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Functional chimeric mRNAs encode proteins in mammalian immunity.

Individual mammalian mRNAs and proteins are typically believed to originate from single genomic loci, with isoform diversity arising through cis-splicing of pre-mRNA. Whether mRNA from distant genes can undergo trans-splicing to generate functionally relevant chimeric transcripts has remained unclear. Here we develop a pipeline combining long-read direct RNA sequencing with non-targeted and targeted validation to identify chimeric transcripts in macrophages. Chromatin conformation capture studies reveal that inflammation induces interchromosomal DNA interactions, positioning parent genes proximally to facilitate the formation of chimeric mRNA. Notably, we identify a protein-coding chimeric mRNA representing a fusion between the pore-forming protein gasdermin D (GSDMD)1,2 and a C-terminal domain translated out of frame from Tmem106a (Gsdmd-Tmem106a) in mice. We show that inflammasome priming upregulates Gsdmd-Tmem106a, with the protein localizing to the plasma membrane. After activation of the inflammasome, GSDMD-TMEM106A directly interacts with canonical GSDMD N termini to accelerate and enhance pore formation and IL-1β release. Finally, we show that GSDMD-TMEM106A balances host defence and immunopathology in vivo: its loss protects against lethal sepsis but compromises antibacterial defence, whereas overexpression enhances host protection while increasing sepsis lethality. We establish that protein-coding chimeric mRNAs formed by regulated transcript fusion events are operative during inflammation and immunity.

Journal Article

Chimeric vaccine based on Iraqi HLA alleles against a predominant local Escherichia coli phylogroup.

INTRODUCTION: Escherichia coli remains amongst the most globally important pathogens implicated in severe clinical manifestations. The progressive rise in multidrug-resistant strains highlights the urgent need for new vaccines. Therefore, this study was designed to develop a new multi-epitope vaccine containing the most conserved epitopes across E. coli pathotypes. Consequently, the study aimed to investigate the immunoadjuvant role of faecal microbiota transplantation in enhancing vaccine efficacy. METHODS: Eighteen of the most conserved B-cell and T-cell epitopes of FimH, LptD, and BamA proteins were selected and included in a single construct. During the epitope selection process, HLA alleles predominant in the Iraqi population, as reported in previous studies, were used as criteria for selecting T-cell epitopes. The chimeric protein was expressed in BL21 E. coli and purified using affinity chromatography. Vaccine cross-protective immunity and protection were tested in in vivo experiments. Different formulations were used in the experimental evaluation: three doses of 100 μg of purified chimeric protein, injected intraperitoneally alone or encapsulated in PLGA nanoparticles, after faecal microbiota transplantation with and without gut microbiota modulation mediated by a cocktail of antibiotics. IgG1, IL-4, INF-γ, and NLRP3 levels were measured at 30 and 75 days after the first immunisation dose. Immunised mice were challenged with the local B2 UPEC phylogroup, and protection efficacy was considered 48 h later. Finally, the histological effects of the different chimeric protein formulations on the liver were assessed. RESULTS: All vaccine formulations except those after faecal microbiota transplantation without gut microbiota modulation induce significant increases in IgG1, IL-4, and INF-γ levels at different times. Only vaccination after faecal microbiota transplantation with gut microbiota modulation elicited robust NLRP3 levels at 30 and 75 days after, and this was linked to the highest reduction in bladder bacterial load by 813-fold compared to the other formulations, as well as the mildest effect on liver histological changes. DISCUSSION: These results demonstrated that the chimeric vaccine provides preliminary protection against a local B2 UPEC isolate. Furthermore, modulating gut microbiota via faecal transplantation markedly enhances the immunogenicity and protective efficacy of vaccination, suggesting its adjuvanticity.

Animals

Whole-genome sequences reveal zygotic composition in chimeric twins.

