Quantitative modeling of tumor dynamics and development of drug resistance in non-small cell lung cancer patients treated with erlotinib

Insight into the development of treatment resistance can support the optimization of anticancer treatments. This study aims to characterize the tumor dynamics and development of drug resistance in patients with non-small cell lung cancer treated with erlotinib, and investigate the relationship between baseline circulating tumor DNA (ctDNA) data and tumor dynamics. Data obtained for the analysis included (1) intensively sampled erlotinib concentrations from 29 patients from two previous pharmacokinetic (PK) studies, and (2) tumor sizes, ctDNA measurements, and sparsely sampled erlotinib concentrations from 18 patients from the START-TKI study. A two-compartment population PK model was first developed which well-described the PK data. The PK model was subsequently applied to investigate the exposure-tumor dynamics relationship. To characterize the tumor dynamics, models accounting for intra-tumor heterogeneity and acquired resistance with or without primary resistance were investigated. Eventually, the model assumed acquired resistance only resulted in an adequate fit. Additionally, models with or without exposure-dependent treatment effect were explored, and no significant exposure-response relationship for erlotinib was identified within the observed exposure range. Subsequently, the correlation of baseline ctDNA data on EGFR and TP53 variants with tumor dynamics' parameters was explored. The analysis indicated that higher baseline plasma EGFR mutation levels correlated with increased tumor growth rates, and the inclusion of ctDNA measurements improved model fit. This result suggests that quantitative ctDNA measurements at baseline have the potential to be a predictor of anticancer treatment response. The developed model can potentially be applied to design optimal treatment regimens that better overcome resistance.

Exploring the impact of patient-specific clinical features on osimertinib effectiveness in a real-world cohort of patients with EGFR mutated non-small cell lung cancer

Osimertinib is prescribed to patients with metastatic non-small cell lung cancer (NSCLC) and a sensitizing EGFR mutation. Limited data exists on the impact of patient characteristics or osimertinib exposure on effectiveness outcomes. This was a Dutch, multicenter cohort study. Eligible patients were ≥18 years, with metastatic EGFRm+ NSCLC, receiving osimertinib. Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS) and safety. Kaplan-Meier analyses and multivariate Cox proportional hazard models were performed. In total, 294 patients were included. Primary EGFR-mutations were mainly exon 19 deletions (54%) and p.L858R point mutations (30%). Osimertinib was given in first-line (40%), second-line (46%) or beyond (14%), with median PFS 14.4 (95% CI: 9.4-19.3), 13.9 (95% CI: 11.3-16.1) and 8.7 months (95% CI: 4.6-12.7), respectively. Patients with low BMI (<20.0 kg/m2 ) had significantly shorter PFS/OS compared to all other subgroups. Patients with a high plasma trough concentration in steady state (Cmin,SS ; >271 ng/mL) had shorter PFS compared to a low Cmin,SS (<163 ng/mL; aHR 2.29; 95% CI: 1.13-4.63). A significant longer PFS was seen in females (aHR = 0.61, 95% CI: 0.45-0.82) and patients with the exon 19 deletion (aHR = 0.58, 95% CI: 0.36-0.92). A trend towards longer PFS was seen for TP53 wild-type patients, while age did not impact PFS. Patients with a primary EGFR exon 19 deletion had longer PFS, while a low BMI, male sex and a high Cmin,SS were indicative for shorter PFS and/or OS. Age was not associated with effectiveness outcomes of osimertinib.

Analysis of Serious Weight Gain in Patients Using Alectinib for ALK-Positive Lung Cancer

INTRODUCTION

Alectinib is a standard-of-care treatment for metastatic ALK+ NSCLC. Weight gain is an unexplored side effect reported in approximately 10%. To prevent or intervene alectinib-induced weight gain, more insight in its extent and etiology is needed.

METHODS

Change in body composition was analyzed in a prospective series of 46 patients with ALK+ NSCLC, treated with alectinib. Waist circumference, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and skeletal muscle were quantified using sliceOmatic software on computed tomography images at baseline, 3 months (3M), and 1 year (1Y). To investigate an exposure-toxicity relationship, alectinib plasma concentrations were quantified. Four patients with more than 10 kg weight gain were referred to Erasmus MC Obesity Center CGG for in-depth analysis (e.g., assessments of appetite, dietary habits, other lifestyle, medical and psychosocial factors, and extensive metabolic and endocrine assessments, including resting energy expenditure).

