Effect of severe renal impairment on the pharmacokinetics of brigatinib

Re-discover the value of protein binding assessments in hepatic and renal impairment studies and its contributions in drug labels and dose decisions

One of the key pharmacokinetic properties of most small molecule drugs is their ability to bind to serum proteins. Unbound or free drug is responsible for pharmacological activity while the balance between free and bound drug can impact drug distribution, elimination, and other safety parameters. In the hepatic impairment (HI) and renal impairment (RI) clinical studies, unbound drug concentration is often assessed; however, the relevance and impact of the protein binding (PB) results is largely limited. We analyzed published clinical safety and pharmacokinetic studies in subjects with HI or RI with PB assessment up to October 2022 and summarized the contribution of PB results on their label dose recommendations. Among drugs with HI publication, 32% (17/53) associated product labels include PB results in HI section. Of these, the majority (9/17, 53%) recommend dose adjustments consistent with observed PB change. Among drugs with RI publication, 27% (12/44) of associated product labels include PB results in RI section with the majority (7/12, 58%) recommending no dose adjustment, consistent with the reported absence of PB change. PB results were found to be consistent with a tailored dose recommendation in 53% and 58% of the approved labels for HI and RI section, respectively. We further discussed the interpretation challenges of PB results, explored treatment decision factors including total drug concentration, exposure-response relationships, and safety considerations in these case examples. Collectively, comprehending the alterations in free drug levels in HI and RI informs treatment decision through a risk-based approach.

Evaluation of the drug-drug interaction potential of brigatinib using a physiologically-based pharmacokinetic modeling approach

Brigatinib is an oral anaplastic lymphoma kinase (ALK) inhibitor approved for the treatment of ALK-positive metastatic non-small cell lung cancer. In vitro studies indicated that brigatinib is primarily metabolized by CYP2C8 and CYP3A4 and inhibits P-gp, BCRP, OCT1, MATE1, and MATE2K. Clinical drug-drug interaction (DDI) studies with the strong CYP3A inhibitor itraconazole or the strong CYP3A inducer rifampin demonstrated that CYP3A-mediated metabolism was the primary contributor to overall brigatinib clearance in humans. A physiologically-based pharmacokinetic (PBPK) model for brigatinib was developed to predict potential DDIs, including the effect of moderate CYP3A inhibitors or inducers on brigatinib pharmacokinetics (PK) and the effect of brigatinib on the PK of transporter substrates. The developed model was able to predict clinical DDIs with itraconazole (area under the plasma concentration-time curve from time 0 to infinity [AUC∞] ratio [with/without itraconazole]: predicted 1.86; observed 2.01) and rifampin (AUC∞ ratio [with/without rifampin]: predicted 0.16; observed 0.20). Simulations using the developed model predicted that moderate CYP3A inhibitors (e.g., verapamil and diltiazem) may increase brigatinib AUC∞ by ~40%, whereas moderate CYP3A inducers (e.g., efavirenz) may decrease brigatinib AUC∞ by ~50%. Simulations of potential transporter-mediated DDIs predicted that brigatinib may increase systemic exposures (AUC∞) of P-gp substrates (e.g., digoxin and dabigatran) by 15%-43% and MATE1 substrates (e.g., metformin) by up to 29%; however, negligible effects were predicted on BCRP-mediated efflux and OCT1-mediated uptake. The PBPK analysis results informed dosing recommendations for patients receiving moderate CYP3A inhibitors (40% brigatinib dose reduction) or inducers (up to 100% increase in brigatinib dose) during treatment, as reflected in the brigatinib prescribing information.

Identify novel inflammation-related prognostic signature in pancreatic cancer patients

