Effects of Histamine 2-receptor Antagonists and Proton Pump Inhibitors on the Pharmacokinetics of Gefitinib in Patients With Non-small-cell Lung Cancer

Proton pump inhibitors and cancer treatments: Emerging evidence against coadministration

BACKGROUND

Proton pump inhibitors (PPIs) are widely used in cancer patients despite accumulating data showing that they can impact the efficacy of major anticancer drugs. This is particularly important with tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (CPIs).

RESULTS

Most TKIs require gastric acidity for their absorption and some retrospective series demonstrated that coprescription decreases the survival benefit of some TKI use (erlotinib, gefitinib and pazopanib). Relations between microbiota, the immune system, and the efficacy of immunotherapy are now obvious, just as modifications to gut flora after PPIs use are well-known. Many retrospective articles, including articles based on individual-participant data from randomized studies, demonstrated that patients treated with CPIs have a poorer outcome (overall survival, progression-free survival and response rate) when they received PPIs concomitantly, while there was no impact of such coprescription among patients in control arms, not treated with immunotherapies. Similar data were also observed in patients treated with palbociclib.

CONCLUSION

For these interactions, it is very important to use the precautionary principle and warn patients and physicians about this. In patients who require acid suppression because of severe symptoms, using antacids or H2 blockers could be recommended.

Tyrosine kinase inhibitors in cancers: Treatment optimization - Part II

Real-life populations are more heterogeneous than those included in prospective clinical studies. In cancer patients, comorbidities and co-medications favor the appearance of severe adverse effects which can significantly impact quality of life and treatment effectiveness. Most of tyrosine kinase inhibitors (TKI) have been developed with flat oral dosing exposing patients to the risk of poor adherence due to side effects. Additionally, genetic or physiological factors, differences in diet, and drug-drug interactions can lead to inter-individual variability affecting treatment outcomes and increasing the risk of adverse events. Knowledge of the different factors of variability allows individualized patient management. This review examines the effects of adherence, food intake, and pharmaceutical form on the pharmacokinetics of oral TKI, as well as evaluating pharmacokinetics considerations improving TKI management. Concentration-effectiveness and concentration-toxicity data are presented for the selected TKI, and a simple therapeutic drug monitoring schema is outlined to help individualize dosing of oral TKI.

H2 antihistamines: May be useful for combination therapies in cancer?

Cancer morbimortality is still a great concern despite advances in research and therapies. Histamine and its receptors' ligands can modulate different biological responses according to the cell type and the receptor subtype involved. Besides the wide variety of histamine functions in normal tissues, diverse roles in the acquisition of hallmarks of cancer such as sustained proliferative signaling, resistance to cell death, angiogenesis, metastasis, altered immunity and modified microenvironment have been described. This review summarizes the present knowledge of the various roles of histamine H2 receptor (H2R) ligands in neoplasias. A bioinformatic analysis of human tumors showed dissimilar results in the expression of the H2R gene according to tumor type when comparing malignant versus normal tissues. As well, the relationship between patients' survival parameters and H2R gene expression levels also varied, signaling important divergences in the role of H2R in neoplastic progression in different cancer types. Revised experimental evidence showed multiple effects of H2R antihistamines on several of the cited hallmarks of cancer. Interventional and retrospective clinical studies evaluated different H2R antihistamines in cancer patients with two main adjuvant uses: improving antitumor efficacy (which includes regulation of immune response) and preventing toxic adverse effects produced by chemo or radiotherapy. While there is a long path to go, research on H2R antihistamines may provide new opportunities for developing more refined combination therapeutic strategies for certain cancer types to improve patients' survival and health-related quality of life.

Deleterious association between proton pump inhibitor and protein kinase inhibitor exposure and survival for patients with lung cancer: A nationwide cohort study

INTRODUCTION

Previous studies have identified an interaction between protein kinase inhibitors (PKIs) and proton pump inhibitors (PPIs) in patients with lung cancer. This type of interaction may reduce the efficacy of PKIs. However, the effect of PKI-PPI interaction on patient mortality remains controversial. This study set out to determine the impact of PKI-PPI interaction on overall survival for lung cancer patients.

