Search Results (5,007)

Messenger RNA (mRNA) entered clinical medicine through vaccines, where the innate immune reactivity that complicates protein therapeutics acts as a built-in adjuvant. The success of the coronavirus disease 2019 (COVID-19) mRNA vaccines inspired an expansive vision of an mRNA 2.0 era extending the modality to rare and common diseases, with delivery framed as the principal challenge. This review accepts much of that vision but argues it rests on an unstated assumption: that all protein therapeutics form a single pharmacological class. They do not. We propose a taxonomy, the Dose–Response Architecture Classification, separating two classes. Exposure-controlled therapeutics require a specific quantity of active protein on a defined regimen, as outcomes depend on reproducible exposure; examples include insulin, erythropoietin, growth hormone, coagulation factors, and narrow-therapeutic-index biologics. Threshold-response therapeutics depend on surpassing a functional threshold rather than maintaining a precise concentration; these include vaccines, many enzyme-replacement therapies, genome editing, receptor-saturating antibodies, and immune-cell reprogramming. Because an mRNA drug is dosed as an instruction, and a single message is translated into a variable number of proteins through a multiplicative, stochastic intracellular chain, the dose-to-effect relationship is inherently variable. Our central, deliberately falsifiable proposition is that mRNA is suitable for threshold-response therapeutics but unsuitable for exposure-controlled therapeutics unless a construct or delivery system demonstrates validated post-delivery output control within predefined pharmacokinetic and pharmacodynamic limits. This is a pharmacological boundary, not a delivery obstacle. We conclude that the greatest advances in mRNA 2.0 will come not from delivery alone but from disciplined indication triage by class. Full article

Snakebite envenomation causes severe tissue damage, often resulting in permanent disability with long-term complications like amputations and organ dysfunction. Current antivenoms, which are antibody-based, have lower tissue penetrability and limited efficacy in minimizing the local effects, highlighting the need for adjunct therapies. Emerging evidence indicates that venom-induced pathology is not restricted to direct cytotoxicity and necrosis; rather, it also involves multiple interconnected Regulated Cell Death (RCD) pathways, but their mechanistic interplay and therapeutic implications remain poorly understood. This review examines how venom toxins induce a cellular stress response characterized by oxidative stress, membrane disruption, and calcium overload, leading to the activation of interconnected regulated cell death (RCD) pathways, including apoptosis, ferroptosis, and pyroptosis, together with autophagy and mitophagy, which primarily function as cellular stress responses that modulate these forms of regulated cell death. We further discuss the crosstalk between these RCD pathways and emerging therapeutic approaches targeting these mechanisms. Understanding these interconnected RCD pathways may facilitate the development of adjunct therapies that complement antivenom, reduce snakebite-induced morbidity, and improve clinical outcomes. Full article

The epidermal growth factor receptor (EGFR) was the first receptor tyrosine kinase identified soon after v-Src was recognized as a tyrosine kinase. EGFR signaling begins when EGF binds to EGFR at the cell surface, inducing receptor dimerization, activation, and autophosphorylation. The resulting phosphotyrosine sites recruit downstream effectors that activate signaling cascades such as the RAS-RAF-MEK-ERK and PI3K-Akt pathways, thereby regulating cell growth, proliferation, and survival. EGF binding also promotes EGFR endocytosis, which can direct the receptor to lysosomal degradation. Aberrant EGFR activity is associated with many cancers, and the receptor has been therapeutically targeted using small-molecule tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAbs). Furthermore, EGFR endocytosis has been exploited for the targeted delivery of anticancer agents into EGFR-expressing cancer cells through antibody–drug conjugates (ADCs) and antibody–nanoparticle conjugates (ANCs). Although ADCs and ANCs both utilize mAbs as homing mechanisms to recognize cancer-associated antigens, they further harness EGFR endocytosis to deliver therapeutic payloads directly into target cells. In this review, we briefly discuss EGFR structure, activation, signaling, and endocytosis, as well as the mechanisms underlying EGFR function in cancer development. We then focus on current advances and future perspectives in using EGFR endocytosis pathways to improve targeted cancer drug delivery and therapy, particularly in the context of ANCs. Full article