While most dizygotic twins have a dichorionic placenta, rare cases of dizygotic twins with a monochorionic placenta have been reported. The monochorionic placenta in dizygotic twins allows in utero exchange of embryonic cells, resulting in chimerism in the twins. In practice, this chimerism is incidentally identified in mixed ABO blood types or in the presence of cells with a discordant sex chromosome. Here, we applied whole-genome sequencing to one triplet and one twin family to precisely understand their zygotic compositions, using millions of genomic variants as barcodes of zygotic origins. Peripheral blood showed asymmetrical contributions from two sister zygotes, where one of the zygotes was the major clone in both twins. Single-cell RNA sequencing of peripheral blood tissues further showed differential contributions from the two sister zygotes across blood cell types. In contrast, buccal tissues were pure in genetic composition, suggesting that in utero cellular exchanges were confined to the blood tissues. Our study illustrates the cellular history of twinning during human development, which is critical for managing the health of chimeric individuals in the era of genomic medicine.

Humans

Multi-Step Synthesis of Chimeric Nutlin-DCA Compounds Targeting Dual Pathways for Treatment of Cancer.

Chimeric compounds represent a promising strategy in cancer therapy by simultaneously targeting multiple pathways responsible for tumour growth and survival. Their structure comprises two or more pharmacophores connected through suitable chemical linker. These dual or multi-functional drugs can interact with several biological targets for a more pronounced pharmacological effect. In order to identify new multi-targeting agents with anticancer efficacy, we designed and synthesised a series of novel multi-functional molecules by covalently linking antitumor compounds dichloroacetate (DCA) and Nutlin-3a. The design was aimed at addressing two critical events in cancer: (1) the Warburg effect and (2) the dysregulations of protein p53 pathway, both of which are directly linked to the predominant survival and aggressive proliferation of malignant cells. DCA reactivate oxidative phosphorylation by inhibiting mitochondria pyruvate dehydrogenase kinase (PDK), thereby unlocking the Warburg metabolism of cancer cells and its antiapoptosis state. Concurrently, Nutlin-3a restores the protective function of the "genome guardian" p53 protein, by blocking its antagonist oncoprotein E3 ligase MDM2. Chimeric compounds were obtained using a chemoenzymatic multi-step procedure that included a key lipase-catalysed asymmetric reaction. Biological evaluation of the synthesised Nutlin-DCA chimeras in a panel of three cancer cell lines demonstrated promising results in vitro. Specifically, compounds rac-19a, rac-19b, rac-20a, rac-20b and enantioenriched 20a caused a statistically significant reduction in cell viability at micromolar concentrations. These findings suggest that targeting both the Warburg effect and the p53 pathway with a single molecule is a viable approach for future cancer therapeutic development.

Humans

Directing fratricide within T cell products using an anti-uPAR chimeric antigen receptor to drive the production of potent therapeutic cells.

Cell therapy manufacturing of primary T cells often results in heterogeneous cell populations in the final product, with many cells lacking desired receptor expression or exhausted and other dysfunctional phenotypes. Here, we design a novel cell-intrinsic strategy to genetically reprogram primary human T cells to autonomously detect and eliminate dysfunctional cells. This integrated detection and elimination process, known as directed fratricide, is programmed via non-viral CRISPR genome editing to eliminate the T cell receptor (TCR) alpha chain (TRAC gene knockout) and integrate a chimeric antigen receptor (CAR) against the urokinase-type plasminogen activator receptor (uPAR), also known as CD87. In these cell products, strong T cell stimulation or activation during manufacturing causes a small subset of cells to express uPAR, which triggers CAR-mediated killing within the product. This fratricide induces proliferation in the desired cells and destroys undesired cells, a process that could be modeled computationally and controlled robustly via supplements to the culture media. The strategy enabled enrichment of anti-uPAR and anti-disialoganglioside (GD2) CAR-T cell products up to ≥99% CAR+/TCR-, favoring a memory-like phenotype. Understanding growth dynamics among T cell subsets and reprogramming them via CRISPR could accelerate the biomanufacturing of potent cell products without extensive selection methods.

Humans

Modulating the PPARγ pathway upregulates NECTIN4 and enhances chimeric antigen receptor (CAR) T cell therapy in bladder cancer.