RESULTS

Mean increase in waist circumference was 9 cm (9.7%, p < 0.001) in 1Y with a 40% increase in abdominal obesity (p = 0.014). VAT increased to 10.8 cm2 (15.0%, p = 0.003) in 3M and 35.7 cm2 (39.0%, p < 0.001) in 1Y. SAT increased to 18.8 cm2 (12.4%, p < 0.001) in 3M and 45.4 cm2 (33.3%, p < 0.001) in 1Y. The incidence of sarcopenic obesity increased from 23.7% to 47.4% during 1Y of treatment. Baseline waist circumference was a positive predictor of increase in VAT (p = 0.037). No exposure-toxicity relationship was found. In-depth analysis (n = 4) revealed increased appetite in two patients and metabolic syndrome in all four patients.

CONCLUSIONS

Alectinib may cause relevant increased sarcopenic abdominal obesity, with increases of both VAT and SAT, quickly after initiation. This may lead to many serious metabolic, physical, and mental disturbances in long-surviving patients.

Influence of Food With Different Fat Concentrations on Alectinib Exposure: A Randomized Crossover Pharmacokinetic Trial

BACKGROUND

Alectinib is the keystone treatment in advanced anaplastic lymphoma kinase-positive (ALK+) non-small cell lung cancer (NSCLC). An exposure-response threshold of 435 ng/mL has recently been established, albeit 37% of patients do not reach this threshold. Alectinib is orally administered, and absorption is largely influenced by food. Hence, further investigation into this relationship is needed to optimize its bioavailability.

PATIENTS AND METHODS

In this randomized 3-period crossover clinical study in ALK+ NSCLC, alectinib exposure was compared among patients with different diets. Every 7 days, the first alectinib dose was taken with either a continental breakfast, 250-g of low-fat yogurt, or a self-chosen lunch, and the second dose was taken with a self-chosen dinner. Sampling for alectinib exposure (Ctrough) was performed at day 8, just prior to alectinib intake, and the relative difference in Ctrough was compared.

RESULTS

In 20 evaluable patients, the mean Ctrough was 14% (95% CI, -23% to -5%; P=.009) and 20% (95% CI, -25% to -14%; P<.001) lower when taken with low-fat yogurt compared with a continental breakfast and a self-chosen lunch, respectively. Administration with a self-chosen lunch did not change exposure compared with a continental breakfast (+7%; 95% CI, -2% to +17%; P=.243). In the low-fat yogurt period, 35% of patients did not reach the threshold versus 5% with the other meals (P<.01).

CONCLUSIONS

Patients and physicians should be warned for a detrimental food-drug interaction when alectinib is taken with low-fat yogurt, because it results in a clinically relevant lower alectinib exposure. Intake with a self-chosen lunch did not change drug exposure and could be a safe and patient-friendly alternative.

Design and statistics of pharmacokinetic drug-drug, herb-drug, and food-drug interaction studies in oncology patients

Polypharmacy is becoming increasingly prevalent in society. Patients with polypharmacy are at greater risk for drug-drug interactions, which can influence the efficacy of treatment. Especially, in oncology this is a concern since neoplasms are increasing prevalent with age, as well as polypharmacy is. Besides drug-drug interactions, also herb-drug and food-drug interactions could be present. Knowledge of these interactions is of great importance for safe and effective anti-cancer treatment, because the therapeutic window of most of these oncologic drugs are small. To study pharmacokinetic interaction effects, a cross-over pharmacokinetic study is a widely used, efficient and scientifically robust design. Yet, several aspects need to be considered when carrying out an interaction study. This includes the knowledge of the advantages and disadvantages of a cross-over design. Furthermore, determination of the end point and research question of interest, calculation of the required sample size, analysis of the generated data with a robust statistical plan and consideration of the logtransformation for some pharmacokinetic parameters are important aspects to consider. Even though some guidelines exist regarding these key issues, no clear overview exists. In this article an overview of these aspects is provided and their effect is discussed.

