Pharmacogenomics and ALL treatment: How to optimize therapy

Diagnosis of acute lymphoblastic leukaemia: an overview of the current genomic classification, diagnostic approaches, and future directions

B-acute lymphoblastic leukaemia (B-ALL) is a haematological disease resulting from haematopoietic system dysfunction, leading to the unchecked growth of immature B lymphoblasts. The disease's complexity is underscored by the spectrum of genetic aberrations that underlie B-ALL entities, necessitating advanced genetic analyses for precise classification and risk determination. Prior to the adoption of next-generation sequencing into standard diagnostic practices, up to 30% of B-ALL cases were not assigned to specific entities due to the limitations of traditional diagnostic methods. The advent of comprehensive genomic analysis, especially whole-genome transcriptome sequencing, has significantly enhanced our understanding of B-ALL's molecular heterogeneity, paving the way for the exploration of novel, tailored treatment strategies. Furthermore, recent technological innovations, such as optical genome mapping, methylation profiling, and single-cell sequencing, have propelled forward the fields of cancer research and B-ALL management. These innovations introduce novel diagnostic approaches and prognostic markers, facilitating a deeper, more nuanced understanding of individual patient disease profiles. This review focuses on the latest diagnostic standards and assays for B-ALL, the importance of new technologies and biomarkers in enhancing diagnostic accuracy, and the expected role of innovative advancements in the future diagnosis and treatment of B-ALL.

Effect of American genomic ancestry on severe toxicities in children with acute lymphoblastic leukemia in the Amazon region

BACKGROUND

Acute Lymphoblastic Leukemia (ALL) is a neoplasm of the hematopoietic system characterized by a clonal expansion of abnormal lymphocyte precursor cells. ALL is the most common form of cancer in children, but despite advances in treatment, it can still be fatal. Ethnic differences influence survival rates, and genomic ancestry plays an important role, especially in mixed-race populations such as Latin America. This study aims to analyze the influence of genomic ancestry on toxicity in children with ALL in the Amazon region.

METHODS

The study included 171 patients (protocol number 119,649/2012-Ethics Committee) with ALL treated at a pediatric treatment center in Belém do Pará, in the Brazilian Amazon. The patients were submitted to the BFM protocol of induction therapy for ALL. Toxicity was assessed based on laboratory tests and adverse events, classified according to the CTC-NCI guide. Genomic ancestry was determined using autosomal informative markers.

RESULTS

The majority of children (94.74%) developed some type of toxicity during treatment, 87.04% of which were severe. Infectious toxicity was the most common, present in 84.8% of cases, 77.24% of which were severe. Amerindian ancestry showed an association with the risk of severe general toxicity and severe infectious toxicity, with a contribution of 35.0% demonstrating a significant increase in risk. In addition, post-induction refractoriness and relapse were also associated with an increased risk of death.

CONCLUSION

This study highlights the influence of Amerindian genomic ancestry on response to therapy and toxicity in children with ALL in the Amazon region. Understanding these associations can contribute to personalizing treatment and improving clinical outcomes.

Key factors associated with 6-thioguanine and 6-methylmercaptopurine nucleotide concentrations in children treated by thiopurine for acute leukaemia and inflammatory bowel disease

AIMS

Azathioprine (AZA) and 6-mercaptopurine are prescribed in acute lymphoblastic leukaemia (ALL) and inflammatory bowel diseases (IBD). Metabolism to active 6-thioguanine (6TGN) and 6-methylmercaptopurine nucleotides (6MMPN) is variable but therapeutic drug monitoring (TDM) remains debatable. This study reports on factors impacting on red blood cell (RBC) metabolites concentrations in children to facilitate TDM interpretation.

METHODS

The first paediatric TDM samples received during year 2021 were analysed, whatever indication and thiopurine drug. Target concentration ranges were 200-500, <6000 pmol/8 × 108 RBC for 6TGN and 6MMPN.