Pancreatic cancer (PC) is a malignant tumor of the digestive system with a poor prognosis. PC patients with pancreatitis have a worse prognosis. But nobody reported the relationship between inflammation and prognosis in PC. Based on this, we are going to explore inflammation-related prognostic signature to predict patients' survival and potential therapeutic target. We screened gene expression profile and corresponding clinical information of patients from The Cancer Genome Atlas (TCGA) database. Gene set enrichment analysis (GSEA) was performed to identify differentially expressed genes (DEGs) between tumor and normal tissues with P value < .05. Univariate and multivariate Cox regression analysis was applied to identify possible prognostic inflammation genes and establish an inflammation-related risk score system, which was validated by Kaplan-Meier and Receiver operating characteristic (ROC) curves. Finally, we used the TISIDB database to predict targeted drugs for up-regulated gene hepatocyte growth factor receptor (MET) and used AUTODOCK software for molecular docking. We built a prognostic model consisted of 3 inflammation-related genes (tumor necrosis factor receptor associated factor 1/TFAR1, tyrosine kinase 2/TYK2, MET). According to the median value of those genes' risk score, PC patients were ranked into high- (88) and low-risk (89) groups. Then, the results of the Kaplan-Meier curves and the area under the curve (AUC) of the ROC curves showed this model had a good predictive power (P < .001, AUC = 0.806). The result of human protein atlas (HPA) database showed the expression of TRAF1 and TYK2 were low in pancreatic cancer, the expression of MET was high. TISIDB database founded brigatinib could target to MET. And AUTODOCK showed brigatinib had a nice docking with MET. Taken together, our study suggested that inflammation-associated prognostic signature might be used as novel biomarkers for predicting prognosis in PC patients and potential therapeutic target of the disease.

Clinical Pharmacology of Brigatinib: A Next-Generation Anaplastic Lymphoma Kinase Inhibitor

Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor designed to overcome mechanisms of resistance associated with crizotinib, is approved for the treatment of ALK-positive advanced or metastatic non-small cell lung cancer. After oral administration of single doses of brigatinib 30-240 mg, the median time to reach maximum plasma concentration ranged from 1 to 4 h. In patients with advanced malignancies, brigatinib showed dose linearity over the dose range of 60-240 mg once daily. A high-fat meal had no clinically meaningful effect on systemic exposures of brigatinib (area under the plasma concentration-time curve); thus, brigatinib can be administered with or without food. In a population pharmacokinetic analysis, a three-compartment pharmacokinetic model with transit absorption compartments was found to adequately describe brigatinib pharmacokinetics. In addition, the population pharmacokinetic analyses showed that no dose adjustment is required based on body weight, age, race, sex, total bilirubin (< 1.5× upper limit of normal), and mild-to-moderate renal impairment. Data from dedicated phase I trials have indicated that no dose adjustment is required for patients with mild or moderate hepatic impairment, while a dose reduction of approximately 40% (e.g., from 180 to 120 mg) is recommended for patients with severe hepatic impairment, and a reduction of approximately 50% (e.g., from 180 to 90 mg) is recommended when administering brigatinib to patients with severe renal impairment. Brigatinib is primarily metabolized by cytochrome P450 (CYP) 3A, and results of clinical drug-drug interaction studies and physiologically based pharmacokinetic analyses have demonstrated that coadministration of strong or moderate CYP3A inhibitors or inducers with brigatinib should be avoided. If coadministration with a strong or moderate CYP3A inhibitor cannot be avoided, the dose of brigatinib should be reduced by approximately 50% (strong CYP3A inhibitor) or approximately 40% (moderate CYP3A inhibitor), respectively. Brigatinib is a weak inducer of CYP3A in vivo; data from a phase I drug-drug interaction study showed that coadministration of brigatinib 180 mg once daily reduced the oral midazolam area under the plasma concentration-time curve from time zero to infinity by approximately 26%. Brigatinib did not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, or CYP2D6 at clinically relevant concentrations in vitro. Exposure-response analyses based on data from the ALTA (ALK in Lung Cancer Trial of AP26113) and ALTA-1L pivotal trials of brigatinib confirm the favorable benefit versus risk profile of the approved titration dosing regimen of 180 mg once daily (after a 7-day lead-in at 90 mg once daily).

Brigatinib pharmacokinetics in patients with chronic hepatic impairment

Brigatinib is an anaplastic lymphoma kinase (ALK) inhibitor approved for the treatment of ALK-positive non-small cell lung cancer. This open-label, parallel-group study investigated the effect of chronic hepatic impairment on the pharmacokinetics (PK) of brigatinib to inform dosing recommendations for these patients. Participants with hepatic impairment classified according to Child-Pugh categories of mild (A), moderate (B), or severe (C) and matched-healthy participants with normal hepatic function received a single oral dose of 90-mg brigatinib. Plasma samples were collected for the determination of brigatinib plasma protein binding and estimation of plasma PK parameters. Twenty-seven participants were enrolled (Child-Pugh A-C, n = 6 each; matched-healthy participants, n = 9). The mean fraction of free plasma brigatinib was comparable for the Child-Pugh A (11.1%), Child-Pugh B (10.8%), and healthy participant groups (8.5%); free brigatinib was higher in the Child-Pugh C group (23.1%). There were no clinically meaningful effects of mild or moderate hepatic impairment on unbound systemic exposures (area under the plasma concentration-time curve [AUC]) of brigatinib (geometric least-squares mean ratios [90% CI] of 89.32% [69.79%-114.31%] and 99.55% [77.78%-127.41%], respectively). In the severe hepatic impairment group, brigatinib unbound AUC was approximately 37% higher (geometric least-squares mean ratio [90% CI] of 137.41% [107.37%-175.86%]) compared with healthy participants with normal hepatic function. Brigatinib was well tolerated in healthy participants and in participants with hepatic impairment. No dose adjustment is required for patients with mild or moderate hepatic impairment. The brigatinib dose should be reduced by approximately 40% for patients with severe hepatic impairment.

