Assessing cognitive function in patients treated with immune checkpoint inhibitors: A feasibility study

Cognitive adverse events in patients with lung cancer treated with checkpoint inhibitor monotherapy: a propensity score-matched analysis

Background

Cancer-related cognitive decline is a serious problem in long-term survival but no pivotal study has investigated whether checkpoint inhibitors (ICI) may be associated with cognitive adverse events.

Methods

This propensity score-matched analysis recruited non-small cell lung cancer (NSCLC) patients prescribed with or without ICI monotherapy from three Chinese tertiary hospitals. Patients were excluded from study who developed brain metastasis or had disorders severely affecting cognitive abilities. Primary outcomes were changes in neuropsychological battery test (NBT) at baseline, 6- and 12-month sessions, and any NBT score changes that exceeded 3∗SD of baseline scores would be marked as objective cognitive adverse events (CoAE). Secondary endpoint was the 20-item Perceived Cognitive Impairment (PCI) sub-scale score change in Functional Assessment of Cancer Therapy-Cognitive Function questionnaire, administered at baseline, 3-, 6-, 9-, 12-, and 15-month follow-up session. Per-protocol ICI and control arms were matched with propensity scores that incorporated baseline variables to compare both NBT and PCI assessment results. Patients participating in PCI assessments were analysed in intention-to-treat analysis. Kaplan-Meier survival curves with log-rank tests were adopted to analyse incidence of perceived cognitive decline events (PCDE).

Findings

Between March 12, 2020, and March 28, 2021, 908 participants were enrolled. Compared to control, 3 of 4 subtest of NBT scores in ICI arm showed significant cognitive decline in 6- and 12-month sessions, in which Trail Making Test score change (13.56 ± 11.73) reached threshold of cognitive deficit diagnosis in the 12-month session. In 1:1 matched 292 pairs from 908 patients, PCI score changes in ICI arms were -4.26 ± 8.54 (3rd month), -4.72 ± 11.83 (6th month), -6.16 ± 15.41 (9th month), -6.07 ± 15.71 (12th month), and -7.96 ± 13.97 (15th month). The scores were significantly lower than control arm in 3-, 6-, and 12-session follow-up. The result was validated after adjusting quality of life scores and in intention-to-treat analysis. Mean PCI change exceeded 1/2 SD of baseline PCI score (5.81) in 9-, 12-, and 15-month sessions in ICI arm, but not in control arm. PCDE incidence/prevalence was significantly higher in ICI arm (incidence 26.4% vs. 5.1%, and prevalence 16.2% vs. 1.7%). Immune-related adverse events related to incidence of PCDE after adjusting for baseline variables.

Interpretation

ICI monotherapy seemed to relate to higher cognitive decline represented by score changes and incidence/prevalence rates. The decline deteriorated as treatment progressed, and immune-related adverse events seemed to be associated with higher cognitive adverse events incidence in the ICI treatment.

Funding

The Fellowship of China Postdoctoral Science Foundation and National Natural Science Foundation of China Youth Science Fund Project.

Cognitive assessment in patients treated by immunotherapy: the prospective Cog-Immuno trial

BACKGROUND

The discovery of the importance of the immune system and its role in oncogenesis led to the development of immunotherapy, a treatment that represents a major advance in oncology management. Due to the recent nature of immunotherapy, little is known about its side effects and their impact on quality of life. To date, there is no published study that accurately assesses the impact of immunotherapy on cognition, mood and/or fatigue in patients treated for cancer, despite potential neurological toxicities. The purpose of this study is to prospectively assess the incidence of cognitive impairment and cognitive complaints among cancer patients naïve for immunotherapy without concomitant anti-cancer treatment.

METHODS

The Cog-Immuno trial is a multicentre longitudinal study addressing patients with cancer candidate to receive immunotherapy alone (n = 100). Immunotherapy treatment will include either anti-PD1/PDL1 or anti-CTLA4 monotherapy or combination therapy. Cognitive and quality of life assessment, electrocardiogram (ECG) and biological tests will be performed at baseline, thereafter 3, and 6 months after immunotherapy initiation. The primary endpoint is the proportion of patients treated by immunotherapy who will experience a decline in cognitive performances or in Montreal Cognitive Assessment (MoCA) score within 3 months after inclusion. Secondary endpoints concern: anxiety, depression, fatigue, clinical characteristics, biological data and neurophysiological measures (heart rate variability and hemispheric lateralization). A pre-clinical study will be conducted in cancer bearing mice receiving checkpoint inhibitors (ICI) with the evaluation of cognitive functions and emotional reactivity, collection of blood samples and investigation of neurobiological mechanisms from brain slices.