MATERIALS AND METHODS

This study was conducted using data from the French National Health Care Database from January 1, 2011 to December 31, 2021. We identified patients with: (i) an age equal to or greater than 18 years; (ii) lung cancer; and (iii) at least one reimbursement for one of the following drugs: erlotinib, gefitinib, afatinib and osimertinib. Patients were followed-up between the first date of PKI reimbursement and either December 31, 2021 or if they died, the date on which death occurred. The cumulative exposure to PPI duration during PKI treatment was calculated as the ratio between the number of concomitant exposure days to PKI and PPI and the number of exposure days to PKI. A survival analysis using a Cox proportional hazards model was then performed to assess the risk of death following exposure to a PKI-PPI interaction.

RESULTS

34,048 patients received at least one reimbursement for PKIs of interest in our study: 26,133 (76.8 %) were exposed to erlotinib; 3,142 (9.2 %) to gefitinib; 1,417 (4.2 %) to afatinib; and 3,356 (9.9 %) to osimertinib. Patients with concomitant exposure to PKI-PPI interaction during 20 % or more of the PKI treatment period demonstrated an increased risk of death (HR, 1.60 [95 % CI, 1.57-1.64]) compared to other patients. When this cut-off varied from 10 % to 80 %, the estimated HR ranged from 1.46 [95 % CI, 1.43-1.50] to 2.19 [95 % CI, 2.12-2.25].

DISCUSSION/CONCLUSION

In our study, an elevated risk of death was observed in patients exposed to PKI-PPI interaction. Finally, we were able to identify a dose-dependent effect for this interaction. This deleterious effect of osimertinib and PPI was revealed for the first time in real life conditions.

The status of TKI/acid-suppressant concomitant use in 44 hospitals in China: A cross-sectional descriptive study

The irrational use of tyrosine kinase inhibitors (TKIs) has attracted increasing attention, especially because of drug-drug interactions. The objective of this study was to analyze TKI prescriptions and evaluate the rationality of concomitant use of TKIs and acid-suppressants. TKI prescriptions from 2016 to 2018 were collected from hospitals in Beijing, Guangzhou, Hangzhou, and Zhengzhou for 40 d/yr. Focusing on the data in 2018, we analyzed the pharmacoeconomic indicators of TKIs and the number and proportion of different coprescriptions. The evaluation criteria for coprescriptions were based on clinical literature and package inserts. A total of 41,738 TKI prescriptions were assessed. The total dose and sales of imatinib were the highest, the medication days and defined daily doses of gefitinib were the highest, and the highest defined daily cost was sunitinib. Meanwhile, there were 17 TKIs with drug utilization indices of ≤ 1.0. The irrational combination rate of prescriptions of non-cancer-related departments was high in 3 cities, but not Hangzhou. The irrational combination rate of prescription of inpatient prescriptions was > 23% in the 4 cities. The combined use of TKIs and acid-suppressants is common in China and may have a clear or potential impact on the pharmacokinetics, pharmacodynamics, and adverse drug reactions of TKIs. Therefore, it is urgent to implement necessary interventions to stop such irrational use or if the combined use is necessary, to correct adverse consequences. The aims should be to achieve safe and effective use of TKIs and reduce unnecessary costs.

An update on drug-drug interactions associated with proton pump inhibitors

INTRODUCTION

Proton pump inhibitors (PPIs) block the gastric H/K-ATPase, therefore inhibiting acid gastric secretion, leading to an increased pH (>4). They account for an extremely high number of prescriptions worldwide. Numerous drug-drug interactions have been described with PPIs, but all the described interactions do not have clinical significance.

AREAS COVERED

This review will discuss the latest updates on drug-drug interactions with PPIs, focusing on the last ten-year publications in the following areas: anti-infective agents, anticancer drugs, antiplatelet agents and anticoagulants, and antidiabetics.

