Clinical Characteristics and Pharmacokinetics Change of Long-Term Responders to Antiprogrammed Cell Death Protein 1 Inhibitor Among Patients With Advanced NSCLC.

Introduction: Immune checkpoint inhibitors (ICIs) induce long-term, durable responses in patients with advanced NSCLC. Nevertheless, these responses are limited to a few patients, and most responders have disease progression. The purpose of this study was to determine the differences in clinical factors and blood drug concentrations between long-term responders (LTRs) and non-LTRs. Methods: We retrospectively analyzed consecutive patients with advanced NSCLC who received antiprogrammed cell death protein 1 (PD-1) inhibitor monotherapy (nivolumab) from December 22, 2015, to May 31, 2017. Patients who obtained a clinical benefit for more than 6 months were referred to as "responders"; among these, individuals who had a durable response for more than 2 years were defined as "LTRs." Those with a clinical benefit for less than 2 years were defined as "non-LTRs." Results: A total of 212 patients received anti-PD-1 inhibitor monotherapy. The responders accounted for 35% (75 of 212) of the patients. Of these, 29 (39%) were LTRs and 46 (61%) were non-LTRs. The overall response rate and median tumor shrinkage in the LTR group were significantly higher than those in the non-LTR group (76% versus 35%, p < 0.0001, and 66% versus 16%, p < 0.001, respectively). The groups had no significant difference in PD-L1 expression and serum drug concentration at 3- and 6-month post-treatment initiation. Conclusions: Significant tumor shrinkage was associated with a long-term response to an anti-PD-1 inhibitor. Nevertheless, the PD-L1 expression level and pharmacokinetic profile of the inhibitor could not be used to predict the durable response among the responders.

Impact of ramucirumab pharmacokinetics in combination with docetaxel on the efficacy and survival in patients with advanced non-small cell lung cancer.

OBJECTIVES: Ramucirumab, an anti-vascular endothelial growth factor receptor-2 antibody, has been approved for the treatment of non-small cell lung cancer (NSCLC); however, its pharmacokinetic properties in clinical practice are unknown. We aimed to measure ramucirumab concentrations and conduct a retrospective pharmacokinetic analysis using real-world data. MATERIALS AND METHODS: Patients with stage III-IV and recurrent NSCLC who received ramucirumab plus docetaxel were evaluated in this study. After the first administration, the ramucirumab trough concentration (Ctrough) was measured using liquid chromatography-mass spectrometry. Patient characteristics, adverse events, tumor response, and survival time were retrospectively extracted from medical records from August 2, 2016 to July 16, 2021. RESULTS: A total of 131 patients were examined to assess serum ramucirumab concentrations. Ctrough ranged from below the lower limit of quantification (BLQ) to 48.8 µg/mL (BLQ ≤ 1st quartile (Q1) ≤ 7.34, 7.34 < 2nd quartile (Q2) ≤ 14.7, 14.7 < 3rd quartile (Q3) ≤ 21.9 and 21.9 < 4th quartile (Q4) ≤ 48.8 µg/mL). The overall response rate was significantly higher in Q2-4 than that in Q1 (p = 0.011). The median progression-free survival was marginally longer, and overall survival was significantly longer in Q2-4 (p = 0.009). The Glasgow prognostic score (GPS) in Q1 was significantly higher than in Q2-4 (p = 0.034) and associated with Ctrough (p = 0.002). CONCLUSION: Patients with higher ramucirumab exposure had a high ORR and prolonged survival time, whereas patients with lower ramucirumab exposure were characterized by a high GPS and poor prognosis. Cachexia may reduce the exposure level of ramucirumab in certain patients, reducing the clinical benefits of ramucirumab treatment.

Early change in the clearance of pembrolizumab reflects the survival and therapeutic response: A population pharmacokinetic analysis in real-world non-small cell lung cancer patients.