DISCUSSION

Assessing and understanding the incidence and the severity of cognitive impairment and its impact on quality of life in cancer patients treated by immunotherapy is a major issue. The results of this study will provide information on the impact of these treatments on cognitive functions in order to help the physicians in the choice of the treatment.

TRIAL REGISTRATION

NCT03599830, registered July 26, 2018.

PROTOCOL VERSION

Version 5.1 dated from 2020/10/02.

[Immunological mechanisms of cognitive dysfunction under systemic therapy in metastatic melanoma]

Neurocognitive impairments of memory, speech, and attention can occur in cancer patients as a direct result of the cancer but also in the context of therapy. With the development of modern immunotherapies and their use in combination with surgery and radiation therapy, the number of long-term survivors has significantly increased. As a result, detrimental effects on brain function and structure in cancer patients not only during treatment but also after completion of therapy have become a key issue in clinical oncology. Early diagnosis and treatment of neurocognitive disorders is of great importance for quality of life, therapy adherence, and overall survival of the affected patients. In this review, we discuss the underlying mechanisms with a special focus on metastatic melanoma. Furthermore, practice-relevant diagnostics, prophylaxis, and intervention options are discussed.

Neurological adverse events of immune checkpoint blockade: from pathophysiology to treatment

PURPOSE OF REVIEW

We review the recent advances in neurological toxicities of immune checkpoint inhibitors, with a focus on underlying pathophysiologic mechanisms and the implications on their therapeutical management.

RECENT FINDINGS

A growing number of cancer patients benefit from immune checkpoint agents and oncologists are increasingly confronted with these novel autoimmune syndromes. During the last years, further progresses have occurred in this field, notably in the identification of specific clinical patterns, such as the association of myasthenic syndrome with myositis and myocarditis, and polyradiculoneuropathies accompanied by cerebrospinal fluid lymphocytic pleocytosis. In addition, recent immune-histological studies improved the understanding of the pathophysiologic mechanisms behind immune-related neurotoxicities.

SUMMARY

Neurological toxicity is rare compared with other organs and systems, but its potential morbidity and mortality requires a prompt management. If there is a consensus for steroids as a first-line treatment, no exhaustive clinical data exist for other treatments. Recent advances in the knowledge of pathophysiological mechanisms (behind these toxicities) should be taken into account for the management of these patients. Drugs targeting T-cell mediated inflammation should be preferred in patients who are refractory to steroids, whereas therapies targeting humoral mechanisms should be considered in specific cases associated with autoantibodies such as immune-related myasthenic syndrome.

Reintroduction of immune-checkpoint inhibitors after immune-related meningitis: a case series of melanoma patients

Immune-checkpoint inhibitors (ICIs) targeting cytotoxic T lymphocyte-associated antigen-4 and programmed cell death ligand-1) are associated with several immune-related neurological disorders. Cases of meningitis related to ICIs are poorly described in literature and probably underestimated. Several guidelines are available for the acute management of these adverse events, but the safety of resuming ICIs in these patients remains unclear. We conducted a retrospective case series of immune-related meningitis associated with ICIs that occurred between October 1 2015 and October 31 2019 in two centers: Saint-Louis and Cochin hospitals, Paris, France. Diagnosis was defined by a (1) high count of lymphocytes (>8 cells/mm3) and/or high level of proteins (>0.45 g/L) without bacteria/virus or tumor cells detection, in cerebrospinal fluid and (2) normal brain and spine imaging. Patients were followed-up for at least 6 months from the meningitis onset. Seven cases of immune-related meningitis are here reported. Median delay of meningitis occurrence after ICIs onset was 9 days. Steroid treatment was introduced in four patients at a dose of 1 mg/kg (prednisone), allowing a complete recovery within 2 weeks. The other three patients spontaneously improved within 3 weeks. Given the favorable outcome, ICIs were reintroduced in all patients. The rechallenge was well tolerated and no patients experienced meningitis recurrence. In conclusion, in our series, the clinical course was favorable and steroids were not always required. Resuming ICIs in these patients appeared safe and can thus be considered in case of isolated meningitis. However, a careful analysis of the risk/benefit ratio should be done on a case-by-case basis.

Microglia in Cancer Therapy-Related Cognitive Impairment

Millions of cancer survivors experience a persistent neurological syndrome that includes deficits in memory, attention, information processing, and mental health. Cancer therapy-related cognitive impairment can cause mild to severe disruptions to quality of life for these cancer survivors. Understanding the cellular and molecular underpinnings of this disorder will facilitate new therapeutic strategies aimed at ameliorating these long-lasting impairments. Accumulating evidence suggests that a range of cancer therapies induce persistent activation of the brain's resident immune cells, microglia. Cancer therapy-induced microglial activation disrupts numerous mechanisms of neuroplasticity, and emerging findings suggest that this impairment in plasticity is central to cancer therapy-related cognitive impairment. This review explores reactive microglial dysregulation of neural circuit structure and function following cancer therapy.

