Thrombosis and inflammation are primary contributors to the onset and progression of ischemic stroke. The contact-kinin pathway, initiated by plasma kallikrein (PK) and activated factor XII (FXIIa), functions bidirectionally with the coagulation and inflammation cascades, providing a novel target for therapeutic drug development in ischemic stroke. In this study, we identified a bat-derived oligopeptide from Myotis myotis (Borkhausen, 1797), designated LE6 (Leu-Ser-Glu-Glu-Pro-Glu, 702 Da), with considerable potential in stroke therapy due to its effects on the contact kinin pathway. Notably, LE6 demonstrated significant inhibitory effects on PK and FXIIa, with inhibition constants of 43.97 μmol/L and 6.37 μmol/L, respectively. In vitro analyses revealed that LE6 prolonged plasma recalcification time and activated partial thromboplastin time. In murine models, LE6 effectively inhibited carrageenan-induced mouse tail thrombosis, FeCl 3-induced carotid artery thrombosis, and photochemically induced intracerebral thrombosis. Furthermore, LE6 significantly decreased inflammation and stroke injury in transient middle cerebral artery occlusion models. Notably, the low toxicity, hemolytic activity, and bleeding risk of LE6, along with its synthetic simplicity, underscore its clinical applicability. In conclusion, as an inhibitor of FXIIa and PK, LE6 offers potential therapeutic benefits in stroke treatment by mitigating inflammation and preventing thrombus formation.
血栓形成和炎症是缺血性脑卒中的主要病因。由于血浆激肽释放酶（PK）和凝血因子XII（FXIIa）启动的接触-激肽通路与凝血和炎症级联反应具有双向作用，因此，为缺血性脑卒中治疗药物的开发提供了方向。该研究发现蝙蝠（ Myotis myotis）源蛋白序列的寡肽 LE6（Leu-Ser-Glu-Glu-Pro-Glu，702 Da）能高效抑制PK 和 FXIIa 的活性，抑制常数分别为 43.97 μmol/L和 6.37 μmol/L。这是首次探究的PK和FXIIa双靶点活性抑制的寡肽与缺血性脑卒中治疗的关系。在体外，LE6 可延长血浆复钙和活化部分凝血活酶时间。在小鼠模型中，LE6能抑制卡拉胶诱导的小鼠尾部血栓形成、氯化铁诱导的颈动脉血栓形成和光化学诱导的脑内血栓形成。此外，LE6 还能明显减轻缺血性脑卒中小鼠模型中的炎症和脑缺血损伤。重要的是，LE6 的低毒性、低溶血性和低出血潜能，以及其合成的简易性，都凸显了其潜在的临床应用前景。该研究显示，蝙蝠源寡肽LE6作为FXIIa和PK的抑制剂，通过减少炎症和抑制血栓形成，对中风治疗有益。.

We present a novel computational approach for predicting human pharmacokinetics (PK) that addresses the challenges of early stage drug design. Our study introduces and describes a large-scale data set of 11 clinical PK end points, encompassing over 2700 unique chemical structures to train machine learning models. To that end multiple advanced training strategies are compared, including the integration of in vitro data and a novel self-supervised pretraining task. In addition to the predictions, our final model provides meaningful epistemic uncertainties for every data point. This allows us to successfully identify regions of exceptional predictive performance, with an absolute average fold error (AAFE/geometric mean fold error) of less than 2.5 across multiple end points. Together, these advancements represent a significant leap toward actionable PK predictions, which can be utilized early on in the drug design process to expedite development and reduce reliance on nonclinical studies.

Aim: A new, selective and simple UPLC-MS/MS method was developed and validated for the determination of lifitegrast in human plasma and tear in order to obtain PK data. Materials & methods: Lifitegrast-d4 solutions were added in the samples, and then were extracted and transferred to a UPLC vial. Results: The respective working ranges were 25.00-2000.00 pg/ml in plasma and 4.00-1000.00 μg/ml in tear. The fully validated method complied with existing regulatory criteria for accuracy and precision, recovery, etc. It was applied to plasma and tear samples, which were from a clinical study, successfully. Conclusion: This method is useful in the evaluation of lifitegrast in plasma and tear.
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Duplicate analysis has been a conventional practice in the industry for ligand-binding assays (LBA), particularly for plate-based platforms like Enzyme-linked immunosorbent assay (ELISA) and Meso Scale Discovery (MSD) assays. Recent whitepapers and guidance have opened a door to exploring the implementation of single-well (singlicate) analysis approach for LBAs. Although the bioanalytical industry has actively investigated the suitability of singlicate analysis, applications in supporting regulated LBA bioanalysis are limited. The primary reason for this limitation is the absence of appropriate strategy to facilitate the transition from duplicate to singlicate analysis. In this paper we present the first case study with our data-driven approach to implement singlicate analysis in a clinical pharmacokinetics (PK) plate based LBA assay with ISR data. The central aspect of this strategy is a head-to-head comparison with Precision and Accuracy assessment in both duplicate and singlicate formats as the initial stage of assay validation. Subsequently, statistical analysis is conducted to evaluate method variability in both precision and accuracy. The results of our study indicated that there was no impactful difference between duplicate vs singlicate, affirming the suitability of singlicate analysis for the remaining steps of PK assay validation. The validation results obtained through singlicate analysis demonstrated acceptable assay performance characteristics across all validation parameters, aligning with regulatory guidance. The validated PK assay in singlicate has been employed to support a Phase I study. The appropriateness of singlicate analyses is further supported by initial Incurred Sample Reanalysis (ISR) data in which 90.1% of ISR samples fall within the acceptable criteria.

