Efficacy and safety of trastuzumab with or without a tyrosine kinase inhibitor for HER2-positive breast cancer: A systematic review and meta-analysis

BACKGROUND

This study aimed to explore the efficacy and safety of trastuzumab plus tyrosine kinase inhibitors (TKIs) compared with those of trastuzumab monotherapy in patients with human epidermal growth factor receptor (HER2)-positive breast cancer.

METHODS

The PubMed, Embase, Cochrane, and Web of Science databases were systematically searched for relevant articles from inception until September 2022. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Subgroup analyses were performed based on disease status, TKI type, and hormone receptor status.

RESULTS

Sixteen studies were included in the current analysis. Trastuzumab plus TKI significantly improved OS and PFS compared to trastuzumab monotherapy. In the neoadjuvant setting, trastuzumab plus TKI significantly increased the pathologic complete response (pCR) rate compared to trastuzumab monotherapy. Moreover, a higher objective response rate (ORR) was observed with trastuzumab plus TKI. Patients who received the combination therapy had a higher incidence of discontinuation, all-grade diarrhea, and grade ≥ 3 diarrhea.

CONCLUSIONS

Trastuzumab plus TKI was better than trastuzumab monotherapy for treating different stages of HER2-positive breast cancer. The safety of trastuzumab plus TKI anti-HER2 therapy was controllable. The different efficacies of TKIs combined with trastuzumab may be related to the mechanism of action of the different TKIs, needing further investigations.

Relevance of Therapeutic Drug Monitoring of Tyrosine Kinase Inhibitors in Routine Clinical Practice: A Pilot Study

INTRODUCTION

The main goal of treatment in cancer patients is to achieve the highest therapeutic effectiveness with the least iatrogenic toxicity. Tyrosine kinase inhibitors (TKIs) are anticancer oral agents, usually administered at fixed doses, which present high inter- and intra-individual variability due to their pharmacokinetic characteristics. Therapeutic drug monitoring (TDM) can be used to optimize the use of several types of medication.

OBJECTIVE

We evaluated the use of TDM of TKIs in routine clinical practice through studying the variability in exposure to erlotinib, imatinib, lapatinib, and sorafenib and dose adjustment.

MATERIALS AND METHODS

We conducted a retrospective analytical study involving patients who received treatment with TKIs, guided by TDM and with subsequent recommendation of dose adjustment. The quantification of the plasma levels of the different drugs was performed using high-performance liquid chromatography (HPLC). The Clinical Research Ethics Committee of the Hospital Quirónsalud Torrevieja approved this study.

RESULTS

The inter-individual variability in the first cycle and in the last monitored cycle was 46.2% and 44.0% for erlotinib, 48.9 and 50.8% for imatinib, 60.7% and 56.0% for lapatinib and 89.7% and 72.5% for sorafenib. Relationships between exposure and baseline characteristics for erlotinib, imatinib, lapatinib and sorafenib were not statistically significant for any of the variables evaluated (weight, height, body surface area (BSA), age and sex). Relationships between height (p = 0.021) and BSA (p = 0.022) were statistically significant for sorafenib. No significant relationships were observed between C_trough and progression-free survival (PFS) or overall survival (OS) for any drug, except in the case of sunitinib (correlation between C_trough and PFS p = 0.023) in the exposure-efficacy analysis.

CONCLUSIONS

Erlotinib, imatinib, lapatinib and sorafenib show large inter-individual variability in exposure. TDM entails a significant improvement in exposure and enables more effective and safe use of TKIs in routine clinical practice.

Estimating Similarity of Dose-Response Relationships in Phase I Clinical Trials-Case Study in Bridging Data Package

Bridging studies are designed to fill the gap between two populations in terms of clinical trial data, such as toxicity, efficacy, comorbidities and doses. According to ICH-E5 guidelines, clinical data can be extrapolated from one region to another if dose–reponse curves are similar between two populations. For instance, in Japan, Phase I clinical trials are often repeated due to this physiological/metabolic paradigm: the maximum tolerated dose (MTD) for Japanese patients is assumed to be lower than that for Caucasian patients, but not necessarily for all molecules. Therefore, proposing a statistical tool evaluating the similarity between two populations dose–response curves is of most interest. The aim of our work is to propose several indicators to evaluate the distance and the similarity of dose–toxicity curves and MTD distributions at the end of some of the Phase I trials, conducted on two populations or regions. For this purpose, we extended and adapted the commensurability criterion, initially proposed by Ollier et al. (2019), in the setting of completed phase I clinical trials. We evaluated their performance using three synthetic sets, built as examples, and six case studies found in the literature. Visualization plots and guidelines on the way to interpret the results are proposed.