With the approval of the antibody-drug conjugate enfortumab vedotin (EV), NECTIN4 has emerged as a bona fide therapeutic target in urothelial carcinoma (UC). Here, we report the development of a NECTIN4-directed chimeric antigen receptor (CAR) T cell, which exhibits reactivity across cells expressing a range of endogenous NECTIN4, with enhanced activity in high expressors. We demonstrate that the PPARγ pathway, critical for luminal differentiation, transcriptionally controls NECTIN4, and that the PPARγ agonist rosiglitazone primes and augments NECTIN4 expression, thereby increasing sensitivity to NECTIN4-CAR T cell-mediated killing. NECTIN4-CAR T cells have potent anti-tumor activity even against EV resistant cells, which largely retain NECTIN4 expression, including in a post-EV biopsy cohort. Our results elucidate a therapeutically actionable mechanism that UC cells use to control NECTIN4 expression and suggest therapeutic approaches that leverage PPARγ agonists for rational combinations with NECTIN4-targeting agents in UC, as well as future potential treatment options for EV-refractory patients.

Humans

An immune exhaustion signature predicts prognosis and identifies patients with diffuse large B-cell lymphoma (DLBCL) who derive preferential benefit from chimeric antigen receptor (CAR)-T cell therapy.

BACKGROUND: The tumor microenvironment (TME) is a key determinant of prognosis in diffuse large B-cell lymphoma (DLBCL). While T-cell exhaustion is implicated in therapeutic failure, its precise molecular hallmarks and utility for predicting response to modern immunotherapies, such as chimeric antigen receptor (CAR)-T cell therapy, remain unclear. METHODS: We performed an integrative analysis of transcriptomic and clinical data from multiple DLBCL cohorts (The Cancer Genome Atlas [TCGA], GSE181063, GSE10846, GSE248835, GSE182434). We used unsupervised clustering, exploratory analysis of single-cell RNA sequencing data, and the least absolute shrinkage and selection operator for variable selection (LASSO-Cox) regression to characterize the exhausted TME, construct a prognostic model, and evaluate its predictive value for CAR-T cell therapy. The model's dynamic behavior was assessed in a proof-of-concept longitudinal cohort of patients treated with the T-cell-engaging bispecific antibody glofitamab. RESULTS: We identified a "high-exhaustion" subtype associated with significantly poorer overall survival (OS; log-rank P = 0.016). Based on this, we developed a five-gene immune exhaustion-Related Prognostic Score (IERPS) that served as a robust independent predictor of poor OS across multiple cohorts. Critically, in a cohort of 256 relapsed/refractory patients, the IERPS was strongly prognostic for event-free survival (EFS) in the standard-of-care (SOC) arm (HR = 2.02, 95% confidence interval [95% CI]: 1.07-3.81, P = 0.029) but lost prognostic significance in the CAR-T arm (HR = 0.70, 95 % CI: 0.35-1.40, P = 0.314). This significant interaction suggests that CAR-T cell therapy may abrogate the poor prognosis associated with a high IERPS. Biologically, exploratory single-cell analysis (n = 4 samples) defined the high-IERPS state by hallmarks of classical T-cell exhaustion, and a descriptive case study showed the score dynamically tracked clinical response to glofitamab. CONCLUSIONS: A state of active T-cell exhaustion and a suppressive TME drive the adverse immune phenotype in DLBCL. Our IERPS model captures this dysfunctional state, acting as a powerful prognostic tool and, more importantly, as a potential predictive biomarker to identify high-risk patients who appear to overcome their inherently poor prognosis through CAR-T cell therapy.

Biomarkers

Programmable antibody-based chimeric entry receptors for sarbecoviruses.

