A Review of Olanzapine in the Treatment of Cancer Anorexia-Cachexia Syndrome

BACKGROUND

Cancer anorexia-cachexia syndrome (CAS) is a multifactorial condition that is highly prevalent in advanced cancer patients and associated with significant reduction in functional performance, reduction in quality of life, and increased mortality. Currently, no medications are approved for this indication. Recently, the American Society of Clinical Oncology (ASCO) released a rapid recommendation suggesting that low-dose olanzapine once daily may be used to treat cancer cachexia. Many questions still exist on how to use olanzapine for this indication in clinical practice. The objective of this review is to identify existing knowledge on the use of olanzapine for CAS.

METHODS

A comprehensive search was conducted to identify the primary literature that involved olanzapine for anorexia and cachexia in cancer patients between 2000 and 2023.

RESULTS

Seven articles were identified and are discussed here, including two randomized double-blinded placebo-controlled studies, one randomized comparative study, two prospective open-label studies, one retrospective chart review, and one case report.

CONCLUSIONS

Low dose olanzapine (2.5-5 mg once daily) may be useful in the treatment of CAS for increasing appetite, reducing nausea and vomiting, and promoting weight gain. Further large-scale multi-center randomized placebo-controlled studies will be needed to investigate the impact of olanzapine on weight change in CAS patients.

The atypical antipsychotic, olanzapine, potentiates ghrelin-induced receptor signaling: An in vitro study with cells expressing cloned human growth hormone secretagogue receptor

The growth hormone secretagogue receptor (GHS-R) belongs to Gαq-coupled G protein-coupled receptor (GPCR) that mediates growth hormone release, food intake, appetite, glucose metabolism and body composition. Ghrelin has been identified as an endogenous ligand for GHS-R, and it is the only orexigenic peptide found in the peripheral organs. Olanzapine, an atypical antipsychotic agent that binds to and inhibits the activation of GPCR for several neurotransmitters, has metabolic side effects such as excessive appetite and weight gain. Recently, studies have revealed that the orexigenic mechanism of olanzapine is mediated via GHS-R signaling, although the precise mechanisms have not been clarified. In this study, we investigated the effect of olanzapine on ghrelin-mediated GHS-R signaling by using an electrical impedance-based receptor biosensor assay system (CellKey™). Olanzapine at concentrations of 10(-7) and 10(-6)mol/L enhanced ghrelin-induced (10(-10)-10(-8)mol/L) GHS-R activation. A Ca(2+) imaging assay revealed that olanzapine (10(-7) and 10(-6)mol/L) enhanced ghrelin (10(-7) M)-induced GHS-R activity. In contrast, haloperidol (an antipsychotic agent) failed to enhance this ghrelin-mediated GHS-R activation, as demonstrated by both the CellKey™ and Ca(2+) imaging assays. Together, these results suggest that olanzapine, but not haloperidol, promotes appetite by enhancing ghrelin-mediated GHS-R signaling.

Current pharmacotherapy options for cancer anorexia and cachexia

INTRODUCTION

Anorexia and cachexia syndrome represents a complex clinical picture that occurs in the late stage of several chronic inflammatory diseases, including cancer. Unless counteracted cancer-related anorexia and cachexia syndrome affects quality of life (QL) and survival. However, to date a standard effective treatment is lacking.

AREAS COVERED

The aim of this review is to describe the current pharmacological approaches for anorexia and cachexia syndrome, focusing on cancer-related syndrome. The several pharmacological agents tested so far are discussed, distinguishing them in unproven drugs, effective drugs, and drugs under investigation. Moreover, a section is devoted to the promising use of nutritional supplements and nutraceuticals. The emerging role of a multitargeted combined treatment approach is exhaustively reviewed.

EXPERT OPINION

Considering the complex clinical picture and the multifactorial pathogenesis of anorexia and cachexia syndrome, we believe that its clinical management requires a multidisciplinary and multipharmacological approach. In our opinion the anorexia and cachexia syndrome treatment should include drugs that target the following conditions: inflammatory status, oxidative stress, nutritional disorders, muscle catabolism, anemia, immunosuppression, and fatigue. The multidimensional therapies for anorexia and cachexia syndrome should ideally be introduced within a context of the "best supportive care," which includes optimal symptom management and careful psychosocial counseling.

Treatment of cachexia in oncology

Cachexia is a complex metabolic syndrome associated with many chronic or end-stage diseases, especially cancer, and is characterized by loss of muscle with or without loss of fat mass. The management of cachexia is a complex challenge that should address the different causes underlying this clinical event with an integrated or multimodal treatment approach targeting the different factors involved in its pathophysiology. The purpose of this article was to review the current medical treatment of cancer-related cachexia, in particular focusing on combination therapy and ongoing research. Among the treatments proposed in the literature for cancer-related cachexia, some proved to be ineffective, namely, cyproheptadine, hydrazine, metoclopramide, and pentoxifylline. Among effective treatments, progestagens are currently considered the best available treatment option for cancer-related cachexia, and they are the only drugs approved in Europe. Drugs with a strong rationale that have failed or have not shown univocal results in clinical trials so far include eicosapentaenoic acid, cannabinoids, bortezomib, and anti-TNF-alpha MoAb. Several emerging drugs have shown promising results but are still under clinical investigation (thalidomide, selective cox-2 inhibitors, ghrelin mimetics, insulin, oxandrolone, and olanzapine). To date, despite several years of coordinated efforts in basic and clinical research, practice guidelines for the prevention and treatment of cancer-related muscle wasting are lacking, mainly because of the multifactorial pathogenesis of the syndrome. From all the data presented, one can speculate that one single therapy may not be completely successful in the treatment of cachexia. From this point of view, treatments involving different combinations are more likely to be successful.

Cancer cachexia: medical management

BACKGROUND

Cachexia is a complex metabolic syndrome associated with many chronic or end-stage diseases, especially cancer, and is characterized by loss of muscle with or without loss of fat mass. The management of cachexia is a complex challenge that should address the different causes underlying this clinical event with an integrated or multimodal treatment approach targeting the different factors involved in its pathophysiology.

MATERIALS AND METHODS

The purpose of this article was to review the current medical treatment of cancer-related cachexia, in particular focusing on combination therapy and ongoing research.

RESULTS

Among the treatments proposed in the literature for cancer-related cachexia, some proved to be ineffective, namely, cyproheptadine, hydrazine, metoclopramide, and pentoxifylline. Among effective treatments, progestagens are currently considered the best available treatment option for cancer-related cachexia, and they are the only drugs approved in Europe. Drugs with a strong rationale that have failed or have not shown univocal results in clinical trials so far include eicosapentaenoic acid, cannabinoids, bortezomib, and anti-TNF-alpha MoAb. Several emerging drugs have shown promising results but are still under clinical investigation (thalidomide, selective cox-2 inhibitors, ghrelin mimetics, insulin, oxandrolone, and olanzapine).

CONCLUSIONS

To date, despite several years of co-ordinated efforts in basic and clinical research, practice guidelines for the prevention and treatment of cancer-related muscle wasting are lacking, mainly because of the multifactorial pathogenesis of the syndrome. From all the data presented, one can speculate that one single therapy may not be completely successful in the treatment of cachexia. From this point of view, treatments involving different combinations are more likely to be successful.