OBJECTIVES: The dosing pattern of pembrolizumab is based on population pharmacokinetic (Pop-PK) analysis of clinical trials. Data for Japanese patients or patient populations with poor conditions such as cachexia are scarce. In this study, we performed a Pop-PK analysis of Japanese non-small cell lung cancer patients and analyzed the relationship between exposure, treatment effect, and survival. MATERIALS AND METHODS: A total of 270 blood samples from 76 patients who received 200 mg pembrolizumab every 3 weeks between March 2017 and December 2018 were included. Blood concentrations of pembrolizumab were measured using mass spectrometry, and Pop-PK analysis was conducted using the Phoenix NLME software with a one-compartment model. RESULTS: The estimated median of clearance (CL) in this analysis population was 0.104 L/day, about half of the historical data for Western data. Overall, pembrolizumab CL decreased over time, with some populations showing increased CL early in the treatment and others showing decreased CL over time. When the time-varying CL was stratified by quartile, the group with decreasing CL showed significantly better treatment response and survival than the group with increasing CL, even though the group included more patients with cachexia. Detailed analysis suggested that the patient population that responded to pembrolizumab treatment had an improved general condition and reduced protein catabolism, further decreasing CL. CONCLUSION: In populations that benefit from pembrolizumab treatment, CL may be reduced early in their treatment, which may be a predictive and prognostic factor. However, further prospective validation of our findings is needed.

Safety Implications of Switching Pembrolizumab Dosage From 200 mg Every 3 Weeks to 400 mg Every 6 Weeks in Patients With Advanced NSCLC.

INTRODUCTION: Administration of 400 mg pembrolizumab every 6 weeks (400 mg Q6W) has been approved on the basis of the results of simulated pharmacokinetic modeling and exposure-response analyses. Nevertheless, the safety of switching dosage from 200 mg every 3 weeks (Q3W) to 400 mg Q6W during treatment remains unclear. METHODS: This study involved patients (N = 45) with advanced NSCLC, in whom the pembrolizumab dosage was switched from 200 mg Q3W to 400 mg Q6W between August 2020 and November 2021 in our institute. RESULTS: At the time of switching, the median age of the patients was 71 (range: 32-84) years, and 32 patients (71.1 %) were males. The median number of cycles of 200 mg Q3W before switching was six (range: 1-31). After switching, new or worsening immune-related adverse events (irAEs) occurred in 17 of the 45 patients (37.8%) within three cycles. The irAEs were pneumonitis in 11 patients (24.4%), diarrhea in three patients (6.7%), renal dysfunction in two patients (4.4%), adrenal dysfunction in two patients (4.4%), a skin rash in one patient (2.2%), fulminant type 1 diabetes mellitus in one patient (2.2%). CONCLUSIONS: The switching of pembrolizumab dosage from 200 mg Q3W to 400 mg Q6W resulted in the occurrence of new or worsening irAEs, in particular, pneumonitis, in the early cycles even in patients who had received stable treatment with 200 mg Q3W.

Development of an analytical method to determine E7130 concentration in mouse plasma by micro-sampling using ultra-performance liquid chromatography-high resolution mass spectrometry.

E7130 is a novel microtubule inhibitor and a promising tumor microenvironment ameliorator. Since the amount of the administration in preclinical study is very small due to the high potency of E7130, this study aimed to establish a sensitive analytical method to measure E7130 concentration in mouse plasma samples obtained via microsampling. A sensitive and validated method was developed based on ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). Chromatographic separation was achieved using a Waters ACQUITY UPLC BEH C18 1.7 µm (2.1 × 50 mm) column. Mobile phase A comprised 0.1% formic acid and 10 mM ammonium formate in water, and mobile phase B was methanol. A gradient elution was applied at a flow rate of 0.5 mL/min. The calibration curve drawn was linear in the 0.2-100 ng/mL E7130 concentration range for mouse plasma microsamples (10 µL). Analytical results demonstrated good precision (<6.7%) and accuracy (88.5%-100.0%) in E7130 quantitation, indicating that UHPLC-HRMS is a useful method for pharmacokinetic analysis and a valuable approach for the quantitation of hardly fragmented compounds.

Augmented Clearance of Nivolumab Is Associated with Renal Functions in Chronic Renal Disease Model Rats.