Incidence of Bone Metastases and Skeletal-Related Events in Patients With EGFR-Mutated NSCLC Treated With Osimertinib

Introduction

Bone metastases are frequent in patients with EGFR-mutated (EGFR+) NSCLC. Skeletal-related events (SREs) are common in these patients; however, no data on SRE in osimertinib-treated patients are reported. We investigated the development of bone metastases and SREs in patients with EGFR+ NSCLC treated with osimertinib.

Methods

This is a retrospective multicenter cohort study that included patients with metastatic EGFR+ NSCLC who were treated with osimertinib between February 2016 and September 2021. Demographics, bone metastases-related outcomes, SREs, treatment efficacy, and overall survival (OS) were collected.

Results

In total, 250 patients treated with osimertinib (43% first line) were included. Of the patients, 51% had bone metastases at initiation of osimertinib. Furthermore, 16% of the patients with bone metastases used bone-targeted agents. Median follow-up from initiation of osimertinib was 23.4 months (95% confidence interval [CI]: 19.9-26.9 mo). During osimertinib treatment, 10% developed new bone metastases or bone progression. Of the patients with bone metastases, 39% had more than or equal to one SREs: 28% developed first SRE before osimertinib treatment, 1% after, and 11% during. Median OS post-bone metastasis was 30.8 months (95% CI: 21.9-39.7). Median OS after first SRE was 31.1 months (95% CI: 15.8-46.5).

Conclusions

Bone metastases and SREs are frequent before and during treatment with osimertinib in EGFR+ NSCLC. Because of these findings and the long OS post-bone metastases, we advocate prescription of bone-targeted agents in these patients and recommend adding bone-specific end points in clinical trials.

Quantitation of osimertinib, alectinib and lorlatinib in human cerebrospinal fluid by UPLC-MS/MS

Overall survival in metastatic lung cancer has been dramatically improved with the use of small molecule kinase inhibitors (SMKIs). Quantification of SMKI in cerebrospinal fluid (CSF) can be used to assess penetration of these drugs into the central nervous system. This paper describes an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for quantification of the SMKIs alectinib, lorlatinib and osimertinib in human CSF. Alectinib-d8 and dasatinib-d8 were used as internal standards. Aliquots with 25 µL CSF/30% albumin (9:1,v/v) were mixed with 100 µL internal standard solution consisting of 1 ng/mL dasatinib-d8 and alectinib-d8 in acetonitrile. The analytes were separated by an Acquity UPLC® HSS T3 column (2.1 ×150 mm, 1.8 µm), using gradient elution (ammonium formate pH 4.5, acetonitrile) with a flow rate of 0.400 mL/min. All calibration curves were linear for the concentration range from 2.50 to 250 ng/mL. Within-run and between-run precision varied from 0.72% to 11.7%, with accuracy ranging from 95.3% to 113.2%. For all compounds, a high degree of non-specific binding to the vacutainer was observed. This issue could be countered easily by a combination of pre-coating with BSA solution (30%) in phosphate buffer pH 4.2, and immediate sample mixture with BSA solution after collection. To test the clinical applicability, CSF was collected in seven unique patients using alectinib (n = 1), lorlatinib (n = 2), and osimertinib (n = 4). Measured CSF trough concentrations ranged between 3.37 and 116 ng/mL.

Cardiac Toxicity of Alectinib in Patients With ALK+ Lung Cancer: Outcomes of Cardio-Oncology Follow-Up

Background

Anaplastic lymphoma kinase (ALK) translocations in metastatic non-small cell lung cancer (3% to 7%) predict for response to ALK-inhibitors (eg, alectinib, first line), resulting in a 5-year survival rate of ∼60% and median progression-free survival of 34.8 months. Although the overall toxicity rate of alectinib is acceptable, unexplained adverse events, including edema and bradycardia, may indicate potential cardiac toxicity.

Objectives

This study's aim was to investigate the cardiotoxicity profile and exposure-toxicity relationship of alectinib.

