A highly sensitive LC-MS/MS method to determine novel Bruton's tyrosine kinase inhibitor spebrutinib: application to metabolic stability evaluation

Pretreatment and analysis techniques development of TKIs in biological samples for pharmacokinetic studies and therapeutic drug monitoring

Tyrosine kinase inhibitors (TKIs) have emerged as the first-line small molecule drugs in many cancer therapies, exerting their effects by impeding aberrant cell growth and proliferation through the modulation of tyrosine kinase-mediated signaling pathways. However, there exists a substantial inter-individual variability in the concentrations of certain TKIs and their metabolites, which may render patients with compromised immune function susceptible to diverse infections despite receiving theoretically efficacious anticancer treatments, alongside other potential side effects or adverse reactions. Therefore, an urgent need exists for an up-to-date review concerning the biological matrices relevant to bioanalysis and the sampling methods, clinical pharmacokinetics, and therapeutic drug monitoring of different TKIs. This paper provides a comprehensive overview of the advancements in pretreatment methods, such as protein precipitation (PPT), liquid-liquid extraction (LLE), solid-phase extraction (SPE), micro-SPE (μ-SPE), magnetic SPE (MSPE), and vortex-assisted dispersive SPE (VA-DSPE) achieved since 2017. It also highlights the latest analysis techniques such as newly developed high performance liquid chromatography (HPLC) and high-resolution mass spectrometry (HRMS) methods, capillary electrophoresis (CE), gas chromatography (GC), supercritical fluid chromatography (SFC) procedures, surface plasmon resonance (SPR) assays as well as novel nanoprobes-based biosensing techniques. In addition, a comparison is made between the advantages and disadvantages of different approaches while presenting critical challenges and prospects in pharmacokinetic studies and therapeutic drug monitoring.

Safety, pharmacokinetics and pharmacodynamics of HWH486 capsules in healthy adults: A randomized, double-blind, placebo-controlled, phase I dose-escalation study

OBJECTIVES

HWH486 inhibits Bruton's tyrosine kinase and therefore shows promise as a treatment against rheumatoid arthritis and chronic spontaneous urticaria. This phase I trial assessed tolerability, safety, pharmacokinetics and pharmacodynamics of a single oral dose of HWH486 capsules in healthy adults.

METHODS

A single-center, randomized, double-blind, placebo-controlled, dose-escalation study from 10 to 800 mg was conducted in 96 healthy Chinese adults, of whom 80 received HWH486 and 16 received placebo.

RESULTS

A total of 96 subjects were enrolled, and all completed the study. In the HWH486 group, mean Tmax ranged from 1.03 to 2.00 h, and mean T1/2 ranged from 0.85 to 8.67 h across the dose range from 10 to 800 mg. Mean Cmax increased linearly with dose, while mean AUC0-t increased non-linearly. Occupancy of Bruton's tyrosine kinase peaked within 0.50-4.00 h after administration across the dose groups, and the delay until peak occupancy decreased with increasing dose. Twenty-five subjects (31.25 %) in the HWH486 group experienced 35 treatment-emergent adverse events, while four subjects (25.00 %) in the placebo group experienced eight such events.

CONCLUSIONS

HWH486 is well tolerated and safe in healthy adults, in whom it can strongly bind Bruton's tyrosine kinase. These findings justify clinical studies of HWH486 efficacy against autoimmune diseases.

