Erlotinib pharmacokinetics: a critical parameter influencing acute toxicity in elderly patients over 75 years-old

In Search of the Perfect Thrombosis and Bleeding-Associated Cancer Scale

Thrombosis and bleeding are commonly observed in cancer patients, and their management is crucial for positive patient outcomes. A comprehensive, prophylactic, and therapeutic management of venous thrombosis should focus on identifying the patients who would benefit most from treatment to reduce mortality and minimize the risk of thrombosis recurrence without significantly increasing the risk of bleeding. Existing cancer scales provide valuable information for assessing the overall burden of cancer and guiding treatment decisions, but their ability to predict thrombotic and bleeding events remains limited. With increasing knowledge of the pathophysiology of cancer and the availability of advanced anticancer therapies, new risk factors for cancer-associated thrombosis and bleeding are being identified. In this report, we analyze the current literature and identify new risk factors for venous thrombosis and bleeding which are not included in routinely used risk scores. While some existing cancer scales partially capture the risk of thrombosis and bleeding, there is a need for more specific and accurate scales tailored to these complications. The development of such scales could improve risk stratification, aid in treatment selection, and enhance patient care. Therefore, further research and development of novel cancer scales focused on thrombosis and bleeding are warranted to optimize patient management and outcomes.

Exposure-Response Analysis of Osimertinib in Patients with Advanced Non-Small-Cell Lung Cancer

High interindividual variability (IIV) of the clinical response to epidermal growth factor receptor (EGFR) inhibitors such as osimertinib in non-small-cell lung cancer (NSCLC) might be related to the IIV in plasma exposure. The aim of this study was to evaluate the exposure−response relationship for toxicity and efficacy of osimertinib in unselected patients with advanced EGFR-mutant NSCLC. This retrospective analysis included 87 patients treated with osimertinib. Exposure−toxicity analysis was performed in the entire cohort and survival analysis only in second-line patients (n = 45). No significant relationship between occurrence of dose-limiting toxicity and plasma exposure was observed in the entire cohort (p = 0.23, n = 86). The median overall survival (OS) was approximately two-fold shorter in the 4th quartile (Q4) of osimertinib trough plasma concentration (>235 ng/mL) than in the Q1−Q3 group (12.2 months [CI95% = 8.0−not reached (NR)] vs. 22.7 months [CI95% = 17.1−34.1]), but the difference was not statistically significant (p = 0.15). To refine this result, the exposure−survival relationship was explored in a cohort of 41 NSCLC patients treated with erlotinib. The Q4 erlotinib exposure group (>1728 ng/mL) exhibited a six-fold shorter median OS than the Q1−Q3 group (4.8 months [CI95% = 3.3-NR] vs. 22.8 months (CI95% = 10.6−37.4), p = 0.00011). These results suggest that high exposure to EGFR inhibitors might be related to worse survival in NSCLC patients.

Biomarker guided treatment in oncogene-driven advanced non-small cell lung cancer in older adults: A Young International Society of Geriatric Oncology Report

Lung cancer remains the leading cause of cancer-related deaths worldwide, with most patients diagnosed at an advanced age. The treatment of non-small cell lung cancer (NSCLC) has been revolutionized with the introduction of molecular guided therapy. Despites the challenges when considering treatment of older adults, they are still systematically underrepresented in registrational trials. This review aims to summarize the existing evidence on treatment of older patients with lung cancer with a targetable driver mutation or alteration (EGFR, ALK, ROS, BRAF^V600E, MET, RET, KRAS^G12C and NTRK), and consider the evidence from a geriatric oncology perspective. Early generation EGFR-tyrosine kinase inhibitors (TKIs). TKIs are fairly well-studied in older adults and have been shown to be safe and efficient. However, older adult-specific data regarding the standard-of-care first-line agent osimertinib are lacking. Erlotinib, dacomitinib, and afatinib may be more toxic than other EGFR-TKIs. Next generation ALK-TKIs are preferred over crizotinib due to increased efficacy, as demonstrated in phase III trials. Alectinib seems to be safer than crizotinib, while brigatinib is associated with increased toxicity. Lorlatinib overcomes most resistance mutations, but data regarding this agent have only recently emerged. Regarding ROS1-fusion positive NSCLC, crizotinib is an option in older adults, while entrectinib is similarly effective but shows increased neurotoxicity. In BRAF^V600E-mutant NSCLC, the combination darbafenib/tramectinib is effective, but no safety data for older adults exist. MET alterations can be targeted with capmatinib and tepotinib, and registrational trials included primarily older patients, due to the association of this alteration with advanced age. For RET-rearranged-NSCLC selpercatinib and pralsetinib are approved, and no differences in safety or efficacy between older and younger patients were shown. KRAS^G12C mutations, which are more frequent in older adults, became recently druggable with sotorasib, and advanced age does not seem to affect safety or efficacy. In NTRK-fusion positive tumors, larotrectinib and entrectinib have tumor agnostic approval, however, not enough data on older patients are available. Based on currently available data, molecularly-guided therapy for most alterations is safe and efficacious in older adults with oncogene-driven advanced NSCLC. However, for many TKIs, older adult-specific data are lacking, and should be subject of future prospective evaluations.