RESULTS

Children (n = 492) had IBD (64.8%), ALL (22.6%) or another autoimmune disease (12.6%): mean ages at TDM were 7.5 in ALL and 13.7 years in IBD (P < .0001). ALL received 6-mercaptopurine (mean dose 1.7 mg/kg/d with methotrexate), IBD received AZA (1.9 mg/kg/d with anti-inflammatory drugs and/or monoclonal antibodies). Median 6TGN and 6MMPN concentrations were 213.7 [interquartile range: 142.5; 309.6] and 1144.6 [419.4; 3574.3] pmol/8 × 108 RBC, 38.8% of patients were in the recommended therapeutic range for both compounds. Aminotransferases and blood tests were abnormal in 57/260 patients: 8.1% patients had high alanine aminotransaminase, 3.4% of patients had abnormal blood count. Factors associated with increased 6TGN were age at TDM and thiopurine methyltransferase genotype in ALL and AZA dose in IBD. The impact of associated treatment in IBD patients was also significant.

CONCLUSION

TDM allowed identification of children who do not reach target levels or remain over treated. Including TDM in follow-up may help physicians to adjust dosage with the aim of reducing adverse effects and improve treatment outcome.

A systematic review of knowledge, attitude and practice of pharmacogenomics in pediatric oncology patients

Pharmacogenomics remains underutilized in clinical practice, despite the existence of internationally recognized, evidence-based guidelines. This systematic review aims to understand enablers and barriers to pharmacogenomics implementation in pediatric oncology by assessing the knowledge, attitudes, and practice of healthcare professionals and consumers. Medline, Embase, Emcare, and PsycINFO database searches identified 146 relevant studies of which only three met the inclusion criteria. These studies reveal that consumers were concerned with pharmacogenomic test costs, insurance discrimination, data sharing, and privacy. Healthcare professionals possessed mostly positive attitudes toward pharmacogenomic testing yet identified lack of experience and training as barriers to implementation. Education emerged as the key enabler, reported in all three studies and both healthcare professionals and consumer groups. However, despite the need for education, no studies utilizing a pediatric oncology consumer or healthcare professional group have reported on the implementation or analysis of a pharmacogenomic education program in pediatric oncology. Increased access to guidelines, expert collaborations and additional guidance interpreting results were further enablers established by healthcare professionals. The themes identified mirror those reported in broader pediatric genetic testing literature. As only a small number of studies met inclusion criteria for this review, further research is warranted to elicit implementation determinants and advance pediatric pharmacogenomics.

From alchemy to personalised medicine: the journey of laboratory medicine

This review summarises the long period in which man has approached nature to understand its powers, and has tried to control it through physical and chemical, and also magical, practices. From the attempt to manage nature to the development of primordial drugs and medical practices and later to achieve modern biomedical science, laboratory practices always played a pivotal role. Over the years and centuries, the laboratory has acquired more and more importance in the improvement of health.In addition to the well-known importance of laboratory medicine in the early diagnosis and appropriateness, the discoveries of the last 50 years have also given the Laboratory a decisive role in regenerative and personalised medicine.This paper examines the evolution of the laboratory and is not meant to be a treatise on the history of medicine. The goal is to highlight the moments of the transition from magic and alchemy to laboratory science.-------------------------------Roberto Verna is President of the World Association of Societies of Pathology and Laboratory Medicine and President of the Academy for Health and Clinical Research.