Development and Validation of a Rapid LC-MS/MS Method for Quantifying Alvocidib: In Silico and In Vitro Metabolic Stability Estimation in Human Liver Microsomes

Alvocidib (AVC; flavopiridol) is a potent cyclin-dependent kinase inhibitor used in patients with acute myeloid leukemia (AML). The FDA has approved orphan drug designation to AVC for treating patients with AML. In the current work, the in silico calculation of AVC metabolic lability was done using the P450 metabolism module of the StarDrop software package, that is expressed as a composite site lability (CSL). This was followed by establishing an LC-MS/MS analytical method for AVC estimation in human liver microsomes (HLMs) to assess metabolic stability. AVC and glasdegib (GSB), used as internal standards (IS), were separated utilizing a C18 column (reversed chromatography) with an isocratic mobile phase. The lower limit of quantification (LLOQ) was 5.0 ng/mL, revealing the sensitivity of the established LC-MS/MS analytical method that exhibited a linearity in the range 5-500 ng/mL in the HLMs matrix with correlation coefficient (R² = 0.9995). The interday and intraday accuracy and precision of the established LC-MS/MS analytical method were -1.4% to 6.7% and -0.8% to 6.4%, respectively, confirming the reproducibility of the LC-MS/MS analytical method. The calculated metabolic stability parameters were intrinsic clearance (CL_int) and in vitro half-life (t_1/2) of AVC at 26.9 µL/min/mg and 25.8 min, respectively. The in silico results from the P450 metabolism model matched the results generated from in vitro metabolic incubations; therefore, the in silico software can be used to predict the metabolic stability of the drugs, saving time and resources. AVC exhibits a moderate extraction ratio, indicating reasonable in vivo bioavailability. The established chromatographic methodology was the first LC-MS/MS method designed for AVC estimation in HLMs matrix that was applied for AVC metabolic stability estimation.

Metabolite Profiling of Swertia cincta Extract in Rats and Pharmacokinetics Study of Three Bioactive Compounds Using UHPLC-MS/MS

Swertia cincta, a plant of the genus Swertia in Gentianceae, has "heat-clearing" and detoxifying effects that normalize the gallbladder function in the treatment of jaundice. Although numerous studies on Swertia cincta have been performed, the absorption and pharmacokinetic behaviors remain unclear. In this study, the compounds of Swertia cincta in serum, bile, feces, and urine of rats were analyzed using a ultra-high-performance liquid chromatography-tandem mass spectrometry. A total of 9 prototype components and 48 metabolites were detected in biological samples. Furthermore, we determined the main components absorbed in the blood of Swertia cincta and established a method for simultaneously determining these components (sweroside, swertiamarin, and gentiopicroside) in positive ionization mode within 6 min. The quantitative method was successfully applied for the multiple-component pharmacokinetic study of Swertia cincta.

A Novel Green Micellar HPLC-UV Method for the Estimation of Vandetanib in Pure Form, Human Urine, Human Plasma and Human Liver Microsomes Matrices with Application to Metabolic Stability Evaluation

Vandetanib (Caprelsa^®; VNB) is a prescription medicine that is used for the treatment of medullary thyroid cancer that has disrupted other body parts or that cannot be removed by surgery. It is considered a tyrosine kinase inhibitor (TKI). Fast, sensitive and validated HPLC-UV was established for VNB quantification in pure human biological fluids (urine and plasma) and human liver microsomes (HLMs). This analytical methodology was applied also to the metabolic stability assessment of VNB. This method was performed using a phenyl column (250 mm × 4.6 mm id, 5 µm particle size). A sodium dodecyl sulphate solution (0.05 M, pH 3.0 using 0.02 M orthophosphoric acid) containing 0.3% triethylamine and 10% n-butanol was used as a mobile phase and was pumped isocratically at a flow rate of 0.7 mL/min and at a 260 nm detection wavelength. The total elution time was 6 min with an injection volume of 20 μL. The linearity of the established methodology ranged from 30 to 500 ng/mL in pure form and 50 to 500 ng/mL (r² ≥ 0.9994) in human biological fluids and HLMs. No significant interference from the matrix components was observed. The proposed methodology revealed the benefits of being green, reliable and economic.