Potential Effect of Immunotherapy Agents on Cognitive Function in Cancer Patients

A paradigm shift is occurring in cancer therapy, where instead of targeting tumor cells, immunotherapy agents (IA) target the immune system to overcome cancer tolerance and to stimulate an antitumor immune response. IA using immune checkpoint inhibitors (CPI) or chimeric antigen receptor T-cells have emerged as the most encouraging approaches to treat cancer patients. CPI are reported to induce moderate-to-severe neurologic immune-related adverse events in less than 1% of patients, whereas chimeric antigen receptor T-cell therapy is associated with frequent neurological toxicities that can be severe or even fatal. Cognitive difficulties have been described following chemotherapy and targeted therapy, but not specifically explored in patients receiving IA. The aim of this review is to establish a picture of the first published studies suggesting some biological and physiopathological effects of IA on cognitive functions among cancer patients. The first results originate from a preclinical study evaluating the role of CPI associated with peripheral radiation on cognitive dysfunction and the recent discovery of the central nervous lymphatic system allowing leukocytes to penetrate the central nervous system. Evaluating possible side effects of IA on cognitive function will be an important challenge for future clinical trials and for better understanding the underlying mechanisms through preclinical animal models.

Post-chemotherapy cognitive impairment in hematological patients: current understanding of chemobrain in hematology

Introduction: Cognitive impairment caused by chemotherapies, a condition known as chemobrain, is a possible side effect that affects alertness, learning, memory, and concentration.Areas covered: Chemobrain has been principally investigated as a possible side-effect among cancer patients. However, numerous drugs used to treat hematological malignancies can determine the appearance of chemobrain. In this review, we have examined some commonly used drugs for the treatment of hematological malignancies which are known to have a deleterious action on cognitive functions.Numerous mechanisms have been suggested, comprising the direct neurotoxicity of chemotherapeutic drugs, oxidative stress, genetic predisposition, cytokine-provoked damage, histone modifications, immune alteration, and the action of chemotherapeutic on trophic factors and structural proteins of brain cells.Expert commentary: Cognitive dysfunction provoked by the treatment of hematological diseases is an actual challenge in clinical practice. Actually, there are no totally efficient and innocuous treatments for this syndrome. It is important that further investigations specify the existence of predictors and gravity factors to pre- and post-therapy cognitive change and identify the influence of tumor treatments on the cognitive alterations in long-term, cancer survivors. Moreover, future studies are needed to analyze the interactions between genetic risk, amyloid accumulation, intrinsic brain networks, and chemotherapy.

Chemobrain as a Product of Growing Success in Chemotherapy - Focus on Glia as both a Victim and a Cure

Chemotherapy-induced cognitive impairment or chemobrain is a frequent consequence of cancer treatment with many psychiatric features. Ironically, the increasing efficacy of chemotherapy leaves growing number of patients alive with chemobrain. Therefore, there is an urgent need for strategies capable of returning cancer survivors back to their pre-morbid quality of life. Molecular mechanisms of chemobrain are largely unknown. Over the last decade there was a lot of emphasis in preclinical research on inflammatory consequences of chemotherapy and oxidative stress but so far none of these approaches were translated into clinical scenario. The co-administration of chemotherapy with protective agents was evaluated preclinically but it should be introduced with caution as potential interference was not yet studied and that could blunt therapeutic efficacy. Stem cell-based regenerative medicine approach has so far been exploited very sparsely in the context of chemobrain and the focus was on indirect mechanisms or neuronal replacement in the hippocampus. However, there is evidence for widespread white matter abnormalities in patients with chemobrain. This is quite logical considering life-long proliferation and turnover of glial cells, which makes them vulnerable to chemotherapeutic agents. Feasibility of glia replacement has been established in mice with global dysmyelination where profound therapeutic effect has been observed but only in case of global cell engraftment (across the entire brain). While global glia replacement has been achieved in mice translation to clinical setting might be challenging due to much larger brain size. Therefore, a lot of attention should be directed towards the route of administration to accomplish widespread cell delivery. Techniques facilitating that broad cell distribution including intra-arterial and intrathecal methods should be considered as very compelling options. Summarizing, chemobrain is a rapidly growing medical problem and global glia replacement should be considered as worthwhile therapeutic strategy.