Pharmacokinetics of Lapatinib, a Nonrenally Cleared Drug, in Patients With End-Stage Renal Disease on Maintenance Hemodialysis

Lapatinib, a tyrosine kinase inhibitor, is approved for the treatment of breast cancer. The literature shows that it is metabolized by CYP3A4 and eliminated predominantly (>90%) by the fecal route, with minimal (<2%) renal elimination in healthy subjects (dose of 250 mg); in cancer patients, renal elimination is minimal at therapeutic doses. For nonrenally cleared drugs, while there is ample evidence of pharmacokinetic alterations secondary to renal impairment-induced effects on drug metabolizing enzymes and/or transporters, the effect of end-stage renal disease (ESRD) on lapatinib pharmacokinetics has not been determined. Rather, as stated in the drug's label, the expectation is lack of effect of renal impairment on lapatinib pharmacokinetics based on its minimal renal elimination. The current report addresses this gap with pharmacokinetic data (obtained in a 1-way drug interaction study) in ESRD patients (n = 11) on maintenance hemodialysis and compared with published data in 37 healthy subjects in 3 separate studies. Following a 250-mg oral dose in ESRD patients, the median t_max was 3.0 hours, and geometric mean (95%CI) values for C_max , AUC_inf , and t_1/2 were 349 ng/mL (245-499 ng/mL), 4410 ng·h/mL (2960-6580 ng·h/mL), and 14.8 hours (9.7-22.5 hours), respectively. These parameters approximated published values in healthy subjects and demonstrated that renal impairment and hemodialysis did not affect lapatinib pharmacokinetics. The results of the present study in this renally impaired population, the only such information available to date, support the drug's label and are valuable in view of the recognized difficulties in enrolling organ-impaired patients in oncology trials.

Impact of race on dose selection of molecular-targeted agents in early-phase oncology trials

Background

We examined the impact of race on the maximum tolerated doses (MTD) and final approved doses (FAD) of single-agent molecular-targeted agents (MTA) in North America/Europe (NA/EU) and Asia.

Methods

We searched PubMed and regulatory databases to identify targeted drugs approved globally and compared their FAD and MTD in corresponding phase I/II studies conducted separately in NA/EU and Asia. To evaluate this further, we conducted parallel, prospective, first-in-human studies of DS-7423, a dual PI3K/mTOR inhibitor, in patients with advanced solid tumours in the US and Japan. We pooled and compared the pharmacokinetics (PK), pharmacodynamics (PD), toxicity, and efficacy between these populations.

Results

17 MTA were approved in NA/EU and Asia from 2001 to 2015. Recommended phase 2 doses (RP2D) were identical across races in 14 of 17 (80%) studies and differences were not clinically meaningful. FAD were identical across all regions. 42 and 27 patients from US and Japan, respectively, were enrolled in the phase I studies of DS-7423. Despite differences in race, body weight, and body mass index, the RP2D were 240 mg/day with no differences in toxicities, PK, PD, or efficacy.

Conclusions

Conducting separate clinical trials of single-agent MTA in Caucasian and Asian populations may be redundant.

Prediction of Apparent Oral Clearance of Small-Molecule Inhibitors in Pediatric Patients

The purpose of this study was to build regression models for the prediction of apparent oral clearance (CL/F) for small-molecule inhibitors in the pediatric population using data obtained from adults. Two approaches were taken; a simple allometric regression model which considers no interdrug or interindividual variability and an allometric regression model with mixed-effects modeling where some variability parameters are included in the model. Average CL/F values were obtained for 15 drugs at various dosages from 31 literatures (a total of 139 data sets) conducted in adults and for 15 drugs from 26 literatures (62 data sets) conducted in children. Data were randomly separated into the "modeling" or "validation" data set, and the 2 allometric regression models were applied to the modeling data set. The predictive ability of the models was examined by comparing the observed and model-predicted CL/F in children using the validation data set. The percentage root mean square error was 17.2% and 26.3% in the simple allometric regression model and the allometric regression model with mixed-effects modeling, respectively. The predictive ability of the 2 models seems acceptable, suggesting that they could be useful for predicting the CL/F of new small-molecule inhibitors and for determining adequate doses in clinical pharmacotherapy for children.