Bruton's Kinase Inhibitors for the Treatment of Immunological Diseases: Current Status and Perspectives

The use of Bruton’s tyrosine kinase (BTK) inhibitors has changed the management of patients with B-cell lymphoid malignancies. BTK is an important molecule that interconnects B-cell antigen receptor (BCR) signaling. BTK inhibitors (BTKis) are classified into three categories, namely covalent irreversible inhibitors, covalent reversible inhibitors, and non-covalent reversible inhibitors. Ibrutinib is the first covalent, irreversible BTK inhibitor approved in 2013 as a breakthrough therapy for chronic lymphocytic leukemia patients. Subsequently, two other covalent, irreversible, second-generation BTKis, acalabrutinib and zanubrutinib, have been developed for lymphoid malignancies to reduce the ibrutinib-mediated adverse effects. More recently, irreversible and reversible BTKis have been under development for immune-mediated diseases, including autoimmune hemolytic anemia, immune thrombocytopenia, multiple sclerosis, pemphigus vulgaris, atopic dermatitis, rheumatoid arthritis, systemic lupus erythematosus, Sjögren’s disease, and chronic spontaneous urticaria, among others. This review article summarizes the preclinical and clinical evidence supporting the role of BTKis in various autoimmune, allergic, and inflammatory conditions.

Development of novel univariate and multivariate validated chemometric methods for the analysis of dasatinib, sorafenib, and vandetanib in pure form, dosage forms and biological fluids

New precise, responsive and selective univariate and multivariate chemometric spectrophotometric methods were developed and validated for determination of vandetanib (VTB), dasatinib (DTB), and sorafenib (SFB) in pure form, tablets, spiked human (plasma and urine). Determination of these drugs is essential because of their therapeutic benefits. These methods included double divisor ratio spectra derivative univariate method and chemometric multivariate method including partial least-squares (PLS) and principal component regression (PCR). A novel univariate method was developed for the estimation of these drugs. This method depends on the UV-Spectrophotometric data for simultaneous analysis of a ternary overlapped mixture. The Double divisor ratio spectra derivative absorption minima at 358.4 nm was used for quantification of VTB, absorption maxima at 300.3 nm for quantification of DTB and absorption maxima at 259.8 nm for quantification of SFB. This method shown a linearity in the extent of 2-9 μg/mL for VTB and DTB and over the concentration range of 3-9 μg/mL SFB within correlation coefficient (r2) of 0.9999. This method was successfully applied to pure form, tablet dosage form, spiked human (urine and plasma). Chemometric PLS and PCR models were found to be linear in the range of 2-9, 2-9, and 3-9 μg/mL for VTB, DTB and SFB, respectively. These models were estimated using eighteen mixtures as calibration set and seven mixtures as validation set. In the original data, the minimum root mean square error of prediction (RMSEP) was 0.11, 0.09 and 0.09 for VTB, DTB and SFB by PLS and 0.05, 0.04 and 0.03 by PCR while in the derivative data, the RMSEP was 0.09, 0.10 and 0.09 by PLS and 0.06, 0.06 and 0.03, by PCR for VTB, DTB and SFB, respectively. These methods were applied for the determination of the drugs in pure form and dosage form. Updating PLS model permitted the determination of the VTB, DTB and SFB in spiked human urine, plasma and drug-dissolution test of their tablet.

A validated LC-MS/MS analytical method for the quantification of pemigatinib: metabolic stability evaluation in human liver microsomes

Pemigatinib (PMB) is a small molecule inhibitor of fibroblast growth factor receptor 1 (FGFR1), FGFR2 and FGFR3. On April 17, 2020, the US Food and Drug Administration granted accelerated approval for PMB for the treatment of adults with previously treated, unresectable metastatic or locally advanced cholangiocarcinoma with a fibroblast growth factor receptor 2 (FGFR2) fusion or other rearrangement. PMB is considered the first targeted treatment for cholangiocarcinoma approved in the US. In this study, in silico prediction of PMB metabolic stability was done using the WhichP450 module of the StarDrop software package. Further, an LC-MS/MS analytical method was developed for PMB quantification in human liver microsomes (HLM) to experimentally assess metabolic stability. PMB and flavopiridol (FVL), used as an internal standard IS, were resolved using an isocratic mobile phase and a C18 stationary phase. The LC-MS/MS method showed linearity in the range of 5 to 500 ng mL⁻¹ in an HLM matrix (R² = 0.9995). The lower limit of quantification (LLOQ) was 5 ng mL⁻¹, indicating sensitivity. The inter- and intra-day accuracy and precision were within a variability of 10, confirming the reproducibility of the method. The measured in vitro half-life and intrinsic clearance of PMB were 27.29 min and 25.40 μL min⁻¹ mg⁻¹, respectively. PMB showed a moderate extraction ratio suggesting good bioavailability. The developed analytical method is the first LC-MS/MS method specific for PMB quantification with application to metabolic stability assessment.

