CLAG Regimen Research Articles

CLAG±DAC regimen in the treatment of refractory/relapsed acute myeloid leukemia

Objective: To investigate the efficacy and prognosis of CLAG±DAC (Clofarabine, Cytarabine, G-CSF±Decitabine) chemotherapy in patients with relapsed/refractory acute myeloid leukemia (R/R AML) . Methods: Continuous cases of R/R AML treated with the CLAG+DAC protocol or CLAG alone at the First Affiliated Hospital of Soochow University from January 2017 to December 2021 were retrospectively analyzed. The baseline characteristics, individual treatment regimen, treatment effect, disease progression, and survival status of patients were recorded. The factors influencing the efficacy of the CLAG±DAC chemotherapy regimens were analyzed, and the overall survival (OS) time after reinduction was calculated using the Kaplan-Meier method. Results: This study included a total of 53 patients, with 33 male patients and an average age of 40.6 years. Thirty-three patients achieved complete remission (CR+CRi) of the disease after the CLAG±DAC chemotherapy regimen and six patients achieved partial remission (PR), while 14 did not. Thirty-two patients eventually underwent hematopoietic stem cell transplantation, and the median OS of the patients was 55.9 months until follow-up. Patients with disease remission after the application of the CLAG±DAC chemotherapy had a significantly longer survival time than those without remission (P<0.001). The results of the multifactorial analysis have revealed that combined DAC (OR=4.60, 95% CI 1.14-23.5, P=0.04) and DNMT3A mutation (OR=0.14, 95% CI 0.01-0.89, P=0.05) were the factors influencing the efficacy of the CLAG±DAC chemotherapy regimen. The remission rate was relatively higher in patients with R/R AML combined with FLT3-ITD mutation by applying the DAC+CLAG regimen (OR=10.84, 95%CI 1.48-288.50, P=0.04) . Conclusion: The CLAG±DAC regimen is considered effective in patients with R/R AML, whereas decitabine combined with the CLAG regimen is more suitable for patients with R/R AML combined with FLT3-ITD mutation.

Decitabine as epigenetic priming with CLAG induce improved outcome of relapsed or refractory acute myeloid leukemia in children

BackgroundDecitabine (DAC), a DNA methyltransferase inhibitor, has shown efficacy combined with chemotherapy for relapsed or refractory (R/R) acute myeloid leukemia (AML) in adults, but less is known about its efficacy in children. Accordingly, we conducted a study which involved a priming regimen consisting of DAC with cladribine, cytarabine, and granulocyte-stimulating factor (DAC-CLAG) and compared the efficacy and safety of this regimen with CLAG alone.MethodsA total of 39 R/R AML children who received the CLAG or DAC-CLAG regimen in Shanghai Children’s Hospital were retrospectively enrolled in this non-randomized study. These regimens were studied sequentially over time. Twenty-two patients received CLAG from 2015, while 17 patients were administered epigenetic priming with DAC before CLAG from 2020. Patients were subsequently bridged to stem cell transplantation (SCT) or consolidation chemotherapy. Complete remission (CR) and adverse effects were analyzed by Fisher’s exact test, and survival was analyzed by the Kaplan–Meier method.ResultsDAC-CLAG conferred a numerically higher CR compared to CLAG (70.59% vs 63.64%; P = 0.740). High CR rates occurred in patients with good cytogenetics (P = 0.029) and prior induction without cladribine (P = 0.099). The 1-year event-free survival (EFS) was 64.71% ± 11.59% and 63.31% ± 10.35% in the DAC-CLAG and CLAG group (P = 0.595), and 1-year overall survival (OS) was 81.45% ± 9.72% and 77.01% ± 9.04%, respectively (P = 0.265). The 1-year OS and EFS after SCT were higher in the DAC-CLAG than in the CLAG cohort (100% vs 92.31% ± 7.39%, P = 0.072; 92.31% ± 7.39% vs 85.71% ± 9.35%, P = 0.158). Univariate analysis revealed that a good prognosis included good cytogenetics (P = 0.002), non-complex karyotype (P = 0.056), CR on reinduction (P < 0.0001), and bridging to SCT (P = 0.0007). Use of a hypomethylating agent (P = 0.049) and bridging to SCT (P = 0.011) were independent prognostic factors. Grade 3/4 hematologic toxicity and infection were the main adverse events.ConclusionsDAC prior to the CLAG regimen improved remission in pediatric R/R AML, and was feasible and well tolerated. CLAG ± DAC as a salvage therapy prior to SCT induced improved survival.

Cladribine, cytarabine, and filgrastim based regimen in relapsed or refractory acute myeloid leukemia: A systematic review and meta-analysis.

To ascertain the efficacy and safety of cladribine, cytarabine, and filgrastim-based regimen in relapsed or refractory (R/R) AML patients. Clinical studies were searched in PubMed, Cochrane Library, Embase data. We selected available factors including complete remission (CR), overall response rate (ORR), overall survival (OS) to evaluate the efficacy, and early death (ED), and adverse events to evaluate safety. 15 records with 812 R/R AML patients were finally included and analyzed using the R software. Subgroups analysis was also conducted. The pooled CR rate for CLAG regimen, CLAG-M regimen, and CLAG combined with any other drugs regimen is 56% (95% CI: 46-66), 46% (95% CI: 34-56), 44% (95% CI: 26-64), respectively. The relapsed and refractory groups showed a CR rate of 68% (95% CI: 53-80), and 51% (95% CI: 45-58) with CLAG related regimens. As risk grade decreases, the pooled CR rate increases. Regarding the safety for CLAG-related protocols, systematic review was conducted. The CLAG-related regimen is an effective and safe therapy for R/R AML patients, CLAG seems to have more superiority than CLAG combined therapy, though further studies including cladribine combination treatment protocols, are still needed to confirm our results further.

