Reviews & Analysis

Despite considerable progress in the development of targeted therapies, only three biomarkers are currently used to guide the treatment of patients with gastric or gastro-oesophageal junction cancers using approved targeted therapies. Nonetheless, owing to advances in our understanding of tumour biology and sequencing technologies, several novel therapies are expected to soon become available. In this Review, the authors describe current and future biomarker-guided therapies for patients with G/GEJ cancers.

In this Perspective, members of the group that previously proposed the Pharmacological Audit Trail (PhAT) as a tool to improve and accelerate drug development through the use of tissue biomarkers discuss the promise of integrating liquid biopsy approaches into this paradigm. They focus on the potential applications of plasma circulating cell-free tumour DNA and circulating tumour cells as prognostic, predictive, pharmacodynamic, clinical response and resistance biomarkers, while also highlighting key technological considerations, limitations and challenges, and the importance of analytical validation and clinical qualification.

Antibody–drug conjugates (ADCs) were originally developed for patients with haematological malignancies. In light of the recent increase in interest in this type of therapy, this Review describes the clinical experience with two ADCs — gemtuzumab ozogamicin and inotuzumab ozogamicin — in patients with haematological malignancies and provides guidance on the future directions for the development of novel ADCs for patients with leukaemias.

An unfavourable gut bacterial composition has been shown to reduce the likelihood of clinical benefit from immune-checkpoint inhibitors (ICIs). The results of two first-in-human studies of faecal microbiota transplantation in patients with melanoma refractory to anti-PD-1 antibodies validate preclinical evidence that this approach can improve the gut microbiota and overcome resistance to ICIs; however, many questions remain.

A recent meta-analysis examined and validated biomarkers of response to immune-checkpoint inhibitors (ICIs). Herein, we discuss the findings of this analysis, which are consistent with previously identified determinants of ICI efficacy and demonstrate that some genetic variables influence response across multiple cancer types.

Patients with cancer have a high risk of morbidity and mortality from COVID-19. The rapid development of COVID-19 vaccines has provided new hope of mitigating the disease. Herein, the COVID19 and Cancer Clinical Trials Working Group calls for prioritization of patients with cancer, importantly including those participating in oncology clinical trials, for COVID-19 vaccination. The authors also provide operational COVID-19 vaccine guidance for patients participating in oncology clinical trials.

ATM, BRCA1, BRCA2, CHEK2, PALB2 and TP53 are all established breast cancer susceptibility genes. Over the past 30 years, many other genes have been proposed as candidates. In these two large studies, the candidacy of several questionable genes has been largely resolved, and a final list of ten genes for breast and, importantly, ovarian cancer risk has emerged.

Talimogene laherparepvec (T-VEC) is an oncolytic virus approved for the treatment of patients with recurrent melanoma. Now, a recent study in patients with primary cutaneous B cell lymphoma confirms prior results in melanoma and reveals new mechanisms of action. Herein, we discuss these findings and their implications for expanding the role of oncolytic viruses.

The discovery that the anticancer activity of thalidomide and its analogues, such as lenalidomide, reflects drug-induced degradation of specific target proteins has heightened interest in novel ‘degrader’ drugs. Herein, the authors review the wide and expanding use of thalidomide analogues in the treatment of multiple cancers and outline how lessons learned from this experience, particularly with lenalidomide, can guide the clinical development of new targeted protein degradation platforms.

CD19-specific chimeric antigen (CAR)-modified T cells are approved for patients with advanced-stage forms of certain B cell malignancies. However, a subset of patients will have anti-CAR immune responses, leading to a lack of CAR T cell persistence and a rapid loss of any antitumour efficacy. In this Review, the authors describe the extent of anti-CAR immune responses in patients and suggest measures that could be used to better monitor for these events. Additionally, they describe novel approaches to CAR T cell therapy that might reduce the risk of such responses in the future.

The question of whether allogeneic chimeric antigen receptor (CAR) T cells could replace autologous CAR T cell therapy has garnered considerable interest, but limited data have been available for comparisons to date. Now, Benjamin et al. have reported their experience with allogeneic anti-CD19 CAR T cells in 21 paediatric and adult patients with acute lymphoblastic leukaemia.

In this Consensus Statement, members from five working groups or societies provide updated comprehensive recommendations to manage toxicities from cancer immunotherapies in children, adolescents and young adults. In their recommendations, they advocate for the adoption of age-based and discipline-specific management criteria, and call for an increased inclusion of young patients with cancer in clinical trials.

PD-L1 expression is currently the best available biomarker for the prediction of responsiveness to immune-checkpoint inhibitors. However, several immunohistochemical assays are now approved for clinical use in various settings, despite imperfect inter-assay concordance, with important implications for pathology services and, potentially, for clinical outcomes. In this Review, the authors compare the performance of the various FDA-approved PD-L1 assays, discuss the varying implications of PD-L1 expression across different tumour types and provide guidance on possible novel approaches that might optimize the clinical utility of PD-L1 as a biomarker.

Antibody–drug conjugates (ADCs) constitute a unique class of anticancer agents with demonstrated clinical efficacy against several different cancer types. Herein, the authors discuss the design and mechanisms of action of ADCs and how these properties are reflected in the clinical activity and toxicity profiles of such agents. Potential strategies to overcome the limitations of ADCs and thereby maximize their therapeutic benefit for patients with cancer are also proposed.

Ferroptosis is an iron-dependent form of regulated cell death driven by excessive lipid peroxidation. Pharmacological agents, ionizing radiation and cytokines can induce ferroptosis and thus suppress tumour growth, but ferroptosis can also trigger inflammation-associated immunosuppression. The authors describe the key molecular mechanisms of ferroptosis, including crosstalk with tumour-associated signalling pathways, and discuss potential therapeutic applications of ferroptosis.

A host of additional toxicities and/or potential late effects of chimeric antigen receptor (CAR) T cell therapy beyond cytokine release syndrome (CRS) warrant further investigation. Herein, experts in paediatric cell therapy, supportive care and/or study of late effects from cancer and haematopoietic stem cell transplantation present six key focus research areas related to CAR T cell-related outcomes beyond CRS.

Liquid biopsy assays have the potential to revolutionize the diagnosis and management of cancer, and rapid progress is being made in the clinical translation of such assays. This Perspective outlines notable advances in the use of liquid biopsy technologies in the management of solid tumours, as well as future research avenues, clinical trial methodologies and implementation logistics for the eventual integration of liquid biopsy into the clinical workflow.

Personalized neoantigen-based therapeutic vaccines hold promise as cancer immunotherapies. This Review provides an overview of the complex personalized neoantigen vaccine production process, vaccine-induced T cell responses and strategies to enhance these responses. Completed and ongoing clinical studies testing such vaccines are discussed, and considerations for future clinical investigation of this novel, individualized form of immunotherapy are outlined.

Chronic inflammation can promote the development of various cancers. In this Review, the current clinical advances in ameliorating inflammation for the prevention or treatment of cancer are highlighted, and the experimental insights into the biological mechanisms supporting current and potential novel anti-inflammatory approaches to the management of cancer are discussed.

Renal cell carcinomas (RCCs) are generally immunogenic, but only a subset of patients receiving currently approved immune-checkpoint inhibitors have long-term disease remission. In this Review, the authors provide a conceptual framework for developing novel immunotherapy approaches, including an overview of the most promising novel immune checkpoints and antigen-directed therapies, and highlighting the potential of these agents to further improve the outcomes in patients with RCC.