The clinically approved dose of nivolumab is 240 mg every 2 weeks. However, previous studies have shown that baseline nivolumab clearance (CL) is associated with treatment outcomes in patients with solid cancers, thus motivating researchers to identify prognostic factors and indices influencing nivolumab CL. This study used chronic kidney disease model rats to investigate whether chronic renal impairment affected nivolumab CL and explored the surrogate markers associated with nivolumab CL. We observed that the total CL for nivolumab (CLtot) was approximately 1.42 times higher in chronic kidney disease model rats than that in sham rats with an increased urinary excretion. Additionally, CLtot showed positive correlation with renal CL for nivolumab (CLR) but not with extrarenal CL. Furthermore, the baseline levels of creatinine, blood urea nitrogen, creatinine CL, and urinary albumin/creatine ratio based on laboratory data were also significantly correlated with CLR Our findings suggest that nivolumab CL increases as renal function deteriorates because of an increased excretion of nivolumab in the urine; additionally, laboratory data reflecting renal function may be a feasible index to qualitatively estimate nivolumab CL prior to nivolumab treatment under conditions of renal impairment. SIGNIFICANCE STATEMENT: This study demonstrated that nivolumab was rapidly eliminated from the circulation in chronic kidney disease model rats compared with sham rats with an increased urinary nivolumab excretion. Moreover, nivolumab clearance was significantly correlated with the baseline levels of certain laboratory parameters reflecting renal functions. These results indicate the potential applicability of baseline renal function as a prognostic index to qualitatively estimate nivolumab clearance prior to nivolumab treatment under conditions with renal impairment.

Visualization of Intratumor Pharmacokinetics of [fam-] Trastuzumab Deruxtecan (DS-8201a) in HER2 Heterogeneous Model Using Phosphor-integrated Dots Imaging Analysis.

PURPOSE: We assessed the intratumor pharmacokinetics of [fam-] trastuzumab deruxtecan, T-DXd (known as DS-8201a), a novel HER2-targeted antibody-drug conjugate, using phosphor-integrated dots (PID)-imaging analysis to elucidate its pharmacologic mechanism. EXPERIMENTAL DESIGN: We used two mouse xenograft models administered T-DXd at the concentration of 4 mg/kg: (i) a heterogeneous model in which HER2-positive and HER2-negative cell lines were mixed, and (ii) a homogeneous model in which both cell types were transplanted separately into the same mouse. PID imaging involved immunostaining using novel high-intensity fluorescent nanoparticles. The distribution of T-DXd was assessed by PID imaging targeting the parent antibody, trastuzumab, and the payload, DXd, in serial frozen sections, respectively. RESULTS: After T-DXd administration in the heterogeneous model, HER2 expression tended to decrease in a time-dependent manner. The distribution of trastuzumab and DXd was observed by PID imaging along the HER2-positive area throughout the observation period. A detailed comparison of the PID distribution between trastuzumab and DXd showed that trastuzumab matched almost perfectly with the HER2-positive area. In contrast, DXd exhibited widespread distribution in the surrounding HER2-negative area as well. In the HER2-negative tumor of the homogeneous model, the PID distribution of trastuzumab and DXd remained extremely low throughout the observation period. CONCLUSIONS: Our results suggest that T-DXd is distributed to tumor tissues via trastuzumab in a HER2-dependent manner and then to adjacent HER2-negative areas. We successfully visualized the intratumor distribution of T-DXd and its mechanism of action, the so-called "bystander effect."

A procedure for method development and protein binding ratio as the indicator of sensitivity with anticancer agents on MALDI mass spectrometry imaging.