Sequential Use of Flamsa, FLAG, CLAG or TEC-Based Conditioning Regimen Followed By Allogeneic Hematopoietic Transplantation Results in Favorable Outcome for High Risk Acute Myeloid Leukemia, Myelodysplastic Syndrome and Myeloproliferative Neoplasia Patients: 15 Year Follow-up of the Multicenter Study in Singapore

Introduction: Allogeneic hematopoietic cell transplant (allo-HCT) is an effective consolidative treatment for patients with certain hematological malignancies and gives the best outcome when done in remission. However, patients with refractory acute myeloid leukemia (AML) or some myeloproliferative neoplasia (MPN) and myelodysplastic syndrome (MDS) deemed unable to achieve remission with standard induction are often excluded from allo-HCT with conventional conditioning regimen as pre-transplant remission could not be achieved. Recently, a sequential transplant approach, as developed by the Munich group, comprising of intensive cytoreductive chemotherapy FLAMSA (Fludarabine/Amsacrine/Cytarabine) to decrease leukemia cell burden shortly prior to conditioning regimen, has been successfully used for high-risk (HR) AML/MDS with promising results. Methods: We studied 72 patients (median age 51 years, range 17-68) with HR AML (n=57), as defined by refractory, relapsed disease, secondary leukemia, complete remission with adverse-risk cytogenetics according to ELN criteria, or high/very risk refined Disease Risk Index (DRI), MPN (n=3) and HR MDS (n=12) according to IPSS-R, undergoing allo-HCT using the sequential transplant approach in 2 transplant centers in Singapore between January 2009 and July 2022. The sequential transplant approach combined a cytoreductive chemotherapy, which consisted of either FLAMSA (n=21), FLAG [Fludarabine/Cytarabine/Granulocyte Colony Stimulating Factor (GCSF)] +/- Idarubicin (n=30), CLAG (Clofarabine +/- Cytarabine +/- GCSF) (n=18), or TEC (Thiotepa, Etoposide, Cyclophosphamide) (n=3) followed by reduced intensity (RIC) (n=61) or myeloablative (MAC) (n=11) conditioning regimen. All patients received peripheral blood stem cell from matched related donors (MRD) (n=36), mismatched related donors (MMRD) (n=7), matched unrelated donors (MUD) (n=21), or mismatched unrelated donors (MMURD) (n=8). Post-grafting immunosuppression consisted of calcineurin inhibitor and mycophenolate mofetil (MMF) in all patients. Thymoglobulin and post-transplant cyclophosphamide were added for GVHD prophylaxis for MUD/MMURD and MMRD transplant, respectively. One MMRD had selective ex vivo T-cell depleted transplant followed by MMF as GVHD prophylaxis. Results: The median time to neutrophil > 1000/μL was 11 days (range, 8-25). With a median follow-up duration of 51 months (range, 1-148), the Kaplan-Meier estimate of overall survival (OS) and leukemia-free survival (LFS) at 5 years were 42% (95% CI, 30-54) and 32% (95% CI 20-44), respectively. The cumulative incidence of relapse and non-relapse mortality (NRM) at 2 years were 47% (95% CI, 35-59) and 16% (95% CI, 9-26), respectively. Patients receiving FLAG, CLAG or TEC-based sequential regimen showed a trend towards lower NRM and relapse compared to FLAMSA-based regimen, although the difference was not statistically significant. This translated into a more favorable 5-year LFS (40% vs 13%, p=0.04), but no statistically significant difference in 5-year OS (42% vs 40%, p=0.56). Patients with refractory disease (n=49) were at higher risk of relapse compared to patients whom had achieved at least a partial remission prior to sequential allo-HCT (n=17) (2-year cumulative incidence of relapse: 59.0% vs 34.0%, p=0.02). This resulted in an inferior 5-year OS (31% vs 66%; p=0.02) and LFS (20% vs 75%, p<0.01). On multivariable analysis, only refined DRI showed significant impact on OS (p=0.01) and LFS (p=0.02) but had no significant impact on NRM and relapse. The 5-year OS for patients with intermediate/high risk and very high risk DRI were 51% and 21% (p<0.01), and the corresponding 5-year LFS were 42% and 10% (p<0.01), respectively (Figure 1 and Figure 2). Conclusions: Sequential transplant conditioning with FLAMSA, FLAG, CLAG or TEC-based cytoreductive regimen followed by allo-HCT is an effective strategy in overcoming the dismal prognosis of HR AML, MDS and MPN, including patients with high risk DRI, and enabling favorable long-term disease-free survival. More studies on effective strategies such as optimising the conditioning regimen intensity or post-transplant maintenance therapy with prophylactic donor lymphocyte infusion, are needed to further eliminate the risk of relapse, without increasing risk of treatment-related toxicity. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

First Reported Case Series of Combined Treatment with CLAG and Venetoclax for Acute Myeloid Leukemia (AML)