Methods

Between April 2020 and September 2021, 53 patients with ALK-positive non-small cell lung cancer treated with alectinib were included. Patients starting with alectinib after April 2020 underwent a cardiac work-up at start, at 6 months and at 1 year at the cardio-oncology outpatients' clinic. Patients already receiving alectinib >6 months underwent 1 cardiac evaluation. Bradycardia, edema, and severe alectinib toxicity (grade ≥3 and grade ≥2 adverse events leading to dose modifications) data were collected. Alectinib steady-state trough concentrations were used for exposure-toxicity analyses.

Results

Left ventricular ejection fraction remained stable in all patients who underwent an on-treatment cardiac evaluation (n = 34; median 62%; IQR: 58%-64%). Twenty-two patients (42%) developed alectinib-related bradycardia (6 symptomatic bradycardia). One patient underwent a pacemaker implantation for severe symptomatic bradycardia. Severe toxicity was significantly associated with a 35% higher alectinib mean C_trough (728 vs 539 ng/mL, SD = 83 ng/mL; 1-sided P = 0.015).

Conclusions

No patients showed signs of a diminished left ventricular ejection fraction. Alectinib caused more bradycardia than previously reported (42%) with some instances of severe symptomatic bradycardia. Patients with severe toxicity generally had an elevated exposure above the therapeutic threshold.

Influence of esomeprazole on the bioavailability of afatinib: A pharmacokinetic cross-over study in patients with non-small cell lung cancer

Afatinib is an oral small-molecule kinase inhibitor (SMKI) approved for treatment of metastatic non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor (EGFR) driver mutation. Although oral administration is convenient, most SMKIs experience pH-dependent solubility. A drug-drug interaction between afatinib and proton-pump inhibitors (PPIs) has, however, never been studied in humans. Hence, we performed a randomized, three-period cross-over study. Afatinib (30 mg or 40 mg) was administered without PPI (period A), concomitantly with esomeprazole (period B) and three hours after esomeprazole intake (period C). Primary objective was the area under the curve (AUC_0-24 h) comparing period A to period B and period A to period C. Secondary objectives were other pharmacokinetic parameters and toxicity. Linear mixed effect modelling was performed for differences in AUC_0-24 h and C_max between periods A and B and periods A and C. In 18 evaluable NSCLC patients, concomitant use of 40 mg esomeprazole decreased the steady-state afatinib AUC_0-24 h with 10.2% (95% CI -29.2 to +14.0%; p = 0.564) compared to afatinib administration without PPI. Esomeprazole intake three hours prior to afatinib did not significantly influence afatinib AUC_0-24 h (-0.6%; 95% CI -14.9 to +16.1%; p = 1.0). No differences in toxicity were observed. To conclude, esomeprazole did not change the exposure to afatinib in patients with NSCLC. Since there is no clinically relevant drug-drug interaction, esomeprazole can safely be co-administered with afatinib. This is important for clinical practice, because other EGFR-SMKIs (e.g. erlotinib and gefitinib) do experience clinically relevant drug-drug interactions with acid-suppressive agents.

The influence of green tea extract on nintedanib's bioavailability in patients with pulmonary fibrosis

Nintedanib is an oral small-molecule kinase inhibitor and first-line treatment for idiopathic pulmonary fibrosis. Nintedanib is a substrate of the drug efflux transporter ABCB1. Green tea flavonoids --especially epigallocatechin gallate (EGCG)-- are potent ABCB1 modulators. We investigated if concomitant administration of green tea extract (GTE) could result in a clinically relevant herb-drug interaction. Patients were randomized between A-B and B-A, with A being nintedanib alone and B nintedanib with GTE. Both periods lasted 7 days, in which nintedanib was administered twice daily directly after a meal. In period B, patients additionally received capsules with GTE (500 mg BID, >60% EGCG). Pharmacokinetic sampling for 12 h was performed at day 7 of each period. Primary endpoint was change in geometric mean for the area under the curve (AUC_0-12 h). A linear mixed model was used to analyse AUCs and maximal concentration (C_max). In 26 included patients, the nintedanib AUC_0-12 h was 21% lower (95% CI -29% to -12%; P < 0.001) in period B (with GTE) compared to period A. C_max did not differ significantly between periods; - 14% (95% CI -29% to +4%; P = 0.12). The detrimental effect was predominant in patients with the ABCB1 3435 C>T wild type variant. No differences in toxicities were observed. Exposure to nintedanib decreased with 21% when administered 60 min after GTC for only 7 days. This is a statistically significant interaction which could potentially impair treatment efficacy. Before patients and physicians should definitely be warned to avoid this combination, prospective clinical validation of an exposure-response relationship is necessary.