EXPERT OPINION

Although pharmacokinetic interactions of PPIs have been described with many drugs, their clinical relevance remains controversial. However, given the extremely high number of people being treated with PPIs, clinicians should remain vigilant for interactions that may be clinically significant and require dose adjustment or therapeutic monitoring. Interestingly, not all PPIs have the same pharmacokinetic and pharmacodynamic profile, with some having a strong potential to inhibit CYP2C19, such as omeprazole, esomeprazole and lansoprazole, while others, pantoprazole, rabeprazole and dexlansoprazole, are weak CYP2C19 inhibitors. These may be preferred depending on co-prescribed treatments.In addition, new formulations have been developed to prevent some of the gastric pH-dependent drug interactions and should be evaluated in further large-scale prospective comparative studies.

Impact of the Gastric Acid Suppressant Use on the Safety and Effectiveness of EGFR-TKIs: A Systematic Review and Meta-Analysis

Background The use of gastric acid suppressants (GASs) has an influence on the exposure of some epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and therefore may affect the effectiveness and safety of EGFR-TKIs. The impact of GASs, including proton pump inhibitors (PPIs) and histamine type 2 receptor antagonists (H₂RAs), on the effectiveness and safety of EGFR-TKIs remains unclear. We conducted a meta-analysis to explore the impact of GASs on the effectiveness and safety of EGFR-TKIs in non–small cell lung cancer (NSCLC) patients.

Method We searched the PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases thoroughly from inception to 2nd February 2021, including the studies for NSCLC patients who used GASs, offering the adjusted hazard ratio (HR) of effectiveness outcomes such as overall survival (OS) and progression-free survival (PFS) or adjusted odds ratio (OR) of the adverse drug reaction (ADRs), and the results were calculated with a random effect. Two researchers independently screened the literature, extracted data, and evaluated the quality. Stata 15.0 was used for meta-analysis.

Result Twelve studies were finally included. Nine of them were cohort studies, and three of them were case–control studies. For effectiveness outcomes, the use of GASs was associated with shorter PFS (HR 1.66 [1.40, 1.98]) and OS (HR 1.50 [1.31, 1.72]), and the use of PPIs was associated with shorter OS (HR 1.56 [1.21, 2.02]), regardless of the overlap time and type of EGFR-TKIs. For safety outcomes, the use of GASs (OR 1.98 [1.19, 3.31]) or PPIs (OR 1.91 [1.17, 3.12]) were both associated with an increased risk of hepatotoxicity.

Conclusion The concomitant use of GASs is associated with shorter PFS and OS for NSCLC patients taking EGFR-TKIs and is also associated with a higher risk of hepatotoxicity. The co-administration of GASs should be avoided; if they cannot be avoided, H₂RAs is a better choice.

Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021235018), identifier (PROSPERO 2021 CRD42021235018)

Applications, Challenges, and Outlook for PBPK Modeling and Simulation: A Regulatory, Industrial and Academic Perspective

Several regulatory guidances on the use of physiologically based pharmacokinetic (PBPK) analyses and physiologically based biopharmaceutics model(s) (PBBM(s)) have been issued. Workshops are routinely held, demonstrating substantial interest in applying these modeling approaches to address scientific questions in drug development. PBPK models and PBBMs have remarkably contributed to model-informed drug development (MIDD) such as anticipating clinical PK outcomes affected by extrinsic and intrinsic factors in general and specific populations. In this review, we proposed practical considerations for a "base" PBPK model construction and development, summarized current status, challenges including model validation and gaps in system models, and future perspectives in PBPK evaluation to assess a) drug metabolizing enzyme(s)- or drug transporter(s)- mediated drug-drug interactions b) dosing regimen prediction, sampling timepoint selection and dose validation in pediatric patients from newborns to adolescents, c) drug exposure in patients with renal and/or and hepatic organ impairment, d) maternal-fetal drug disposition during pregnancy, and e) pH-mediated drug-drug interactions in patients treated with proton pump inhibitors/acid-reducing agents (PPIs/ARAs) intended for gastric protection. Since PBPK can simulate outcomes in clinical studies with enrollment challenges or ethical issues, the impact of PBPK models on waivers and how to strengthen study waiver is discussed.