Despite frequent spillover of sarbecoviruses, most SARS-related viruses discovered in animals fail to engage human ACE2 (hACE2), limiting mechanistic insight and risk assessment. Here we developed antibody-based chimeric entry receptors (ABCERs) that reprogram antibody-antigen recognition into a synthetic, cell-anchored receptor interface. By replacing the extracellular protease domain of hACE2 with single-chain variable fragments (scFvs) from broadly neutralizing antibodies, ABCERs mimic viral receptor engagement while preserving the intracellular architecture required for cathepsin L-dependent endocytic fusion. This modular design converts antibody specificity into a programmable entry module, supporting efficient infection and replication of diverse sarbecoviruses from both clinical and animal sources. Among the tested scFvs, E7 exhibited exceptional breadth, recognizing conserved epitopes shared across representative sarbecoviruses from all clades. Sera from Pfizer-BioNTech mRNA-vaccinated individuals potently blocked E7 binding to SARS-CoV-2 but showed limited cross-inhibition of E7 interactions with RBDs from hACE2-independent sarbecoviruses, revealing a substantial gap in current vaccine-induced humoral immunity. Together, our findings establish E7-based ABCERs as a programmable synthetic receptor platform that bridges antibody recognition and viral propagation, offering a universal tool for isolating, studying, and surveying sarbecoviruses beyond the hACE2-dependent paradigm.

Humans

Chimeric structural isomer fragments as cost-efficient internal standards for amino acid quantification by mass spectrometry.

Amino acid (AA) profiles from body fluids such as blood and urine are clinical indicators for diagnosing metabolic and hepatic diseases. Current quantitative methods, such as liquid chromatography-mass spectrometry (LC-MS) with isotopically labelled internal standards (ISs), are costly and technically demanding. This study proposes a cost-efficient alternative using structural isomers as ISs in a direct liquid infusion (DLI) tandem mass spectrometry (MS/MS) approach. The method leverages chimeric spectra and fragment intensity ratios to quantify AAs, demonstrating high linearity and precision even with a 3D ion trap mass analyser. This approach offers a viable strategy for AA quantification in preventive medicine, particularly for screening metabolic diseases such as phenylketonuria, diabetes, and liver dysfunction.

Amino Acids

Quantifying HLA transcripts by genotype in chimeric mixtures at single-cell resolution.

Gene products from the highly variable major histocompatibility locus, including HLA, are essential for self-recognition and immune surveillance of malignancy. Following allogeneic hematopoietic cell transplantation (alloHCT), genetic and epigenetic alterations in HLA can drive disease recurrence, making precise HLA assessment critical for determining future therapy. However, current methods lack the sensitivity to quantify HLA transcripts at the single-cell level, limiting their clinical utility. We introduce scrHLA-typing, a novel technique that accurately identifies and quantifies HLA transcripts in single cells using long-read sequencing. When applied to samples from patients with post-transplant relapse, scrHLA-typing successfully detected HLA allele-specific expression, across a range of levels of donor-recipient chimerism, at clinically actionable levels. By characterizing allele expression in residual leukemia cells, our assay identified differences in expression patterns among patients. This capability highlights scrHLA-typing's potential to improve risk stratification and guide the selection of appropriate salvage therapies, enhancing personalized treatment strategies after relapse.

Journal Article

Real-World Efficacy and Safety of Standard-of-Care Chimeric Antigen Receptor T-Cell (CART) and Bispecific T-Cell Engager (TCE) Therapies in Relapsed/Refractory Multiple Myeloma (RRMM).

We aimed to evaluate the real-world (RW) efficacy and safety of standard-of-care CART versus TCE therapies in relapsed/refractory myeloma (RRMM), to assess utilization, outcomes, and tolerability of these therapies in a RW oncology in the US. Data were derived from the US-based, electronic health record-derived deidentified Flatiron Health Research Database, 2021-2024. A total of 419 patients (CART n = 220; TCE n = 199) with a confirmed diagnosis of myeloma who received CART or TCE as a standard-of-care treatment after at least 2 prior lines of therapy were included. Patients in the CART cohort were younger, had better ECOG PS, and a higher receipt of a prior autologous stem cell transplant versus bispecific TCE cohort. In CART versus TCE cohort, the overall response rates (ORR) were 83.3% versus 66.3%, median duration of response 7.9 months versus 4.3 months, progression free survival (PFS) 13.6 months versus 10.5 months, and overall survival (OS) of 29.8 months versus 21.9 months, respectively. A higher percentage of hematologic toxicity, infections, and cytokine release syndrome (CRS) were noted in the CART versus TCE cohort. This study provides insights on the RW effectiveness of CART versus TCE in the treatment of RRMM; highlights the differences in patient selection, clinical responses, treatment duration, and toxicity profiles.