PMB showed a moderate extraction ratio suggesting good bioavailability. The developed analytical method is the first LC-MS/MS method specific for PMB quantification with application to metabolic stability assessment.

Bruton's Tyrosine Kinase Inhibition for the Treatment of Rheumatoid Arthritis

Bruton’s tyrosine kinase (BTK) inhibitors are an emerging class of drugs that inhibit B cell receptor activation, FC-γ receptor signaling, and osteoclast proliferation. Following on approval for treatment of hematologic malignancies, BTK inhibitors are now under investigation to treat a number of different autoimmune diseases, including rheumatoid arthritis (RA). While the results of BTK inhibitors in RA animal models have been promising, the ensuing human clinical trial outcomes have been rather equivocal. This review will outline the mechanisms of BTK inhibition and its potential impact on immune mediated disease, the types of BTK inhibitors being studied for RA, the findings from both preclinical and clinical trials of BTK inhibitors in RA, and directions for future research.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

Chromatographic bioanalytical assays for targeted covalent kinase inhibitors and their metabolites

Deriving from targeted kinase inhibitors (TKIs), targeted covalent kinase inhibitors (TCKIs) are a new class of TKIs that are covalently bound to their target residue of kinase receptors. Currently, there are many new TCKIs under clinical development besides afatinib, ibrutinib, osimertinib, neratinib, acalabrutinib, dacomitinib, and zanubrutinib that are already approved by the FDA. Subsequently, there is an increasing demand for bioanalytical methods to qualitatively and quantitively investigate those compounds, leading to a number of papers reporting the development, validation, and use of bioanalytical methods for TCKIs. Most publications describe the technological set up of analytical methods that allow quantification of TCKIs in various biomatrices such as plasma, cerebrospinal fluid, urine, tissue, and liver microsomes. In addition, the identification of metabolites and biotransformation pathways of new TCKIs has gained more interest in recent years. We provide an overview of bioanalytical methods of this new class of TCKIs. The included issues are sample pretreatment, chromatographic separation, detection, and method validation. In the scope of bioanalysis of TCKIs, protein precipitation is mostly applied to treat the biological matrices sample. Liquid chromatographic in reversed-phase mode (RPLC) and mass detection with triple quadrupole (QqQ) are the most often utilized separation and quantitative detection modes, respectively. There may be a possibility of increased use of the high-resolution mass spectrometry (HRMS) for qualitative investigation purposes in the future. We also found that US FDA and EMA guidelines are the most common guidelines employed as validation framework for the bioanalytical methods of TCKIs.

Characterization of Stable and Reactive Metabolites of the Anticancer Drug, Ensartinib, in Human Liver Microsomes Using LC-MS/MS: An in silico and Practical Bioactivation Approach

BACKGROUND

Ensartinib (ESB) is a novel anaplastic lymphoma kinase inhibitor (ALK) with additional activity against Abelson murine leukemia (ABL), met proto-oncogene (MET), receptor tyrosine kinase (AXL), and v-ros UR2 sarcoma virus oncogene homolog 1 (ROS1) and is considered a safer alternative for other ALK inhibitors. ESB chemical structure contains a dichloro-fluorophenyl ring and cyclic tertiary amine rings (piperazine) that can be bioactivated generating reactive intermediates.