The concentration and distribution of a drug and its metabolites in tissues are key factors for elucidating both drug efficacy and toxicity in drug development. In this study we developed a pharamaco-imaging procedure for 12 agents and investigated the relationship between the properties of target compounds and the sensitivities of detection in matrix-assisted laser desorption/ionization-mass spectrometer imaging (MALDI-MSI). We prepared mock samples with mouse liver homogenates diluted with gelatin solution, limit of detection concentrations of each compound was confirmed. The correlation was evaluated between the intensities of mass signals obtained in MALDI-MSI with each test compound (the intensities of the test compounds) at a consistent concentration and the properties of each test compound. The liver homogenate diluted with gelatin solution showed easier handling and lower coefficients of variation than did liver homogenate only, and can be used as a good surrogate matrix. Based on the analysis of 12 agents, the protein binding ratios showed significant correlation to the detection sensitivities. We presented a procedure for standardization of pharmaco-imaging method development with an in-tissue method using MALDI-MS. Our results indicated the correlation between test compound's sensitivity and their protein binding ratios in plasma or serum.

Use of an alternative signature peptide during development of a LC-MS/MS assay of plasma nivolumab levels applicable for multiple species.

Recently, immune checkpoint inhibitors, including anti-programmed cell death protein 1 (PD-1) antibodies, have dramatically changed treatment strategies for several cancers. In pharmacokinetic/pharmacodynamic studies, experiments using a variety of animal species are assumed. We have identified optimal multiple reaction monitoring transitions for signature candidate peptides of nivolumab in human, mouse, and rat plasma and developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify nivolumab (an anti-PD-1 antibody) using trastuzumab as the internal standard. Calibration curves were linear in the range of 1-200 µg/mL. The intra- and inter-day precision and accuracy in human plasma fulfilled Food and Drug Administration guideline criteria for bioanalytical validation. There was no need to change the measurement method in mouse plasma. On the other hand, in rat plasma, an interference peak was observed at a retention time similar to that of the surrogate peptide ASGITFSNSGMHWVR (550.75 > 661.50) employed in human and mouse plasma. Therefore, we confirmed that ASQSVSSYLAWYQQKPGQAPR (785.0 > 940.2) can be used as an alternate nivolumab surrogate peptide in rat plasma at the same concentration range as used in human and mouse plasma. Using our method, the concentration range and a gradual increase in trough value were confirmed in clinical samples from two antibody-treated patients, including one with gastric cancer and one with non-small-cell lung cancer. The time course and blood concentration transition also were evaluated in nivolumab administration experiments in mouse and rat. The present study showed that the selection of the optimal peptide is essential for accurate LC-MS/MS measurement of nivolumab concentration in human, mouse, and rat plasma. The method developed here is expected to be of use in non-clinical and clinical pharmacokinetic studies.

Visualization of the distribution of nanoparticle-formulated AZD2811 in mouse tumor model using matrix-assisted laser desorption ionization mass spectrometry imaging.

Penetration of nanoparticles into viable tumor regions is essential for an effective response. Mass spectrometry imaging (MSI) is a novel method for evaluating the intratumoral pharmacokinetics (PK) of a drug in terms of spatial distribution. The application of MSI for analysis of nanomedicine PK remains in its infancy. In this study, we evaluated the applicability of MALDI-MSI for nanoparticle-formulated drug visualization in tumors and biopsies, with an aim toward future application in clinical nanomedicine research. We established an analytic method for the free drug (AZD2811) and then applied it to visualize nanoparticle-formulated AZD2811. MSI analysis demonstrated heterogeneous intratumoral drug distribution in three xenograft tumors. The intensity of MSI signals correlated well with total drug concentration in tumors, indicating that drug distribution can be monitored quantitatively. Analysis of tumor biopsies indicated that MSI is applicable for analyzing the distribution of nanoparticle-formulated drugs in tumor biopsies, suggesting clinical applicability.

The Long Half-Life of Programmed Cell Death Protein 1 Inhibitors May Increase the Frequency of Immune-Related Adverse Events After Subsequent EGFR Tyrosine Kinase Inhibitor Therapy.

