A phase I study of pemetrexed in patients with relapsed or refractory acute leukemia

Clinical review of substitutions or alternatives for critical chemotherapy drug shortages in hematologic malignancies

PURPOSE

Over the past decade, drug shortages have become increasingly more problematic for clinicians, with over 300 drug shortages reported in the first quarter of 2023. Shortages of chemotherapy drugs can have a negative impact on patient care, as omission or delay of treatment can lead to worse outcomes. Although many articles have been published on this topic, currently no review articles discuss strategies for using alternative regimens or substitutions in the event of severe chemotherapy drug shortages.

SUMMARY

In this article, we review the literature on antineoplastic agents used to treat hematologic malignancies that experienced a drug shortage from 2010 through 2023, providing recommendations for substitutions and alternative regimens in the event of a critical shortage. In particular, we discuss how shortages of fludarabine, cytarabine, daunorubicin, methotrexate, and platinum agents may be addressed, including supporting clinical evidence.

CONCLUSION

Further publications assessing possible alternatives and substitutions for chemotherapy agents and examining the efficacy of previous strategies are needed to mitigate potentially devastating interruptions to care for patients with cancer during severe drug shortages.

Drug susceptibility testing of circulating lung cancer cells for personalized treatment

The presence of Circulating tumor cells (CTCs) has been proven to be correlated with disease progression and the patient's response to treatment. However, the culture of CTCs for clinical utility is still a big challenge. We have developed a short-term method that enables CTCs culture and provides an opportunity to monitor drug susceptibility testing in individual patients. In a proof-of-concept study, we established a unique method using Matrigel® coated in 96 well plate to enable cancer cell clusters to attach and proliferate. The culture method using Matrigel® provides in vitro conditions and improves the attachment and differentiation of anchorage-dependent epithelial cells proliferation and mimics the tumor microenvironment. We further treated the cells attached to Matrigel® with the same drug regimen as the patient has undergone. Around 30.7% of the CTCs were viable after the drug treatment. We also correlated the decrease in cell viability after drug treatment with the reduction in the pleural effusion of the patient as seen by the images obtained from CT scans pre-and post-treatment. Moreover, as per the RECIST criterion, the patient had exhibited a positive response to the treatment. The short-term culturing of CTC along with the drug susceptibility testing offers a novel method to predict patient response to the treatment and could be utilized for screening suitable drug combinations for personalized treatment.

Isocitrate dehydrogenase mutations in myeloid malignancies

Alterations to genes involved in cellular metabolism and epigenetic regulation are implicated in the pathogenesis of myeloid malignancies. Recurring mutations in isocitrate dehydrogenase (IDH) genes are detected in approximately 20% of adult patients with acute myeloid leukemia (AML) and 5% of adults with myelodysplastic syndromes (MDS). IDH proteins are homodimeric enzymes involved in diverse cellular processes, including adaptation to hypoxia, histone demethylation and DNA modification. The IDH2 protein is localized in the mitochondria and is a critical component of the tricarboxylic acid (also called the ‘citric acid' or Krebs) cycle. Both IDH2 and IDH1 (localized in the cytoplasm) proteins catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG). Mutant IDH enzymes have neomorphic activity and catalyze reduction of α-KG to the (R) enantiomer of 2-hydroxyglutarate, which is associated with DNA and histone hypermethylation, altered gene expression and blocked differentiation of hematopoietic progenitor cells. The prognostic significance of mutant IDH (mIDH) is controversial but appears to be influenced by co-mutational status and the specific location of the mutation (IDH1-R132, IDH2-R140, IDH2-R172). Treatments specifically or indirectly targeted to mIDH are currently under clinical investigation; these therapies have been generally well tolerated and, when used as single agents, have shown promise for inducing responses in some mIDH patients when used as first-line treatment or in relapsed or refractory AML or MDS. Use of mIDH inhibitors in combination with drugs with non-overlapping mechanisms of action is especially promising, as such regimens may address the clonal heterogeneity and the multifactorial pathogenic processes involved in mIDH myeloid malignancies. Advances in mutational analysis have made testing more rapid and convenient, and less expensive; such testing should become part of routine diagnostic workup and repeated at relapse to identify patients who may benefit from treatments that target mIDH.