Acute hepatitis B virus (HBV) infection is rare during infancy, and severe symptomatic HBV-associated hepatitis is even less common. We describe two siblings who developed severe HBV-associated liver injury during infancy, two years apart, but experienced markedly divergent clinical outcomes. Clinical, laboratory, virological, microbiological, imaging, therapeutic, and follow-up data were retrospectively reviewed. Household members were subsequently tested for HBV and HDV. The first infant, a 5-month-old girl, presented with HBsAg positivity, negative serological markers for HAV, HCV, and HEV, and severe acute liver injury with a fulminant clinical course that resulted in death. Because anti-HBc IgM, HBV DNA, repeat HBsAg testing, and follow-up serology were unavailable, acute HBV infection could not be confirmed, and the episode was therefore classified as presumed HBV-associated fulminant hepatitis. The rapidly fatal clinical course precluded a comprehensive etiological evaluation, and the available medical records did not fully document the diagnostic work-up. The second patient, a 4-month-old boy, presented with serological and molecular evidence of acute HBV infection, including low-level HBV DNA, total anti-HDV positivity of uncertain clinical significance, and positive CMV IgM/IgG serology. He also had a urinary tract infection (UTI) caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. Without HDV RNA and CMV DNA testing, active HDV infection and clinically significant CMV disease could not be definitively confirmed, while passive transfer of maternal anti-HDV antibodies could not be excluded. The patient required prolonged hospitalization, during which he received supportive, replacement, and antimicrobial therapy. He recovered, and long-term follow-up demonstrated HBsAg clearance with undetectable HBV DNA. Testing of household members revealed chronic HBV infection in the mother and maternal grandmother, both of whom had detectable HDV RNA, consistent with ongoing HBV/HDV circulation within the family. However, without viral sequence data from the infants, the source, route, timing, and direction of transmission could not be established. These cases illustrate the potential severity of HBV-associated hepatitis during infancy and its highly variable clinical outcomes. They also underscore the importance of antenatal HBV screening, timely immunoprophylaxis, and cautious interpretation of suspected viral coinfections when molecular confirmation is unavailable. Full article

Background/Objectives: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies because of aggressive tumor biology, pervasive therapeutic resistance, rapid adaptive reprogramming, and a profoundly immunosuppressive tumor microenvironment. This review summarizes recent advances in KRAS-targeted therapies, DNA damage response (DDR)-directed strategies, immune-redirection platforms, and tumor microenvironment modulation. Methods: We conducted a narrative review of peer-reviewed publications, clinical trial reports, trial registries, and selected conference data addressing emerging therapeutic strategies for PDAC. Results: KRAS-targeted therapies, including KRAS G12D-selective and multi-selective RAS(ON) inhibitors, have demonstrated substantial preclinical and emerging clinical activity while revealing diverse mechanisms of adaptive resistance. DDR-directed approaches are expanding beyond BRCA-mutated disease toward functional homologous recombination deficiency, replication stress, and synthetic lethality. In parallel, bispecific antibodies, T-cell engagers, and CAR-T-cell therapies have generated preliminary evidence of antitumor activity, although stromal exclusion, antigen heterogeneity, and immune suppression remain major barriers. These advances indicate that therapeutic resistance in PDAC is a dynamic process involving interconnected oncogenic, genomic, stromal, metabolic, and immune mechanisms. Conclusions: Future progress will require biologically informed treatment frameworks integrating complementary therapeutic modalities according to baseline tumor biology and treatment-induced adaptive states, supported by longitudinal biomarkers and rational clinical trial design. Full article

Human epidermal growth factor receptor 2 (HER2) and trophoblast cell surface antigen 2 (Trop-2) are tumor-associated antigens widely overexpressed in multiple malignant tumors, which drive malignant proliferation, invasion, metastasis, and therapeutic resistance by activating key downstream signaling pathways. Antibody–drug conjugates (ADCs) targeting HER2 and Trop-2 leverage their antigen-specific binding capacity to achieve precise targeted delivery of cytotoxic drugs, representing a significant breakthrough in solid tumor therapy. This review systematically outlines the biological functions and carcinogenic mechanisms of HER2 and Trop-2, focusing on the latest research and development progress of related ADCs. We also summarize and analyze key clinical data and application prospects in breast cancer (BC), gastric cancer (GC), non-small cell lung cancer (NSCLC), and urothelial carcinoma (UC), while also delving into the challenges and future directions within this field. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by the buildup of aggregated amyloid-beta (Aβ) peptides. We previously demonstrated that Aβ is produced from APP following its lysosomal internalization via macropinocytosis. However, the regulation of APP macropinocytosis in neuronal cells remained uncharacterized. Arf6 and the Rho GTPases Rac1, Cdc42 and RhoA are known to regulate macropinocytosis in response to signaling at the cell surface. Fe65, an adaptor protein known to interact with APP, may link APP to these regulatory elements. We hypothesized that APP binding/crosslinking recruits Fe65, which recruits/activates Arf6 and then Rac1, Cdc42, and RhoA, driving APP macropinocytosis. We found that antibody-mediated binding/crosslinking APP resulted in the transient recruitment of Fe65 and Arf6 to APP within 30 s of APP binding/crosslinking. Rac1, Cdc42, and RhoA were also recruited at 30 s, but remained recruited through 2 min. The mutation of the APP ‘YENPTY’ sequence and Arf6 inhibition by NAV-2729 prevented the recruitment of Rac1, Cdc42, and RhoA. Together, these observations are the first to demonstrate that a network of regulatory proteins is recruited to bound/crosslinked APP and regulates its macropinocytosis. Targeting these regulatory proteins to modulate APP trafficking to the lysosome could be a therapeutic strategy to reduce Aβ production in AD. Full article