Background: Since the 1970s, the standard of care for patients with AML has been a "7+3" induction regimen consisting of 7 days of cytarabine and 3 days of anthracycline. CLAG has been demonstrated to be effective in patients with newly diagnosed, high-risk AML. Venetoclax is a Bcl2 inhibitor FDA approved to treat AML in elderly patients in combination with hypomethylating agents. Here we describe two patients who received both CLAG and venetoclax to treat R/R AML. Both patients were heavily treated (unsuccessfully), and this novel combination therapy was administered near the end of their treatment. Patient #1 was a 54 year old female with AML. Genetic analysis revealed a FLT3-ITD mutation. Patient was treated with cytarabine 3mg/m2 x 5 and mitoxantrone 60 mg/m2 on day 1 of cycle 1. She went into morphologic remission and then received 2 cycles of HIDAC. Unfortunately, patient relapsed 5 months after starting chemotherapy, thus was not a candidate for allo-SCT. At relapse, the patient had mutations of FLT3-ITD, DNMT3A, NPM1, and WT1. The patient was then treated with CLAG -Idarubicin. Venetoclax was added on day 3 of the cycle, in combination to the CLAG regimen, and she received the venetoclax for 7 days (titrated on day 1 at 50 mg, then 100 mg on day 2, and 200 mg for the next 5 days). She also received midostaurin starting day 6 of the CLAG cycle at a dose of 50 mg and received it for 14 days. Patient #2 was a 71 year old female with AML. Patient Karyotype was 45, XX, add(5)(q11), der(6;7)(p10;q10)[20]. Analysis did not detect a targetable mutation, but an NRAS mutation was detected. The patient began cycle 1 of CLAG-Ida, and on day 23 bone marrow biopsy showed myeloid hyperplasia without increased blasts. The patient then received two more cycles of CLAG-Ida at approximate 1 month intervals. 4 months after diagnosis, the patient underwent an allo-SCT. Patient developed skin lesions and on day +96 biopsy revealed leukemia cutis. Bone marrow biopsy showed no morphologic evidence of AML but abnormal karyotype was noted 45,XX,del(5)(q13q33), dic(6;7)(q11;p11.2)[4]/46,XX[16]. On day +103 the patient began decitabine-venetoclax 200 mg. She received 2 more cycles of decitabine-venetoclax. A right axillary lymph node biopsy was done day on day +238 and showed an abnormal immature population expressing CD34, CD117, MPO, CD4, and CD56. Patient then started on GO 4.5mg and then HIDAC. Patient did not respond to these regiments and received CLAG and Venetoclax starting day +307. She completed this cycle but progressed further. She then received hydrea. This was followed by vyxeos on day+357. Patient did not respond and elected to go to hospice; she died day+381 post SCT. Discussion: To our knowledge, this is the first reported case series of concomitant treatment with CLAG and Venetoclax. During the literature review, we looked at FLAG, which is similar to CLAG but uses a different purine analogue fludarabine instead of cladribine. We also saw that FLAG and venetoclax have been combined to treat AML patients as they transition into SCT. When compared to FLAG, CLAG has been shown to be more effective in treating patients with high risk AML. Although in both cases the patients ultimately succumbed to AML, this was a proof of concept, and we suspect the CLAG venetoclax combination will be more efficacious than FLAG-venetoclax in treating high risk patients. This case series is intended to show that these two therapies can be combined, and we propose a further, more complete investigation into the concomitant use of CLAG and venetoclax to treat patients with AML.

Variables associated with hematological remission and survival in patients with acute myeloid leukemia after induction failure and relapse

Objective: This study aimed to explore variables associated with remission rate and survival in patients with acute myeloid leukemia (AML) after induction failure and relapse. Methods: Data of 373 consecutive patients with AML were analyzed after induction failure and relapse. Binary logistics and the Cox model regression were used to identify variables associated with remission rate and outcomes. Results: In patients with AML after induction failure and relapse, the total CR+CRi rates were 50.6% and 40.3%, respectively; among those who achieved CR/CRi, the 3-year RFS rates were 34.4% and 30.4%, respectively, and the 3-year overall survival rates were 40.1% and 31.6%, respectively. In the multivariate analyses, using CLAG or FLAG regimen as a re-induction chemotherapy regimen, age <39 years and SWOG low-risk were significantly associated with higher remission rates in patients with induction failure. Male, secondary AML, SWOG high-risk, the interval from the first remission to relapse within 12 months, and bone marrow blasts ≥20% at the time of relapse were significantly associated with lower remission rates in relapsed patients. Transplantation was significantly associated with prolonged relapse-free survival and overall survival in patients achieving hematologic remission; the SWOG low-risk group was significantly associated with longer overall survival in those with induction failure; and achieving CR (not CRi) or having female gender was associated with longer RFS or overall survival in relapsed patients. Conclusion: Reinduction chemotherapy regimen, age, gender, SWOG risk, secondary AML, the interval from the first remission to relapse, and bone marrow blast percentage at the time of relapse were significantly associated with remission rates in the patients with AML after induction failure and relapse. Transplantation, SWOG low-risk, achieving CR, or female gender were associated with longer survivals in those achieving remission.