EBV-driven lymphoid neoplasms associated with pediatric ALL maintenance therapy

The development of a second malignancy after the diagnosis of childhood acute lymphoblastic leukemia (ALL) is a rare event. Certain second malignancies have been linked with specific elements of leukemia therapy, yet the etiology of most second neoplasms remains obscure and their optimal management strategies are unclear. This is a first comprehensive report of non-Hodgkin lymphomas (NHLs) following pediatric ALL therapy, excluding stem-cell transplantation. We analyzed data of patients who developed NHL following ALL diagnosis and were enrolled in 12 collaborative pediatric ALL trials between 1980-2018. Eighty-five patients developed NHL, with mature B-cell lymphoproliferations as the dominant subtype (56 of 85 cases). Forty-six of these 56 cases (82%) occurred during or within 6 months of maintenance therapy. The majority exhibited histopathological characteristics associated with immunodeficiency (65%), predominantly evidence of Epstein-Barr virus-driven lymphoproliferation. We investigated 66 cases of post-ALL immunodeficiency-associated lymphoid neoplasms, 52 from our study and 14 additional cases from a literature search. With a median follow-up of 4.9 years, the 5-year overall survival for the 66 patients with immunodeficiency-associated lymphoid neoplasms was 67.4% (95% confidence interval [CI], 56-81). Five-year cumulative risks of lymphoid neoplasm- and leukemia-related mortality were 20% (95% CI, 10.2-30) and 12.4% (95% CI, 2.7-22), respectively. Concurrent hemophagocytic lymphohistiocytosis was associated with increased mortality (hazard ratio, 7.32; 95% CI, 1.62-32.98; P = .01). A large proportion of post-ALL lymphoid neoplasms are associated with an immunodeficient state, likely precipitated by ALL maintenance therapy. Awareness of this underrecognized entity and pertinent diagnostic tests are crucial for early diagnosis and optimal therapy.

Artificial Intelligence, Healthcare, Clinical Genomics, and Pharmacogenomics Approaches in Precision Medicine

Precision medicine has greatly aided in improving health outcomes using earlier diagnosis and better prognosis for chronic diseases. It makes use of clinical data associated with the patient as well as their multi-omics/genomic data to reach a conclusion regarding how a physician should proceed with a specific treatment. Compared to the symptom-driven approach in medicine, precision medicine considers the critical fact that all patients do not react to the same treatment or medication in the same way. When considering the intersection of traditionally distinct arenas of medicine, that is, artificial intelligence, healthcare, clinical genomics, and pharmacogenomics—what ties them together is their impact on the development of precision medicine as a field and how they each contribute to patient-specific, rather than symptom-specific patient outcomes. This study discusses the impact and integration of these different fields in the scope of precision medicine and how they can be used in preventing and predicting acute or chronic diseases. Additionally, this study also discusses the advantages as well as the current challenges associated with artificial intelligence, healthcare, clinical genomics, and pharmacogenomics.

Severe toxicity free survival: physician-derived definitions of unacceptable long-term toxicities following acute lymphocytic leukaemia

5-year overall survival rates have surpassed 90% for childhood acute lymphocytic leukaemia, but survivors are at risk for permanent health sequelae. Although event-free survival appropriately represents the outcome for cancers with poor overall survival, this metric is inadequate when cure rates are high but challenged by serious, persistent complications. Accordingly, a group of experts in paediatric haematology-oncology, representative of 17 international acute lymphocytic leukaemia study groups, launched an initiative to construct a measure, designated severe toxicity-free survival (STFS), to quantify the occurrence of physician-prioritised toxicities to be integrated with standard cancer outcome reporting. Five generic inclusion criteria (not present before cancer diagnosis, symptomatic, objectifiable, of unacceptable severity, permanent, or requiring unacceptable treatments) were used to assess 855 health conditions, which resulted in inclusion of 21 severe toxicities. Consensus definitions were reached through a modified Delphi process supplemented by two additional plenary meetings. The 21 severe toxicities include severe adverse health conditions that substantially affect activities of daily living and are refractory to therapy (eg, refractory seizures), are without therapeutic options (eg, blindness), or require substantially invasive treatment (eg, cardiac transplantation). Incorporation of STFS assessment into clinical trials has the potential to improve and diversify treatment strategies, focusing not only on traditional outcome events and overall survival but also the frequencies of the most severe toxicities. The two major aims of this Review were to: prioritise and define unacceptable long-term toxicity for patients with childhood acute lymphocytic leukaemia, and define how these toxicities should be combined into a composite quantity to be integrated with other reported outcomes. Although STFS quantifies the clinically unacceptable health tradeoff for cure using childhood acute lymphocytic leukaemia as a model disease, the prioritised severe toxicities are based on generic considerations of relevance to any other cancer diagnosis and age group.