Population pharmacokinetic modeling of pyrotinib in patients with HER2-positive advanced or metastatic breast cancer

A validated UPLC-MS/MS method for quantification of pyrotinib and population pharmacokinetic study of pyrotinib in HER2-positive breast cancer patients

Objective

Pyrotinb has been approved for the treatment of HER2-positive advanced or metastatic breast cancer in China. However, the plasma concentration of pyrotinb in different patients varies greatly, and in the course of treatment, if patients have intolerable adverse reactions, the drug dosage will be reduced or even stopped. This study set out to establish an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the determination of pyrotinb in human plasma, analyze the population pharmacokinetics (PPK) of pyrotinib and assess the influence of patient variables on PK of pyrotinib in patients with HER2 positive breast cancer.

Method

An UPLC-MS/MS method was developed to measure pyrotinib in human plasma. Utilizing a gradient elution procedure and a Kinetex C18 column (2.1 mm × 100 mm, 1.7 μm), sample separation was accomplished in 5.5 min. Pyrotinb extraction via protein precipitation was used as a sample pre-treatment technique. In total, 50 patients provided 158 plasma samples, which were identified and used in the PPK investigation. The non-linear mixed-effects modeling (NONMEM) approach was used to assess the plasma concentrations and covariates information. For the final PPK model evaluation, external evaluation, non-parametric bootstrap, visual predictive check (VPC), and goodness-of-fit (GOF) were used.

Results

The UPLC-MS/MS method for determining plasma concentration of pyrotinib in patients had good selectivity and linearity in the range of 1-1,000 ng/mL. Pyrotinib concentration profile in HER2-positive breast cancer patients was well described by a single-compartment PPK model with first-order absorption and elimination. The formulas for the final estimated values of overall parameters of CL/F and Vd/F and Ka are respectively: C L / F L / h = 88.8 × e TP / 67.2 × 0.376 , V / F L = 3940 , K A h - 1 = 0.357 F I X E D . No dosage adjustment was advised, despite the possibility that the total protein levels could have a substantial impact on the apparent distribution volume of pyrotinib with limited magnitude.

Conclusion

In this study, an UPLC-MS/MS method was established to determine the concentration of pyrotinib in human plasma. A population pharmacokinetic model of pyrotinib in HER2 positive breast cancer patients suggested that low serum total protein reduced the clearance rate of pyrotinib in patients. Clinical medical staff should pay attention to the liver function of patients with abnormal serum total protein and be alert to the occurrence of adverse drug reactions.

Quantitative systems pharmacology modeling of HER2-positive metastatic breast cancer for translational efficacy evaluation and combination assessment across therapeutic modalities

HER2-positive (HER2+) metastatic breast cancer (mBC) is highly aggressive and a major threat to human health. Despite the significant improvement in patients' prognosis given the drug development efforts during the past several decades, many clinical questions still remain to be addressed such as efficacy when combining different therapeutic modalities, best treatment sequences, interindividual variability as well as resistance and potential coping strategies. To better answer these questions, we developed a mechanistic quantitative systems pharmacology model of the pathophysiology of HER2+ mBC that was extensively calibrated and validated against multiscale data to quantitatively predict and characterize the signal transduction and preclinical tumor growth kinetics under different therapeutic interventions. Focusing on the second-line treatment for HER2+ mBC, e.g., antibody-drug conjugates (ADC), small molecule inhibitors/TKI and chemotherapy, the model accurately predicted the efficacy of various drug combinations and dosing regimens at the in vitro and in vivo levels. Sensitivity analyses and subsequent heterogeneous phenotype simulations revealed important insights into the design of new drug combinations to effectively overcome various resistance scenarios in HER2+ mBC treatments. In addition, the model predicted a better efficacy of the new TKI plus ADC combination which can potentially reduce drug dosage and toxicity, while it also shed light on the optimal treatment ordering of ADC versus TKI plus capecitabine regimens, and these findings were validated by new in vivo experiments. Our model is the first that mechanistically integrates multiple key drug modalities in HER2+ mBC research and it can serve as a high-throughput computational platform to guide future model-informed drug development and clinical translation.