Proton Pump Inhibitors and Cancer: Current State of Play

Background: Proton pump inhibitors (PPIs) are one of the most widely used drugs worldwide and are overprescribed in patients with cancer; there is increasing evidence of their effects on cancer development and survival. The objective of this narrative review is to comprehensively identify cancer medications that have clinically meaningful drug–drug interactions (DDIs) with PPIs, including loss of efficacy or adverse effects, and to explore the association between PPIs and cancer.

Methods: A PubMed search of English language studies published from 1 January 2016, to 1 June 2021 was conducted. The search terms included “proton pump inhibitors,” “cancer,” “chemotherapy,” “immunotherapy,” “hormonotherapies,” “targeted therapies,” “tyrosine kinase inhibitors,” and “gut microbiome”. Recent and relevant clinical trials, meta-analyses, and reviews were included.

Results: PPIs may have pro-tumor activity by increasing plasma gastrin levels or anti-tumor activity by inhibiting V-ATPases. However, their impact on cancer survival remains unclear. PPIs may decrease the efficacy of some antineoplastic agents through direct DDIs (e.g., some tyrosine kinase inhibitors, capecitabine, irinotecan, methotrexate). More complex DDIs seem to exist for immunotherapies with indirect interactions through the microbiome. PPIs worsen hypomagnesemia, bone loss, iron, and vitamin B12 deficiencies but may have a protective effect on the renal system.

Discussion/Conclusions: PPIs may interact with the cancer microbiome and the efficacy of various antineoplastic agents, although only a few DDIs involving PPIs are clinically significant. Further pharmaco-epidemiological studies are warranted, but physicians should be aware of the potential consequences of PPI use, which should be dose appropriate and prescribed according to guidelines.

Concomitant Gastric Acid Suppressants on the Survival of Patients with Non-Small-Cell Lung Cancer Treated with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors: A Meta-Analysis

BACKGROUND

The influence of concomitant use of gastric acid suppressants (AS) on survival of patients with non-small-cell lung cancer (NSCLC) treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) is inconsistent according to previous studies. We performed a meta-analysis to evaluate the effect of additional AS in patients with NSCLC taking TKIs.

METHODS

Relevant observational studies were identified by a search of Medline, Embase, and Web of Science databases. Only studies with multivariate analyses were included. A random-effect model was used to combine the results.

RESULTS

Thirteen retrospective studies with 12259 patients were included. Pooled results showed that concomitant use of AS was associated with worse progression-free survival (PFS, adjusted hazard ratio (HR): 1.57, 95% confidence interval (CI): 1.31 to 1.89, P < 0.001; I ² = 65%) and overall survival (OS, adjusted HR: 1.38, 95% CI: 1.19 to 1.61, P < 0.001; I ² = 70%) in NSCLC patients taking TKIs. Sensitivity analysis limited to studies including NSCLC with EGFR mutation showed consistent results (HR for PFS: 1.53, P=0.003; HR for OS: 1.43, P=0.001). Subgroup analyses indicated that the association between concomitant use of AS and poor survival was not significantly affected by the category of AS used (proton pump inhibitors or histamine type-2 receptor antagonists) or the country of the study (Asian or non-Asian, P for subgroup analysis all >0.05).

CONCLUSIONS

Concomitant use of AS in patients with NSCLC taking TKIs may be associated with poor survival outcomes.