CART

Hemophagocytic Lymphohistiocytosis and Fibroblast Growth Factor 23 (FGF23)-Induced Hypophosphatemia.

Hypophosphatemia is a frequent complication of chimeric antigen receptor T-cell therapy. In this setting, hypophosphatemia has been previously associated with cytokine release syndrome. The mechanisms underlying this electrolyte derangement are not fully understood. Extracellular phosphate consumption by chimeric antigen receptor T cells was demonstrated in vitro, but inflammation is also thought to play a contributing role. We present a case of severe, refractory hypophosphatemia with renal phosphate wasting triggered by hemophagocytic lymphohistiocytosis in acute lymphoblastic leukemia. The diagnosis of phosphate wasting was made at the onset of leukemia and a clinical exacerbation occurred after chimeric antigen receptor T-cell therapy. Diagnostic workup revealed very high fibroblast growth factor 23 (FGF23) levels in the absence of recognized acquired or genetic causes of impaired FGF23 cleavage. This case suggests that inflammation associated with hemophagocytic lymphohistiocytosis may induce FGF23 as a potential mechanism for hypophosphatemia. In this context, we recommend evaluation of renal phosphate wasting and subsequently FGF23 in patients with persistent hypophosphatemia despite standard supplementation.

Humans

Orthoplastic management of open calcaneal fractures: A systematic review of flap selection and complications.

BACKGROUND: Open calcaneal fractures are rare, high-energy injuries involving extensive soft-tissue loss and comminuted bone disruption. Successful management depends on coordinated orthoplastic reconstruction to achieve stable fixation and durable coverage. Multiple flap types have been described, yet comparative outcomes remain poorly defined. METHODS: A systematic review was performed in accordance with PRISMA guidelines (PROSPERO: CRD420251138394). MEDLINE, Embase, Cochrane CENTRAL, and Scopus were searched from January 2000 to July 2025. Studies reporting flap-based reconstruction for open calcaneal fractures in adults were included. Extracted data included flap type, fixation method, follow-up duration, and complications such as infection, necrosis, vascular crises, flap loss, and amputation. RESULTS: Thirteen studies comprising 88 major flap reconstructions were analysed. Overall flap survival was 97.7%, with two failures (both muscle/myocutaneous). Fasciocutaneous flaps showed the lowest complication rates (8.3%) with no reported cases of infection, while muscle/myocutaneous flaps demonstrated cases of infection (20%) and accounted for both flap failures and the only reported amputation. Chimeric flaps were increasingly used in recent series (n = 32), achieving reliable survival but higher vascular compromise (6.3%). Osteocutaneous flaps were rare (n = 4) and primarily used for defects with bone loss, showing infection in 50% of cases. Meta-analysis was not possible due to heterogeneity and small sample sizes. CONCLUSIONS: Fasciocutaneous flaps provide reliable, low-complication coverage for clean wounds, while muscle flaps remain valuable for contamination or complex cases with extensive tissue loss. Chimeric, and osteocutaneous flaps show promise, but larger, standardised studies are needed to clarify their roles in hindfoot reconstruction.

Humans

Adaptation of lentiviral vectors for viral gene therapy and their impact on host cell biology.