A Phase 1 Drug-Drug Interaction Study Between Brigatinib and the CYP3A Substrate Midazolam in Patients With ALK-Positive or ROS1-Positive Solid Tumors

Brigatinib is a next-generation anaplastic lymphoma kinase (ALK) inhibitor approved for the treatment of patients with ALK-positive (ALK+) non-small cell lung cancer (NSCLC). A phase 1 drug-drug interaction study was conducted to evaluate the effect of multiple-dose administration of brigatinib on the single-dose pharmacokinetics of midazolam, a sensitive cytochrome P450 3A substrate. In cycle 1, patients with ALK+ or ROS1+ solid tumors, including NSCLC, received a single 3-mg dose of midazolam as an oral solution alone on day 1 and then coadministered with brigatinib on day 21 (brigatinib 90 mg once daily on days 2-8; 180 mg once daily on days 9-28). After cycle 1, patients could continue to receive brigatinib in 28-day treatment cycles. The primary study objective was to characterize the effect of brigatinib 180 mg once daily on midazolam pharmacokinetics. The secondary objective was to assess safety. Exploratory efficacy endpoints included objective response rate and progression-free survival. Brigatinib was generally well tolerated, and safety data were consistent with the known safety profile. Among the 10 patients with ALK+ NSCLC, the confirmed objective response rate was 30% and median progression-free survival was 7.2 months. Coadministration of brigatinib reduced midazolam maximum observed plasma concentration by ≈16% (geometric least-squares mean ratio, 0.836 [90%CI, 0.662-1.056]) and area under the plasma concentration-time curve from time 0 to infinity by ≈26% (geometric least-squares mean ratio, 0.741 [90%CI, 0.600-0.915]). Thus, brigatinib is a weak inducer of cytochrome P450 3A in vivo.

Population Pharmacokinetic and Exposure-Response Analyses From ALTA-1L: Model-Based Analyses Supporting the Brigatinib Dose in ALK-Positive NSCLC

The ALK in Lung Cancer Trial of brigAtinib in 1st Line (ALTA-1L) compared brigatinib versus crizotinib in ALK inhibitor-naive patients with ALK+ NSCLC. A population pharmacokinetic (PK) model was used to estimate brigatinib exposures for exposure-efficacy and exposure-safety analyses in ALTA-1L. A previously developed population PK model for brigatinib was applied to estimate brigatinib PK parameters. Relationships between static (time-independent) and dynamic (time-varying) exposure metrics and efficacy (progression-free survival [PFS], objective response rate [ORR], and intracranial ORR) and safety outcomes (selected grade ≥ 2 and grade ≥ 3 adverse events) were evaluated using logistic regression and time-to-event analyses. There were no meaningful differences in brigatinib PK in the first-line and second-line settings, supporting use of the previous population PK model for the first-line population. Exposure-response analyses showed no significant effect of time-varying brigatinib exposure on PFS. Brigatinib exposure was not significantly related to ORR, but higher exposure was associated with higher intracranial ORR (odds ratio: 1.13; 95% confidence interval: 1.01-1.28; P = 0.049). Across the observed median exposure (5th-95th percentile) at steady state for 180 mg once daily, the predicted probability of intracranial ORR was 0.83 (0.58-0.99). Adverse events significantly associated with higher exposure were elevated lipase (grade ≥ 3) and amylase (grade ≥ 2). Time to first brigatinib dose reduction was not related to exposure. These results support the benefit-risk profile of first-line brigatinib 180 mg once daily (7-day lead-in dose at 90 mg once daily) in patients with ALK+ NSCLC.