%) adverse reactions were pyrexia, headache, edema, febrile neutropenia, nausea, tremor, and rash. Neutropenia, thrombocytopenia, and elevated transaminases were the most common (>10%) laboratory abnormalities related to blinatumomab. A randomized trial is required in order to confirm clinical benefit.

Inotuzumab ozogamicin in the treatment of acute lymphoblastic leukemia

Over 90% of leukemic blasts in patients with acute lymphoblastic leukemia express the marker CD22. Inotuzumab ozogamicin (INO) is a CD22-directed humanized monoclonal antibody conjugated to the potent cytotoxin, calicheamicin, via an acid labile linker. INO has shown high rates of response in the treatment of relapsed and refractory (R/R) ALL in single-agent studies, with fewer adverse effects than traditional cytotoxic chemotherapy. Given this experience, studies are now being done to evaluate INO in combination with low-intensity chemotherapy as frontline treatment for older adults with ALL and patients with R/R disease. Herein we will discuss the use of INO in the treatment of acute lymphoblastic leukemia.

The clinical potential of inotuzumab ozogamicin in relapsed and refractory acute lymphocytic leukemia

Antibody-drug conjugates (ADCs) are likely to make a significant contribution in the treatment of acute lymphoblastic leukemia (ALL) by combining the cytotoxicity of chemotherapy with the specificity of monoclonal antibodies. CD22, an endocytic receptor expressed by the majority of B cells, is an excellent target for ADCs. Inotuzumab ozogamicin (INO) is an ADC that consists of a cytotoxic moiety (derivative of calicheamicin) attached to a humanized monoclonal anti-CD22 antibody. As a single agent, INO, was shown to be effective with an objective response rate of 50% in the treatment of relapsed and refractory CD22 positive ALL patients. Clinical trials investigating the combination of INO with the conventional chemotherapies are ongoing. This review summarizes the clinical potential of INO in treatment of relapsed and refractory ALL, based on currently available data in the literature.

Efficacy of cytarabine, aclarubicin and granulocyte colony-stimulating factor (CAG) regimen compared to FLAG regimen for adult patients with relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia

In this study, we retrospectively assess the results in comparing the efficacies and toxicities of the three chemotherapy regimens: CAG (cytarabine, aclarubicin and granulocyte colony-stimulating factor (G-CSF), n=87), HD-CAG (increasing the dose of aclarubicin in CAG regimen, n=73), and FLAG (fludarabine, cytarabine and G-CSF, n=41) regimens in patients with relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph--ALL). Our study indicated that after one therapy course, the overall response (OR, complete reimssion (CR)+partial remission (PR)) rate was higher in CAG than that in FLAG regimen (55.2% vs. 31.7%, P=0.013), while the CR (50.7% vs. 26.8%, P =0.013) and OR (64.4% vs. 31.7%, P=0.001) rates in HD-CAG regimen were both higher than that in FLAG regimen. Furthermore, the results were more pronounced in the subgroup of patients with T cell and refractory Ph--ALL. There were no significant differences in CR and OR rates between the CAG and HD-CAG regimens. Meanwhile, the adverse effects of CAG regimen were less toxic than the FLAG and HD-CAG regimens. There were no statistically significant differences in overall survival rates at two years among the three groups (FLAG: 9.8%±4.6%, CAG: 11.8%±4.5%, HD-CAG: 11.1%±4.0%; P>0.05). Our preliminary results indicated that CAG and HD-CAG regimens could be more effective and safer than FLAG regimen for relapsed/refractory Ph--ALL.

