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Small molecule induced STING degradation facilitated by the HECT ligase HERC4
No full textStimulator of interferon genes (STING) is a central component of the cytosolic nucleic acids sensing pathway and as such master regulator of the type I interferon response. Due to its critical role in physiology and its’ involvement in a variety of diseases, STING has been a focus for drug discovery. Targeted protein degradation (TPD) has emerged as a promising pharmacology for targeting previously considered undruggable proteins by hijacking the cellular ubiquitin proteasome system (UPS) with small molecules. Here, we identify AK59 as a STING degrader leveraging HERC4, a HECT-domain E3 ligase. Additionally, our data reveals that AK59 is effective on the common pathological STING mutations, suggesting a potential clinical application of this mechanism. Thus, these findings introduce HERC4 to the field of TPD and a compound-induced degradation of STING, suggesting potential therapeutic applications
Clinical Pharmacology of Asciminib: A Systematic Review
No full textAsciminib is the first-in-class allosteric inhibitor of the kinase activity of BCR::ABL1, Specifically Targeting the ABL Myristoyl Pocket (STAMP). This review focuses on the pharmacokinetic (PK) and pharmacodynamic data of asciminib, which is approved for the treatment of adult patients with chronic myeloid leukemia in chronic phase (CML-CP) who are either resistant or intolerant to ≥2 alternative therapies (at a total daily dose of 80 mg), or those harboring the T315I mutation (at a dose of 200 mg twice-daily (b.i.d.).
Asciminib is predicted to be almost completely absorbed from the gut, with an absolute bioavailability (F) of approximately 73%. Asciminib displays a slightly greater than dose-proportional increase in exposure, and no time-dependent changes in PK have been observed following repeated dosing.
This drug shows low clearance (4.34 L/hr), with a moderate volume of distribution (111 L) and high human plasma protein binding (97.3%). The apparent terminal elimination half-life (T1/2) across studies was estimated to be between 7 and 15 hours. The PK of asciminib is not substantially affected by body weight, age, gender, race, or renal or hepatic impairment.
Asciminib is primarily metabolized via CYP3A4-mediated oxidation (36.0%) and UGT2B7- and UGT2B17-mediated glucuronidation (13.3% and 7.8%, respectively); biliary secretion via breast cancer resistance protein (BCRP) contributes to about 31.1% to total systemic clearance, which is mainly through hepatic metabolism and biliary secretion through the fecal pathway, with renal excretion playing a minor role.
Potential for pharmacokinetic drug interaction for asciminib both as a victim as well as a perpetrator have been summarized here based on clinical and predicted drug-drug interaction studies.
Administration of asciminib with food reduced exposure compared to administration in the fasted state; the observed decrease was more substantial with high-fat meals.
Robust exposure-response models characterized asciminib exposure-efficacy and exposure-safety relationships. In patients without the T315I mutation, the exposure-efficacy analysis of the time course of BCR::ABL1IS percentages highlighted the existence of a slightly positive, albeit not clinically significant, relationship. Higher exposure was required for efficacy in patients harboring the T315I mutation compared to those who did not. The exposure-safety relationship analysis showed no apparent association between exposure and adverse events of interest over the broad range of exposure or dose levels investigated. Asciminib has also been shown to have no clinically relevant effect on cardiac repolarization.
Here, we review the clinical pharmacology data available to date for asciminib that supported its clinical development program and regulatory applications
Aggressive Lymphoma after CD19 CAR T-Cell Therapy.
No full textThe development of a fatal, clonal, autonomously proliferating CD4-CD8- chimeric antigen receptor (CAR)+ peripheral T-cell lymphoma (PTCL) occurred 1 month after a patient received treatment with tisagenlecleucel for relapsed primary central nervous system lymphoma. The PTCL had a clonal T-cell receptor rearrangement, which was already detectable in the apheresis product for CAR T-cell manufacturing and 7 months earlier for autologous transplantation. Somatic DNMT3A and TET2 mutations in CD34+ stem cells and their progeny were detected in the PTCL, in the apheresis specimen that was obtained for CAR T-cell production, and in the autotransplant. The PTCL harbored an additional somatic TET2 mutation, which was already detectable in the CAR T-cell apheresis product and the final CAR T-cell product at very low frequencies, providing evidence that clonal hematopoiesis had contributed to lymphomagenesis
Comprehensive functional characterization of complement factor I rare variant genotypes identified in the SCOPE geographic atrophy cohort.
No full textRare variants (RVs) in the gene encoding the regulatory enzyme complement factor I (CFI; FI) that reduce protein function or levels increase age-related macular degeneration risk. A total of 3357 subjects underwent screening in the SCOPE natural history study for geographic atrophy secondary to age-related macular degeneration, including CFI sequencing and serum FI measurement. Eleven CFI RV genotypes that were challenging to categorize as type I (low serum level) or type II (normal serum level, reduced enzymatic function) were characterized in the context of pure FI protein in C3b and C4b fluid phase cleavage assays and a novel bead-based functional assay (BBFA) of C3b cleavage. Four variants predicted or previously characterized as benign were analyzed by BBFA for comparison. In all, three variants (W51S, C67R, and I370T) resulted in low expression. Furthermore, four variants (P64L, R339Q, G527V, and P528T) were identified as being highly deleterious with IC50s for C3b breakdown >1 log increased versus the WT protein, while two variants (K476E and R474Q) were ∼1 log reduced in function. Meanwhile, six variants (P50A, T203I, K441R, E548Q, P553S, and S570T) had IC50s similar to WT. Odds ratios and BBFA IC50s were positively correlated (r = 0.76, p < 0.01), while odds ratios versus combined annotation dependent depletion (CADD) scores were not (r = 0.43, p = 0.16). Overall, 15 CFI RVs were functionally characterized which may aid future patient stratification for complement-targeted therapies. Pure protein in vitro analysis remains the gold standard for determining the functional consequence of CFI RVs
Genotoxicity evaluation of gene therapies: A report from the International Workshop on Genotoxicity Testing (IWGT) 2022.