Improving the tolerability of osimertinib by identifying its toxic limit

Background:

Osimertinib is the cornerstone in the treatment of epidermal growth factor receptor-mutated non-small cell lung cancer (NSCLC). Nonetheless, ±25% of patients experience severe treatment-related toxicities. Currently, it is impossible to identify patients at risk of severe toxicity beforehand. Therefore, we aimed to study the relationship between osimertinib exposure and severe toxicity and to identify a safe toxic limit for a preventive dose reduction.

Methods:

In this real-life prospective cohort study, patients with NSCLC treated with osimertinib were followed for severe toxicity (grade ⩾3 toxicity, dose reduction or discontinuation, hospital admission, or treatment termination). Blood for pharmacokinetic analyses was withdrawn during every out-patient visit. Primary endpoint was the correlation between osimertinib clearance (exposure) and severe toxicity. Secondary endpoint was the exposure–efficacy relationship, defined as progression-free survival (PFS) and overall survival (OS).

Results:

In total, 819 samples from 159 patients were included in the analysis. Multivariate competing risk analysis showed osimertinib clearance (c.q. exposure) to be significantly correlated with severe toxicity (hazard ratio 0.93, 95% CI: 0.88–0.99). An relative operating characteristic curve showed the optimal toxic limit to be 259 ng/mL osimertinib. A 50% dose reduction in the high-exposure group, that is 25.8% of the total cohort, would reduce the risk of severe toxicity by 53%. Osimertinib exposure was not associated with PFS nor OS.

Conclusion:

Osimertinib exposure is highly correlated with the occurrence of severe toxicity. To optimize tolerability, patients above the toxic limit concentration of 259 ng/mL could benefit from a preventive dose reduction, without fear for diminished effectiveness.

Influence of Cow's Milk and Esomeprazole on the Absorption of Erlotinib: A Randomized, Crossover Pharmacokinetic Study in Lung Cancer Patients

INTRODUCTION

Erlotinib's gastrointestinal solubility and absorption are decreased by proton pump inhibitors (PPIs). Since erlotinib is a lipophilic drug, we hypothesized that concomitant intake with the fatty beverage milk may be a feasible way to increase erlotinib uptake. We performed a two-period, randomized, crossover study to investigate the influence of cow's milk with 3.9% fat on the exposure of erlotinib with and without the PPI esomeprazole in patients with non-small cell lung cancer (NSCLC). The effect of esomeprazole was studied in an additional intrapatient comparison.

METHOD

Pharmacokinetic sampling was performed on days 7 and 14 during 24 consecutive hours. During the 7 days prior to pharmacokinetic sampling, erlotinib was taken daily with 250 mL of either water or milk. In the PPI arm, esomeprazole (40 mg once daily 3 h prior to erlotinib) was taken for 3 days.

RESULTS

Erlotinib area under the curve from time zero to 24 h (AUC24) did not significantly change when administered with milk, compared with water, in both non-PPI users (n = 14; - 3%; 95% confidence interval [CI] - 12 to 8%; p = 0.57) and patients who used esomeprazole (n = 15; 0%; 95% CI - 15 to 17%; p = 0.95). Esomeprazole decreased erlotinib AUC24 by 47% (n = 9; 95% CI - 57 to - 34%; p < 0.001) and Cmax by 56% (95% CI - 64 to - 46%; p < 0.001). No differences in toxicities were observed between milk and water.

CONCLUSION

Milk with 3.9% fat has no effect on the exposure to erlotinib in NSCLC patients, independent of PPI use. The combination with milk is safe and well tolerated. Concomitant esomeprazole treatment strongly decreased both erlotinib AUC24 and Cmax and should be avoided if possible.

