Publications by authors named "Purohit V"

Article Synopsis
  • - Ritlecitinib is an oral medication being developed for treating moderate-to-severe alopecia areata, functioning as an irreversible inhibitor of specific kinases.
  • - A study using advanced mass spectroscopy explored how ritlecitinib is absorbed, distributed, metabolized, and eliminated in the body, revealing key pharmacokinetic parameters like a clearance rate of 43.7 L/h and a bioavailability of 64%.
  • - The research found that ritlecitinib binds to plasma proteins and is mainly cleared through urine, with metabolic processes involving various cytochrome P450 enzymes and glutathione-related conjugation playing significant roles.
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studies of formulation performance with and/or simulations are often limited by significant gaps in our knowledge of the interaction between administered dosage forms and the human gastrointestinal tract. This work presents a novel approach for the investigation of gastric motility influence on dosage form performance, by combining biopredictive dissolution tests in an innovative apparatus with mechanistic physiology-based pharmacokinetic modeling. The methodology was based on the pharmacokinetic data from a large ( = 118) cohort of healthy volunteers who ingested a capsule containing a highly soluble and rapidly absorbed drug under fasted conditions.

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The recruitment of a parallel, healthy participants (HPs) arm in renal and hepatic impairment (RI and HI) studies is a common strategy to assess differences in pharmacokinetics. Limitations in this approach include the underpowered estimate of exposure differences and the use of the drug in a population for which there is no benefit. Recently, a method was published by Purohit et.

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Article Synopsis
  • * To gain regulatory approval for the MR microsphere, researchers needed to establish bioequivalence (BE) with the IR solution, which was achieved by conducting physiologically-based pharmacokinetic (PBPK) virtual BE trials instead of traditional clinical ones.
  • * The trials showed that the MR microsphere (10 mg once daily) is bioequivalent to the IR solution (5 mg twice daily) after both a single and multiple doses, highlighting a new method that minimizes unnecessary testing on healthy volunteers while aiding in drug formulation development.
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Introduction: Topical brepocitinib, a tyrosine kinase (TYK)2/Janus kinase (JAK)1 inhibitor, is in development for psoriasis (PsO) and atopic dermatitis (AD). Quantitative analyses of prior clinical trial data were used to inform future clinical trial designs.

Methods: Two phase 2b studies in patients with AD and PsO were used to characterize the amount of topical brepocitinib and the resultant systemic trough concentration (C) using a linear mixed-effects regression (LMER).

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Article Synopsis
  • - The paper discusses the use of model-informed drug development (MIDD) in accelerating the availability of the new therapy ritlecitinib for alopecia areata, showcasing its effectiveness through a combined phase 2b and pivotal study.
  • - Researchers conducted exposure-response modeling using the Severity of Alopecia Tool (SALT) score to understand the drug's efficacy, finding that dose levels tested were appropriate and that disease severity was the only significant factor influencing effectiveness.
  • - The study concluded that the modeling approach supported the drug's clinical trial strategy and informed dosage decisions, demonstrating its potential application to other treatments measured on similar efficacy scales.
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Serial crystallography and time-resolved data collection can readily be employed to investigate the catalytic mechanism of Pseudomonas mevalonii 3-hydroxy-3-methylglutaryl (HMG)-coenzyme-A (CoA) reductase (PmHMGR) by changing the environmental conditions in the crystal and so manipulating the reaction rate. This enzyme uses a complex mechanism to convert mevalonate to HMG-CoA using the co-substrate CoA and cofactor NAD. The multi-step reaction mechanism involves an exchange of bound NAD and large conformational changes by a 50-residue subdomain.

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Anti-inflammatory and immune suppressive agents are required to moderate hyper-activation of lymphocytes under disease conditions or organ transplantation. However, selective disruption of mitochondrial redox has not been evaluated as a therapeutic strategy for suppression of T-cell-mediated pathologies. Using mitochondrial targeted curcumin (MitoC), we studied the effect of mitochondrial redox modulation on T-cell responses by flow cytometry, transmission electron microscopy, transcriptomics, and proteomics, and the role of Nrf2 was studied using Nrf2 / mice.

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Article Synopsis
  • * Due to the dissolution differences between 100-mg and 50-mg capsules, a biowaiver for the lower dose couldn't be granted based solely on traditional tests.
  • * A physiologically based pharmacokinetic (PBPK) model was used to predict in vivo behavior from in vitro data, showing that 50-mg capsules are likely bioequivalent to 100-mg capsules with over a 90% success probability in virtual trials.
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Background: Chronic airway infection by significantly impacts the health of people with cystic fibrosis (PwCF), presenting complex treatment challenges.

Research Design And Methods: To gain insights into PwCF's experiences, a virtual European Patient Advisory Board was convened. Board explored inhaled antibiotic usage, treatment adherence, and associated challenges.