No full textAt the 8th International Workshop on Genotoxicity Testing meeting in Ottawa, in August 2022, a plenary session was dedicated to the genotoxicity risk evaluation of gene therapies, including insertional oncogenesis and off-target genome editing. This brief communication summarizes the topics of discussion and the main insights from the speakers. Common themes included recommendations to conduct tailored risk assessments based on a weight-of-evidence approach, to promote data sharing, transparency, and cooperation between stakeholders, and to develop state-of-the-art validated tests relevant to clinical scenarios
ADA2 is a lysosomal deoxyadenosine deaminase acting on DNA involved in regulating TLR9-mediated immune sensing of DNA.
No full textAlthough adenosine deaminase 2 (ADA2) is considered an extracellular ADA, evidence questions the physiological relevance of this activity. Our study reveals that ADA2 localizes within the lysosomes, where it is targeted through modifications of its glycan structures. We show that ADA2 interacts with DNA molecules, altering their sequences by converting deoxyadenosine (dA) to deoxyinosine (dI). We characterize its DNA substrate preferences and provide data suggesting that DNA, rather than free adenosine, is its natural substrate. Finally, we demonstrate that dA-to-dI editing of DNA molecules and ADA2 regulate lysosomal immune sensing of nucleic acids (NAs) by modulating Toll-like receptor 9 (TLR9) activation. Our results describe a mechanism involved in the complex interplay between NA metabolism and immune response, possibly impacting ADA2 deficiency (DADA2) and other diseases involving this pathway, including autoimmune diseases, cancer, or infectious diseases
Design and synthesis of inhibitors of the E3 ligase SMAD Specific E3 Ubiquitin Protein Ligase 1 (SMURF1) as a treatment for lung remodeling in Pulmonary Arterial Hypertension (PAH)
No full textDesign and synthesis of inhibitors of the E3 ligase SMAD Specific E3 Ubiquitin Protein Ligase 1 (SMURF1) as a treatment for lung remodeling in Pulmonary Arterial Hypertension (PAH)
A series of selective SMURF1 ligase inhibitors have been identified, optimized for potency and properties to enable excellant rat pharmacokinetic properties. Furthermore compounds from the series have been shown to potently block the remodeling of vascular smooth muscle in the rat Hypoxia –Sugen model of PAH
Current Industry Best Practice on in-use Stability and Compatibility Studies for Biological Products.
No full textEvaluating the in-use stability of a biological product including its compatibility with administration components allows to define handling instructions and potential hold times that retain product quality during dose preparation and administration. The intended drug product usage may involve the dilution of drug formulation into admixtures for infusion and exposure to new interfaces of administration components like intravenous (iv) bags, syringes, and tubing. In-use studies assess the potential impact on product quality by simulating drug handling throughout the defined in-use period. Considering the wide range of in-use conditions and administration components available globally, only limited guidance is available from regulators on expected in-use stability data. A working group reviewed and consolidated industry approaches to assess physicochemical stability of traditional protein-based biological products during clinical development and for commercial use. The insights compiled in this review article can be leveraged across the industry and encompass topics such as representative drug product material and administration components, testing conditions, quality attributes evaluated and respective acceptance criteria, applied quality standards, and regulatory requirements. These practices may help companies in the study design, and they may inform discussions with global regulators
Optimizing the Cell Painting assay for image-based profiling
No full textIn image-based profiling, software extracts thousands of morphological features of cells from multi-channel fluorescence microscopy images, yielding single-cell profiles that can be used for basic research and drug discovery. Powerful applications have been proven, including clustering chemical and genetic perturbations based on their similar morphological impact, identifying disease phenotypes by observing differences in profiles between healthy and diseased cells, and predicting assay outcomes using machine learning, among many others. Here we provide an updated protocol for the most popular assay for image-based profiling, Cell Painting. Introduced in 2013, it uses six stains imaged in five channels and labels eight diverse components of the cell: DNA, cytoplasmic RNA, nucleoli, actin, Golgi apparatus, plasma membrane, endoplasmic reticulum, and mitochondria. The original protocol was updated in 2016 based on several years’ experience running it at two sites, after optimizing it by visual stain quality. Here we describe the work of the Joint Undertaking for Morphological Profiling (JUMP) Cell Painting Consortium, aiming to improve upon the assay via quantitative optimization, based on the measured ability of the assay to detect morphological phenotypes and group similar perturbations together. We find that the assay gives very robust outputs despite a variety of changes to the protocol and that two vendors’ dyes work equivalently well. We present Cell Painting version 3, in which some steps are simplified and several stain concentrations can be reduced, saving costs. Cell culture and image acquisition take 1–2 weeks for a typically sized batch of 20 or fewer plates; feature extraction and data analysis take an additional 1–2 weeks