BACKGROUND: Lentiviral vectors (LVVs) are used as a viral gene therapeutic and were derived from human immunodeficiency virus subtype 1 (HIV-1). LVVs are used to deliver and induce the stable expression of transgenes through genome integration. Current clinical LVV delivery systems do not include HIV-1 major accessory genes; however, critical structural and non-structural HIV-1 proteins are encoded by the 4-plasmid combination that composes the 3rd generation LVV transduction systems. LVVs use HIV-1-like mechanisms for viral genome integration and both transgene delivery and expression. LVVs rely on host cell machinery to transcribe and translate transgenes for either knocking down disease-causing genes and/or supplying functional genes in a targeted disease. LVVs integrate into host intronic and intergenic regions due to genomic accessibility, but there are no known biases toward specific target integration motifs. MAIN BODY: Investigation of LVV integration has uncovered the generation of chimeric LVV-host transcripts and altered host transcript splicing patterns. Several Food and Drug Administration (FDA)-approved LVV-derived therapies are used for treating diseases ranging from beta thalassemia to sickle cell anemia. An increasingly popular application of LVV is in the generation of chimeric antigen receptor (CAR) T cell therapies, which change and enhance T cell antigen specificity and effector function in liquid cancers. In November 2023, all CAR T cell therapies were placed under FDA investigation due to higher-than-expected rates of malignant transformation, hospitalization, and death in treated individuals. LVV integrations driving oncogene expression could be a cause for malignancy development. Current methods for resolving LVV integration patterns are technically limited by the sequencing approach applied allowing for only limited characterization of LVV integration profiles and altered host gene regulation. CONCLUSIONS: A comprehensive understanding of LVV integration and its consequences is necessary for understanding how these events influence host cell gene regulation and splicing, possibly identifying tunable variables for enhanced positive clinical outcomes. Here, we review the development of LVV systems, what is known about LVV integration patterns, technologies used to characterize patterns of LVV integration, and what is understood about the subsequent impact on host cell gene regulation and its potential linkage to patient malignancies.

Humans

Beckwith-Wiedemann spectrum exhibiting a 46,XY karyotype caused by genome-wide paternal uniparental heterodisomy: a case report.

BACKGROUNDS: Patients with genome-wide paternal uniparental disomy (GWpUPD) usually exhibit clinical features of Beckwith-Wiedemann syndrome (BWS) and a 46,XX karyotype, with all chromosomes showing isodisomy. To date, male patients with GWpUPD and a complete 46,XY karyotype, specifically involving heterodisomy, have not been described. RESULTS: We report a male infant exhibiting classical BWS clinical features. DNA methylation analyses showed paternal-specific methylation across multiple imprinted loci, suggesting GWpUPD. Genetic analysis of autosomes and sex chromosomes indicated two distinct paternal genomes in peripheral blood leukocytes, whereas a normal biparental genome was detected in other tissues under chimeric conditions. These findings indicated that the patient had genome-wide paternal uniparental heterodisomy (GWpUPhD). The SNP array revealed the presence of one copy of the X chromosome and one copy of the Y chromosome, the patient is a chimera composed of 46,XY biparental cells (with maternal X) and 46,XY GWpUPhD cells (with paternal X). CONCLUSIONS: This is the first report of a male patient with a GWpUPhD chimera. We propose a potential mechanism of GWpUPhD formation. Our findings expand the molecular spectrum of GWpUPD and provide valuable insights into its pathogenesis in chimeric conditions. Furthermore, the potential for clinical manifestations unique to 46,XY heterodisomy warrants careful long-term follow-up.

Humans

Directed evolution of adeno-associated virus for glioma cell transduction.