CLAG Regimen Composed of Continuous Intravenous Infusion of Cladribine in the Treatment of Refractory/Relapsed Acute Myeloid Leukemia

To study the efficacy and safety of continuous intravenous infusion of 2-Chlorodeoxyadenosine (2-CdA) combined with high-dose cytarabine (Ara-C) and granulocyte colony-stimulating factor (G-CSF) (CLAG regiem) in the treatment of relapsed/refractory acute myeloid leukemia (AML). Fifteen patients with refractory/relapsed AML hospitalized in 5 medical units such as Department of Hematology, the Affiliated Tumor Hospital of Zhengzhou University and received one course of CLAG regimen from June 2014 to August 2019 were analyzed retrospectively (specifically: cladribine 5 mg/M2, day 1 to day 5, continuous 24-hour intravenous infusion; Ara-C 2 g/M2, 1 time/day, day 1 to day 5, intravenous infusion; G-CSF 300 mg, 1 time/day, day 0 to day 5, subcutaneous injection). Among the 15 patients with refractory/relapsed AML, 9 males and 6 females, the median age was 35 (13-63) years old. FAB classification: 1 case of M1, 3 cases of M2a, 4 cases of M2b (including 1 case with extramedullary invasion), 1 case of M4 with extramedullary invasion, 5 cases of M5, 1 case of HAL; NCCN classification: 6 cases in intermediate risk group, 9 cases in high risk group; 8 cases refractory, 7 cases relapsed. The median time of pre-chemotherapy was 4 (2-8) (of which NO.15 had received 8 cycles of chemotherapy and received CLL1-CAR-T), and the median white blood cell count before chemotherapy was 12.27 (from 0.78 to 5.29)×109/L. After 1 course of treatment with CLAG regimen, 12 patients achieved complete remission (12/15, 80%), and the median duration of CR was 65 days (0-528) days. IV grade leukopenia and thrombocytopenia was found in all the patients after chemotherapy. The median duration of granulocytosis was 20 (14 to 33) days, and 1 patient died. Seven patients received allogeneic hematopoietic stem cell transplantation. The median EFS and OS time of 15 patients was 85 (19-558) days and 117 (19-558) days, respectively. The CLAG regimen consisting of continuous intravenous infusion of cladribine shows high CR in the treatment of AML patients, but the duration of CR is short, myelosuppression is sever, so that infection control is the key. Allogeneic hematopoietic stem cells transplantation should be performed as soon as possible after CR.

High Dose Flamsa, CLAG or FLAG-Based Sequential Conditioning Regimen Followed By Allogeneic Hematopoietic Transplantation Results in Favorable Outcome for High Risk Acute Myeloid Leukemia, Myelodysplastic Syndrome, Myeloproliferative Neoplasia Patients : A Multicenter Study in Singapore

Introduction: Allogeneic hematopoietic cell transplant (allo-HCT) is an effective consolidative treatment for patients with certain hematological malignancies and gives the best outcome when done in remission. However, patients with refractory acute myeloid leukemia (AML), certain forms of myeloproliferative neoplasia (MPN), and myelodysplastic syndrome (MDS) deemed unable to achieve remission with standard induction are often excluded from allo-HCT with conventional conditioning regimen as pre-transplant remission could not be achieved. Recently, a sequential transplant approach, as developed by the Munich group, comprising of intensive cytoreductive chemotherapy FLAMSA (fludarabine/amsacrine/cytarabine) to decrease leukemia cell burden shortly prior to conditioning regimen, had been successfully used for high-risk (HR) AML/MDS with promising results. Methods: We studied 56 patients (median age, 52 years; range 17-68) with HR AML (n=45), as defined by refractory, relapsed disease, secondary leukemia, complete remission with adverse-risk cytogenetics according to ELN criteria, or high/very high risk refined Disease Risk Index (DRI), MPN (n=2), and HR MDS (n=9) according to IPSS-R, undergoing allo-HCT using the sequential transplant approach in 2 transplant centers in Singapore between January 2009 and June 2020. The sequential transplant approach combined a cytoreductive chemotherapy, which consisted of either FLAMSA (n=17), FLAG +/- Ida [fludarabine/cytarabine/granulocyte colony stimulating factor (GCSF) +/- idarubicin] (n=23), or CLAG (clofarabine +/- cytarabine +/- GCSF) (n=15), followed by reduced intensity (RIC) (N=48) or myeloablative (MAC) (N=8) conditioning regimen. All patients received peripheral blood stem cell from matched related donors (N=30), mismatched related donors (N=3), matched unrelated donors (N=16), or mismatched unrelated donors (N=7). Post-grafting immunosuppression consisted of calcineurin inhibitor and mycophenolate mofetil in all patients. Thymoglobuline or post-transplant cyclophosphamide were added for GVHD prophylaxis in unrelated donor transplant and mismatched related donors, respectively. Results: The median time to neutrophil &amp;gt; 1000/μL was 11 days (range, 8-19). With a median follow-up of 44 months (range, 1-123), the Kaplan-Meier estimate of overall (OS) and leukemia-free (LFS) survivals at 5 years were 49% (95% CI, 35-62) and 37% (95% CI, 23-52), respectively. The 2-years cumulative incidence of relapse and non-relapse mortality (NRM) were 47% (95% CI, 32-60) and 13% (95% CI, 6-24), respectively. Patients receiving FLAG or CLAG-based sequential regimen showed lower cumulative incidence of NRM (2-year cumulative incidence for NRM: 5% vs 29%; p=0.018), and similar relapse (2-year cumulative incidence for relapse: 49% vs 53%; p=0.64), as compared to patients given FLAMSA-based sequential regimen, resulting in a trend towards more favourable OS (5-year OS: 53% vs 41%; p=0.29) and LFS (5-year LFS: 46% vs 20%; p=0.08). In multivariable analysis, only refined DRI showed significant impact on OS (p=0.04), but has no significant impact on LFS, NRM, and relapse. The 5-year OS for patients with intermediate/high risk and very high risk DRI were 59% and 27%, respectively (p=0.017), and the corresponding 5-year LFS were 46%, and 20% (p=0.06), respectively (Figure 1 &amp; Figure 2). The intensity of conditioning regimen did not significantly impact on OS, LFS, relapse, and NRM. Conclusions: Sequential transplant conditioning with FLAMSA, FLAG or CLAG followed by allo-HCT is an effective strategy in overcoming the dismal prognosis of HR AML, MDS and MPN, and enabling favourable long-term disease-free survival. More studies on effective strategies such as post-transplant maintenance therapy with prophylactic donor lymphocyte infusion, are needed to further eliminate the risk of relapse, without increasing risk of treatment related toxicity. Disclosures No relevant conflicts of interest to declare.