METHODS

In vitro metabolic study of ESB with human liver microsomes (HLMs) was performed and the hypothesis of generating reactive intermediates during metabolism was tested utilizing trapping agents to capture and stabilize reactive intermediates to facilitate their LC-MS/MS detection. Reduced glutathione (GSH) and potassium cyanide (KCN) were utilized as trapping agents for quinone methide and iminium intermediates, respectively.

RESULTS

Four in vitro ESB phase I metabolites were characterized. Three reactive intermediates including one epoxide and one iminium intermediates were characterized. ESB bioactivation is proposed to occur through unexpected metabolic pathways. The piperazine ring was bioactivated through iminium ions intermediates generation, while the dichloro-phenyl group was bioactivated through a special mechanism that was revealed by LC-MS/MS.

CONCLUSION

These findings lay the foundations for additional work on ESB toxicity. Substituents to the bioactive centers (piperazine ring), either for blocking or isosteric replacement, would likely block or interrupt hydroxylation reaction that will end the bioactivation sequence.

Identification of Iminium Intermediates Generation in the Metabolism of Tepotinib Using LC-MS/MS: In Silico and Practical Approaches to Bioactivation Pathway Elucidation

Tepotinib (Tepmetko™, Merck) is a potent inhibitor of c-Met (mesenchymal-epithelial transition factor). In March 2020, tepotinib (TEP) was approved for use in Japan for the treatment of patients who suffered from non-small cell lung cancers (NSCLC) harboring an MET exon 14 skipping alteration and have progressed after platinum-based therapy. Practical and in silico experiments were used to screen for the metabolic profile and reactive intermediates of TEP. Knowing the bioactive center and structural alerts in the TEP structure helped in making targeted modifications to improve its safety. First, the prediction of metabolism vulnerable sites and reactivity metabolic pathways was performed using the StarDrop WhichP450™ module and the online Xenosite reactivity predictor tool, respectively. Subsequently, in silico data were used as a guide for the in vitro practical work. Second, in vitro phase I metabolites of TEP were generated from human liver microsome (HLM) incubations. Testing for the generation of unstable reactive intermediates was performed using potassium cyanide as a capturing agent forming stable cyano adduct that can be characterized and identified using liquid chromatography tandem mass spectrometry (LC-MS/MS). Third, in silico toxicity assessment of TEP metabolites was performed, and structural modification was proposed to decrease their side effects and to validate the proposed bioactivation pathway using the DEREK software. Four TEP phase I metabolites and four cyano adducts were characterized. The reactive intermediate generation mechanism of TEP may provide an explanation of its adverse reactions. The piperidine ring is considered a structural alert for toxicity as proposed by the DEREK software and a Xenosite reactivity model, which was confirmed by practical experiments. Steric hindrance or isosteric replacement at α-carbon of the piperidine ring stop the bioactivation sequence that was confirmed using the DEREK software. More drug discovery studies can be performed using this perception permitting the design of new drugs with an increased safety profile. To our knowledge, this is the first study for the identification of in vitro phase I metabolites and reactive intermediates in addition to toxicological properties of the metabolites for TEP that will be helpful for the evaluation of TEP side effects and drug-drug interactions in TEP-treated patients.

A review of bioanalytical methods for chronic lymphocytic leukemia drugs and metabolites in biological matrices

Quantitation of drugs used for the treatment of chronic lymphocytic leukemia in various biological matrices during both pre-clinical and clinical developments is very important, often in routine therapeutic drug monitoring. The first developed methods for quantitation were traditionally done on LC in combination with either UV or fluorescence detection. However, the emergence of LC with mass spectrometry in tandem in early 1990s has revolutionized the quantitation as it has provided better sensitivity and selectivity within a shorter run time; therefore it has become the choice of method for the analysis of various drugs. In this article, an overview of various bioanalytical methods (HPLC or LC-MS/MS) for the quantification of drugs for the treatment of chronic lymphocytic leukemia, along with applicability of these methods, is given.