Exploring the Relationship of Drug BCS Classification, Food Effect, and Gastric pH-Dependent Drug Interactions

Food effect (FE) and gastric pH-dependent drug-drug interactions (DDIs) are both absorption-related. Here, we evaluated if Biopharmaceutics Classification System (BCS) classes may be correlated with FE or pH-dependent DDIs. Trends in FE data were investigated for 170 drugs with clinical FE studies from the literature and new drugs approved from 2013 to 2019 by US Food and Drug Administration. A subset of 38 drugs was also evaluated to determine whether FE results can inform the need for a gastric pH-dependent DDI study. The results of FE studies were defined as no effect (AUC ratio 0.80-1.25), increased exposure (AUC ratio ≥1.25), or decreased exposure (AUC ratio ≤0.8). Drugs with significantly increased exposure FE (AUC ratio ≥2.0; N=14) were BCS Class 2 or 4, while drugs with significantly decreased exposure FE (AUC ratio ≤0.5; N=2) were BCS Class 1/3 or 3. The lack of FE was aligned with the lack of a pH-dependent DDI for all 7 BCS Class 1 or 3 drugs as expected. For the 13 BCS Class 2 or 4 weak base drugs with an increased exposure FE, 6 had a pH-dependent DDI (AUC ratio ≤0.8). Among the 16 BCS Class 2 or 4 weak base drugs with no FE, 6 had a pH-dependent DDI (AUC ratio ≤0.8). FE appears to have limited correlation with BCS classes except for BCS Class 1 drugs, confirming that multiple physiological mechanisms can impact FE. Lack of FE does not indicate absence of pH-dependent DDI for BCS Class 2 or 4 drugs. Graphical Abstract.

Relationship between Plasma Concentrations of Afatinib and the Onset of Diarrhea in Patients with Non-Small Cell Lung Cancer

Simple Summary

Higher afatinib plasma concentrations have been reported to be associated with the severity of diarrhea; however, the specific target plasma concentration of afatinib required to avoid severe diarrhea onset is unclear. We found that an afatinib AUC_0–24 of greater than or equal to 823.5 ng·h/mL and C₀ of greater than or equal to 28.5 ng/mL may be used as cut-off values for the incidence of afatinib-induced grade 2 diarrhea. A significant correlation between the AUC_0–24 and C₀ of afatinib was observed (r² = 0.761; p < 0.001). Therefore, we could use C₀ as a marker of therapeutic drug monitoring. In the current study, the median time to the incidence of grade 2 diarrhea in patients with a C₀ of more than 28.5 ng/mL was 16 days. Therefore, we recommend monitoring the C₀ of afatinib on day 8 after the beginning of afatinib therapy.

Abstract

We evaluated the area under the plasma concentration–time curve (AUC) of afatinib required to avoid the onset of grade 2 or higher diarrhea. The C₀ and AUC_0–24 of afatinib were significant higher in patients with grade 2 diarrhea than in those with grade 0–1 diarrhea. The areas under the receiver operator curves were 0.795 with the highest sensitivity (89%) and specificity (74%) at an AUC_0–24 threshold of 823.5 ng·h/mL, and 0.754 with the highest sensitivity (89%) and specificity (74%) at a C₀ threshold of 28.5 ng/mL. In Kaplan–Meier analysis based on these cut-off AUC_0–24 and C₀ values, the median time to the incidence of grade 2 diarrhea was 16 days. The predicted AUC_0–24 of afatinib from the single point of C₆ showed the highest correlation with the measured AUC_0–24 (r² = 0.840); however, a significant correlation between the AUC_0–24 and C₀ was also observed (r² = 0.761). C₀ could be used as a marker of therapeutic drug monitoring because afatinib C₀ was related to AUC_0–24. Therefore, afatinib C₀ should be monitored on day 8 after beginning therapy, and the daily dose of afatinib should be adjusted as an index with a cut-off value of 28.5 ng/mL.