Relapsed or refractory pediatric acute lymphoblastic leukemia: current and emerging treatments

Relapsed acute lymphoblastic leukemia (ALL) represents a major cause of morbidity and mortality in pediatrics. With contemporary chemotherapy, >85% of patients with newly diagnosed ALL survive. Unfortunately, 20% of these patients will relapse and for these children, outcomes remain poor despite our best known chemotherapy protocols. Most of these children will achieve a second complete remission, but maintaining this remission remains difficult. Because relapsed ALL is such a significant cause of morbidity and mortality, it is the focus of much research interest. Efforts have been made and continue to focus on understanding the underlying biology that drives relapse. The role of hematopoietic stem cell transplantation in relapsed ALL remains unclear, but many clinicians still favor this for high-risk patients given the poor prognosis with current chemotherapy alone. It is important to use new drugs with little cross-resistance in the treatment of relapsed ALL. New classes of agents are currently being studied. We also discuss prognostic factors and the biology of relapsed ALL.

Novel therapeutic approaches for acute lymphoblastic leukemia

Therapy for ALL in adults remains a tremendous challenge for clinicians. The use of pediatric-intensive regimens in young and middle-aged adults shows promise in improving outcomes. The addition of monoclonal antibody therapy to chemotherapy appears to hold great promise in lessening relapse rates. The anti-CD20 antibody, rituximab, which has been of such benefit in patients with non-Hodgkin lymphoma, now seems poised to bring significant benefit to adults with ALL. Other monoclonal antibody approaches are in earlier stages of development, but will likely be of significant benefit. The BiTE antibody, blinatumomab, represents an exciting new approach in this arena. As new molecular abnormalities are identified in ALL, these will certainly become new targets for drug development. The increasing use of MRD testing by molecular or flow cytometric techniques will also be invaluable in further refining prognostication in ALL in helping with the selection of patients most likely to benefit from BMT. Several new small molecules and chemotherapeutic agents will, it is hoped, also find a niche in the therapy for ALL. Early examples including NOTCH1 inhibitors; hypomethylating agents such as decitabine, folic acid, antagonists, flavopiridol, bortezomib, and mTOR inhibitors will all hopefully find a role in the therapy for this challenging disorder. Although many challenges remain, there is hope that the therapy for adults with ALL can make significant progress in the next few years, in comparison with the relative plateau that has been experienced over the last several decades.

Pharmacotherapeutic advances in the treatment of acute lymphoblastic leukaemia in adults

Acute lymphoblastic leukaemia (ALL) in adults is a challenging malignancy in that many patients will show evidence of initial chemotherapy responsiveness but will subsequently relapse. The disease is heterogeneous and outcomes vary dramatically depending on the prognostic factors present in an individual patient. An important determinant of outcome is the age of the patient. The stunning success of therapy in paediatric ALL has led to the use of intensive paediatric regimens in adolescents and young adults with what appear to be improved outcomes. For patients who relapse or have high-risk features, blood and marrow transplantation (BMT) continues to play an important role in the therapeutic armamentarium. The use of reduced-intensity conditioning regimens for allogeneic BMT suggests that outcomes may be improved by this approach. Monoclonal antibodies are showing benefit as single agents in the relapsed setting or in combination with chemotherapy in newly diagnosed patients. In recent years, several new chemotherapeutic agents have shown promise as single agents and are being incorporated into multi-agent chemotherapy. The development of tyrosine kinase inhibitors for Philadelphia chromosome-positive leukaemias has significantly improved outcomes. The molecular revolution has led to the identification of new aberrant molecular pathways in the pathogenesis of ALL, and drugs targeting these aberrancies are in various stages of development preclinically and clinically. These developments bring the hope that therapeutic outcomes in adult ALL can begin to approach those seen in the paediatric setting.