New chemical scaffolds for human african trypanosomiasis lead discovery from a screen of tyrosine kinase inhibitor drugs

Human African trypanosomiasis (HAT) is caused by the protozoan Trypanosoma brucei. New drugs are needed to treat HAT because of undesirable side effects and difficulties in the administration of the antiquated drugs that are currently used. In human proliferative diseases, protein tyrosine kinase (PTK) inhibitors (PTKIs) have been developed into drugs (e.g., lapatinib and erlotinib) by optimization of a 4-anilinoquinazoline scaffold. Two sets of facts raise a possibility that drugs targeted against human PTKs could be "hits" for antitrypanosomal lead discoveries. First, trypanosome protein kinases bind some drugs, namely, lapatinib, CI-1033, and AEE788. Second, the pan-PTK inhibitor tyrphostin A47 blocks the endocytosis of transferrin and inhibits trypanosome replication. Following up on these concepts, we performed a focused screen of various PTKI drugs as possible antitrypanosomal hits. Lapatinib, CI-1033, erlotinib, axitinib, sunitinib, PKI-166, and AEE788 inhibited the replication of bloodstream T. brucei, with a 50% growth inhibitory concentration (GI50) between 1.3 μM and 2.5 μM. Imatinib had no effect (i.e., GI50>10 μM). To discover leads among the drugs, a mouse model of HAT was used in a proof-of-concept study. Orally administered lapatinib reduced parasitemia, extended the survival of all treated mice, and cured the trypanosomal infection in 25% of the mice. CI-1033 and AEE788 reduced parasitemia and extended the survival of the infected mice. On the strength of these data and noting their oral bioavailabilities, we propose that the 4-anilinoquinazoline and pyrrolopyrimidine scaffolds of lapatinib, CI-1033, and AEE788 are worth optimizing against T. brucei in medicinal chemistry campaigns (i.e., scaffold repurposing) to discover new drugs against HAT.

Physiologically based pharmacokinetic model of lapatinib developed in mice and scaled to humans

Lapatinib is an oral 4-anilinoquinazoline derivative that dually inhibits epidermal growth factor receptor and human epidermal growth factor receptor 2 (HER2). This drug is a mere decade old and has only been approved by the FDA for the treatment of breast cancer since 2007. Consequently, the intricacies of the pharmacokinetics are still being elucidated. In the work presented herein, we determined the biodistribution of orally administered lapatinib in mouse plasma, brain, heart, lung, kidney, intestine, liver, muscle and adipose tissue. Using this data, we subsequently developed a physiologically based pharmacokinetic (PBPK) model of lapatinib in mice that accurately predicted the tissue concentrations after doses of 30, 60 and 90 mg/kg. By taking into account interspecies differences in physiology and physiochemistry, we then extrapolated the mouse PBPK model to humans. Our model predictions closely reflected lapatinib plasma pharmacokinetics in healthy subjects. Additionally, we were also able to simulate the pharmacokinetics of this drug in the plasma of patients with solid malignancies by incorporating a decrease in liver metabolism into the model. Finally, our PBPK model also facilitated the estimation of various human tissue exposures to lapatinib, which harmonize with the organ-specific toxicities observed in clinical trials. This first-generation PBPK model of lapatinib can be further improved with a greater understanding of lapatinib absorption, distribution, metabolism and excretion garnered from subsequent in vitro and in vivo studies and expanded to include other pharmacokinetic determinants, including efflux transporters, metabolite generation, combination dosing, etc., to better predict lapatinib disposition in both mouse and man.

A phase II study of lapatinib for brain metastases in patients with HER2-overexpressing breast cancer following trastuzumab based systemic therapy and cranial radiotherapy: subset analysis of Japanese patients

BACKGROUND

It is known that one third of patients with human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic breast cancer (MBC) treated with trastuzumab will develop brain metastases. As the development of brain metastases is fatal, controlling its progression is clinically meaningful. However, effective therapy for MBC patients with brain metastasis after cranial radiation is limited. The international clinical study in which six Japanese patients participated indicated the antitumor activity of lapatinib against brain metastases of HER2-overexpressing breast cancer.

METHODS

The efficacy, safety, and pharmacokinetics of lapatinib 750 mg given twice daily to Japanese HER2-overexpressing MBC patients with brain metastases were assessed as part of the international clinical study.

