Quantifying payloads of antibody‒drug conjugates using a postcolumn infused-internal standard strategy with LC‒MS.

BACKGROUND: Antibody‒drug conjugates (ADCs) are innovative biopharmaceutics consisting of a monoclonal antibody, linkers, and cytotoxic payloads. Monitoring circulating payload concentrations has the potential to identify ADC toxicity; however, accurate quantification faces challenges, including low plasma concentrations, severe matrix effects, and the absence of stable isotope-labeled internal standards (SIL-IS) for payloads and their derivatives. Previous studies used structural analogs as internal standards, but different retention times between structural analogs and target analytes may hinder effective matrix correction. Therefore, a more flexible approach is required for precise payload quantification. RESULTS: We developed an LC‒MS/MS method incorporating a postcolumn-infused internal standard (PCI-IS) strategy for quantifying payloads and their derivatives of trastuzumab emtansine, trastuzumab deruxtecan, and sacituzumab govitecan, including DM1, MCC-DM1, DXd, SN-38, and SN-38G. Structural analogs (maytansine, Lys-MCC-DM1, and exatecan) were selected as PCI-IS candidates, and their accuracy performance was evaluated based on the percentage of samples within 80%-120% quantification accuracy. Compared to the approach without PCI-IS correction, exatecan enhanced the accuracy performance from 30-40%-100% for SN-38 and DXd, while maytansine and Lys-MCC-DM1 showed comparable accuracy for DM1 and MCC-DM1. This validated PCI-IS analytical method showed superior normalization of matrix effect in all analytes compared to the conventional internal standard approach. The clinical application of this approach showed pronounced differences in DXd and SN-38 concentrations before and after PCI-IS correction. Moreover, only DXd concentrations after PCI-IS correction were significantly higher in patients with thrombocytopenia (p = 0.037). SIGNIFICANCE: This approach effectively addressed the issue of unavailability of SIL-IS for novel ADC payloads and provided more accurate quantification, potentially yielding more robust statistical outcomes for understanding the exposure-toxicity relationship in ADCs. It is anticipated that this PCI-IS strategy may be extrapolated to quantify payloads and derivatives in diverse ADCs, thereby providing invaluable insights into drug toxicity and fortifying patient safety in ADC usage.

Enhancing the identification of voriconazole-associated hepatotoxicity by targeted metabolomics.

Voriconazole-associated hepatotoxicity is a common condition that generally manifests as elevated liver enzymes and can lead to drug discontinuation. Careful monitoring of voriconazole-associated hepatotoxicity is needed but there are no specific plasma biomarkers for this condition. Metabolomics has emerged as a promising technique for investigating biomarkers associated with drug-induced toxicity. The aim of this study was to use targeted metabolomics to evaluate seven endogenous metabolites as potential biomarkers of voriconazole-associated hepatotoxicity. Patients undergoing therapeutic drug monitoring of voriconazole were classified into a hepatotoxicity group (18 patients) or a control group (153 patients). Plasma samples were analysed using ultra-high-performance liquid chromatography coupled to mass spectrometry. Metabolite concentrations in the two groups were compared. Areas under the receiver operating characteristic (AUROC) curves generated from logistic regressions were used to correlate the concentrations of these seven metabolites with voriconazole trough concentrations and conventional liver biochemistry tests. Glycocholate and α-ketoglutarate levels were significantly higher in the hepatotoxicity group compared with the control group (false discovery rate-corrected P < 0.001 and P = 0.024, respectively). The metabolites glycocholate (AUROC = 0.795) and α-ketoglutarate (AUROC = 0.696) outperformed voriconazole trough concentrations (AUROC = 0.555) and approached the performance of alkaline phosphatase (AUROC = 0.876) and total bilirubin (AUROC = 0.815). A panel of glycocholate combined with voriconazole trough concentrations (AUROC = 0.827) substantially improved the performance of voriconazole trough concentrations alone in predicting hepatotoxicity. In conclusion, the panel integrating glycocholate with voriconazole trough concentrations has great potential for identifying voriconazole-associated hepatotoxicity.

Development of the dried blood spot preparation protocol for comprehensive evaluation of the hematocrit effect.