Re-induction with modified CLAG regimen in relapsed or refractory acute myeloid leukemia in children bridging to allogeneic hematopoietic stem cell transplantation.

The prognosis for relapsed or refractory acute myeloid leukemia (RR-AML) in children is poor, and the preferred salvage chemotherapy is unclear. One regimen is cladribine, cytarabine, and granulocyte-colony stimulating factor (CLAG), but little is knownabout its efficacy and safety in childrenwith RR-AML. We enrolledRR-AML patients aged 0-18years who received modified CLAG regimen for re-induction between July 1, 2015 and April 1, 2018, or conventional induction between August 1, 2011 and April 1, 2018. Patients were followed up to March 31, 2019. Patients underwent allogeneic stem cell transplantation (allo-SCT) or chemotherapy after the induction of complete remission (CR). The CR rate, survival, and side effects were analyzed. The CR rate for induction was 66.7% after one cycle and 75.0% after two cycles of the CLAG regimen in 12 children. The nine children who received conventional chemotherapy had a CR rate of 22.2% after one cycle and 33.3% after two cycles (P = 0.087 vs. CLAG). The 3-year event-free survival (EFS) ofthe CLAG group and the conventional treatment group were 44.4 ± 15.7% and 22.2 ± 13.8% (P = 0.112). The 3-year overall survival of the two groups were 59.5 ± 16.2% and 22.2% ± 13.8% (P = 0.057). The 3-year EFS for allo-SCT and chemotherapy after CLAG regimen was 66.7 ± 19.2% and 25.0 ± 21.7% (P = 0.015). A single case of chemotherapy-related death was recorded. Our data suggest a promising CR rate using CLAG salvage treatment in childhood RR-AML. Allo-SCT after CR may improve the long-term outcome in these patients.

Acute myeloid leukemia M2 patient with negative ETO combined with CEBPA mutation and positive WT1 treated by CLAG regimen: report of one case and review of literature

目的 观察CLAG方案治疗ETO阴性合并CEBPA突变WT1阳性急性髓系白血病（AML）M2的临床疗效。 方法 对兰州军区兰州总医院1例采用CLAG方案治疗的ETO阴性合并CEBPA突变WT1阳性AML-M2患者的诊疗情况进行分析，并复习相关文献。 结果 该例患者行IA方案化疗1个疗程后未获得缓解，改行CLAG方案化疗1个疗程，复查骨髓完全缓解，后转外院进一步治疗。 结论 CLAG方案治疗ETO阴性合并CEBPA突变WT1阳性AML-M2患者短期疗效良好，长期疗效仍需积累更多的病例进一步观察。

Analysis of Efficacy and Prognostic Factors of CLAG Treatment in Chinese Patients with Refractory or Relapsed Acute Myeloid Leukemia

Background/Aims: The aim of this work was to investigate the efficacy and predictive factors of CLAG treatment in refractory or relapsed (R/R) acute myeloid leukemia (AML) patients. Methods: Sixty-seven R/R AML patients were enrolled in this prospective cohort study and treated by a CLAG regimen: 5 mg/m²/day cladribine (days 1–5), 2 g/m²/day cytarabine (days 1–5), and 300 μg/day filgrastim (days 0–5). The median follow-up duration was 10 months. Results: A total of 57 out of 67 patients were evaluable for remission after CLAG therapy, of whom 57.9% achieved a complete remission (CR) and the overall remission rate was 77.2%. The median overall survival (OS) was 10.0 months, with a 1-year OS of 40.3 ± 6.0% and 3-year OS of 16.7 ± 5.7%. CR at first induction after the initial diagnosis was associated with a favorable CR. Age above 60 years, high risk stratification, second or higher salvage therapy, and bone marrow (BM) blasts ≥42.1% were correlated with an unfavorable CR. Secondary disease, age ≥60 years, high risk stratification, and second or higher salvage therapy were associated with worse OS. Patients developed thrombocytopenia (41, 61%), febrile neutropenia (37, 55%), leukopenia (33, 49%), neutropenia (18, 27%), and anemia (9, 13%). Conclusion: CLAG was effective and well tolerated for R/R AML. BM blasts ≥42.1%, age ≥60 years, high risk stratification, and second or higher salvage therapy were independent factors for a poor prognosis.