Efficacy of low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (CAG regimen) compared to Hyper-CVAD regimen as salvage chemotherapy in relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia

We treated 90 relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph(-)-ALL) patients with CAG regimen [cytarabine (10mg/m(2)/12h, days 1-14), aclarubicin (5-7 mg/m(2)/day, days 1-8), granulocyte colony-stimulating factor (200 μg/m(2)/day, days 1-14)], 82 relapsed/refractory Ph(-)-ALL patients were treated with increasing aclarubicin dose CAG (5-7 mg/m(2)/day, days 1-14, HD-CAG). 96 relapsed/refractory Ph(-)-ALL patients treated with Hyper-CVAD regimen (control group). After one therapy course, among all groups, there were no statistically significant differences with complete remission (CR) and overall response [OR, CR+partial remission (PR)] rates (P>0.05). In CAG group, CR and OR rates for T-ALL exceeded those for B-ALL (P=0.001, 0.007), while in HD-CAG and control groups, those were not statistically significantly different (P>0.05). CR and OR rates of CAG group for B-ALL were lower than control group (P=0.004, 0.012). Among all groups, there were no statistically significant differences with CR and OR rates for T-ALL (P>0.05). CAG had lesser adverse event than Hyper-CVAD. The overall survival at 3 years for all groups were similar. Efficacy of CAG regimen was similar in comparison to Hyper-CVAD for relapsed/refractory Ph(-)-T-ALL. HD-CAG could not improve efficacy than CAG regimen.

Role of allogeneic hematopoietic stem cell transplantation in adult patients with acute lymphoblastic leukemia

Adult acute lymphoblastic leukemia (ALL) is a heterogeneous disease, due to the expression of different biological and clinical risk factors, for which allogeneic stem cell transplantation (alloHSCT) is an effective consolidation therapy. The non-relapse mortality of alloHSCT remains significantly higher compared with that of conventional chemotherapy. Therefore, one of the main challenges in the care of ALL is to establish a more precise prognostic definition to select patients who could take advantage from an alloHSCT. Currently, the use of minimal residual disease following induction and early consolidation therapy has improved the prognostic accuracy in defining ALL risk class. In Philadelphia-positive ALL, the introduction of tyrosine kinase inhibitors pre and post alloHSCT appears to improve outcomes significantly and, in the absence of specially designed clinical trials, alloHSCT remains the most effective post-remission therapy. Nowadays, alloHSCT can be performed according to various modalities encompassing the use of different conditioning regimens, as well as distinct donors and stem cell source, with a significant accessibility to transplant.

Clinical efficacy of mitoxantrone and Ara-C with or without etoposide salvage chemotherapy in adult patients with relapsed or refractory acute lymphoblastic leukemia: retrospective multicenter study of the Korean Adult ALL Working Party

Mitoxantrone is a conventional agent for relapsed or refractory acute lymphoblastic leukemia (ALL). However, an effective combination with other drugs and a feasible dosage has not been identified. A retrospective study of 46 patients with relapsed or refractory ALL was conducted to determine the efficacy of mitoxantrone and Ara-C treatment with (MEC) and or without etoposide (MC). Twenty-seven and 19 patients received MC and MEC chemotherapy, respectively. Twenty-two (48%) patients showed overall response [complete response (CR), 33%; CR with incomplete platelet recovery (CRp), 15%], and 10 of 22 responders received allogeneic stem cell transplantation (SCT). Median overall survival (OS) was 6.2 months (95% confidence interval, 3.41-9.0). Thirteen (48%) patients in the MC group and 9 (47%) in the MEC group achieved CR/CRp (p = 0.96). Treatment-related mortalities in the MC and MEC groups were 3 (11%) and 4 (21%), respectively (p = 0.36). However, the MEC group frequently presented with grade 3 or higher bacteremia/candidemia (p = 0.013). No difference in OS was observed between the two groups (p = 0.769). In conclusion, salvage therapy consisting of mitoxantrone and Ara-C without etoposide appeared to be an effective bridge therapy to allogeneic SCT for patients with refractory or relapsed ALL.

High relapse rate of T cell acute lymphoblastic leukemia in adults treated with Hyper-CVAD chemotherapy in Sweden

BACKGROUND

Hyper-CVAD is widely used to treat acute lymphoblastic leukemia (ALL) and aggressive lymphomas. This multicenter, population-based study assessed the efficacy of Hyper-CVAD as first-line therapy in patients with T-cell ALL (T-ALL).