Plasma Predictive Features in Treating EGFR-Mutated Non-Small Cell Lung Cancer

Although epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) are the preferred treatment for patients with EGFR-mutated non-small cell lung cancer (NSCLC), not all patients benefit. We therefore explored the impact of the presence of mutations found in cell-free DNA (cfDNA) and TKI plasma concentrations during treatment on progression-free survival (PFS). In the prospective START-TKI study blood samples from 41 patients with EGFR-mutated NSCLC treated with EGFR-TKIs were available. Next generation sequencing (NGS) on cfDNA was performed, and plasma TKI concentrations were measured. Patients without complete plasma conversion of EGFR mutation at week 6 had a significantly shorter PFS (5.5 vs. 17.0 months, p = 0.002) and OS (14.0 vs. 25.5 months, p = 0.003) compared to patients with plasma conversion. In thirteen (second line) osimertinib-treated patients with a (plasma or tissue) concomitant TP53 mutation at baseline, PFS was significantly shorter compared to six wild-type cases; 8.8 vs. 18.8 months, p = 0.017. Erlotinib Cmean decrease of ≥10% in the second tertile of treatment was also associated with a significantly shorter PFS; 8.9 vs. 23.6 months, p = 0.037. We obtained evidence that absence of plasma loss of the primary EGFR mutation, isolated plasma p.T790M loss after six weeks, baseline concomitant TP53 mutations, and erlotinib Cmean decrease during treatment are probably related to worse outcome.

Pleural metastasis of anaplastic meningioma

A 52-year-old woman presented to the emergency department with several days of progressive dyspnoea and thoracic pain. Her medical history included a (recurrent) anaplastic meningioma, for which she was treated with surgery and radiotherapy. A chest X-ray showed occurrence of total opacification of the left lower lobe and a chest computed tomography demonstrated a pleural mass of 12 × 9 × 15 cm in the left lower lobe. Biopsy of the pleural mass revealed a metastasis of the patient's anaplastic meningioma. Extracranial metastases from meningioma are extremely uncommon (≤ 0.1%-0.2% of cases), but important for a patient's prognosis.

Clinical implications of food-drug interactions with small-molecule kinase inhibitors

During the past two decades, small-molecule kinase inhibitors have proven to be valuable in the treatment of solid and haematological tumours. However, because of their oral administration, the intrapatient and interpatient exposure to small-molecule kinase inhibitors (SMKIs) is highly variable and is affected by many factors, such as concomitant use of food and herbs. Food-drug interactions are capable of altering the systemic bioavailability and pharmacokinetics of these drugs. The most important mechanisms underlying food-drug interactions are gastrointestinal drug absorption and hepatic metabolism through cytochrome P450 isoenzymes. As food-drug interactions can lead to therapy failure or severe toxicity, knowledge of these interactions is essential. This Review provides a comprehensive overview of published studies involving food-drug interactions and herb-drug interactions for all registered SMKIs up to Oct 1, 2019. We critically discuss US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines concerning food-drug interactions and offer clear recommendations for their management in clinical practice.

Diagnosis and quantification of bronchiectasis using computed tomography or magnetic resonance imaging: A systematic review

BACKGROUND

Bronchiectasis is an irreversible dilatation of the airways caused by inflammation and infection. To diagnose bronchiectasis in clinical care and to use bronchiectasis as outcome parameter in clinical trials, a radiological definition with exact cut-off values along with image analysis methods to assess its severity are needed. The aim of this study was to review diagnostic criteria and quantification methods for bronchiectasis.

METHODS

A systematic literature search was performed using Embase, Medline Ovid, Web of Science, Cochrane and Google Scholar. English written, clinical studies that included bronchiectasis as outcome measure and used image quantification methods were selected. Criteria for bronchiectasis, quantification methods, patient demographics, and data on image acquisition were extracted.

RESULTS

We screened 4182 abstracts, selected 972 full texts, and included 122 studies. The most often used criterion for bronchiectasis was an inner airway-artery ratio ≥1.0 (42%), however no validation studies for this cut-off value were found. Importantly, studies showed that airway-artery ratios are influenced by age. To quantify bronchiectasis, 42 different scoring methods were described.

CONCLUSION

Different diagnostic criteria for bronchiectasis are being used, but no validation studies were found to support these criteria. To use bronchiectasis as outcome in future studies, validated and age-specific cut-off values are needed.