Comprehensive identification, fragmentation pattern, and metabolic pathways of gefitinib metabolites via UHPLC-Q-TOF-MS/MS: in vivo study of rat plasma, urine, bile, and faeces

Gefitinib, the first approved inhibitor for oral epidermal growth factor receptor (EGFR), has been proved to be effective in non-small cell lung cancer with EGFR mutation. However, there are many metabolites of gefitinib that have not been identified in vivo. This study aims to identify the metabolites of gefitinib and its metabolic pathways in rats using ultra-high-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) detector. Protein precipitation, solid-phase and ultrasonic extraction were used for the pre-treatment of plasma, urine, bile and faeces samples. In this study, a total of 28 compounds were identified in rat plasma, 29 in bile, 20 in urine and 16 in faeces. 20 new compounds were firstly reported as metabolites of gefitinib. Reduction, hydroxylation, dealkylation and dehalogenation were the major metabolic pathways in phase I. For phase II, the main pathways were sulphate and glucuronide conjugation. The fragment ions of gefitinib and its metabolites were usually generated via the fracture of C₁-O bond of propoxy on the C₆ position of aniline quinazoline ring. The results may be valuable and important for understanding the metabolic process of gefitinib in clinical application and drug safety.

Impact of histamine type-2 receptor antagonists on the anticancer efficacy of gefitinib in patients with non-small cell lung cancer

PURPOSE

Gefitinib is one of the standard treatments for non-small cell lung cancer (NSCLC) with epidermal growth factor receptor mutations. It has been reported that acid suppressants (AS) decrease the anti-tumor effect of gefitinib by reducing its solubility. AS is sometimes necessary in cancer patients; however, previous reports have not shown the most compatible AS with gefitinib administration in cancer patients. This study was conducted to determine if histamine type 2 receptor antagonists (H2RAs) can affect the anti-tumor efficacy of gefitinib.

METHODS

Eighty-seven patients with NSCLC who were administered gefitinib were retrospectively investigated. Patients who were co-administered H2RA were compared with non-AS control patients. H2RA was administered once a day at about 3-5 or 8-12 h after gefitinib intake. The primary endpoint of this study was progression-free survival (PFS), and secondary endpoints were overall survival (OS), overall response rate (ORR), and adverse effects.

RESULTS

Median PFS in H2RA group and control group was 8.0 months and 9.0 months, respectively, with no significant difference (p = 0.82). The incidence of liver dysfunction was significantly less in patients administered H2RA, whereas there were no differences between the two groups with regard to skin toxicity and diarrhea. Multivariate analysis suggested that H2RA co-administration is not a risk factor for worse PFS and OS (hazard ratio of 0.95, 0.86; 95% confidence interval of 0.60-1.48, 0.52-1.43; p = 0.82 and 0.60, respectively).

CONCLUSION

This study demonstrated that concomitant administration of H2RA with gefitinib does not affect the efficacy of gefitinib.

ABCG2 C421A polymorphisms affect exposure of the epidermal growth factor receptor inhibitor gefitinib

ATP-binding castle protein G2 (ABCG2) is thought to inhibit the activities of certain gefitinib transporters, thereby affecting drug pharmacokinetics. The C421A polymorphism affects the function and expression of ABCG2 on the cell membrane. Previous studies have shown that proton-pump inhibitors (PPIs) inhibit gefitinib absorption, as well as the function of ABCG2. We evaluated the plasma concentrations of gefitinib in patients with and without the ABCG2 C421A polymorphism, who were or were not taking PPIs. In total, 61 patients with advanced epidermal-growth-factor-positive non-small-cell lung cancer were enrolled in this study. They were treated with gefitinib at a dose of 250 mg per day. Plasma gefitinib concentration and ABCG2 C421A status were determined after 2 weeks. The patients were divided into CC- and CA/AA genotype groups. We compared the trough and peak gefitinib levels and the area under the curve (AUC) values for 24-h gefitinib concentrations. We also compared these parameters among four groups distinguished according to the presence or absence of the polymorphism and PPI use. The mean trough gefitinib level and AUC value for 24-h gefitinib concentration were significantly lower in the CA/AA group compared to the CC group (mean trough level: 333.2 vs. 454.5 ng/mL, respectively, P = 0.021; AUC: 9949.9 vs. 13,085.4 ng・h/mL, respectively, P = 0.034). Among patients taking PPIs, the mean trough gefitinib level was significantly lower in the CA/AA group than the CC group (220.1 vs. 340.5 ng/mL, respectively, P = 0.033). The CA/AA-type of ABCG2 C421A polymorphism may be associated with lower gefitinib plasma concentrations.