The application of dried blood spots (DBS) has gradually increased in different fields because of its several advantages. The hematocrit (Hct) effect is one major analytical challenge that may affect the quantification accuracy of DBS samples and should be investigated when developing a novel DBS method. However, previous studies usually overlooked the Hct-related distribution bias when evaluating the Hct effect. This study aimed to propose an effective DBS preparation protocol for the comprehensive evaluation of the Hct effect. We selected voriconazole and posaconazole as the demonstration drugs. Fifteen microliters of the blood samples were spotted on DBS cards followed by whole spot extraction. An LC-MS/MS method was first developed to quantify voriconazole and posaconazole in DBS samples. The quantitation accuracy for both azole drugs was within 93.5%-111.7%, except for the accuracies of posaconazole at the LLOQ, which were less than 119%. The intra- and interday precision were below 11%. The validated LC-MS/MS method was used to develop the DBS preparation protocol for evaluating the Hct effect. Three critical parameters that may affect the observed Hct effect were investigated. The results showed that using the solid-state of the target analytes, spiking the target analytes before preparing different Hct levels, and allowing enough equilibrium time after spiking target analytes can provide a more holistic Hct effect evaluation. The validity of the proposed new protocol was verified by conversion factors obtained from 71 paired DBS and plasma samples. Conversion factors calculated by clinical samples were consistent with the Hct effect evaluated by manually prepared DBS samples. This new DBS preparation protocol eliminated the common pitfalls in studying the Hct effect and offered a comprehensive strategy to assess the Hct effect for further DBS studies.

Investigating sphingolipids as biomarkers for the outcomes of acute ischemic stroke patients receiving endovascular treatment.

BACKGROUND: Long-chain ceramides are associated with the mechanisms and clinical outcomes of acute ischemic stroke (AIS). This study aimed to investigate the plasma ceramides and sphingosine-1-phosphate in AIS patients undergoing endovascular thrombectomy (EVT) and their associations with outcomes. METHODS: Plasma samples were collected from 75 AIS patients who underwent EVT before (T1), immediately after (T2), and 24 h after (T3) the procedures and 19 controls that were matched with age, sex, and co-morbidities. The levels of ceramides with different fatty acyl chain lengths and sphingosine-1-phosphate were measured by UHPLC-ESI-MS/MS. A poor outcome was defined as a modified Rankin Scale score of 3-6 at 3 months after stroke. RESULTS: The plasma levels of long-chain ceramides Cer (d18:1/16:0) at all three time points, Cer (d18:1/18:0) at T1 and T3, and Cer (d18:1/20:0) at T1 and very-long-chain ceramide Cer (d18:1/24:1) at T1 were significantly higher in AIS patients than those in the controls. In contrast, the plasma levels of sphingosine-1-phosphate in AIS patients were significantly lower than those in the controls at all three time points. Among the AIS patients, 34 (45.3%) had poor functional outcomes at 3 months poststroke. Multivariable analysis showed that higher levels of Cer (d18:1/16:0) and Cer (d18:1/18:0) at all three time points, Cer (d18:1/20:0) at T1 and T2, and Cer (d18:1/24:0) at T2 remained significantly associated with poor functional outcomes after adjustment for potential confounding factors. CONCLUSION: Plasma ceramides were elevated early in AIS patients with acute large artery occlusion. Furthermore, Cer (d18:1/16:0) and Cer (d18:1/18:0) could be early prognostic indicators for AIS patients undergoing EVT.

Plasma ceramides are associated with outcomes in acute ischemic stroke patients.

BACKGROUND/PURPOSE: Sphingolipids are major constituents of eukaryotic cell membranes and play key roles in cellular regulatory processes. Our recent results in an experimental stroke animal model demonstrated changes in sphingolipids in response to acute ischemic brain injury. This study aimed to investigate the plasma levels of sphingosine-1-phosphate (S1P) and ceramides in acute ischemic stroke (AIS) patients and their associations with functional outcomes. METHODS: Plasma samples were collected from patients with AIS at <48 and 48-72 h post stroke and from nonstroke controls. The levels of S1P and ceramides with different fatty acyl chain lengths were measured by the ultra-high-pressure liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS). A poor functional outcome was defined as a modified Rankin Scale (mRS) score ≥2 at 3 months after AIS. RESULTS: The results showed that S1P and very-long-chain ceramides were significantly decreased in AIS patients (n = 87; poor outcome, 56.3%) compared to nonstroke controls (n = 30). In contrast, long-chain ceramides were significantly increased in AIS patients. More importantly, higher levels of Cer(d18:1/18:0), Cer(d18:1/20:0), and Cer(d18:1/22:0) at 48-72 h were significantly associated with poor functional outcomes after adjusting for potential clinical confounders, including age, sex, hypertension, and National Institutes of Health Stroke Scale score at admission. CONCLUSION: Our study supported the dynamic metabolism of sphingolipids after the occurrence of AIS. Ceramides could be potential prognostic markers for patients with AIS.

