Hypogonadism related to crizotinib therapy

Crizotinib, an Effective Agent in ROS1-Rearranged Adenocarcinoma of Lungs: A Case Report

Introduction:

ROS1 rearrangement has recently emerged as a new molecular subtype in non–small-cell lung cancer (NSCLC) and is predominantly found in lung adenocarcinoma compared with other oncogenes such as EGFR, KRAS, or ALK. It has been identified in only 1% to 2% of NSCLC cases.

Case Report:

We report a case of 52-year-old man (nonsmoker) with a medical history of allergic rhinitis and bronchial asthma. Histopathologic examination of bronchoscopic-guided biopsy showed adenocarcinoma histology on September 2015. After 2 months, he developed left-sided pneumonia for which he was treated with multiple intravenous antibiotics. In the meantime, fiberoptic bronchoscopy was done which revealed purulent secretion from right upper lobe and narrowed opening of right middle lobe. His cancer symptoms got worsened and bronchial biopsy showed EGFR mutation negative. For further diagnosis, fluorescent in situ hybridization test was done which showed ROS1 mutation positive. By then, the patient was started with crizotinib 250 mg twice daily for ROS1 mutation in July 2016. Later, patient appears to benefit from treatment with crizotinib. X-ray report and positron emission tomographic-computed tomographic scan revealed that the patient was overall better with clear chest and well tolerated with the therapy. Crizotinib was approved on March 11, 2016 by Food and Drug Administration for the treatment of patients with ROS1-positive NSCLC.

Conclusions:

In this report, crizotinib showed marked antitumor activity in patients with advanced ROS1 rearrangement, a third molecular subgroup of NSCLC.

Towards manageable toxicities from targeted lung cancer treatment

Targeted agents are now considered standard of care for patients whose tumors possess a sensitizing mutation in EGFR or ALK rearrangement. As the toxicity profiles of these agents differ significantly from that of cytotoxic chemotherapy, physicians need to be cognizant of the clinically relevant adverse events and manage them aggressively. Early recognition of these toxicities is vital to ensure medication compliance and maintain quality of life for patients. As more novel agents enter the treatment armamentarium, such as third-generation EGFR and ALK inhibitors, it will be important for physicians to understand class-specific toxicities and rare but serious side effects associated with these drugs.

ALK-rearranged non-small cell lung cancers: how best to optimize the safety of crizotinib in clinical practice?

Crizotinib (XALKORI™, Pfizer) is a tyrosine kinase inhibitor targeting ALK, MET and ROS1, currently approved for the treatment of adults with ALK-rearranged non-small-cell lung cancer. Optimizing the management of frequent crizotinib-related adverse events is crucial to ensure its continuous administration and reproduce the response and survival rates reported in clinical trials. Here, we propose some practical measures, which are mostly derived from the recommendations given to the investigators of the PROFILE 1001, 1005, 1007 and 1014 trials and are based on experience and scientific findings regarding the management of these disorders. While visual disturbances or bradycardia are frequent but benign, the severity of the cardiac and hepatic adverse events requires special attention potential to QT interval prolongations and to the monitoring of electrolyte levels and liver function, taking into account potential drug-drug interactions.

[ALK-rearranged non-small cell lung cancer: how to optimize treatment with crizotinib in routine practice?]

Crizotinib (XALKORI(™), Pfizer) is a tyrosine kinase inhibitor of ALK, MET, and ROS1, which is currently approved for the second line treatment for ALK-rearranged lung cancer. This work from an expert group, based on the review of the data from the Profile studies, aims to provide practical elements in order to optimize the tolerability of crizotinib. Specific major or frequent side effects of crizotinib are discussed: visual disturbances, cardiac effects, elevated transaminases, and hypogonadism. In the routine practice, patients should be advised about visual disturbances, especially with regard to driving in low brightness. Digestive disorders related to crizotinib are exceptionally persistent or severe. Dietary measures and symptomatic treatments usually control these disorders. It is recommended to perform an electrocardiogram before introduction of crizotinib, to identify prolonged QT interval. Torsades de pointes may produce dizziness or syncope. Hypogonadism should be considered in case of fatigue, decreased libido, and even depression, taking into account that these symptoms may be related to cancer; testosterone serum level should be measured to identify patients that may be eligible to receive a supplementation. Monitoring of liver function tests, including transaminases and bilirubin, is necessary. To conclude, these practical elements are helpful to optimize treatment with crizotinib in patients with ALK-rearranged lung cancer; in the future, academic initiatives should be taken to study these aspects, based on the monitoring of large cohorts of patients treated with crizotinib.