RESULTS

Of six Japanese patients treated in this study, two patients had shown volumetric reduction >20 % in their central nervous system (CNS), one of whom had >50 % reduction. Three patients, including two of these patients, had shown >20 % volumetric reduction in non-CNS lesions. Frequently reported adverse events were diarrhea and rash, all of which were controllable. The AUC0-12 of lapatinib on day 28 was 1.74 times higher than that on day 1.

CONCLUSION

These results suggest that lapatinib monotherapy 750 mg given twice daily can exert some efficacy and has potential as a clinically meaningful treatment option for Japanese HER2-overexpressing breast cancer patients with brain metastases after cranial radiation.

Evaluation of cardiac safety of lapatinib therapy for ErbB2-positive metastatic breast cancer: a single center experience

Lapatinib is a dual tyrosine kinase inhibitor (TKI) that has a considerable efficacy in ErbB2-positive metastatic breast cancer (MBC). Previous studies revealed that TKIs caused cardiotoxicity in approximately 10 % of the patients. This study assessed the cardiac safety of lapatinib in women with ErbB2-positive MBC. In this observational single center study, all patients with ErbB2-positive MBC who were previously treated with anthracycline, taxanes, and trastuzumab in the adjuvant and/or metastatic setting were assigned to receive lapatinib at a dose of 1,250 mg per day continuously plus capecitabine at a dose of 2,000 mg/m(2) in two divided doses on days 1 through 14 of a 21-day cycle. Cardiac toxicity was assessed with symptoms, transthoracic echocardiography, electrocardiography and biochemical markers (brain natriuretic peptide (BNP), creatine kinase (CK) and creatine kinase-MB) at baseline and every 9 weeks until disease progression. Twenty-six patients were treated with lapatinib and capecitabine therapy for a median of 18 (range 3-60) weeks. The median age was 48 (range 28-83) years. All patients had ErbB2-positive MBC. Among 25 eligible patients, 5 (19.2 %) patients experienced new cardiac events compared with baseline findings. Of these 5 patients, 1 (3.8 %) had T wave negativity, 1 (3.8 %) had sinus tachycardia, 1 (3.8 %) had grade 1 (453 ms) QT prolongation, and 2 (7.7 %) had decreased LVEF below the critical level. Among eligible 21 patients, 2 (7.7 %) had increased BNP, 1 (3.8 %) had increased CK, and 1 (3.8 %) had increased CK-MB level compared with baseline. No serious cardiac events that required monitorization or medication occurred. There was no statistically significant relationship between the duration of lapatinib administration and LVEF changes, QT prolongation, BNP, CK, and CK-MB level. According to our findings, lapatinib was safe and well tolerated and has a low incidence of cardiac side effects. Therefore, it seemed that cardiotoxicity was not a class effect of TKIs. However, despite the absence of clinically significant adverse cardiac effects under lapatinib therapy, the incidence of cardiotoxicity reported in our study was higher than previous lapatinib studies.

Interactions of tyrosine kinase inhibitors with organic cation transporters and multidrug and toxic compound extrusion proteins

The drug-drug interaction (DDI) potential of tyrosine kinase inhibitors (TKI) as interacting drugs via transporter inhibition has not been fully assessed. Here, we estimated the half maximal inhibitory concentration (IC(50)) values for 8 small-molecule TKIs (imatinib, dasatinib, nilotinib, gefitinib, erlotinib, sunitinib, lapatinib, and sorafenib) on [(14)C]metformin transport by human organic cation transporters (OCT), OCT1, OCT2, and OCT3, and multidrug and toxic compound extrusion (MATE) proteins, MATE1 and MATE2-K, using human embryonic kidney cells stably expressing these transporters. We then compared the estimated IC(50) values to the maximum clinical concentrations of unbound TKIs in plasma (unbound C(max,sys,p)). Results showed that imatinib, nilotinib, gefitinib, and erlotinib exerted selectively potent inhibitory effects, with unbound C(max,sys,p)/IC(50) values ≥0.1, on MATE1, OCT3, MATE2-K, and OCT1, respectively. In comparison to the common form of OCT1, the OCT1 polymorphism, M420del, was more sensitive to drug inhibition by erlotinib. Major metabolites of several TKIs showed IC(50) values similar to those for unchanged TKIs. Taken together, these findings suggest the potential of clinical transporter-mediated DDIs between specific TKIs and OCTs and MATEs, which may affect the disposition, efficacy, and toxicity of metformin and other drugs that are substrates of these transporters. The study provides the basis for further clinical DDI studies with TKIs.