Background/Objectives: CD89 (FcaRI), the receptor for immunoglobulin A (IgA), is expressed on myeloid cells, including neutrophils, monocytes, and macrophages. It is known to mediate potent effector functions against tumor cells, but the clinical development of IgA-based therapeutics is hindered by manufacturing challenges and IgA’s short plasma half-life. Methods: Using yeast display, we generated EGFR × CD89 bispecific common light chain antibodies and investigated their biophysical properties, neutrophil-mediated cytotoxicity and macrophage phagocytosis in vitro. Results: CD89-targeting constructs induced potent neutrophil cytotoxicity and macrophage phagocytosis in vitro. A symmetric 2 + 2 IgG1 Fc-silenced variant showed the most consistent potency across neutrophil and macrophage effector functions. Fc silencing enhanced neutrophil ADCC and did not induce detectable neutrophil or PBMC fratricide under the conditions tested, suggesting a limited propensity for off-target immune cell killing. Conclusions: These findings support further preclinical evaluation of CD89-targeting bispecific antibodies and indicate that Fc silencing may differentially shape neutrophil- and macrophage-mediated antitumor activity. Full article

Acinetobacter baumannii, a Gram-negative opportunistic bacterium in the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, A. baumannii, Pseudomonas aeruginosa and Enterobacter spp.), has emerged as a leading cause of nosocomial infections worldwide. It is known to possess diverse virulence traits and antimicrobial resistance, making it a critical priority pathogen on the World Health Organization’s 2024 Bacterial Priority Pathogens List. Carbapenem-resistant A. baumannii (CRAB) is currently endemic across several continents, with global carbapenem resistance exceeding 70% in healthcare settings and multidrug-resistant infections being associated with alarming mortality rates. This review comprehensively discusses the molecular underpinnings of A. baumannii pathogenesis and virulence, detailing the array of factors coordinated by complex regulatory networks. The convergence of this pathogen’s virulence and antimicrobial resistance traits, resulting in multidrug resistance, leaves clinicians with only a handful of therapeutic options. The review also discusses upcoming therapeutic strategies, including phage therapy, antimicrobial peptides, monoclonal antibodies, photodynamic therapy, and vaccine candidates in the pipeline. While emerging therapeutics show promise, several challenges remain, and integrated approaches are warranted to efficiently combat A. baumannii’s virulence and resistance armamentarium. Full article

The therapeutic monoclonal antibody bevacizumab is typically purified using protein A affinity chromatography, a highly effective but costly method. Affinity-based precipitation for antibody purification is a lower-cost approach. In this work, a precipitation protocol was developed for bevacizumab purification using a branched peptide (Ac-PHQGQHIG-Ahx₃)₂-K-Ahx₃-PHQGQHIG-NH₂, which contains the epitope PHQGQHIG that is responsible for interacting with bevacizumab. The peptide was synthesised by a microwave-assisted solid-phase peptide method, employing LiCl as an additive to prevent aggregation and ensure high purity and yield. Three molecules of 6-aminohexanoic acid were introduced between each epitope branch as spacer arms to promote the formation of cyclic complexes. Bevacizumab purification from cell-free culture broth was achieved through a fractional precipitation process. First, a negative precipitation step using (NH₄)₂SO₄ 1.18 M was performed to remove contaminants. Afterwards, 5 moles of peptide per mol of bevacizumab was added to the supernatant, together with additional (NH₄)₂SO₄, to reach a final concentration of 1.20 M. Under these conditions, bevacizumab was recovered in the precipitate with 98% purity and a yield of 73%. In addition to being recyclable, the peptide’s relatively low production cost could enable the development of a single-use purification process, which would be particularly advantageous for biopharmaceutical manufacturing. Full article