INTRODUCTION: EGFR tyrosine kinase inhibitors are one of the key drugs for treatment of NSCLC with EGFR mutations. In recent times, immune check-point inhibitors (ICIs) have also been widely used for patients with NSCLC. Although a subset of patients obtain benefit from ICIs, adverse events (AEs) that are different from those of cytotoxic chemotherapies may occur. Moreover, some patients develop AEs, which seem to be caused by the previously discontinued nivolumab. METHODS: We identified patients with NSCLC who developed AEs, which started shortly after discontinuation of nivolumab and during treatment with osimertinib. We conducted liquid chromatography-mass spectrometry analyses to estimate the concentration of serum nivolumab. RESULTS: Three patients with AEs were identified. Two patients developed interstitial lung disease (cases 1 and 2) and one developed hepatotoxicity (case 3) during osimertinib therapy initiated after nivolumab administration. They received several treatments, including cytotoxic chemotherapies or EGFR tyrosine kinase inhibitors other than osimertinib, followed by nivolumab for three to five cycles; nevertheless, the disease progressed. After discontinuation of nivolumab, osimertinib was administered from day 22 to 46; but treatment-related toxicities developed 56 to 96 days later. Liquid chromatography-mass spectrometry analyses revealed that the remaining levels of nivolumab in the blood (2.1 µg/mL, 12.8 µg/mL, and 31.1 µg/mL, respectively, for cases 1, 2, and 3) were enough to induce an immune response. CONCLUSION: The presence of the ICI antibody that persists even after drug discontinuation may account not only for the prolonged efficacy of these agents but also for the late onset of AEs, especially when the antibodies may have interacted during subsequent treatments.

High-performance liquid chromatography-tandem mass spectrometry for simultaneous determination of raltegravir, dolutegravir and elvitegravir concentrations in human plasma and cerebrospinal fluid samples.

A simple sample treatment procedure and sensitive liquid chromatography-tandem mass spectrometry method were developed for the simultaneous quantification of the concentrations of human immunodeficiency virus-1 integrase strand transfer inhibitors - raltegravir, dolutegravir and elvitegravir - in human plasma and cerebrospinal fluid (CSF). Plasma and CSF samples (20 µL each) were deproteinized with acetonitrile. Raltegravir-d3 was used as the internal standard. Chromatographic separation was achieved on an XBridge C18 column (50 × 2.1 mm i.d., particle size 3.5 µm) using acetonitrile-water (7:3, v/v) containing 0.1% formic acid as the mobile phase at a flow rate of 0.2 mL/min. The run time was 5 min. Calibration curves for all three drugs were linear in the range 5-1500 ng/mL for plasma and 1-200 ng/mL for CSF. The intra- and inter-day precision and accuracy of all three drugs in plasma were coefficient of variation (CV) <12.9% and 100.0 ± 12.2%, respectively, while those in CSF were CV <12.3% and 100.0 ± 7.9%, respectively. Successful validation under the same LC-MS/MS conditions for both plasma and CSF indicates this analytical method is useful for monitoring the levels of these integrase strand transfer inhibitors in the management of treatment of HIV-1 carriers.

Evaluation of the heterogeneous tissue distribution of erlotinib in lung cancer using matrix-assisted laser desorption ionization mass spectrometry imaging.

Although drug distribution in tumor tissues has a significant impact on efficacy, conventional pharmacokinetic analysis has some limitations with regard to its ability to provide a comprehensive assessment of drug tissue distribution. Erlotinib is a tyrosine kinase inhibitor that acts on the epidermal growth factor receptor; however, it is unclear how this drug is histologically distributed in lung cancer. We used matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to analyze erlotinib distribution in the tumor and normal lung tissues of a mouse xenograft model and patient with non-small cell lung cancer. LC-MS/MS showed that the erlotinib tissue concentration in the xenograft tumor tissue was clearly lower than that in the normal tissue at the time of maximum blood concentration. MALDI-MSI showed the heterogeneous distribution of erlotinib at various levels in the murine tissues; interestingly, erlotinib was predominantly localized in the area of viable tumor compared to the necrotic area. In the patient-derived tissue, MALDI-MSI showed that there were different concentrations of erlotinib distributed within the same tissue. For drug development and translational research, the imaging pharmacokinetic study used the combination of MALDI-MSI and LC-MS/MS analyses may be useful in tissues with heterogeneous drug distribution.