Effects of tyrosine kinase inhibitors on androgen, estrogen α, glucocorticoid and thyroid receptors

Modern anticancer therapies favor a targeted approach. Tyrosine kinase inhibitors (TKIs) are drugs that target molecular pathways involved in various types of malignancies. Although TKIs are safe and well tolerated, they remain not completely selective; e.g., endocrine-mediated adverse events have been observed with their use. In the present study, the effects of seven TKIs were determined on the activities of androgen receptor, estrogen receptor α (ERα), glucocorticoid receptor and thyroid receptor in vitro using stably transfected cell lines expressing firefly luciferase reporter gene: AR-EcoScreen, hERα-HeLa9903, MDA-kb2, and GH3.TRE-Luc cells, respectively. Antiandrogenic activity was seen for erlotinib, estrogenic activity for imatinib, antiestrogenic activity for dasatinib, erlotinib, nilotinib, regorafenib and sorafenib, glucocorticoid activity for erlotinib and ibrutinib, antiglucocorticoid activity for regorafenib and sorafenib, and antithyroid activity for ibrutinib. Additionally, synergism was seen for 1-5 μM dasatinib and 500 nM hydrocortisone combination for glucocorticoid activity in MDA-kb2 cells. The estrogenic activity of imatinib was confirmed as mediated through ERα, and interference of the TKIs with the reporter gene assays was ruled out in a cell-lysate-based firefly luciferase enzyme inhibition assay. Imatinib in combination with 4-hydroxytamoxifen showed concentration-dependent effects on the metabolic activity of ERα-expressing AN3CA, MCF-7, and SKOV3 cells, and on cell proliferation and adhesion of MCF-7 cells. These findings contribute to the understanding of the endocrine effects of TKIs, in terms of toxicity and effectiveness, and define the need to further evaluate the endocrine disrupting activities of TKIs to safeguard human and environmental health.

KCa channel blockers increase effectiveness of the EGF receptor TK inhibitor erlotinib in non-small cell lung cancer cells (A549)

Non-small cell lung cancer (NSCLC) has a poor prognosis with a 5 year survival rate of only ~ 10%. Important driver mutations underlying NSCLC affect the epidermal growth factor receptor (EGFR) causing the constitutive activation of its tyrosine kinase domain. There are efficient EGFR tyrosine kinase inhibitors (TKIs), but patients develop inevitably a resistance against these drugs. On the other hand, K_Ca3.1 channels contribute to NSCLC progression so that elevated K_Ca3.1 expression is a strong predictor of poor NSCLC patient prognosis. The present study tests whether blocking K_Ca3.1 channels increases the sensitivity of NSCLC cells towards the EGFR TKI erlotinib and overcomes drug resistance. mRNA expression of K_Ca3.1 channels in erlotinib-sensitive and -resistant NSCLC cells was analysed in datasets from Gene expression omnibus (GEO) and ArrayExpress. We assessed proliferation and migration of NSCLC cells. These (live cell-imaging) experiments were complemented by patch clamp experiments and Western blot analyses. We identified three out of four datasets comparing erlotinib-sensitive and -resistant NSCLC cells which revealed an altered expression of K_Ca3.1 mRNA in erlotinib-resistant NSCLC cells. Therefore, we evaluated the combined effect of erlotinib and the K_Ca3.1 channel inhibition with sencapoc. Erlotinib elicits a dose-dependent inhibition of migration and proliferation of NSCLC cells. The simultaneous application of the K_Ca3.1 channel blocker senicapoc increases the sensitivity towards a low dose of erlotinib (300 nmol/L) which by itself has no effect on migration and proliferation. Partial erlotinib resistance can be overcome by K_Ca3.1 channel blockade. The sensitivity towards erlotinib as well as the potentiating effect of K_Ca3.1 blockade is further increased by mimicking hypoxia. Our results suggest that K_Ca3.1 channel blockade may constitute a therapeutic concept for treating NSCLC and overcome EGFR TKI resistance. We propose that this is due to complementary mechanisms of action of both blockers.