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Article Synopsis
  • Ritlecitinib, an investigational drug targeting certain kinases, was studied for its effects on drug transporters and potential interactions with other medications.
  • In both in vitro and clinical studies, ritlecitinib was assessed for its ability to inhibit various transporters, including BCRP, OATP1B1, and OAT3, using rosuvastatin as a test drug and measuring endogenous biomarkers.
  • Results indicated that ritlecitinib does not inhibit these transporters, suggesting limited potential for clinically significant drug interactions, and supports the use of coproporphyrin I and pyridoxic acid as biomarkers for evaluating transporter activity.
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Article Synopsis
  • The ALLEGRO-2b/3 clinical trial tested the effectiveness and safety of ritlecitinib, a daily pill for treating alopecia areata (AA), an autoimmune disease leading to hair loss.
  • The study involved adults and adolescents, with participants taking ritlecitinib showing significantly more hair regrowth compared to a placebo after 24 weeks, with improvements observed on the scalp, eyebrows, and eyelashes.
  • Ritlecitinib was found to be an effective and well-tolerated treatment for 48 weeks, with side effects being similar in both ritlecitinib and placebo groups, mostly mild to moderate.
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Article Synopsis
  • Alopecia areata causes non-scarring hair loss on the scalp and body, and this study explored the effectiveness and safety of ritlecitinib, an oral medication that inhibits certain kinases, in treating this condition.* -
  • The research was a randomized, double-blind trial across 118 sites in 18 countries, enrolling patients aged 12 and older with significant scalp hair loss, who were assigned to receive either ritlecitinib or a placebo for 24 weeks.* -
  • A total of 718 patients participated, with a majority being female (62%) and White (68%), while 104 patients discontinued treatment during the trial due to various reasons, including adverse events.*
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Article Synopsis
  • Ritlecitinib is a drug that inhibits specific kinases (JAK3 and TEC) and is being studied for its pharmacokinetics and safety in people with liver and kidney issues.
  • Due to the pandemic, one study on healthy participants was paused, but researchers used data from another study with participants having liver impairment to derive new insights using statistical and simulation models.
  • The results showed that people with renal impairment likely won’t need any dose adjustment for ritlecitinib, and the studies confirmed that the drug is generally safe and well-tolerated.
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The present study primarily focuses on the efficacy of Malabaricone C (Mal C) as an anti-inflammatory agent. Mal C inhibited mitogen-induced T-cell proliferation and cytokine secretion. Mal C significantly reduced cellular thiols in lymphocytes.

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Article Synopsis
  • - The clinical study aimed to assess how ritlecitinib affects the way the body processes caffeine, specifically looking at its impact on the cytochrome P450 1A2 enzyme.
  • - Twelve healthy participants received caffeine alone and then again after taking ritlecitinib for eight days; results showed that caffeine levels increased significantly when combined with ritlecitinib.
  • - The study concluded that ritlecitinib acts as a moderate inhibitor of the CYP1A2 enzyme, leading to increased caffeine exposure, but it was generally well-tolerated by participants.
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Article Synopsis
  • Ritlecitinib is being developed as a treatment for inflammatory diseases and inhibits certain transport proteins such as OCT1.
  • A clinical study showed that when ritlecitinib is taken with sumatriptan (a drug that relies on OCT1), its concentration in the bloodstream increased significantly, indicating that ritlecitinib affects OCT1’s function.
  • The study confirmed that while ritlecitinib and its metabolite M2 inhibit OCT1, they do not have a meaningful impact on other transporters like OCT2 or MATE1/2K.
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Enzyme reactivity is often enhanced by changes in oxidation state, spin state, and metal-ligand covalency of associated metallocofactors. The development of spectroscopic methods for studying these processes coincidentally with structural rearrangements is essential for elucidating metalloenzyme mechanisms. Herein, we demonstrate the feasibility of collecting X-ray emission spectra of metalloenzyme crystals at a third-generation synchrotron source.

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Background: The human respiratory syncytial virus (RSV) is responsible for causing upper and lower respiratory tract infections in young children. RSV Fusion (F) protein is a surface glycoprotein that facilitates virus entry into host cells. Thus, newer designing of RSV Fusion (F) protein inhibitors is required on an urgent basis.

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Myostatin, a negative regulator of skeletal muscle growth, is a therapeutic target in muscle-wasting diseases. Domagrozumab, a humanized recombinant monoclonal antibody, binds myostatin and inhibits activity. Domagrozumab was investigated in a phase II trial (NCT02310763) as a potential treatment for boys with Duchenne muscular dystrophy (DMD).

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Shikha Verma  Systemic fluoropyrimidines, both oral and intravenous, are an integral part of colorectal cancer (CRC) management. They can be administered either with curative or palliative intent.  This article examines the literature to analyze the efficacy and safety of the oral fixed-dose combination of uracil and tegafur (UFT)/leucovorin (LV) compared with other fluoropyrimidine agents, with an intention to implement the findings into the current treatment algorithms for CRC.

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Olefin metathesis reactions of diverse polyfunctional substrates were conducted in water emulsions using two hydrophobic ruthenium catalysts in the presence of air. Instead of using surfactants to increase the efficiency of the metathesis reaction in water, ultrasound and microwave techniques were tested on a small-scale reaction, whereas conventional heating and mechanical stirring were effective enough to provide high conversion and selectivity on a larger scale. The developed conditions extend known protocols for the aqueous metathesis methodology, utilizing relatively low catalyst loadings and allowing for simple product isolation and purification.

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Dendritic cells (DCs) sense environmental cues and adopt either an immune-stimulatory or regulatory phenotype, thereby fine-tuning immune responses. Identifying endogenous regulators that determine DC function can thus inform the development of therapeutic strategies for modulating the immune response in different disease contexts. Tim-3 plays an important role in regulating immune responses by inhibiting the activation status and the T cell priming ability of DC in the setting of cancer.

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Technical advances at the interface of biology and computation, such as single-cell RNA-sequencing (scRNA-seq), reveal new layers of complexity in cellular systems. An emerging area of investigation using the systems biology approach is the study of the metabolism of immune cells. The diverse spectra of immune cell phenotypes, sparsity of immune cell numbers in vivo, limitations in the number of metabolites identified, dynamic nature of cellular metabolism and metabolic fluxes, tissue specificity, and high dependence on the local milieu make investigations in immunometabolism challenging, especially at the single-cell level.

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