Pyrotinib and chrysin synergistically potentiate autophagy in HER2-positive breast cancer

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has been the most challenging subtype of BC, consisting of 20% of BC with an apparent correlation with poor prognosis. Despite that pyrotinib, a new HER2 inhibitor, has led to dramatic improvements in prognosis, the efficacy of pyrotinib monotherapy remains largely restricted due to its acquired resistance. Therefore, identifying a new potential antitumor drug in combination with pyrotinib to amplify therapeutic efficacy is a pressing necessity. Here, we reported a novel combination of pyrotinib with chrysin and explored its antitumor efficacy and the underlying mechanism in HER2-positive BC. We determined that pyrotinib combined with chrysin yielded a potent synergistic effect to induce more evident cell cycle arrest, inhibit the proliferation of BT-474 and SK-BR-3 BC cells, and repress in vivo tumor growth in xenograft mice models. This may be attributed to enhanced autophagy induced by endoplasmic reticulum stress. Furthermore, the combined treatment of pyrotinib and chrysin induced ubiquitination and glucose-6-phosphate dehydrogenase (G6PD) degradation by upregulating zinc finger and BTB/POZ domain-containing family protein 16 (ZBTB16) in tumorigenesis of BC. Mechanistically, we identified that miR-16-5p was a potential upstream regulator of ZBTB16, and it showed a significant inverse correlation with ZBTB16. Inhibition of miR-16-5p overexpression by restoring ZBTB16 significantly potentiated the overall antitumor efficacy of pyrotinib combined with chrysin against HER2-positive BC. Together, these findings demonstrate that the combined treatment of pyrotinib and chrysin enhances autophagy in HER2-positive BC through an unrecognized miR-16-5p/ZBTB16/G6PD axis.

A multicenter single-arm trial of neoadjuvant pyrotinib and trastuzumab plus chemotherapy for HER2-positive breast cancer

The objective of this multicenter, single-arm trial (ChiCTR1900022293) was to explore the efficacy and safety of neoadjuvant therapy with epirubicin, cyclophosphamide, and pyrotinib followed by docetaxel, trastuzumab, and pyrotinib (ECPy-THPy) in the treatment of patients with stage II-III HER2-positive breast cancer. The present study enrolled patients with stage II-III HER2-positive breast cancer. Epirubicin and cyclophosphamide were administrated for four 21-day cycles, followed by four cycles of docetaxel and trastuzumab. Pyrotinib was taken orally once per day throughout the treatment period. The primary endpoint was total pathological complete response (tpCR, ypT0/is ypN0) rate in the modified intention-to-treat (mITT) population. In total, 175 patients were included. The tpCR rate was 68.6% (95% CI, 60.7-75.8%), while the objective response rate was 89.1%. In the post-hoc subgroup analysis, no association between clinical characteristics and the tpCR rate was observed. The most common grade ≥3 adverse events were diarrhea (54.3%), followed by white blood cell count decreased (5.1%), and neutrophil count decreased (4.6%). In conclusion, the neoadjuvant regimen with ECPy-THPy showed promising pathological response and clinical benefits with an acceptable safety profile in patients with stage II-III HER2-positive breast cancer.

Real-World Outcome and Prognostic Factors Among HER2-Positive Metastatic Breast Cancer Patients Receiving Pyrotinib-Based Therapy: A Multicenter Retrospective Analysis

Purpose

To explore the efficacy, safety, and potential factors influencing efficacy and outcome of pyrotinib-based therapy in human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) in complex clinical practice.

Methods

Real-world data for HER2-positive MBC patients treated with pyrotinib-based regimens from 6 hospitals in Northern Anhui, China, from September 2018 to February 2022, were retrospectively collected, and clinicopathological features, efficacy, prognosis, and safety were analyzed. Potential influencing factors including baseline serum vascular endothelial growth factor-A (VEGF-A) for evaluating pyrotinib's treatment response and outcome were also explored.

Results

A total of 169 patients with HER2-positive MBC were enrolled. The objective response rate (ORR), disease control rate (DCR), and median progression-free survival (mPFS) of the overall cohort were 65.1%, 87.6%, and 12.4 months, respectively. Pyrotinib is highly beneficial as different treatment lines and appears to be a feasible strategy both in combination with chemotherapeutic drugs and alone. The mPFS values were 16.5 months, 12.4 months, and 9.3 months in the first, second, and third-or-higher lines of anti-HER2 therapy, respectively (P=0.027). The most common adverse event (AE) was diarrhea (88.2%), and patients with < grade 3 diarrhea achieved a longer mPFS than patients with ≥ grade 3 diarrhea (13.3 months vs 6.9 months, P=0.007). Among the patients with available baseline VEGF-A data, the ORR was 43.5% in patients with a high level of VEGF-A, compared to 81.5% in patients with a low level of VEGF-A (P=0.005). Moreover, patients in the VEGF-A-high group exhibited a shorter mPFS time than those in the VEGF-A-low group (7.8 months vs 19.1 months, P=0.004). Further analysis demonstrated AE of diarrhea and VEGF-A at baseline to be independent prognostic factors for PFS.