Effects of STAT3 polymorphisms and pharmacokinetics on the clinical outcomes of gefitinib treatment in patients with EGFR-mutation positive non-small cell lung cancer

WHAT IS KNOWN AND OBJECTIVE

We investigated the correlations among signal transducer and activator of transcription 3 (STAT3) rs4796793C >G polymorphism, gefitinib pharmacokinetics and clinical responses in Japanese patients with non-small cell lung cancer receiving gefitinib therapy.

METHODS

Forty-five patients were enrolled in this study. Plasma trough concentrations (C₀ ) of gefitinib at the steady-state were measured by high-performance liquid chromatography.

RESULTS AND DISCUSSION

Patients having a gefitinib C₀ of at least ≥200 ng/mL had significantly longer PFS than patients having a C₀ of <200 ng/mL (median [95% confidence interval (CI)] PFS: 11.0 [8.2-13.7] and 5.3 [0.0-12.0] months, respectively, P = .042). There were no significant differences in PFS between patients with STAT3 rs4796793C/C and G alleles; however, patients with STAT3 rs4796793C/C having a gefitinib C₀ of ≥ 200 ng/mL had significantly longer progression-free survival (PFS) and overall survival (OS) than those with a C₀ of <200 ng/mL (median [95% CI] PFS: 11.4 [4.1-18.6] and 3.0 [0.0-7.0] months, respectively, P = .008; median [95% CI] OS: 20.6 [7.4-33.7] and 12.6 [10.1-15.1] months, respectively, P = .042). In patients with the STAT3 rs4796793G allele, there were no significant differences in PFS and OS between the two gefitinib C₀ groups. In addition, there were no significant differences in PFS or OS according to smoking, presence of proton pump inhibitor combination, or onset of side effects.

WHAT IS NEW AND CONCLUSION

Clinical outcomes of gefitinib in patients with the STAT3 rs4796793C/C genotype depended on plasma concentrations of gefitinib. In addition to information regarding EGFR mutations, the STAT3 rs4796793C >G polymorphism and gefitinib C₀ may be potential predictors of clinical outcomes after beginning of gefitinib therapy.

Clinical Impact of Gastric Acid Suppressants Use on the Efficacy of Gefitinib in Patients with Advanced Adenocarcinoma of the Lung Harboring Common EGFR Mutations

Background:

Gefitinib was approved by the Food and Drug Administration (FDA) of the United States (US) for the treatment of advanced non-small cell carcinoma harboring sensitizing epidermal growth factor receptor (EGFR) mutations. The use of gastric acid-suppressing medication inhibits gefitinib absorption and reduces its plasma concentration, but retrospective studies on whether there is the corresponding repercussion on progression-free survival (PFS) have yielded variable results, mainly due to heterogeneity in study cohorts and study designs.

Objectives:

To assess the clinical impact of the use of gastric acid-suppressing medication in patients on first-line gefitinib for NSLC harboring common EGFR mutation.

Methods:

This is a retrospective cohort study conducted in a single, tertiary referral center in Hong Kong S.A.R., which included 193 Chinese patients with advanced adenocarcinoma of lung harboring common sensitizing EGFR mutations who received gefitinib as the first-line treatment. The progression- free survival (PFS) and overall survival (OS) for patients who took gastric acid-suppressing agents, namely histamine-2 receptor antagonists (H2RA) or proton pump inhibitors (PPI), were compared with those who did not take such medication (control group).

