Developments on tumour site-specific chrono-oncology towards personalised treatment

Personalization of Cancer Treatment: Exploring the Role of Chronotherapy in Immune Checkpoint Inhibitor Efficacy

In the era of precision medicine, mounting evidence suggests that the time of therapy administration, or chronotherapy, has a great impact on treatment outcomes. Chronotherapy involves planning treatment timing by considering circadian rhythms, which are 24 h oscillations in behavior and physiology driven by synchronized molecular clocks throughout the body. The value of chronotherapy in cancer treatment is currently under investigation, notably in the effects of treatment timing on efficacy and side effects. Immune checkpoint inhibitor (ICI) therapy is a promising cancer treatment. However, many patients still experience disease progression or need to stop the therapy early due to side effects. There is accumulating evidence that the time of day at which ICI therapy is administered can have a substantial effect on ICI efficacy. Thus, it is important to investigate the intersections of circadian rhythms, chronotherapy, and ICI efficacy. In this review, we provide a brief overview of circadian rhythms in the context of immunity and cancer. Additionally, we outline current applications of chronotherapy for cancer treatment. We synthesize the 29 studies conducted to date that examine the impact of time-of-day administration on the efficacy of ICI therapy, its associated side effects, and sex differences in both efficacy and side effects. We also discuss potential mechanisms underlying these observed results. Finally, we highlight the challenges in this area and future directions for research, including the potential for a chronotherapeutic personalized medicine approach that tailors the time of ICI administration to individual patients' circadian rhythms.

Circadian Regulation of Drug Responses: Toward Sex-Specific and Personalized Chronotherapy

Today's challenge for precision medicine involves the integration of the impact of molecular clocks on drug pharmacokinetics, toxicity, and efficacy toward personalized chronotherapy. Meaningful improvements of tolerability and/or efficacy of medications through proper administration timing have been confirmed over the past decade for immunotherapy and chemotherapy against cancer, as well as for commonly used pharmacological agents in cardiovascular, metabolic, inflammatory, and neurological conditions. Experimental and human studies have recently revealed sexually dimorphic circadian drug responses. Dedicated randomized clinical trials should now aim to issue personalized circadian timing recommendations for daily medical practice, integrating innovative technologies for remote longitudinal monitoring of circadian metrics, statistical prediction of molecular clock function from single-timepoint biopsies, and multiscale biorhythmic mathematical modelling. Importantly, chronofit patients with a robust circadian function, who would benefit most from personalized chronotherapy, need to be identified. Conversely, nonchronofit patients could benefit from the emerging pharmacological class of chronobiotics targeting the circadian clock.

Circadian rhythm-based cancer therapy in randomised clinical trials

INTRODUCTION

Since the 2017 Nobel Prize awarded to J. Hall, M. Rosbash and M.W. Young for their discoveries of molecular mechanisms behind the biological clock, circadian rhythm-based therapy, also known as chronotherapy, is receiving more attention in oncology and the number of anatomical sites of interest in this field is increasing. This observation is in line with the clinical evidence provided by trials on head and neck, lung, colorectal and cervical cancers, as well as the presently ongoing chronotherapy trials for breast and brain cancers.

AREAS COVERED

The aim of this review was to collate all randomized trials conducted on chronotherapy for various tumor sites and to appraise the evidence for chrono-oncology to advance personalized therapy. Relevant literature was collected from Pubmed/Medline databases and from clinicatrials.gov.

EXPERT OPINION

Current randomized clinical trials offer a certain level of evidence for the potential of chronotherapy to personalize oncologic treatment. However, comparison of trial results is hindered by the differences in timing of radiation/chemotherapy, the absence of harmonized recommendations for treatment outcome evaluation and not ultimately, the general lack of considering gender as a matched variable in trials, which was found to be a powerful factor influencing response to treatment.