Short-course daily isoniazid and rifapentine for latent tuberculosis infection in people living with HIV who received coformulated bictegravir/emtricitabine/tenofovir alafenamide.

INTRODUCTION: Short-course preventive therapy with 1-month course of daily administration of isoniazid (300-mg) plus rifapentine (600-mg) (1HP) and 3-month course of weekly administration of isoniazid (900-mg) plus rifapentine (900-mg) (3HP) has higher completion rates than 9-month course of daily isoniazid (9H) for individuals with latent tuberculosis infection (LTBI). We aimed to evaluate the effect, safety and tolerability of 1HP in people living with HIV (PLWH) and LTBI who received coformulated bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF). METHODS: PLWH testing positive by interferon-gamma release assay and having received BIC/FTC/TAF for >2 weeks with plasma HIV RNA load (PVL) <200 copies/ml were enrolled. BIC trough plasma concentrations and cytokine profiles were determined before the first dose (day 1/baseline), 24 h after the 14th (day 15) and 28th (day 29) doses of 1HP. PVL were determined on days 15 and 29 of 1HP and every 3 months subsequently after discontinuation of 1HP. RESULTS: From November 2019 to December 2020, 48 PLWH with LTBI were enrolled. One participant (2.1%) discontinued 1HP on day 15 due to fever and generalized rashes with PVL of 72 copies/ml, which was <50 copies/ml in three subsequent determinations while on BIC/FTC/TAF over the 12 months of follow-up. The percentages of BIC trough plasma concentrations above the protein-adjusted 95% effective concentration (paEC95 = 162 ng/ml) were 56.3% and 37.0% on days 15 and 29, respectively. The percentage of PVL <200 copies/ml was 91.7% on day 15, 97.8% on day 29 and 100% at both months 3 and 6. After a median observation of 52 weeks (interquartile range, 51-55), all participants continued BIC/FTC/TAF with a median PVL of 20 copies/ml (range 20-331). Except for the participant who discontinued 1HP because of allergic reactions, none of the participants had relevant symptoms or increases of the cytokine levels assessed between baseline and days 15 and 29 of 1HP. CONCLUSIONS: BIC/FTC/TAF in combination with 1HP was well tolerated with a high completion rate. BIC trough plasma concentrations were significantly decreased with concurrent use of 1HP among PLWH with LTBI. While transient viral blips were observed during 1HP without causing subsequent treatment failure, such combination should be applied with caution.

Acute HIV infection with presentations mimicking acalculous cholecystitis: A case report.

RATIONALE: Acute retroviral syndrome is the symptomatic presentation of acute human immunodeficiency virus (HIV) infection, which often manifests as a self-limited infectious mononucleosis-like syndrome and occurs 2 to 6 weeks after exposure to HIV. Atypical manifestations including hepatitis, meningitis, or hemophagocytic lymphohistiocytosis have been reported. However, manifestations of acute acalculous cholecystitis during acute HIV infection are rarely reported. PATIENT CONCERNS: A 30-year-old man with nausea and loose stools, followed by fever and abdominal pain at the right upper quadrant for 10 days. DIAGNOSIS: Acute retroviral syndrome, complicated with acute acalculous cholecystitis. INTERVENTIONS: Percutaneous transhepatic gallbladder drainage was performed and treatment with co-formulated bictegravir/emtricitabine/tenofovir alafenamide was initiated upon HIV diagnosis. OUTCOMES: The patient's symptoms improved after the drainage. The levels of liver enzyme including aspartate transaminase alanine aminotransferase decreased to a level within normal limits 1 month after initiation of antiretroviral therapy. CONCLUSION: Acalculous cholecystitis in combination with acute hepatitis could be manifestations of acute HIV infection. For individuals at risk of acquiring HIV infection who present with manifestations of acute acalculous cholecystitis, HIV testing should be considered.

Survival, health care resource utilization and expenditures of first-line treatments for multiple myeloma patients ineligible for transplant in Taiwan.