Drug-drug interaction (DDI) with direct oral anticoagulant (DOAC) in patients with cancer

Cancer-associated thrombosis (CAT) is the second leading cause of death in cancer patients after tumor progression. The treatment of CAT is challenging because of a high risk of VTE recurrence, a high risk of bleeding, common presence of comorbidities, poly-medication, and potential drug-drug interactions (DDI). Since 2018, direct oral anticoagulants (DOACs) represent a promising therapeutic alternative and have been recently included into the 2019 update of the International Initiative on Thrombosis and Cancer (ITAC-CME) clinical practice guidelines for management of CAT. However, pharmacokinetic studies suggest that concomitant treatment with P-gp or CYP3A4 inhibitors will result in an increased exposure to rivaroxaban and apixaban, but the clinical relevance of these studies is unknown. In addition, there is an important inter-individual variability in drug absorption, distribution, metabolism and elimination, even more in cancer patients. Overall, the risk of pharmacokinetic DDI should be estimated based on several individual (patient age, renal and liver function, number of comedications) and diseases-related factors, including inflammation, sarcopenia, and low body weight. In this context, DDI with clinical implications could be expected with anti-neoplastic agents or supportive care treatments, especially with drugs known to be moderate or strong inhibitors/inducers of CYP3A4 and P-gp. Consequently, in the presence of potential DDIs through CYP3A4, and/or P-gp, LMWHs remain the first-line anticoagulant of choice for the long-term treatment of CAT. Multidisciplinary consultation meetings and therapeutic patient education should be emphasized in the complex management of CAT.

Population Pharmacokinetics of Erlotinib in Patients With Non-small Cell Lung Cancer: Its Application for Individualized Dosing Regimens in Older Patients

PURPOSE

Erlotinib is an oral first-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor approved for non-small cell lung cancers (NSCLC) with EGFR-activating mutations. Older patients experience more toxicities compared with younger patients at the standard recommended dose of 150 mg once daily. The aims of this study were to describe the pharmacokinetic profile of erlotinib in unselected patients with NSCLC, to quantify and explain its variability, to challenge the standard recommended dose in older patients, and to propose clinical recommendations for the therapeutic management of patients taking erlotinib.

METHODS

A population pharmacokinetic model was developed using erlotinib plasma concentrations collected from patients with NSCLC participating in a routine therapeutic drug monitoring program (with the nonlinear mixed effect modeling program NONMEM). Relevant demographic characteristics, clinical factors, and co-medications were tested as potential covariates. An independent dataset was used for model validation. Simulations based on the final model allowed comparison of expected erlotinib concentrations under standard and alternative dosing regimens for smokers and for several age groups.

FINDINGS

A total of 481 erlotinib plasma concentrations from 91 patients with NSCLC were used for model building and 239 plasma drug concentrations from 107 patients for model validation. A one-compartment model with first-order absorption and elimination provided the best fit. Average erlotinib CL/F with interindividual variability (%CV) was 3.8 L/h (41.5%), and V/F was 166 L (53.8%). The absorption rate constant was 1.48 h^-1. The external validation showed a negligible bias of -4% (95% CI, -7 to -1) in the individual predictions, with a precision of 23%. Current smoking and use of proton pump inhibitors were associated with higher CL/F, whereas age was associated with lower CL/F. Simulations suggest that a lower dose in older patients would decrease the risk of overexposure.

IMPLICATIONS

This large cohort study confirms the substantial interindividual variability in erlotinib plasma exposure and the impact of smoking and proton pump inhibitor intake. This large variability in erlotinib pharmacokinetics indicates that the standard recommended dose of 150 mg once daily is likely not appropriate to reach the expected concentrations in each patient. Concentration monitoring should be performed to individually adjust the erlotinib dosing regimen. The observed decrease in erlotinib CL/F with age suggests that a lower starting daily dose of 100 mg with concentration-guided dose adjustment would prevent overexposure and potential toxicity in older frail patients with co-morbidities.

Population Pharmacokinetic Modeling and Pharmacodynamic Target Attainment Simulation of Piperacillin/Tazobactam for Dosing Optimization in Late Elderly Patients with Pneumonia