Results:

Despite the universal practice to separate the medicating time of gastric acid suppressants and EGFR-TKIs by 12 hours, patients who were on gastric acid suppressants had significantly shorter PFS, especially for those on proton pump inhibitor (Median 368 vs. 189 vs. 166 days - For control, H2RA group and PPI group respectively, p-value <0.001). The OS is also significantly shorter for those taking gastric acid suppressants (Median 825 vs. 485 vs. 422 days - For control, H2RA group and PPI group respectively, p-value <0.001).

Conclusions:

The co-administration of gastric acid suppressants with gefitinib is associated with shorter progression-free survival and overall survival.

[Proton pump inhibitors and cancers: A hazardous association?]

Proton pump inhibitors, a major progress in gastro-enterology, are globally among the most widely prescribed drugs. But, due to their strong gastric acid inhibition, they can be responsible for side effects, particularly in cancer patients. They are involved in renal function impairment, bone fractures, digestive bacterial overgrowth, particularlyclostridium difficile infections, anemia and hypomagnesemia. Long term use can increase the risks of gastric, pancreatic and liver cancers. They decrease absorption of weak bases drugs, particularly tyrosine kinase inhibitors and capecitabine and are responsible for a poorer prognosis if taken concomitantly with erlotinib, gefitinib and pazopanib. Modification of cyclin dependent kinases is also possible as well as decrease of efficacy of immune check point inhibitors (microbiome modifications). Absoption and efficacy of capecitabine seem also poorer with negative prognosis effect on treatment of gastric and colon cancer. Their long term use, particularly in cancer patients, should probably be avoided.

Harnessing the therapeutic potential of anticancer drugs through amorphous solid dispersions

The treatment of cancer is still a major challenge. But tremendous progress in anticancer drug discovery and development has occurred in the last few decades. However, this progress has resulted in few effective oncology products due to challenges associated with anticancer drug delivery. Oral administration is the most preferred route for anticancer drug delivery, but the majority of anticancer drugs currently in product pipelines and the majority of those that have been commercially approved have inherently poor water solubility, and this cannot be mitigated without compromising their potency and stability. The poor water solubility of anticancer drugs, in conjunction with other factors, leads to suboptimal pharmacokinetic performance. Thus, these drugs have limited efficacy and safety when administered orally. The amorphous solid dispersion (ASD) is a promising formulation technology that primarily enhances the aqueous solubility of poorly water-soluble drugs. In this review, we discuss the challenges associated with the oral administration of anticancer drugs and the use of ASD technology in alleviating these challenges. We emphasize the ability of ASDs to improve not only the pharmacokinetics of poorly water-soluble anticancer drugs, but also their efficacy and safety. The goal of this paper is to rationalize the application of ASD technology in the formulation of anticancer drugs, thereby creating superior oncology products that lead to improved therapeutic outcomes.

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.

[Personalized medicine for oral molecular-targeted anticancer drugs]

Therapeutic drug monitoring (TDM) is carried out by evaluating drug plasma (or serum) concentrations in response to individual optimal treatments by dose adjustment to improve efficacy or avoid side effects. Many molecular-targeted anticancer drugs show exposure-efficacy and exposure-toxicity relationships. Therefore, plasma concentrations of anticancer drugs can be used as biomarkers. However, to carry out TDM, therapeutic target ranges indicating exposure-response (efficacy/toxicity) relationships must be determined. In Japan, treatment fees for managing the TDM of imatinib and sunitinib have been assessed since 2012 and 2018, respectively. In therapy for imatinib or sunitinib using TDM, reduced toxicity, discontinuation rates, and costs for treatments as well as improved clinical efficacy have been noted. To establish the use of TDM in clinical practice, it is necessary to determine target plasma concentrations (minimum effective concentration or minimum toxic concentration) of many molecular-targeted anticancer drugs by retrospective and prospective clinical trials. In these clinical trials, analytical methods with high precision are needed. By carrying out TDM, we may determine the optimal anticancer therapy for patients as precision medicine after the start of therapy.