Relapsed and/or refractory follicular lymphoma (R/R FL) remains a therapeutic challenge due to its chronic relapsing course and increasingly complex treatment landscape. Novel therapies, including immunomodulatory combinations, bispecific antibodies (BsAbs), Bruton tyrosine kinase inhibitors, and chimeric antigen receptor (CAR) T-cell therapies, have expanded treatment options and increased the complexity of treatment selection and sequencing. The Canadian Hematology Consensus Group (CHCG) convened a national panel of lymphoma experts to develop evidence-informed consensus recommendations for the management of adults with R/R FL in the Canadian context. Clinical questions informed a structured literature review of studies published through February 2026, including randomized trials, phase II studies, observational data, conference proceedings, and relevant guidelines. Recommendations were developed using a modified Delphi consensus process and graded using a framework adapted from the British Committee for Standards in Haematology. Key recommendations include repeat biopsy to exclude histologic transformation at relapse, individualized treatment selection based on timing of relapse and patient-specific factors, preferential use of lenalidomide-rituximab (LenR)-based triplet combinations in most second-line settings, and incorporation of BsAb and CAR T-cell therapy in third-line and later disease. These recommendations aim to provide practical guidance for Canadian clinicians managing patients with R/R FL. Full article

Epidermal growth factor receptor (EGFR)-targeted therapy represents one of the earliest and most established examples of precision oncology in non-small-cell lung cancer (NSCLC), with more than 10 approved agents, including tyrosine kinase inhibitors, bispecific antibodies and antibody–drug conjugates. Over the past two decades, the diagnostic and therapeutic landscape of EGFR-mutant NSCLC has evolved from empiric treatment to mutation subtype-guided strategies, from advanced disease to earlier-stage interventions, and from monotherapy to rational combination regimens. Somatic EGFR mutations remain key predictive biomarkers guiding treatment selection, therapeutic intensification, resistance mechanism-directed treatment, and disease monitoring through plasma circulating tumor DNA burden. In parallel, germline EGFR alterations are increasingly recognized as contributors to inherited lung cancer susceptibility, particularly among never-smokers and familial clusters. Germline EGFR T790M is the best-characterized pathogenic variant, creating a permissive background for multifocal lung nodules and lung adenocarcinoma development, often following acquisition of a second somatic EGFR driver mutation. Recent familial, regional, and paired tumor–normal sequencing studies have expanded the evidence beyond isolated case reports and support an emerging hereditary lung cancer predisposition phenotype. Clinically, germline EGFR should be suspected when EGFR T790M is detected prior to TKI exposure, particularly at variant allele fractions near 50%, or in patients with multifocal ground-glass nodules, multiple primary lung adenocarcinomas, early-onset disease, never/light smoking history, or family history of lung cancer. Confirmation requires germline testing and genetic counseling. This review highlights the current knowledge, recent advances, and future directions in somatic and germline EGFR-mutant NSCLC, emphasizing translational relevance for clinicians and researchers. Full article

Extramedullary disease (EMD)—the proliferation of clonal plasma cells in soft tissues without direct bone connection—represents one of the most challenging manifestations of multiple myeloma, associated with aggressive biology, treatment resistance, and poor outcomes. EMD is driven by distinct pathophysiologic mechanisms including downregulation of adhesion molecules, acquisition of high-risk cytogenetic abnormalities (del(17p), gain(1q)), activation of the RAS–MAPK pathway, epigenetic dysregulation such as EZH2 upregulation, and remodeling of the immune microenvironment toward an immunosuppressive, T-cell-depleted phenotype. Conventional therapies, including anti-CD38-based regimens, yield limited efficacy in EMD, with pooled overall response rates of approximately 20% in triple-class-exposed relapsed/refractory disease. T-cell-redirecting therapies have emerged as the most promising treatment strategy. Both chimeric antigen receptor (CAR) T-cell therapy and bispecific antibodies have demonstrated clinically meaningful activity in soft tissue EMD, with CAR T-cell therapy providing the deepest and most durable responses, and dual-targeting bispecific combinations showing particularly encouraging efficacy. Central nervous system (CNS) myeloma, the most devastating form of EMD, has historically carried a dismal prognosis. Emerging retrospective data suggest that both CAR T-cell therapy and bispecific antibodies can achieve meaningful CNS responses with acceptable safety profiles, as part of multimodal approaches incorporating CNS-directed therapies. Despite these advances, EMD remains associated with inferior outcomes even in the immunotherapy era, underscoring the need for strategies targeting the immunosuppressive microenvironment, novel therapeutic approaches, and prospective EMD-focused clinical trials. This review provides a comprehensive overview of the biology, classification, and evolving treatment landscape of both non-CNS and CNS EMD in the era of T-cell-redirecting immunotherapy. Full article