Glioblastoma multiforme (GBM) is a serious form of brain cancer for which there is currently no effective treatment. Alternative strategies such as adeno-associated virus (AAV) vector mediated-genetic modification of brain tumor cells with genes encoding anti-tumor proteins have shown promising results in preclinical models of GBM, although the transduction efficiency of these tumors is often low. As higher transduction efficiency of tumor cells should lead to enhanced therapeutic efficacy, a means to rapidly engineer AAV vectors with improved transduction efficiency for individual tumors is an attractive strategy. Here we tested the possibility of identifying high-efficiency AAV vectors for human U87 glioma cells by selection in culture of a newly constructed chimeric AAV capsid library generated by DNA shuffling of six different AAV cap genes (AAV1, AAV2, AAV5, AAVrh.8, AAV9, AAVrh.10). After seven rounds of selection, we obtained a chimeric AAV capsid that transduces U87 cells at high efficiency (97% at a dose of 10(4) genome copies/cell), and at low doses it was 1.45-1.6-fold better than AAV2, which proved to be the most efficient parental capsid. Interestingly, the new AAV capsid displayed robust gene delivery properties to all glioma cells tested (including primary glioma cells) with relative fluorescence indices ranging from 1- to 14-fold higher than AAV2. The selected vector should be useful for in vitro glioma research when efficient transduction of several cell lines is required, and provides proof-of-concept that an AAV library can be used to generate AAV vectors with enhanced transduction efficiency of glioma cells.

Capsid Proteins

Prolonged Cytopenia After Idecabtagene Vicleucel for Multiple Myeloma is Associated with Poor Overall Survival.

Cytopenias are well-recognized toxicities of idecabtagene vicleucel (ide-cel), a chimeric antigen receptor T cell (CAR-T) therapy approved for the treatment of relapsed, refractory multiple myeloma (RRMM). However, little is known of prognostic implications of cytopenias that persist 30 to 100 days after CAR-T infusion. We report the duration, incidence, and impact on outcomes of post-CAR-T cytopenias at Day 30 and Day 100, defined as an absolute neutrophil count of <500 cells/mm3 and/or platelet count <20 &#xd7; 109 cells/L, per the recent definitions of immune effector cell-associated hematotoxicity for neutropenia (N-ICAHT) and thrombocytopenia (T-ICAHT). Using observational data from the Center for International Blood and Marrow Transplant Research, we identified 821 patients treated during 2021 to 2023. The cumulative incidence of cytopenias at Day 30 was 25% and at Day 100 was 2%. Patients with Day 30 cytopenias had inferior progression-free survival (PFS) (39% versus 45%, P = .01) and overall survival (OS) at 12 months (57% versus 76%, P < .01). While there was no significant difference in PFS in patients who had Day 100 cytopenias (42% versus 53%, P = .12), compared to those who did not, patients with Day 100 cytopenias had significantly inferior OS at 12 months (55% versus 82%, P < .01). High (&#x2265;2) chimeric antigen receptor cell-mediated hematotoxicity score was associated with cytopenias at Day 30 (hazard ratio 5.26, P < .001). Cytopenias at Day 30 after ide-cel were associated with inferior PFS and OS. In addition, cytopenias at Day 100 after ide-cel are rare and are associated with inferior OS.

CAR-T

Phase 1 gene therapy for Duchenne muscular dystrophy using a translational optimized AAV vector.

Efficient and widespread gene transfer is required for successful treatment of Duchenne muscular dystrophy (DMD). Here, we performed the first clinical trial using a chimeric adeno-associated virus (AAV) capsid variant (designated AAV2.5) derived from a rational design strategy. AAV2.5 was generated from the AAV2 capsid with five mutations from AAV1. The novel chimeric vector combines the improved muscle transduction capacity of AAV1 with reduced antigenic crossreactivity against both parental serotypes, while keeping the AAV2 receptor binding. In a randomized double-blind placebo-controlled phase I clinical study in DMD boys, AAV2.5 vector was injected into the bicep muscle in one arm, with saline control in the contralateral arm. A subset of patients received AAV empty capsid instead of saline in an effort to distinguish an immune response to vector versus minidystrophin transgene. Recombinant AAV genomes were detected in all patients with up to 2.56 vector copies per diploid genome. There was no cellular immune response to AAV2.5 capsid. This trial established that rationally designed AAV2.5 vector was safe and well tolerated, lays the foundation of customizing AAV vectors that best suit the clinical objective (e.g., limb infusion gene delivery) and should usher in the next generation of viral delivery systems for human gene transfer.

Amino Acid Sequence