CLAG regimen in treatment of relapsed/refractory acute myeloid leukemia: report of six cases and review of literature

目的 分析CLAG方法治疗复发难治急性髓系白血病（AML）患者的临床疗效及不良反应。 方法 对河南省肿瘤医院血液科6例复发难治AML患者采用CLAG（克拉屈滨+阿糖胞苷+粒细胞集落刺激因子）方案治疗，分析6例患者临床资料，并结合文献进行复习。 结果 6例复发难治AML患者中，男性5例，女性1例；中位年龄45岁（13~63岁）；复发和难治各3例。应用CLAG方案后5例达完全缓解，1例未缓解；6例患者均出现骨髓抑制，但是治疗期间无严重不良反应发生。 结论 CLAG方案治疗复发难治AML疗效确切，不良反应耐受性较好，并需后续行异基因造血干细胞移植等积极治疗。

Efficacy and safety analysis of the combination of cladribine, cytarabine, granulocyte colonystimulating factor (CLAG) regime in patients with refractory or relapsed acute myeloid leukemia

目的分析CLAG方案（克拉屈滨＋阿糖胞苷+ G-CSF）对难治复发急性髓系白血病（AML）的疗效及安全性。方法回顾性分析2014年4月1日至2015年12月9日采用1个疗程CLAG方案治疗的33例难治复发AML患者的临床资料。结果33例难治复发AML患者中，男16例，女17例，中位年龄49(14~68）岁。按照WHO分类（第4版）诊断：伴有重现性遗传学异常AML 7例（21.2%），伴有多系病态造血AML 5例（15.2%），治疗相关AML 2例（6.1%），其他类型19例（57.5%）。NCCN危险分层低危、中危、高危组分别为6、18、9例，其中FLT3-ITD基因突变5例。复发16例，难治17例，既往化疗疗程中位数为2(1~36）个。经CLAG方案1个疗程化疗后，26例（78.8%）获得完全缓解（CR），难治组CR率低于复发组[64.7%（11/17）对93.8%（15/16），P=0.041]。5例FLT3-ITD基因突变患者均获CR。所有患者均出现4级白细胞减少和血小板减少和不同部位感染，3例因感染而早期死亡。5例患者CR后接受异基因造血干细胞移植。中位随访142(9~525) d，复发10例，死亡13例，中位无事件生存期为230(9~525）d，中位总生存期为419(9~525) d。获CR患者（26例）中位总生存期长于未缓解患者（7例）[447(165~525) d对52(9~162) d，P <0.001]。结论CLAG方案对难治复发AML疗效肯定，复发患者CR率高于难治患者。控制感染是治疗成功的关键。

CLAG-based induction therapy in previously untreated high risk acute myeloid leukemia patients

The CLAG regimen is highly active in patients with relapsed and/or refractory acute myeloid leukemia (AML). We administered CLAG-based chemotherapy to 20 previously untreated AML patients who were poor candidates for standard induction therapy. Responding patients received further CLAG as post-remission therapy followed by additional therapy that was tailored to their AML subtype. Patients were considered poor candidates for standard therapy due to either cardiac disease, prior chemotherapy for another malignancy, prior myeloproliferative disease, or myelodysplastic syndrome that had progressed after hypomethylator therapy. Overall, thirteen patients had a complete response (CR) to the first cycle of therapy (65%), one patient had a CR without platelet recovery, and 3 patients had a partial response (PR). Two of the patients with PR converted to CR after further therapy. The median duration of response has not been reached; the mean duration of response is 36.8 months (95% CI 28.8–44.8 months). Median overall survival (including deaths from all causes) is 29.0 months (95% CI 18.0–46.0 months). Patients with de novo AML had a CR rate of 90.9% and a median overall survival of 38.5 months. CLAG-based therapy is a well-tolerated, efficacious induction strategy in previously-untreated patients with high risk AML. CLAG-based regimens should be studied in a broader group of newly diagnosed AML patients.

CLAG-Based Induction Therapy in Previously Untreated High Risk AML Patients

The CLAG regimen (G-CSF 300 mcg sc, cladribine 5 mg/m2 over 2 hours, and cytarabine 2 gm/m2 over 4 hours beginning 2 hours after cladribine, all daily times 5 days) was originally devised by Robak et al (Leuk Lymphoma 2000; 36:121-9) as induction therapy for patients with relapsed or refractory acute myeloid leukemia. Fifty percent of patients achieved a CR with a median duration of 22.5 weeks. This group subsequently added mitoxantrone to the regimen (Wrzesien-Kus A, et al. Ann Hematol 2005; 84:557-64). We treated 20 patients with previously untreated acute myeloid leukemia who were considered unsuitable for our intensive high-dose cytarabine, high-dose mitoxantrone frontline induction regimen either due to age or cardiac dysfunction with CLAG-based therapy. Patients with a cardiac ejection fraction above 50% additionally received either mitoxantrone (mito) or idarubicin (ida), 12 mg/m2 times 3 days, concurrently with CLAG. Of 20 patients treated, 5 received CLAG, 12 received CLAG-ida and 3 received CLAG-mito. The median age was 64 years (range 42-79 years). There were 13 men and 7 women. Six patients had received prior chemo and/or RT for a previous malignancy. In addition 3 patients had a prior MPD and 1 had prior MDS (total of 10 patients with secondary AML). Patients had a median of 3 comorbidities (range 0-7). Cytogenetic risk was good: 2 patients (however one was FLT3 ITD+), intermediate: 10 patients, poor: 8 patients. Only one patient was FLT3 ITD+. Responding patients (CR or PR) received 1 (5 pts), 2 (2 pts), 3 (8 pts) or 4 (2 pts) cycles of CLAG+/- ida or mito followed by allogeneic stem cell transplant (4 pts), hidac (2 pts) or decitabine maintenance (4 pts). Most patients responded to therapy. There were 13 formal CRs (65%), 1 CRp (5%), 3 PR (15%, defined as 6-10% blasts on marrow with complete hematologic recovery in the peripheral blood), 2 failures (10%) and one early death (5%). Other than the early death, treatment was well tolerated with few toxicities other than neutropenic fever and cytopenias. Estimated overall survival by Kaplan Meier analysis is 29.6 months (95% CI 20.1-39.2 months). Duration of response is 32.3 months (95% CI 21.6-43.1 months).CLAG-based therapy is a well-tolerated, efficacious induction strategy in previously-untreated patients with high risk AML. CLAG-based regimens should be studied in a broader group of newly diagnosed AML patients. [Display omitted] [Display omitted] DisclosuresOff Label Use: Use of cladribine in AML.