Crizotinib: A comprehensive review

Anaplastic lymphoma kinase (ALK) gene rearrangements are present in a small subset of non-small-cell lung cancers. ALK-positivity confers sensitivity to small-molecule ALK kinase inhibitors, such as crizotinib. The integration of crizotinib into standard treatment practice in NSCLC will rest on the widespread implementation of an effective screening system for newly diagnosed patients with NSCLC which is flexible enough to incorporate new targets as treatments are developed for them. Phase I and II studies of crizotinib in ALK-positive lung cancer have demonstrated significant activity and impressive clinical benefit, which led to its early approval by USFDA in 2011. Although crizotinib induces remissions and extends the lives of patients, there have been reports of emerging resistance to Crizotinib therapy. In this review, we discuss the history, mechanism of action, uses, adverse effects, dose modifications and future challenges and opportunities for patients with ALK-positive lung cancers.

Clinical pharmacokinetics of tyrosine kinase inhibitors: implications for therapeutic drug monitoring

The treatment of many malignancies has been improved in recent years by the introduction of molecular targeted therapies. These drugs interact preferentially with specific targets that are mutated and/or overexpressed in malignant cells. A group of such targets are the tyrosine kinases, against which a number of inhibitors (tyrosine kinase inhibitors, TKIs) have been developed. Imatinib, a TKI with targets that include the breakpoint cluster region-Abelson (bcr-abl) fusion protein kinase and mast/stem cell growth factor receptor kinase (c-Kit), was the first clinically successful drug of this type and revolutionized the treatment and prognosis of chronic myeloid leukemia and gastrointestinal stromal tumors. This success paved the way for the development of other TKIs for the treatment of a range of hematological malignancies and solid tumors. To date, 14 TKIs have been approved for clinical use and many more are under investigation. All these agents are given orally and are substrates of a range of drug transporters and metabolizing enzymes. In addition, some TKIs are capable of inhibiting their own transporters and metabolizing enzymes, making their disposition and metabolism at steady-state unpredictable. A given dose can therefore give rise to markedly different plasma concentrations in different patients, favoring the selection of resistant clones in the case of subtherapeutic exposure, and increasing the risk of toxicity if dosage is excessive. The aim of this review was to summarize current knowledge of the clinical pharmacokinetics and known adverse effects of the TKIs that are available for clinical use and to provide practical guidance on the implications of these data in patient management, in particular with respect to therapeutic drug monitoring.

Symptomatic reduction in free testosterone levels secondary to crizotinib use in male cancer patients

BACKGROUND

Crizotinib is a tyrosine kinase inhibitor active against ALK, MET, and ROS1. We previously reported that crizotinib decreases testosterone in male patients. The detailed etiology of the effect, its symptomatic significance, and the effectiveness of subsequent testosterone replacement have not been previously reported.

METHODS

Male cancer patients treated with crizotinib had total testosterone levels measured and results compared with non-crizotinib-treated patients. Albumin, sex hormone-binding globulin (SHBG), follicle-stimulating hormone (FSH), and/or luteinizing hormone (LH) were tracked longitudinally. A subset of patients had free testosterone levels measured and a hypogonadal screening questionnaire administered. Patients receiving subsequent testosterone supplementation were assessed for symptomatic improvement.

RESULTS

Mean total testosterone levels were -25% below the lower limit of normal (LLN) in 32 crizotinib-treated patients (27 of 32 patients below LLN, 84%) compared with +29% above LLN in 19 non-crizotinib-treated patients (6 of 19 below LLN, 32%), P = .0012. Levels of albumin and SHBG (which both bind testosterone) declined rapidly with crizotinib, but so did FSH, LH, and free testosterone, suggesting a centrally mediated, true hypogonadal effect. Mean free testosterone levels were -17% below LLN (19 of 25 patients below LLN, 76%). Eighty-four percent (16 of 19) with low free levels, and 79% (19/24) with low total levels had symptoms of androgen deficiency. Five of 9 patients (55%) with low testosterone given testosterone supplementation had improvement in symptoms, coincident with increases in testosterone above LLN.

CONCLUSIONS

Symptoms of androgen deficiency and free or total/free testosterone levels should be tracked in male patients on crizotinib with consideration of testosterone replacement as appropriate.