The aim of this study was to develop a population pharmacokinetic model for piperacillin (PIPC)/tazobactam (TAZ) in late elderly patients with pneumonia and to optimize the administration planning by applying pharmacokinetic/pharmacodynamic (PK/PD) criteria. PIPC/TAZ (total dose of 2.25 or 4.5 g) was infused intravenously three times daily to Japanese patients over 75 years old. The plasma concentrations of PIPC and TAZ were determined using high-performance liquid chromatography and modeled using the NONMEM program. PK/PD analysis with a random simulation was conducted using the final population PK model to estimate the probability of target attainment (PTA) profiles for various PIPC/TAZ-regimen–minimum-inhibitory-concentration (MIC) combinations. The PTAs for PIPC and TAZ were determined as the fraction that achieved at least 50% free time > MIC and area under the free-plasma-concentration–time curve over 24 h ≥ 96 μg h/mL, respectively. A total of 18 cases, the mean age of which was 86.5 ± 6.0 (75–101) years, were investigated. The plasma-concentration–time profiles of PIPC and TAZ were characterized by a two-compartment model. The parameter estimates for the final model, namely the total clearance, central distribution volume, peripheral distribution volume, and intercompartmental clearance, were 4.58 + 0.061 × (CL_cr − 37.4) L/h, 5.39 L, 6.96 L, and 20.7 L/h for PIPC, and 5.00 + 0.059 × (CL_cr − 37.4) L/h, 6.29 L, 7.73 L, and 24.0 L/h for TAZ, respectively, where CL_cr is the creatinine clearance. PK/PD analysis using the final model showed that in drug-resistant strains with a MIC > 8 μg/mL, 4.5 g of PIPC/TAZ every 6 h was required, even for the patients with a CL_cr of 50–60 mL/min. The population PK model developed in this study, together with MIC value, can be useful for optimizing the PIPC/TAZ dosage in the over-75-year-old patients, when they are administered PIPC/TAZ. Therefore, the findings of present study may contribute to improving the efficacy and safety of the administration of PIPC/TAZ therapy in late elderly patients with pneumonia.

Recent advances in the treatment and prevention of venous thromboembolism in cancer patients: role of the direct oral anticoagulants and their unique challenges

Venous thromboembolism (VTE) is a common complication in patients with cancer and is associated with poor prognosis. Low-molecular-weight heparins (LMWHs) are the standard of care for the treatment of cancer-associated thrombosis. Primary VTE prophylaxis with LMWH is recommended after cancer surgery and in hospitalized patients with reduced mobility. However, owing to wide variations in VTE and bleeding risk, based on disease stage, anti-cancer treatments, and individual patient characteristics, routine primary prophylaxis is not recommended in ambulatory cancer patients undergoing chemotherapy. Efforts are under way to validate risk assessment models that will help identify those patients in whom the benefits of primary prophylaxis will outweigh the risks. In recent months, long-awaited dedicated clinical trials assessing the direct oral anticoagulants (DOACs) in patients with cancer have reported promising results. In comparison with the LMWHs, the DOACs were reported to be non-inferior to prevent VTE recurrence. However, there was an increased risk of bleeding, particularly in gastrointestinal cancers. Safe and optimal treatment with the DOACs in the patient with cancer will require vigilant patient selection based on patient characteristics, co-morbidities, and the potential for drug-drug interactions.

Treatment of advanced non-small cell lung cancer in the elderly

INTRODUCTION

Lung cancer is predominantly a disease that affects the elderly; about 30-40% of lung cancers are diagnosed in patients aged 70 or more. The increasing number of elderly patients over the next decades is generating a new social and health problem; despite that, these patients are underrepresented in clinical trials and undertreated in clinical practice. Areas covered: The main difficulty in treating elderly patients is to maximize the therapy benefits while minimizing the treatment risk. Elderly patients show a vulnerable clinical profile due to the higher prevalence of comorbid disease, higher polypharmacy interactions and aged organ dysfunction that increase the risk of mortality and toxicity with cancer treatments compared to younger patients. Expert commentary: The choice to treat or not to treat elderly patients cannot be taken only on the basis of the chronological age. Thus, the clinical approach should be to select patients who are effectively suitable for treatment having a better individual functional reserve and a better life expectancy. Elderly patients are a heterogeneous population and those who are fit to receive cancer treatment can be treated similarly to younger patients.

A Review of Recent Advances in the Treatment of Elderly and Poor Performance NSCLC

Until recently, chemotherapy has remained the mainstay of treatment for the majority of patients with advanced non-small cell lung cancer (NSCLC). Excellent responses have been observed with immune-checkpoint inhibitors, and targeted treatments for those tumours with actionable mutations, resulting in a paradigm shift in the treatment approach for these patients. Elderly patients and those with poor performance status (PS), such as Eastern Cooperative Oncology Group (ECOG) 2, have historically been excluded from clinical trials due to poor outcomes. There is therefore a lack of data to define the optimal treatment strategy for these patients. Due to improved tolerability of novel therapies, inclusion of these patients in clinical trials has increased, and sub-group analyses have identified many treatments demonstrating potential activity. Here, we summarise key recent advances in the treatment of NSCLC, specifically evaluating their efficacy and tolerability in these patient cohorts.