Factors Affecting Clinical Outcomes after CLAG/CLAG-M Chemotherapy in Relapsed/Refractory Acute Myeloid Leukemia

Backgroud:Substantial number of acute myeloid leukemia(AML) patients does not respond to induction chemotherapy (refractory) or relapse after achieving complete remission (CR) with standard induction chemotherapy. In relapsed/refractory AML, therapeutic options are still undefined and unsatisfactory. By the way, new regimen integrating cladribine yields promising outcomes in recent studies. We intended to reveal the efficacy of CLAG/CLAGM and to find out predictive markers for outcome in relapsed/refractory AML patients.Methods:Relapsed/refractory AML patients who were treated with CLAG or CLAGM between 2004.5 - 2014.7 in two institutions (Seoul National University Hospital/Seoul National University Bundang Hospital) were retrospectively reviewed. The regime CLAG consists of cladribine 5mg/m2 on days 1-5, cytarabine 2gm/m2 on days 1-5 and filgrastim 5 mcg/kg on days 0-5. The regimen CLAGM includes addition of mitoxantrone 10mg/m2 to CLAG regimen on days 1-3. We analyzed factors affecting complete remission(CR), relapse free survival(RFS) and overall survival(OS).Results:The total of 56 patients (Male:Female = 36:20, median age 51 years) were analyzed. Overall CR rate was 50%, CR rate was 44% for CLAG, 55% for CLAGM respectively, and was not significantly different between the two regimens (p=0.511). Poor predictive markers for CR rates after CLAG/CLAGM included secondary AML (p=0.006), and poor cytogenetic risk group based on MRC criteria (p<0.001). CR rate was higher whether patients achieved CR before CLAG/CLAGM (p = 0.015). In patients who achieved CR after CLAG/CLAGM, the median RFS was 3.4 months (95% CI 2.0 – 4.9 months); 2.0 months (95% CI 0.0 – 4.7 months) for CLAG and 3.4 months (95% CI 1.0 – 5.9 months) for CLAGM.The median OS who received CLAG/CLAGM was 13.5 months (95% CI; 10.2 – 16.7 months); 13.2 months (95% CI ; 8.9 – 17.5 months) for CLAG and 13.5 months (95% CI ; 10.4 – 16.6 months) for CLAGM, no statistical difference (p=0.899). Poor prognostic factor for OS included secondary AML (p<0.001), poor cytogenetic risk group (p<0.001), presence of FLT3-ITD mutation(p=0.019), whether patients failed to achieve CR before CLAG/CLAGM (p<0.001). Moreover, favorable factor for OS was whether CR period was more than 6 months in 1stinduction chemotherapy (p<0.001) in replased AML patients. The survival period after CLAG/CLAGM chemotherapy was improved when allogeneic stem cell transplantation(ASCT) was given after CLAG/CLAGM as consolidation therapy (p=0.044).Conclusion:CLAG/CLAGM is an efficacious regimen for refractory/relapsed AML as previously reported. Especially whether the patients achieved CR before CLAG/CLAGM is favorable prognostic factor. However, only limited benefit is shown in secondary AML patients and poor cytogenetic risk group patients. Allogeneic ASCT as consolidation therapy is definitely necessary to improve outcome. DisclosuresNo relevant conflicts of interest to declare.

A Phase II Study of CLAG Regimen in Combination with Imatinib Mesylate in relapsed or Refractory Acute Myeloid Leukemia

