Low-dose cytarabine and aclarubicin combined with granulocyte colony-stimulating factor for the treatment of relapsed or primary refractory acute lymphocytic leukemia: a retrospective study of 25 Chinese patients

Venetoclax with CAG regimen for early T-cell precursor acute lymphoblastic leukemia: a case report and literature review

This article describes a potential treatment for early T-cell precursor acute lymphoblastic leukemia (ETP-ALL), a relatively rare and highly aggressive hematologic malignancy. A 59-year-old woman admitted to our hospital with enlarged cervical lymph nodes, weight loss, abnormal count, and morphology of peripheral blood cells was diagnosed with ETP-ALL according to morphology, immunology, cytogenetics, and molecular biology. The patient initially received two cycles of the VICP regimen, including vincristine, idarubicin, cyclophosphamide, and prednisone, and had a response with positive minimal residual disease (MRD). The patient was then given venetoclax plus the CAG regimen, including aclarubicin, cytosine arabinoside, and granulocyte colony-stimulating factor. After one cycle, the patient achieved complete remission with negative MRD and was eligible for allogeneic hematopoietic stem cell transplantation.

Therapeutic strategies, including allogeneic stem cell transplantation, to overcome relapsed/refractory adult T-cell acute lymphoblastic leukemia

INTRODUCTION

The long-term survival of relapsed/refractory (R/R) adult T-cell acute lymphoblastic leukemia (T-ALL) is quite poor, and early T-cell precursor (ETP) ALL has recently been described as a high-risk T-ALL subgroup. However, the optimal therapeutic approach to R/R adult T-ALL remains poorly established.

AREAS COVERED

At present, cytoreductive therapy followed by allogeneic stem cell transplantation (allo-SCT) is considered to be the most clinically relevant and curative modality for R/R T-ALL. Above all, achieving minimal residual disease (MRD) is a key factor for successful allo-SCT and maintaining long-term remission for R/R patients. As a salvage regimen, nelarabine is the only therapy that was specifically approved for use in patients with R/R T-ALL. A combination of conventional chemotherapeutic agents and novel agents, such as venetoclax, can be used as alternatives for cytoreduction and bridging to transplantation. Relevant literatures published in the last 30 years were searched from PubMed to review the topic of T-ALL, and allo-SCT.

EXPERT OPINION

An effective salvage regimen, to achieve negative MRD, followed by allo-SCT is currently the best way to improve the clinical outcomes of adult R/R T-ALL. Moreover, posttransplant therapies, such as prophylactic or preemptive donor leukocyte infusion and hypomethylating agents, need to be considered as sequential therapy.

Early T-Cell Precursor Acute Lymphoblastic Leukemia and T/Myeloid Mixed Phenotype Acute Leukemia Possess Overlapping Characteristics and Both Benefit From CAG-Like Regimens and Allogeneic Hematopoietic Stem Cell Transplantation

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) and T-lymphoid/myeloid mixed phenotype acute leukemia (T/M-MPAL) are closely related entities and remain a therapeutic challenge. In this study, we characterized the clinical features of 43 ETP-ALL and 41 T/M-MPAL patients and compared clinical outcomes and safety between cytarabine, aclarubicin, and granulocyte colony-stimulating factor (CAG)-like regimens in 34 patients and conventional ALL regimens in 50 patients. In our series, ETP-ALL and T/M-MPAL showed similar biological characteristics, immunophenotypes, genomic alterations, and outcomes. The complete remission (CR) rate and minimal residual disease (MRD)-negative CR rate of CAG-like regimens were significantly higher compared with conventional ALL regimens (CAG-like: 80.0% and 59.7%, respectively; P = .039; ALL: 51.4% and 31.3%, respectively; P = .048). Overall, 90.0% of cases (18/20) achieved CR using combined decitabine and CAG-like regimens. Additionally, CAG-like regimens had lower rates of grade 3 or 4 infection (18.8% vs. 38.2%; P = .059) and grade 1 or 2 hepatotoxicity (37.5% vs. 60.0%; P = .043) than conventional ALL regimens. The 38 patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the first CR (CR1) had better overall survival (OS) and leukemia-free survival (LFS) than the 11 patients who underwent allo-HSCT in the second CR (CR2) or in no remission (median OS not reached vs. 7.6 months, P = .0004; median LFS not reached vs. 11.6 months, P = .0008). There was a significant difference in 3-year OS (95.7% vs. 52.5%; P = .0039) and LFS (95.8% vs. 43.5%; P = .0003) after allo-HSCT between pre-transplant MRD-negative and MRD-positive patients. The median OS for patients without allo-HSCT was 32.1 months in the CAG-like group compared with 12.1 months in the non-CAG-like group (P = .019). These findings suggest that ETP-ALL and T/M-MPAL possess overlapping characteristics and CAG-like regimens improve their clinical outcomes.

CAG regimen for refractory or relapsed adult T-cell acute lymphoblastic leukemia: A retrospective, multicenter, cohort study

Adult patients with relapsed or refractory T‐cell acute lymphoblastic leukemia (R/R‐T‐ALL) have extremely poor prognosis, representing an urgent unmet medical need. Finding an optimal salvage regimen to bridge transplantation is a priority. The CAG (cytarabine, aclarubicin, and G‐CSF) regimen was initially used by one group in China, showing unexpectedly promising results in 11 R/R‐T‐ALL patients. Here, we report the multicenter results of 41 patients who received the CAG regimen as salvage therapy. After one cycle of the CAG regimen, complete remission and partial remission were achieved in 33 (80.5%) and two (4.9%) patients, respectively. Failure to respond was observed in six patients (14.6%). Early T‐cell precursor (ETP) (n = 26) and non‐ETP (n = 15) patients had a similar CR rate (80.8% vs 80.0%, P = .95). Among 41 patients, allo‐HSCT was successfully performed in 27 (66%) patients (22 in CR and 5 in non‐CR). With a median follow‐up time of 12 months, the estimated 2‐year overall survival and event‐free survival were 68.8% (95% CI, 47.3%‐83.0%) and 56.5% (95% CI, 37.1%‐71.9%), respectively. The CAG regimen was well‐tolerated, and no early death occurred. Our multicenter results show that the CAG regimen is highly effective and safe, representing a novel choice for adult patients with R/R‐T‐ALL and providing a better bridge to transplantation.

Efficacy and safety of G-CSF, low-dose cytarabine and aclarubicin in combination with l-asparaginase, prednisone in the treatment of refractory or relapsed acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) patients who fail to acquire complete remission (CR) or who relapse after initial response have poor prognosis. At present there is no consensus as to the standard salvage therapy for these patients. In this study, we retrospectively evaluate safety and efficacy of a salvage regimen (CAGLP) consisting of G-CSF, low-dose cytarabine, aclarubicin, l-asparaginase and prednisone. Thirty-six patients were included with primary refractory (n=13) or relapse (n=23). The overall response rate (ORR) and CR rate were 86.1% and 63.9%, respectively. With a median follow-up of 34 months, the probability of overall survival (OS) at 2 years was 30%±10% and the disease-free survival (DFS) rate was 15%±8%. Treatment-related mortality was 5.6%. Our preliminary results indicated that CAGLP was feasible, safe and effective as a salvage reinduction chemotherapy for primary refractory and relapsed ALL patients.

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.