Background/Objectives: Recent advances in immunotherapy have revolutionized cancer treatment, as exemplified by multiple monoclonal antibodies against programmed cell death protein 1 (PD-1) or programmed death-ligand 1 (PD-L1). Nevertheless, immunotherapeutic antibodies exhibit certain limitations, which drives the development of alternative approaches, such as small interfering RNA (siRNA)-based therapeutics. The aim of this study was to design and produce new biological PD-L1 siRNA (BioRNA/PD-L1-siRNA) molecules and further define their immunotherapeutic efficacy against non-small cell lung cancer (NSCLC) in vitro. Methods: A novel RNA molecular bioengineering platform was employed to produce new BioRNA/PD-L1-siRNA agents. The functions of BioRNA/PD-L1-siRNAs were determined by quantitative PCR, Western blot, immunofluorescence confocal imaging, flow cytometry, and PD-1/PD-L1 blockade assays in human NSCLC cells, alone and co-cultured with human peripheral blood mononuclear cells (PBMCs). Results: After heterologous overexpression and purification of five BioRNA molecules, one siRNA named BioRNA/PD-L1-siRNA-1 was identified as the most effective to selectively suppress human PD-L1 mRNA and protein levels in H460 and H1975 cells. Disruption of PD-1/PD-L1 interactions by BioRNA/PD-L1-siRNA-1 was further demonstrated via a PD-1/PD-L1 blockade bioassay. In addition, the immunomodulatory effectiveness of BioRNA/PD-L1-siRNA-1 was established in co-culture models, as indicated by the induction of T-cell and natural killer cell populations and an increase in specific cytokines and cytotoxic granules, and subsequent enhancement of apoptosis and greater inhibition of NSCLC cell viability. Conclusions: Overall, these findings demonstrate the potential of bioengineered PD-L1 siRNA entities for NSCLC immunotherapy. Full article

Background/Objectives: Glycation, a non-enzymatic post-translational modification, can increase structural heterogeneity in therapeutic monoclonal antibodies (mAbs) and is considered a critical quality attribute in biosimilar (BS) development. Despite extensive studies on glycation in individual mAbs, comparative reports on originator (OR) and BS mAbs under forced glycation conditions remain limited. This study aimed to comparatively evaluate the glycation profiles of one OR and three BS anti-tumor necrosis factor-alpha (anti TNF-α) mAb products using integrated mass spectrometry-based methods. Methods: Forced glycation was induced by incubating mAbs with 200 mM D-glucose at 37 °C for 7 days. Intact mass analysis and peptide mapping were used to assess glycation extent and site distribution, respectively. Results: Intact mass analysis revealed a consistent mass increase of approximately 486 Da across all major glycoform species for each mAb product, indicating predominant formation of the tri-glycated mAb population under the applied stress conditions. The overall glycation levels were comparable at the intact level, ranging from 67% to 73% among the OR and BS mAb products. Peptide mapping identified nine glycated lysine (K)-containing peptides, among which three major glycation hotspots (LC:V5 K145/K149, LC:V7 K183, and HC:V7 K250/K252) showed elevated occupancies (~10–16%). These sites collectively accounted for the dominant intact level mass shift. The remaining glycated peptides exhibited only minimal modification levels (<2%). Despite their distinct manufacturing processes, all tested mAb products showed nearly identical site-specific glycation profiles. Conclusions: Forced glycation susceptibility in the studied mAbs was driven by a limited set of structurally preferred K hotspots, leading to highly comparable glycation profiles across OR and BS mAb products. The combined intact mass and peptide mapping strategy provides a robust analytical platform for comparative glycation assessment in BS characterization. Full article