Aim: Endogenous interferents can cause nonselectivity in ligand binding pharmacokinetic assays, leading to inaccurate quantification of drug concentrations. We describe the development of a Gyrolab immunoassay to quantify a new modality, CB307 and discuss strategies implemented to overcome matrix effects and achieve selectivity at the desired sensitivity. Results: Matrix effects were mitigated using strategies including increasing minimum required dilution (MRD) and lower limit of quantification, optimization of antibody orientation, assay buffer and solid phase. Conclusion: The strategies described resulted in a selective method for CB307 in disease state matrix that met bioanalytical method validation (BMV) guidance and is currently used to support clinical pharmacokinetic sample analysis in the first-in-human POTENTIA clinical study (NCT04839991) as a secondary clinical end point.
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An appropriately designed pharmacokinetic (PK) assay that is sensitive for anti-drug antibody (ADA) impact on relevant exposure is an alternative strategy to understand the neutralizing potential of ADAs. However, guidance on how to develop such PK assays and how to confirm the functional ADA impact on exposure is missing. Here, the PK assay of a T-cell-engaging bispecific antibody, cibisatamab, was developed based on its mechanism of action (MoA). Using critical monoclonal anti-idiotypic (anti-ID) antibody positive controls as ADA surrogates, the impact on exposure was evaluated pre-clinically. In a phase I clinical trial (NCT02324257), initial data suggest that the combination of ADA and PK assays for correlation of the ADA response with cibisatamab exposure. To understand the neutralizing potential of patient-derived ADAs on drug activity, advanced ADA characterization has been performed. Structural binding analysis of ADAs to antibody domains of the drug and its impact on targeting were assessed. For this purpose, relevant patient ADA binding features were identified and compared with the specific monoclonal anti-ID antibody-positive controls. Comparable results of target binding inhibition and similar impacts on exposure suggest that the observed reduction of Cmax and Ctrough levels in patients is caused by the neutralizing potential of ADAs and allows a correlation between ADA response and loss of exposure. Therefore, the described study provides important functional aspects for the development of an appropriately designed PK assay for bispecific antibodies as an alternative option towards understanding the neutralizing ADA impact on exposure.

In this chapter, we will first consider the overall goal of nonclinical safety testing during drug development and have a brief overview of its regulatory background. We will then discuss some basic requirements of safety/toxicity testing before concentrating on the safety testing of RNA vaccines and developing a sample RNA vaccine safety testing program.

An intramuscular (IM) suspension of benzathine penicillin G (BPG) has been used as first-line therapy for the treatment of syphilis worldwide since its approval in the 1950s. However, there are limited reports about the pharmacokinetics of BPG. A Phase 1 study was conducted on eight Japanese healthy participants to investigate the pharmacokinetics (samples collected predose to 648 h post-dose) and safety of 2.4 million units of BPG after a single IM injection. Following administration, penicillin G, the active moiety of BPG, was absorbed slowly from the injection site with a median time to Cmax (tmax) of 48 h post-dose. After the achievement of Cmax, concentrations of penicillin G declined slowly in a monophasic fashion with a mean apparent terminal half-life of 189 h. Geometric mean AUCinf and Cmax were 50770 ng•h/mL and 259 ng/mL, respectively. Median time (range) above the well-accepted therapeutic concentration (18 ng/mL) for syphilis treatment was 561 h (439-608 h [18-25 days]), which reached and exceeded the necessary duration of 7-10 days for syphilis treatment. Two participants were underdosed with residual drug left in the syringe due to the high viscosity of the drug product. Only one (12.5%) participant reported a mild adverse event of nasopharyngitis, which was considered not related to the study treatment. The study results supported BPG approval in Japan as an option for syphilis treatment.