Abstract 2604 BACKGOUNDThere is no standard salvage chemotherapy regimen for relapsed or refractory (RR) AML. Receptor activated tyrosine kinases such as c-kit, c-fms and PDGFR are known targets of inhibition by imatinib mesylate (IM) and are frequently expressed on AML blasts and marrow stromal cells and are therefore capable of activating survival pathways in these leukemic cells. Preclinical data suggested synergy in vitro between cytarabine and IM on AML cell growth inhibition. A phase I study demonstrated that the combination of IM with CLAG regimen was safe and feasible (Walker, et al, Leukemia Research 2008, 32(12)). We now report the results of a phase 2 clinical study of CLAG in combination with imatinib mesylate in patients with RR-AML. METHODSThis was a single-institution two-stage phase 2 study. The study was approved by scientific review committee and IRB. Eligibility criteria included RR-AML, or CML blast crisis. Key exclusion criteria were: ECOG performance status > 2, inadequate kidney or liver function tests, history of chronic liver disease, hepatitis, or HIV infection, prior therapy with CLAG regimen, or active systemic infection. Relapse was defined as evidence of disease following documented CR (complete response) or CRi (incomplete count recovery) to the most recent prior regimen (divided into early ≤ 12 months and late >12 months). Refractory disease was defined as failure to achieve CR after 2 cycles of induction chemotherapy, persistent disease (less than 50% reduction) in bone marrow blasts after one cycle, or persistent disease following the most recent salvage regimen. The CLAG regimen consisted of: Cladribine, 5mg/m2 administered via 2 hour IV daily for 5 consecutive days starting on day 2; Cytarabine, 2gm/m2 administered through a 4 hour IV starting 2 hours after Cladribine for 5 days starting on day 2; G-CSF: 300mcg SC for 6 days starting 12–24 hours (Day 1) before the first dose of Cladribine. IM 400mg orally twice daily was administered on day 2 to day 15. Re-induction was allowed if patient had partial response (PR). The primary endpoint was remission rate measured by standard AML response criteria; secondary endpoints included overall survival (OS) and progression free survival (PFS). Correlative studies included examinination for exon 8 and 17 c-kit mutations, phosphorylation status of c-kit receptor after IM exposure, and ex-vivo cell viability assays. RESULTSBetween August 2009 and April 2011, 40 patients were consented at Moffitt Cancer Center and 38 patients were treated and evaluable. The median age was 62 years (range 26–79), 22 (58%) were male, and the majority 33 (87%) were Caucasian. Seven patients (18%) had refractory AML, 19 (50%) had early relapse, and 12 (32%) had late relapse. Eight patients (21%) had prior MDS. At original diagnosis, only 2 patients had favorable risk, 18 had intermediate risk, 16 had poor risk and 2 had missing karyotype. The median duration of follow up was 9.4 months. The overall response rate (CR + CRi) for all 38 evaluable patients was 37% (CR=26%,11% CRi). Early death (within 30 days) occurred in only 2 of 38 (5.3%) patients. The CR/CRi rate in early relapse/refractory AML was 8/26 (30.8%) (95%CI 14.3–51.8) and 6/12 (50%) (95%CI 21.1–78.9%) in late relapse.The median OS was 11.1 month (95%CI 4.8–13.4), the median PFS was 4.9 month (95% CI 1.6–11.7). Among responders, 8/14 patients proceeded to allogeneic hematopoietic cell transplant.The regimen was generally well tolerated. Commonly observed non-hematologic toxicities included: edema (81%), nausea (71%), diarrhea (66%), febrile neutropenia (58%), vomiting (50%), pneumonia (40%), anorexia (32%), sepsis (29%) and rash (29%). The most common grade 3 or higher adverse events (>5% of patients) included febrile neutropenia (58%), pneumonia (34%), sepsis (29%), hypokalemia (24%)., diarrhea (11%), and rash (5%). The two early deaths were attributed to hemorrhage and hepatic failure. CONCLUSIONCLAG plus IM was well tolerated, with encouraging signs of activity in patients with poor-risk AML. Future directions for the development of this class of tyrosine kinase inhibitors (TKI) in AML include incorporation of next-generation TKIs, utilization of these agents as maintenance strategy, and identification of molecular signatures which may predict response. Updated survival and molecular correlative data will be presented. Disclosures:Komrokji:Novartis: Research Funding, Speakers Bureau. Off Label Use: Imatinib use in AML. Pinilla-Ibarz:Novartis: Research Funding, Speakers Bureau.

Combination Regimen of Cladribine (2-Chlorodeoxyadenosine), Cytarabine and G-CSF (CLAG) as Induction Therapy for Patients with Relapsed or Refractory Acute Myeloid Leukemia

The aim of the study was efficacy and toxicity evaluation of combination of 2-Chlorodeoxya-denosine (2-CdA) with cytarabine (Ara-C) and G-CSF (CLAG regimen) as reinduction therapy in patients with refractory or relapsed acute myeloid leukemia (AML). The protocol stipulated an infusion of 5 mg/m2 of 2-CdA over 2 hours daily for 5 consecutive days. A 4-hour infusion of Ara-C (2 g/m) was started 2 hours after each infusion of 2-CdA. G-CSF at a dose 300 μg s.c was given 24 hours before the first dose of 2-CdA for 6 days. In case of WBC>20×109/1 G-CSF was started simultaneously with 2-CdA. In the case of complete response (CR) consolidation treatment with 2-CdA containing regimens was started. In case of partial response a second identical course of CLAG was given. Response criteria were established according to those developed by the NCI Sponsored Workshop. Among 20 patients accrued all but 2 received at least one course of CLAG induction therapy in the planned doses. 10/20 (50%) (95% CI 27-73%) patients achieved a CR with a median duration of 22.5 weeks (range 3.5-53 weeks). Two (10%) patients had a PR and 8 were non-responders. One patient underwent peripheral blood stem cell transplantation. Overall 4 patients are in continuous CR with a median duration of 16.2 weeks (range 3.5-36.5). Among non-responders two patients did not receive the full dose of treatment because of complications during the cycle, both of them died; 3 died early after complete induction therapy before recovery of the bone marrow and 3 were resistant to CLAG. All 20 patients but one experienced granulocytopenia <0.2×109/1 and thrombocytopenia <20×109/1. Median time to reach PMN>0.5×109 G/1 was 18.7 days and platelets>50×109/1 was 27.2 days. In conclusion, the CLAG regimen had significant antileukemic activity and acceptable toxicity as reinduction treatment in refractory or relapsed AML patients.