Reviews & Analysis

TRK fusion proteins are pathognomonic in certain rare tumour types and present in a small subset of diverse cancer types, including some common cancers; TRK inhibitors have promising efficacy in the treatment of these cancers, in a histology-agnostic manner. In this Review, the biology of TRK signalling and TRK fusions, strategies to target these drivers, the unique safety profile of TRK inhibitors and mechanisms of and strategies to overcome acquired resistance to these agents are discussed.

The ESMO Scale for Clinical Actionability of molecular Targets (ESCAT) will be useful as a common language to harmonize discussions in precision oncology and could also guide policy and reimbursement decisions, but it is far from perfect. Herein, we highlight how ESCAT can be further improved to increase its utility in clinical and policy decisions.

A minority of patients with gastroesophageal adenocarcinoma derive benefit from immune-checkpoint inhibition (ICI). In a large-cohort phase III study, the nivolumab (1 mg/kg) plus ipilimumab (3 mg/kg) arm (which was based on promising preliminary data from CheckMate 032) was closed owing to unacceptably high levels of mortality and morbidity. Our quest for better biomarkers than programmed cell death 1 ligand 1 (PD-L1) and safer dual ICI strategies must continue.

Merkel cell carcinoma (MCC) is a rare and aggressive form of nonmelanoma skin cancer. The availability of immune checkpoint inhibition has improved the outcomes of a subset of patients with MCC, although many unmet needs continue to exist. In this Consensus Statement, the authors summarize developments in our understanding of MCC while also providing consensus recommendations for future research.

With the expansion of the precision medicine paradigm, seamless trial approaches to drug development hold great promise for accelerating the accessibility of novel therapeutic agents but are also accompanied by important trade-offs. The authors describe several opportunities to improve the efficiency of drug development in oncology, as well as new mechanisms to obtain information about anticancer therapies throughout their life cycle.

Effective therapeutic strategies to target RAS-mutant cancers have proved elusive, but in the past few years, several promising strategies have been tested in clinical trials. The authors describe historical and ongoing therapeutic approaches based on the direct or indirect targeting of RAS.

Chemoprevention for patients with Barrett’s oesophagus remains a controversial topic. Results of the first randomized trial of chemoprevention using a proton pump inhibitor with or without aspirin were recently reported. We highlight strengths and weaknesses in the design of the trial and discuss the clinical implications of the findings.

Intriguing evidence suggests that expression of RANK or RANKL by various cells of the tumour microenvironment modulates the anticancer immune response. Herein, the authors review this evidence, discuss the current preclinical and clinical data supporting a potential of RANKL inhibition to improve anticancer immunotherapy and describe hypothetical immune-related mechanisms of action.

Population-based mammographic screening is widely accepted as an intervention to reduce overall mortality from breast cancer, but at the cost of morbidity due to false positives and substantial overdiagnosis and overtreatment of ultra-low-risk disease, as well as personal and health-economic burdens. Recent data from a modelling study strengthen the rationale for personalized, risk-based screening approaches, now being tested in multiple clinical trials.

Improvements in the management of patients with early stage breast cancer have been achieved through intense therapeutic escalation but also with de-escalation of systemic therapies. The authors of this Review summarize key trials using both approaches and highlight the need to use therapeutic escalation for patients who would benefit from that approach and de-escalation for patients with a favourable prognosis.

The approval of blinatumomab based on achievement of undetectable minimal residual disease (MRD) in patients with B cell acute lymphoblastic leukaemia in complete remission is the first of its kind and raises important considerations. This drug might improve outcomes in this setting, although considerable evidence is needed to validate the performance of MRD as a surrogate end point and confirm the hypothesis.

Androgen receptor (AR) splice variants (AR-Vs) are truncated isoforms of the AR, of which a subset remain constitutively active in the absence of circulating androgens. AR-Vs have been proposed to contribute to therapeutic resistance. The authors of this Review outline the current understanding of the role of the spliceosome in prostate cancer progression and explore the therapeutic utility of manipulating alternative splicing.

The clinical management of patients with non-small-cell lung carcinoma has greatly evolved owing to the development of tyrosine-kinase inhibitors (TKIs) targeted against the driver mutations of this disease. The authors of this Review describe the existing evidence on the sequential administration of TKIs and the use of next-generation TKIs upfront.

Chimeric antigen receptor (CAR) T cell therapies have impressive activity in the treatment of cancer but are associated with potentially fatal toxicities. In light of the approval of CAR T cell therapy for paediatric patients, a panel of experts from the Hematopoietic Stem Cell Transplantation (HSCT) Subgroup of the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network, the CAR T Cell Therapy-Associated Toxicity (CARTOX) Program at The University of Texas MD Anderson Cancer Center, and several other institutions have developed consensus guidelines for the use and management of these treatments in paediatric patients, which are presented herein.

Molecular profiling studies are providing novel insights into the biology of hepatocellular carcinoma, although these remain to be translated into novel effective therapies. Nevertheless, therapeutic advances have been made in the past few years, and further advancements are expected in the near future, including biomarker-driven treatments and immunotherapies, as discussed in this Review.

A recent clinical trial of a virotherapy approach, consisting of an engineered poliovirus, has provided evidence of apparently durable responses in patients with recurrent glioblastoma. The results of this trial and others indicate that virotherapy might be an effective tool in anticancer immunotherapy. Yet, caution must be exercised until appropriately powered randomized clinical trials truly show efficacy.

The majority of patients receiving immunotherapy do not respond to treatment but might still have adverse events. Furthermore, some patients with an initial response will develop acquired resistance to treatment. In this Review, the authors describe the role of circulating tumour DNA in the management of patients receiving immunotherapy.

Comprehensive molecular characterization of infant medulloblastoma has uncovered the high degree of heterogeneity of this disease. Recent results from the SJYC07 study elegantly reveal that risk stratification can be improved if DNA methylation profiling data are incorporated into clinicopathological criteria. Importantly, the delineation of disease subgroups potentially has major clinical implications.

Platinum-based chemotherapy has long been the mainstay first-line therapy for patients with non-small-cell lung cancer without a targetable driver mutation, but has limited effectiveness. Immunotherapy is drastically changing the treatment landscape for this group and improving survival outcomes, with focus turning to frontline immunotherapy combinations.

Accelerated approval enables investigational drugs to reach the US market on the basis of their demonstrated effects in unvalidated surrogate measures, only reasonably likely to predict clinical response. To fulfil the social compromise, regulators should ensure that confirmatory trials testing clinically meaningful end points are already underway at the time of approval.