BACKGROUND: We aimed to provide real-world information on survival, health care resource utilization (HCRU), and expenditures related to various first lines of therapy (1LOTs) in newly diagnosed multiple myeloma (NDMM) patients who were transplant ineligible (TI). PATIENTS AND METHODS: From the Taiwan National Health Insurance Database (2008-2016), we identified 1,511 NDMM-TI patients who had received 1LOT since June 2012. We categorized 1LOT regimens into four groups: bortezomib (V)+thalidomide (T), V, T, and non-V/T. Patients' characteristics were collected. The overall survival (OS), event-free survival (EFS), frequencies of HCRU (hospitalization, visiting outpatient and emergency departments), and related expenditures within one year after commencement of the 1LOT were evaluated and compared. RESULTS: The mean age of the included patients was 71.3 (SD 10.7) years, and 40.4% of patients had a CCI score ≥3. Most patients (747; 49.4%) were in the V+T group and, after adjusting for covariates, had a significantly longer OS (median, 22.2 months) and EFS (9.1 months) than those in the T group (12.6 and 4.5 months, respectively) and the non-V/T group (12.2 and 3.2 months, respectively), but they were mostly comparable with patients in the V group (23.8 and 6.6 months, respectively). Compared to those in the V+T group, patients in the T and non-V/T groups had 29% and 39% fewer outpatient visits and 15% and 24% lower total expenditure, respectively. CONCLUSION: Our real-world data consolidate evidence for the effectiveness of bortezomib-containing regimens as the 1LOT in NDMM-TI patients at the expense of more outpatient visits and higher total costs.

Impact of high plasma concentrations of linezolid in Taiwanese adult patients- therapeutic drug monitoring in improving adverse drug reactions.

BACKGROUND: Previous studies have shown that the development of thrombocytopenia was associated with the elevated plasma concentration of linezolid, but little is known about the relationship between other uncommon adverse drug reactions (ADRs) and plasma concentration. The appropriate dosing adjustment has remained controversial. This prospective observational study was conducted to investigate the association between the plasma concentration of linezolid, ADRs, and clinical outcomes. METHODS: Adult patients on linezolid treatment undergoing at least one therapeutic drug monitoring (TDM) were enrolled. The association between linezolid concentrations and ADRs was examined by multivariate Cox regression model. Predictors of linezolid concentrations was determined by linear regression model. The cut-off point of linezolid concentration and the effect of dosing adjustments based on TDM was also explored. RESULTS: Of 50 patients enrolled in the study, plasma concentrations were 1.5-3 times higher than what was described in the prescribing information. The median minimum concentration (Cmin) was significantly higher in patients with thrombocytopenia compared to patients without thrombocytopenia (13.0 vs. 7.2 µg/mL, P = 0.0273), and a higher median maximum concentration was also observed in patients with lactic acidosis (33.0 vs. 27.5 µg/mL, P = 0.0420). The Cmin was elevated in patients with advanced age and severely impaired renal function. Dosing adjustment tailored by early TDM with the upper limit of Cmin 9 µg/mL may improve platelet counts. CONCLUSION: Elevated linezolid concentrations were associated with thrombocytopenia and lactic acidosis. TDM-guided dosing adjustment could be considered as a pragmatic way to mitigate thrombocytopenia.

Investigating the Association of the Biogenic Amine Profile in Urine with Therapeutic Response to Neoadjuvant Chemotherapy in Breast Cancer Patients.

Neoadjuvant treatment (NAT) can downstage breast cancer and can be utilized for different clinical applications. However, the response to NAT varies among individuals. Having effective biomarkers is important to optimize the treatment of breast cancer. Concentrations of biogenic amines have been found to show an association with cancer cell proliferation, but their clinical utility remains unclear. This study developed a postcolumn-infused internal standard (PCI-IS)-assisted liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) method for profiling biogenic amines in human urine. Putrescine-d8 was selected as the PCI-IS to calibrate the errors caused by matrix effects in the urine sample. The optimized method was applied to investigate the association between changes in 14 amines and the therapeutic response to NAT in breast cancer patients. Urine samples were collected before initiation of chemotherapy (n = 60). Our results indicated that the levels of N1-acetylspermine, spermidine, norepinephrine, and dopamine were significantly higher in the responder group than the nonresponder group. These metabolites were incorporated with clinical factors to identify NAT responders, and the prediction model showed an area under the curve value of 0.949. These observations provide remarkable insights for future studies in elucidating the roles of biogenic amines in breast cancer. Additionally, the PCI-IS-assisted amine profiling method can facilitate these studies.

Metabolomics analysis of plasma reveals voriconazole-induced hepatotoxicity is associated with oxidative stress.