Microbial keratitis in a post-transplant cornea should be considered a distinct entity from microbial keratitis in a non-transplant cornea. Firstly, the use of immunosuppressive treatments and sutures in corneal transplants changes the etiology of keratitis. Secondly, corneal transplant has an impact on corneal biomechanics and structure, which facilitates the spread of infection. Finally, the emergence of lamellar transplants has introduced a new form of keratitis known as interface keratitis. Given these factors, there is a clear need to update our understanding of and management strategies for microbial keratitis following corneal transplantation, especially in the era of lamellar transplants. To address this, a comprehensive review is provided, covering the incidence, risk factors, causes, and timing of microbial keratitis, as well as both clinical and surgical management approaches for its treatment in cases of penetrating and lamellar corneal transplants.

BACKGROUND: Isoniazid (INH) is an important drug in many TB regimens, and unfavorable treatment outcomes can be caused by suboptimal pharmacokinetics. Dose adjustment can be personalized by measuring peak serum concentrations; however, the process involves cold-chain preservation and laboratory techniques such as liquid chromatography (LC)/mass spectrometry (MS), which are unavailable in many high-burden settings. Urine spectrophotometry could provide a low-cost alternative with simple sampling and quantification methods.
METHODS: We enrolled 56 adult patients on treatment for active TB. Serum was collected at 0, 1, 2, 4, 6, and 8 h for measurement of INH concentrations using validated LC-MS/MS methods. Urine was collected at 0-4, 4-8, and 8-24 h intervals, with INH concentrations measured using colorimetric methods.
RESULTS: The median peak serum concentration and total serum exposure over 24 h were 4.8 mg/L and 16.4 mg*hour/L, respectively. Area under the receiver operator characteristic curves for urine values predicting a subtherapeutic serum concentration (peak <3.0 mg/L) were as follows: 0-4 h interval (AUC 0.85, 95% CI 0.7-0.96), 0-8 h interval (AUC 0.85, 95% CI 0.71-0.96), and 0-24 h urine collection interval (AUC 0.84, 95% CI 0.68-0.96).
CONCLUSIONS: Urine spectrophotometry may improve feasibility of personalized dosing in high TB burden regions but requires further study of target attainment following dose adjustment based on a urine threshold.
BACKGROUND: L’isoniazide (INH) est un médicament important dans de nombreux schémas thérapeutiques contre la TB, et des résultats thérapeutiques défavorables peuvent être dus à une pharmacocinétique sous-optimale. L’ajustement de la dose peut être personnalisé en mesurant les concentrations sériques maximales ; cependant, le processus implique la conservation de la chaîne du froid et des techniques de laboratoire telles que la chromatographie liquide (LC)/spectrométrie de masse (MS), qui ne sont pas disponibles dans de nombreuses régions à forte charge de morbidité. La spec-trophotométrie urinaire pourrait constituer une alternative peu coûteuse avec des méthodes d’échantillonnage et de quantification simples.
UNASSIGNED: Nous avons recruté 56 patients adultes sous traitement pour une TB active. Le sérum a été prélevé à 0, 1, 2, 4, 6 et 8 h pour mesurer les concentrations d’INH à l’aide de méthodes LC-MS/MS validées. L’urine a été prélevée à des intervalles de 0–4, 4–8 et 8–24 h, et les concentrations d’INH ont été mesurées à l’aide de méthodes colorimétriques.
UNASSIGNED: La concentration sérique maximale médiane et l’exposition sérique totale sur 24 h étaient respectivement de 4,8 mg/L et de 16,4 mg*heure/L. L’aire sous les courbes caractéristiques de l’opérateur récepteur a été mesurée à l’aide de méthodes color-imétriques. Les aires sous les courbes caractéristiques des récepteurs pour les valeurs urinaires prédisant une concentration sérique sous-thérapeutique (pic <3,0 mg/L) étaient les suivantes : intervalle 0–4 h (AUC 0,85 ; IC 95% 0,7–0,96), intervalle 0–8 h (AUC 0,85 ; IC 95% 0,71–0,96), et intervalle de collecte d’urine 0–24 h (AUC 0,84 ; IC 95% 0,68–0,96).
CONCLUSIONS: La spectrophotométrie urinaire peut améliorer la faisabilité d’un dosage personnalisé dans les régions à forte charge de TB, mais nécessite une étude plus approfondie de l’atteinte de la cible après l’ajustement de la dose sur la base d’un seuil urinaire.