Quantification of the tyrosine kinase inhibitor erlotinib in human scalp hair by liquid chromatography-tandem mass spectrometry: Pitfalls for clinical application

An LC-MS/MS method was developed and validated to quantify the tyrosine kinase inhibitor erlotinib in human scalp hair, as alternative matrix to monitor long-term erlotinib exposure. Hair samples from 10 lung cancer patients were measured and correlated with plasma concentrations. Hair segments of 1 ± 0.1 cm each were pulverized and for at least 18 h incubated in methanol at ambient temperature. A liquid-liquid extraction purified the extracts and they were analyzed with LC-MS/MS, using erlotinib-d6 as internal standard. The procedure method was validated for selectivity, sensitivity, precision, lower limit of detection, linearity and accuracy. The within and between run precisions including the lower limit of quantification did not exceed 12.5%, while the accuracy ranged from 103 to 106%. A weak correlation between hair and plasma concentration was found (R² = 0.48). Furthermore, a large inter-individual variability was noted in the disposition of both plasma and hair samples. The highest hair concentrations were observed in black hair compared with other (grey and brown) hair colors. Generally, a linear reduction in hair concentration was found from proximal to distal hair segments. Additional in vitro experiments suggest an accelerated degradation of erlotinib in hair by artificial UV light and also wash-out by shampoo mixtures pretreatment compared with control samples. In conclusion, a reliable and robust LC-MS/MS method was developed to quantify erlotinib in hair. However, clinical and in vitro evaluations showed that the method is not suitable for monitoring long-term erlotinib exposure. The pitfalls of this application outweigh the current benefits.

Comparison of toxicity and effectiveness between fixed-dose and body surface area-based dose capecitabine

Background

Capecitabine is generally dosed based on body surface area (BSA). This dosing strategy has several limitations; however, evidence for alternative strategies is lacking. Therefore, we analyzed the toxicity and effectiveness of fixed-dose capecitabine and compared this strategy with a BSA-based dose of capecitabine in a large set of patients.

Methods

Patients treated with fixed-dose capecitabine between 2003 and 2015 were studied. A comparable group of patients, dosed based on BSA, was chosen as a control cohort. A total of two combined scores were used: capecitabine-specific toxicity (diarrhea, National Cancer Institute Common Toxicity Criteria grade ⩾3, hand-foot syndrome ⩾2, or neutropenia ⩾2), and clinically relevant events due to toxicity, that is, hospital admission, dose reduction, or discontinuation. Per treatment regimen, patients were divided into three BSA groups based on BSA quartiles corrected for sex. Toxicity scores were compared by a Chi-square test between cohorts, and within cohorts using BSA groups. Progression-free survival (PFS) was estimated by the Kaplan-Meier method.

Results

A total of 2319 patients were included (fixed dosed, n = 1126 and BSA-based dose, n = 1193). Overall, four regimens were evaluated: capecitabine-radiotherapy (n = 1178), capecitabine-oxaliplatin (n = 519), capecitabine triplet (n = 181) and capecitabine monotherapy (n = 441). The incidence of capecitabine-specific toxicity and clinically relevant events was comparable between fixed-dose and BSA-dosed patients, while a small difference (7.1%) in absolute dose was found. Both cohorts showed only a higher incidence of both toxicity scores in the lowest BSA group of the capecitabine-radiotherapy group (p < 0.05). Subgroups of the fixed-dose cohort analyzed for PFS, showed no differences between BSA groups.

Conclusions

Fixed-dose capecitabine is as comparably well tolerated and effective as BSA-based dosing and could be considered as a reasonable alternative for BSA-based dosing.