PATIENTS AND METHODS

Between October 2002 and September 2006, 24 patients were diagnosed with T-ALL in Sweden; 19 were eligible for treatment with the protocol.

RESULTS

The median age was 32 yr (range 18-72 yr). Complete remission (CR) was obtained in 17 of 19 (89%) patients, and the treatment was relatively well tolerated. Allogeneic stem cell transplantation (SCT) was recommended in high-risk disease and was performed in four patients upfront. Two- and 5-yr leukemia-free survivals (LFS) in 17 patients with CR achievement were identical, at 29% (95% confidence interval [CI]: 8-51). Two- and 5-yr overall survival (OS) in whole cohort was 63% (95% CI: 42-85) and 47% (95% CI: 26-69), respectively. The 5-yr LFS for 15 patients who did not receive allogeneic SCT upfront were 20% (95% CI: 0-40), although 14 of 15 completed the protocol (eight cycles). Relapse occurred in 2 of 4 upfront-transplanted patients and in 12 of 15 patients treated with chemotherapy alone, six of whom received allogeneic SCT in CR2. Age ≥35 yr influenced OS negatively in univariate analysis (HR 5.1, 95% CI: 1.55-16.7).

CONCLUSIONS

Hyper-CVAD treatment resulted in a high CR rate and appeared safe, but it showed poor efficacy at preventing relapse. Therefore, this treatment is no longer recommended for adults with T-ALL in Sweden.

Feasibility of allografting in patients with advanced acute lymphoblastic leukemia after salvage therapy with inotuzumab ozogamicin

BACKGROUND

No highly effective salvage therapy exists for patients with relapsed acute lymphoblastic leukemia (ALL). Inotuzumab ozogamicin (IO) is a CD22 monoclonal antibody attached to calicheamycin that targets B lymphocytes in early stages of development, successfully inducing remission in patients with multiply relapsed ALL.

METHODS

We describe our findings in 26 patients who received allogeneic hematopoietic stem cell transplantation (SCT) after treatment with IO between September 2010 and October 2011.

RESULTS

Patients with a median age of 33 years (range, 5-70 years) received an allogeneic matched sibling donor (n = 9), matched- or 1-antigen mismatched unrelated donor (n = 16), or cord blood donor SCT (n = 1) while in complete remission (n = 23) or with active disease (n = 3). At the time of SCT, 15 patients were in complete remission without evidence of minimal residual disease (MRD) measured by multiparameter flow cytometry. Patients were heavily pretreated, including 5 patients who had received previous allogeneic SCT. Patients received a median of 3 courses of IO (range, 1-5 courses) before SCT. Seven patients are alive at a median follow-up of 13 months (range, 5-16 months), with 1-year event-free and overall survival (OS) of 22% and 20%, respectively. Patients without MRD at time of SCT had a markedly better 1-year OS of 42%. The cumulative incidence of nonrelapse mortality (NRM) at 6 months and 1 year were 40% and 60%, respectively, with 5 deaths attributed to venoocclusive disease (VOD).

CONCLUSIONS

Treatment with IO allows more patients to undergo transplantation while in remission, with favorable overall survival in patients without MRD who undergo transplantation. Reduction in hepatic toxicity is needed to improve overall results.

Outcomes of adult patients with relapsed acute lymphoblastic leukemia following frontline treatment with a pediatric regimen

We analyzed the outcome of 46 patients with acute lymphoblastic leukemia (ALL) who relapsed following treatment with a pediatric-based protocol; 34 received intensive re-induction chemotherapy, with a CR2 rate of 62%, median overall survival (OS) 7.8 months, median relapse-free survival 5.2 months and one year OS 19%. Allogeneic HSCT was performed in 8 patients in CR2/3, with a median OS 2.2 months. OS was superior in patients who relapsed after completion of chemotherapy, compared to those relapsing on treatment. The outcome of adult ALL relapsing after treatment was therefore poor, and novel salvage strategies are needed to improve outcomes.