A Phase II Study of CLAG Regimen Combined With Imatinib Mesylate for Relapsed or Refractory Acute Myeloid Leukemia

Cladribine-Based Therapy for Acute Myeloid Leukemia in Child, Adolescent, and Early Young Adult Patients: The MD Anderson Cancer Center Experience

Background: Cladribine-based combination chemotherapy has demonstrated promising efficacy in patients with relapsed/refractory adult acute myeloid leukemia (AML), prompting its increased utilization in the frontline; in pediatrics, it has been typically reserved for relapsed or refractory cases. While fludarabine has been used more commonly as a purine analog in intensive regimens, cladribine may be an important alternative. Methods: We performed a retrospective study at MD Anderson Cancer Center from January 2015 to July 2023, which included patients aged 1-21 years with refractory or relapsed AML who received cladribine outside of a transplant conditioning. Results: A total of 30 patients were included, with a median age of 20 years (range, 2-21), and 55% being male. Similar to adults, cladribine exhibited good tolerability in pediatric and adolescent patients, with the most common adverse events being febrile neutropenia and myelosuppression. The most common grade 3 or 4 adverse events included febrile neutropenia (55%) and sepsis (26%), and there were no treatment discontinuations due to adverse events. Among patients with a median number of 2 (0-7) prior treatments, the overall response rate (CR/CRi) was 45%, and median event-free and overall survival were 6 and 12 months, respectively. Disease progression resulted in 4 deaths within 30 days of treatment. Conclusions: Cladribine was tolerated in pediatrics. No new safety signals were seen with cladribine regimens in this cohort. Response assessment is limited due to the heavily pretreated cohort. Further prospective studies are warranted on the safety and efficacy of cladribine and establish its role in pediatric, adolescent, and early young adult patients with AML.

Targeting multiple signaling pathways: the new approach to acute myeloid leukemia therapy

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults and the second most common form of acute leukemia in children. Despite this, very little improvement in survival rates has been achieved over the past few decades. This is partially due to the heterogeneity of AML and the need for more targeted therapeutics than the traditional cytotoxic chemotherapies that have been a mainstay in therapy for the past 50 years. In the past 20 years, research has been diversifying the approach to treating AML by investigating molecular pathways uniquely relevant to AML cell proliferation and survival. Here we review the development of novel therapeutics in targeting apoptosis, receptor tyrosine kinase (RTK) signaling, hedgehog (HH) pathway, mitochondrial function, DNA repair, and c-Myc signaling. There has been an impressive effort into better understanding the diversity of AML cell characteristics and here we highlight important preclinical studies that have supported therapeutic development and continue to promote new ways to target AML cells. In addition, we describe clinical investigations that have led to FDA approval of new targeted AML therapies and ongoing clinical trials of novel therapies targeting AML survival pathways. We also describe the complexity of targeting leukemia stem cells (LSCs) as an approach to addressing relapse and remission in AML and targetable pathways that are unique to LSC survival. This comprehensive review details what we currently understand about the signaling pathways that support AML cell survival and the exceptional ways in which we disrupt them.

CLAG-M chemotherapy followed by umbilical cord blood stem cell transplantation for primary refractory acute myeloid leukaemia in a child: A case report

BACKGROUND

The prognosis of paediatric primary refractory/relapsed acute myeloid leukaemia (R/R AML) remains poor. Intensive therapy is typically used as salvage treatment for those with R/R AML. No data are currently available about the use of the CLAG-M protocol as salvage therapy in paediatric patients with R/R AML.

CASE SUMMARY

An 8-year-old patient was diagnosed with acute myeloid leukaemia by bone marrow morphology and immunophenotype. The patient showed poor response to two cycles of induction therapy with 60% blast cells in the bone marrow after the second induction cycle. The patient achieved complete remission after being treated with the CLAG-M protocol as salvage therapy before undergoing umbilical cord blood stem cell transplantation. Morphological complete remission with haematological recovery has hitherto been maintained over 4 mo. Abnormal gene mutations detected at diagnosis were undetectable after haematopoietic stem cell transplantation.

CONCLUSION

Here we present a paediatric patient with primary refractory acute myeloid leukaemia who was successfully treated with the CLAG-M protocol. Given the positive results of the presented patient, large-scale clinical studies are required to assess the role of the CLAG-M protocol in the salvage treatment of refractory or relapsed AML in childhood.

Long non-coding RNA taurine-upregulated gene 1 correlates with unfavorable prognosis in patients with refractory or relapsed acute myeloid leukemia treated by purine analogue based chemotherapy regimens

OBJECTIVE

This study aimed to explore the correlation of long non-coding RNA taurine-upregulated gene 1 (lncRNA TUG1) expression with clinicopathological features and its predictive value for treatment response and survival profiles in refractory or relapsed acute myeloid leukemia (R/R AML) patients.

METHODS

Seventy three R/R AML patients who received cladribine combined with cytarabine and granulocyte colony-stimulating factor (G-CSF) (CLAG) or fludarabine combined with cytarabine and G-CSF (FLAG) based chemotherapy and 37 non-malignant controls were recruited. LncRNA TUG1 expression was detected in bone marrow sample obtained before treatment. Complete response (CR), partial response (PR), overall response rate (ORR) and overall survival (OS) were evaluated.

RESULTS

LncRNA TUG1 expression was upregulated in R/R AML patients compared to controls. It was also elevated in R/R AML patients with age ⩾ 60 years (vs. age < 60 years, P= 0.030) and in patients with secondary AML (vs. primary AML, P= 0.035). R/R AML patients with lncRNA TUG1 high expression achieved numerically lower CR (P= 0.053), decreased ORR (P= 0.028) and shorter OS (P< 0.001) than patients with lncRNA TUG1 low expression. Univariate logistic regression and COX's regression disclosed that lncRNA TUG1 high expression correlated with declined ORR, numerically decreased CR, and reduced OS. Furthermore, multivariate analyses verified that lncRNA TUG1 high expression was an independent predictive factor for decreased ORR and worse OS.

CONCLUSIONS

In conclusion, lncRNA TUG1 expression was elevated in R/R AML patients, and it might serve as a potential biomarker for poor prognosis in R/R AML patients treated with CLAG or FLAG based chemotherapy.

Cytotoxic therapy in acute myeloid leukemia: not quite dead yet

Given the recent approvals of new agents for acute myeloid leukemia (AML), a clinical trial pipeline stocked with novel therapies, and the rapid integration of imaginative approaches in diseases like acute lymphocytic leukemia and chronic lymphocytic leukemia, it is reasonable to ask whether treatment of AML might finally depart from the classical cytotoxic induction therapy that has been employed since the 1970s. However, for better or worse, in 2018, cytotoxic induction regimens remain the standard of care for most patients. Indeed, the future likely lies in combinations of therapies that act with a spectrum of mechanisms. Using a case-based format, this review will outline current treatment expectations for patients according to karyotypic risk and familiarize readers with the basis for common induction choices. Relapsed/refractory disease may be especially amenable to interventions with novel agents or clinical trials; however, there are still some patients who most benefit from intensive chemotherapy. This review will outline risk systems that help the practitioner identify those with the best chances for response and survival. Finally, clinical tools, including geriatric assessments and comorbidity calculators, may help clinicians recognize patients for whom disease risk and comorbidity tip the balance against classical chemotherapy, a frequent challenge for those who treat this devastating disease.