Quantification of afatinib, alectinib, crizotinib and osimertinib in human plasma by liquid chromatography/triple-quadrupole mass spectrometry; focusing on the stability of osimertinib

The development and full validation of a sensitive and selective ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method are described for the simultaneous analysis of afatinib, alectinib, crizotinib and osimertinib in human lithium heparinized plasma. Afatinib-d6, crizotinib-d5 and erlotinib-d6 were used as internal standards. Given osimertinib's instability in plasma and whole blood at ambient temperature, samples should be solely processed on ice (T = 0 °C). Chromatographic separation was obtained on an Acquity UPLC ® BEH C18; 2.1 × 50 mm, 1.7 μm column, which was eluted with 0.400 mL/minute flow on a linear gradient, consisting of 10 mM ammonium formate (pH 4.5) and acetonitrile. Calibration curves for all compounds were linear for concentration ranges of 1.00 to 100 ng/mL for afatinib and 10.0 to 1000 ng/mL for alectinib, crizotinib and osimertinib, herewith validating the lower limits of quantification at 1.00 ng/mL for afatinib and 10.0 ng/mL for alectinib, crizotinib and osimertinib. Within-run and between-run precision measurements fell within 10.2%, with accuracy ranging from 89.2 to 110%.

Clinically relevant drug interactions with multikinase inhibitors: a review

Multikinase inhibitors (MKIs), including the tyrosine kinase inhibitors (TKIs), have rapidly become an established factor in daily (hemato)-oncology practice. Although the oral route of administration offers improved flexibility and convenience for the patient, challenges arise in the use of MKIs. As MKIs are prescribed extensively, patients are at increased risk for (severe) drug–drug interactions (DDIs). As a result of these DDIs, plasma pharmacokinetics of MKIs may vary significantly, thereby leading to high interpatient variability and subsequent risk for increased toxicity or a diminished therapeutic outcome. Most clinically relevant DDIs with MKIs concern altered absorption and metabolism. The absorption of MKIs may be decreased by concomitant use of gastric acid-suppressive agents (e.g. proton pump inhibitors) as many kinase inhibitors show pH-dependent solubility. In addition, DDIs concerning drug (uptake and efflux) transporters may be of significant clinical relevance during MKI therapy. Furthermore, since many MKIs are substrates for cytochrome P450 isoenzymes (CYPs), induction or inhibition with strong CYP inhibitors or inducers may lead to significant alterations in MKI exposure. In conclusion, DDIs are of major concern during MKI therapy and need to be monitored closely in clinical practice. Based on the current knowledge and available literature, practical recommendations for management of these DDIs in clinical practice are presented in this review.

Efficacy of Tumor Vaccines and Cellular Immunotherapies in Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

PURPOSE

Programmed cell death protein-1- checkpoint blockers have recently been approved as second-line treatment for advanced non-small-cell lung cancer (NSCLC). Unfortunately, only a subgroup of patients responds and shows long-term survival to these therapies. Tumor vaccines and cellular immunotherapies could synergize with checkpoint blockade, but which of these treatments is most efficacious is unknown. In this meta-analysis, we assessed the efficacy of tumor vaccination and cellular immunotherapy in NSCLC.

METHODS

We searched for randomized controlled trials (RCTs) investigating cellular immunotherapy or vaccines in NSCLC. We used random effects models to analyze overall survival (OS) and progression-free survival (PFS), expressed as hazard ratios (HRs), and differences in time (months). The effect of immunotherapy type, disease stage, tumor histology, and concurrent chemotherapy was assessed using subgroup analysis and meta-regression. All procedures were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

We identified 18 RCTs that matched our selection criteria; these included a total of 6,756 patients. Immunotherapy extended NSCLC survival and PFS, expressed as HR (OS: HR, 0.81, 95% CI, 0.70 to 0.94, P = .01; PFS: HR, 0.83, 95% CI, 0.72 to 0.95, P = .006) and month difference (OS: difference, 5.43 months, 95% CI, 3.20 to 7.65, P < .005; PFS: difference, 3.24 months, 95% CI, 1.61 to 4.88, P < .005). Cellular therapies outperformed tumor vaccines (OS as HR: P = .005, month difference: P < .001; PFS as HR: P = .001, month difference: P = .004). There was a benefit of immunotherapy in low-stage compared with high-stage NSCLC and with concurrent administration of chemotherapy only in one of four outcome measures evaluated (PFS in months: P = .01 and PFS as HR: P = .031, respectively). There was no significant effect of tumor histology on survival or PFS.

CONCLUSION

Tumor vaccines and cellular immunotherapies enhanced OS and PFS in NSCLC. Cellular immunotherapy was found to be more effective than tumor vaccination. These findings have implications for future studies investigating combination immunotherapy in NSCLC.