Conclusion

Pyrotinib-based regimens showed promising efficacy, with manageable tolerance, and AE occurrence of severe diarrhea and baseline level of serum VEGF-A are helpful in predicting the treatment outcome of pyrotinib in HER2-positive MBC.

Pyrotinib-based treatments in HER2-positive breast cancer patients with brain metastases

OBJECTIVES

Extensive application of anti-HER2 targeted therapy improves significantly the HER2-positive advanced breast cancer (BC) prognosis, however, it is still difficult to treat brain metastasis. In current study, we explored effective approaches via combining pyrotinib to treat brain metastasis in patients with HER2-positive advanced BC based upon clinical data.

MATERIALS AND METHODS

Current study included 61 HER2-positive BC patients with brain metastases (BM) who were treated by pyrotinib-based regimens. The systemic regimens included pyrotinib combined with capecitabine, pyrotinib combined with nab-paclitaxel, and pyrotinib combined with vinorelbine. Patients' progression-free survival (PFS), overall survival (OS), clinical benefit rate (CBR) and objective response rate (ORR), as well as drug-related adverse events (AEs) in regard of each combination regimen were analyzed.

RESULTS

Pyrotinib-based systemic therapy resulted in 8.6 months median PFS (mPFS) and 18.0 months median OS (mOS) among the BM patients. Regarding different regimens, the combination of pyrotinib with nab-paclitaxel was superior to the combination with capecitabine and vinorelbine with respect to PFS and OS. The central nervous system (CNS) ORR did not showcase significant difference among 3 regimens, however, nab-paclitaxel combined regimen obtained the best peripheral ORR (84.6%) (p ≤ .05).

CONCLUSIONS

Pyrotinib-based combination therapy is safe for HER2-positive brain metastasis treatment. Compared with vinorelbine or capecitabine, pyrotinib combined with nab-paclitaxel is more effective with less toxicity, which is the preferable regimen for HER2-positive brain metastasis.KEY MESSAGESPresent investigation investigated effective methods through combining pyrotinib to treat brain metastasis with HER2-positive advanced brain cancer. The outcomes verified that pyrotinib-based combination therapy was safe and efficient to treat HER2-positive brain metastasis. Therefore, it is effective to treat brain metastasis applying anti-HER2 targeted therapies although pyrotinib showcases efficiency regarding its treatments for the metastasis.

Differential effects of ketoconazole, fluconazole, and itraconazole on the pharmacokinetics of pyrotinib in vitro and in vivo

It has been reported that drug-drug interactions (DDIs) can affect the pharmacokinetics and pharmacodynamics of various oral drugs. To better understand the effects of azole antifungal drugs (ketoconazole, fluconazole, and itraconazole) on pyrotinib’s pharmacokinetics, DDIs between pyrotinib and three azoles were studied with Sprague-Dawley (SD) rat liver microsomes in vitro. Additionally, in vivo pyrotinib metabolic experiment was also performed. Twenty-four male SD rats were randomly divided into four groups: the ketoconazole (40 mg/kg), fluconazole (40 mg/kg), itraconazole (40 mg/kg), and the control group. UPLC-MS/MS was used for the determination of Pyrotinib’s plasma concentration in rats. In vitro experiments showed that IC₅₀ values of ketoconazole, fluconazole and itraconazole were 0.06, 11.55, and 0.27 μM, respectively, indicating that these drugs might reduce the clearance rate of pyrotinib at different degrees. In rat studies, coadministration of pyrotinib with ketoconazole or fluconazole could dramatically increase the C_max and AUC_(0-t) values and decrease the clearance rate of pyrotinib, especially for ketoconazole. However, coadministration with itraconazole had no impact on the pharmacokinetic characters of pyrotinib. These data indicated that ketoconazole and fluconazole could significantly decrease the metabolism of pyrotinib both in vitro and in vivo. More attentions should be paid when pyrotinib is combined with azole antifungal drugs in clinic although further investigation is still required in future.

Nitrile-containing pharmaceuticals: target, mechanism of action, and their SAR studies

The nitrile group is an important functional group widely found in both pharmaceutical agents and natural products. More than 30 nitrile-containing pharmaceuticals have been approved by the FDA for the management of a broad range of clinical conditions in the last few decades. Incorporation of a nitrile group into lead compounds has gradually become a promising strategy in rational drug design as it can bring additional benefits including enhanced binding affinity to the target, improved pharmacokinetic profile of parent drugs, and reduced drug resistance. This paper reviews the existing drugs with a nitrile moiety that have been approved or in clinical trials, involving their targets, molecular mechanism of pharmacology and SAR studies, and classifies them into different categories based on their clinical usages.