Clinical Characteristics and Responses to Immune Checkpoint Inhibitors in RET-Aberrant Digestive Tract Tumours

BACKGROUND

RET plays an oncogenic role, and its aberrations are potentially actionable. However, they have seldom been reported in tumours other than lung or thyroid cancers. The correlation of RET aberrations with clinical characteristics, co-occurring aberrations, and responses to immune checkpoint inhibitors (ICPi) have not been explored in digestive tract tumours.

OBJECTIVES

The aim of the study was to elucidate the clinical characteristics, frequently co-altered genes, and treatment responses in RET-aberrant digestive tract tumours.

PATIENTS AND METHODS

We retrospectively evaluated patients with digestive tract cancers for RET-aberrant tumours via FoundationOne CDx tumour-based selected genome sequencing from Jan 2016 to Jan 2021.

RESULTS

In a median follow-up time of 51 months, a total of 453 patients were analysed. RET-aberrant tumours accounted for 4.4% in the studied population (n = 20), and 1.1% had an oncogenic fusion (n = 5). APC, KRAS, TP53, MSH6 and STK11 were the differentially co-altered genes (all false discovery rates <0.05). The presence of RET aberrations alone was not a significant prognostic factor. Eleven patients with RET-aberrant tumours received ICPi-based treatment and none achieved an objective response. In contrast, 47 patients with non-aberrant tumours received ICPi treatment and had an objective response rate of 27.7% and a significantly longer treatment duration (6.2 vs 2.8 months, p = 0.0008).

CONCLUSIONS

Albeit rarely, RET aberrations can be found in digestive tract tumours. Patients with RET-aberrant tumours have a blunted response to ICPi and a comparable prognosis as compared with RET-wild type tumours. Together, these results provide insights into this rare but potentially actionable target in digestive tract tumours.

Small Molecule Inhibitors as Therapeutic Agents Targeting Oncogenic Fusion Proteins: Current Status and Clinical

Oncogenic fusion proteins, arising from chromosomal rearrangements, have emerged as prominent drivers of tumorigenesis and crucial therapeutic targets in cancer research. In recent years, the potential of small molecular inhibitors in selectively targeting fusion proteins has exhibited significant prospects, offering a novel approach to combat malignancies harboring these aberrant molecular entities. This review provides a comprehensive overview of the current state of small molecular inhibitors as therapeutic agents for oncogenic fusion proteins. We discuss the rationale for targeting fusion proteins, elucidate the mechanism of action of inhibitors, assess the challenges associated with their utilization, and provide a summary of the clinical progress achieved thus far. The objective is to provide the medicinal community with current and pertinent information and to expedite the drug discovery programs in this area.

Established and Emerging Cancer Therapies and Cardiovascular System: Focus on Hypertension-Mechanisms and Mitigation

Cardiovascular disease and cancer are 2 of the leading causes of death worldwide. Although improvements in outcomes have been noted for both disease entities, the success of cancer therapies has come at the cost of at times very impactful adverse events such as cardiovascular events. Hypertension has been noted as both, a side effect as well as a risk factor for the cardiotoxicity of cancer therapies. Some of these dynamics are in keeping with the role of hypertension as a cardiovascular risk factor not only for heart failure, but also for the development of coronary and cerebrovascular disease, and kidney disease and its association with a higher morbidity and mortality overall. Other aspects such as the molecular mechanisms underlying the amplification of acute and long-term cardiotoxicity risk of anthracyclines and increase in blood pressure with various cancer therapeutics remain to be elucidated. In this review, we cover the latest clinical data regarding the risk of hypertension across a spectrum of novel anticancer therapies as well as the underlying known or postulated pathophysiological mechanisms. Furthermore, we review the acute and long-term implications for the amplification of the development of cardiotoxicity with drugs not commonly associated with hypertension such as anthracyclines. An outline of management strategies, including pharmacological and lifestyle interventions as well as models of care aimed to facilitate early detection and more timely management of hypertension in patients with cancer and survivors concludes this review, which overall aims to improve both cardiovascular and cancer-specific outcomes.

A molecular guide to systemic therapy in salivary gland carcinoma

Salivary gland carcinomas (SGC) are a rare and variable group of head and neck cancers with historically poor response to cytotoxic chemotherapy and immunotherapy in the recurrent, advanced, and metastatic settings. In the last decade, a number of targetable molecular alterations have been identified in SGCs including HER2 upregulation, androgen receptor overexpression, Notch receptor activation, NTRK gene fusions, and RET alterations which have dramatically improved treatment outcomes in this disease. Here, we review the landscape of precision therapy in SGC including current options for systemic management, ongoing clinical trials, and promising future directions.

Changing Landscape of Systemic Therapy in Biliary Tract Cancer

Biliary tract cancers (BTC) are often diagnosed at advanced stages and have a grave outcome due to limited systemic options. Gemcitabine and cisplatin combination (GC) has been the first-line standard for more than a decade. Second-line chemotherapy (CT) options are limited. Targeted therapy or TT (fibroblast growth factor 2 inhibitors or FGFR2, isocitrate dehydrogenase 1 or IDH-1, and neurotrophic tyrosine receptor kinase or NTRK gene fusions inhibitors) have had reasonable success, but <5% of total BTC patients are eligible for them. The use of immune checkpoint inhibitors (ICI) such as pembrolizumab is restricted to microsatellite instability high (MSI-H) patients in the first line. The success of the TOPAZ-1 trial (GC plus durvalumab) is promising, with numerous trials underway that might soon bring targeted therapy (pemigatinib and infrigatinib) and ICI combinations (with CT or TT in microsatellite stable cancers) in the first line. Newer targets and newer agents for established targets are being investigated, and this may change the BTC management landscape in the coming years from traditional CT to individualized therapy (TT) or ICI-centered combinations. The latter group may occupy major space in BTC management due to the paucity of targetable mutations and a greater toxicity profile.

Impact of tissue-agnostic approvals for patients with sarcoma

Tissue-agnostic drug development is a major step forward in offering treatment options for rare tumors. Sarcomas are heterogeneous rare malignancies with more than 100 subtypes. Recent failure of Phase III trials, nonbiomarker-driven clinical trials, and rarity hamper developmental therapeutics in sarcomas. Since a 'one-size-fits-all' approach continues to be the standard of care, tissue-agnostic approvals assume significance in sarcomas. In this review, we focus on the clinical evidence of recent drug approvals for neurotrophic tyrosine receptor kinase (NTRK) fusion, microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR) phenotype, and tumor mutation burden-high (TMB-H) status in the context of sarcomas, and the future landscape of tissue-agnostic targets, such as rearranged during transfection (RET), fibroblast growth factor receptor (FGFR), and neuregulin-1 (NRG1).