Voriconazole is one of the most frequently used antifungal drugs for the initial treatment of invasive aspergillosis, but liver-related adverse events occur frequently and usually lead to drug discontinuation. Moreover, the mechanism of voriconazole-induced hepatotoxicity remains unsettled. A holistic understanding of its mechanism is critical to prevent liver-related adverse events. Metabolomics has been demonstrated to be a helpful strategy for investigating drug-induced toxicity. This study aimed to utilize human plasma samples to investigate the mechanism of voriconazole-induced hepatotoxicity through a metabolomics approach. Patients that were administered voriconazole were classified into a voriconazole-induced hepatotoxicity group and control group (n = 65, 18% hepatotoxicity). Plasma samples were analyzed by targeted metabolomics using ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry. The obtained peak areas for each metabolite were utilized for correlation analysis, fold change evaluation, and univariate statistical tests to identify metabolites associated with voriconazole-induced hepatotoxicity. This study showed a significantly lower glutamine-to-glutamate ratio (p = .04) and a higher ß-N-acetylglucosamine (p = .003) in the voriconazole-induced hepatotoxicity group, implying the presence of oxidative stress. Other significant metabolites also indicated several adaptive responses to oxidative stress in patients with voriconazole-induced toxicity, including cell repair, energy production, and alteration to bile acid hemostasis. Furthermore, a metabolite panel consisting of α-ketoglutarate, glycocholate, and ß-N-acetylglucosamine demonstrated better performance for detecting voriconazole-induced hepatotoxicity than conventional liver function tests. These metabolomics findings reveal that voriconazole-induced hepatotoxicity is associated with oxidative stress.

Clinical outcomes of basal insulin and oral antidiabetic agents as an add-on to dual therapy in patients with type 2 diabetes mellitus.

While basal insulin remains the most effective antidiabetic agent and substantially reduces the risk of hypoglycemia, few studies have examined the comparative effect of basal insulin in the real-world setting. This study aimed to assess the outcomes of adding basal insulin compared with thiazolidinediones (TZDs) or dipeptidyl peptidase-4 inhibitors (DPP-4is) as a third antidiabetic agent in patients with type 2 diabetes mellitus (T2DM). A retrospective cohort study involving T2DM was conducted with health administrative data in Taiwan. Patients starting a third antidiabetic agent after receiving a metformin-containing dual combination were identified. The study endpoints included composite major adverse cardiovascular events (MACEs), all-cause mortality, and hypoglycemia. Propensity score matching and Cox modeling were used for analysis. After matching, the basal insulin and TZD groups contained 6,101 and 11,823 patients, respectively, and the basal insulin and DPP-4i groups contained 6,051 and 11,900 patients, respectively. TZDs and DPP-4is were both associated with similar risks of MACEs and hypoglycemia but a lower risk of all-cause mortality than basal insulin (TZDs: HR 0.55, 95% CI 0.38-0.81; DPP-4is: HR 0.56, 95% CI 0.39-0.82). Further studies are needed to elucidate the findings of increased all-cause mortality risk in patients receiving basal insulin, especially those with advanced diabetes.

Early linezolid-associated lactic acidosis in a patient with Child's class C liver cirrhosis and end stage renal disease.

Linezolid, an oxazolidinone antibiotic, does not required dose adjustment in patients with Child's class A and B liver cirrhosis. The dose adjustment data for Child's class C liver cirrhosis is inadequate. We reported a case of Child's class C liver cirrhosis, in which lactic acidosis, an adverse effect related to prolonged use, occurred only after two weeks of linezolid treatment. A 63-year old male had underlying diseases, such as end-stage renal disease (ESRD) and Child's class C liver cirrhosis, and was admitted for hepatic encephalopathy management and liver transplantation evaluation. Spontaneous bacterial peritonitis and septic shock occurred during admission. Because ascites culture revealed vancomycin-resistant Enterococci (VRE), daptomycin was initially prescribed. Subsequently, VRE bacteremia occurred, and infective endocarditis was confirmed. Following treatment failure with daptomycin use, intravenous linezolid (600 mg q12h) was added for synergic effect. VRE bacteremia quickly resolved following linezolid treatment, and vasopressor use was reduced. Despite stable hemodynamics, lactic acidosis still persisted, and linezolid therapeutic drug monitoring was ordered. High linezolid trough concentration (49 mg/L) was found by therapeutic drug monitoring, and linezolid-associated lactic acidosis was highly suspected. Therefore, linezolid treatment was stopped and patient's lactic acid level returned to normal after one week. VRE bacteremia recurred after discontinuation of linezolid; therefore, linezolid was re-prescribed at the lower dose (600 mg). Linezolid trough concentration was within the therapeutic range this time (6.1 mg/L), and lactic acidosis did not occur when linezolid dose was reduced. Therefore, empirically decreased dose and therapeutic drug monitoring should be considered in patients with Child's class C liver cirrhosis and ESRD.