GNTI-122: an autologous antigen-specific engineered Treg cell therapy for type 1 diabetes.

Tregs have the potential to establish long-term immune tolerance in patients recently diagnosed with type 1 diabetes (T1D) by preserving β cell function. Adoptive transfer of autologous thymic Tregs, although safe, exhibited limited efficacy in previous T1D clinical trials, likely reflecting a lack of tissue specificity, limited IL-2 signaling support, and in vivo plasticity of Tregs. Here, we report a cell engineering strategy using bulk CD4+ T cells to generate a Treg cell therapy (GNTI-122) that stably expresses FOXP3, targets the pancreas and draining lymph nodes, and incorporates a chemically inducible signaling complex (CISC).

Anti-tumor effects of RTX-240: an engineered red blood cell expressing 4-1BB ligand and interleukin-15.

Recombinant agonists that activate co-stimulatory and cytokine receptors have shown limited clinical anticancer utility, potentially due to narrow therapeutic windows, the need for coordinated activation of co-stimulatory and cytokine pathways and the failure of agonistic antibodies to recapitulate signaling by endogenous ligands. RTX-240 is a genetically engineered red blood cell expressing 4-1BBL and IL-15/IL-15Rα fusion (IL-15TP). RTX-240 is designed to potently and simultaneously stimulate the 4-1BB and IL-15 pathways, thereby activating and expanding T cells and NK cells, while potentially offering an improved safety profile through restricted biodistribution.

Engineered red blood cells as an off-the-shelf allogeneic anti-tumor therapeutic.

Checkpoint inhibitors and T-cell therapies have highlighted the critical role of T cells in anti-cancer immunity. However, limitations associated with these treatments drive the need for alternative approaches. Here, we engineer red blood cells into artificial antigen-presenting cells (aAPCs) presenting a peptide bound to the major histocompatibility complex I, the costimulatory ligand 4-1BBL, and interleukin (IL)-12.

The Single Match: Reflections on the National Resident Matching Program's Sustained Partnership With Learners.

In 2020, the National Resident Matching Program (NRMP) sponsored the inaugural "Single Match"-the first time that seniors and graduates of U.S. MD-granting and DO-granting schools participated in one Match.

Nanoliposome targeting in breast cancer is influenced by the tumor microenvironment.

MM-302 is an anti-HER2 antibody-targeted pegylated liposomal doxorubicin designed to deliver doxorubicin specifically to HER2-expressing solid tumors. The delivery and activity of MM-302 were evaluated in orthotopic, transgenic, and intravenous breast cancer models expressing varying levels of HER2 that metastasize to some of the most common sites of dissemination for breast cancer, namely, lung, liver, and brain. Metastatic burden was quantified by gross evaluation, immunohistochemistry (IHC), and bioluminescent imaging.

Safety and pharmacokinetics of MM-302, a HER2-targeted antibody-liposomal doxorubicin conjugate, in patients with advanced HER2-positive breast cancer: a phase 1 dose-escalation study.

Background: This phase 1 dose-escalation trial studied MM-302, a novel HER2-targeted PEGylated antibody-liposomal doxorubicin conjugate, in HER2-positive locally advanced/metastatic breast cancer.

Methods: Patients were enrolled in four cohorts: MM-302 monotherapy (8, 16, 30, 40, and 50 mg/m every 4 weeks [q4w]); MM-302 (30 or 40 mg/m q4w) plus trastuzumab (4 mg/kg q2w); MM-302 (30 mg/m) plus trastuzumab (6 mg/kg) q3w; MM-302 (30 mg/m) plus trastuzumab (6 mg/kg) and cyclophosphamide (450 mg/m) q3w.

Results: Sixty-nine patients were treated.

Companion Diagnostic Cu-Liposome Positron Emission Tomography Enables Characterization of Drug Delivery to Tumors and Predicts Response to Cancer Nanomedicines.

Deposition of liposomal drugs into solid tumors is a potentially rate-limiting step for drug delivery and has substantial variability that may influence probability of response. Tumor deposition is a shared mechanism for liposomal therapeutics such that a single companion diagnostic agent may have utility in predicting response to multiple nanomedicines. We describe the development, characterization and preclinical proof-of-concept of the positron emission tomography (PET) agent, MM-DX-929, a drug-free untargeted 100 nm PEGylated liposome stably entrapping a chelated complex of 4-DEAP-ATSC and Cu (copper-64).

Cu-MM-302 Positron Emission Tomography Quantifies Variability of Enhanced Permeability and Retention of Nanoparticles in Relation to Treatment Response in Patients with Metastatic Breast Cancer.

Therapeutic nanoparticles are designed to deliver their drug payloads through enhanced permeability and retention (EPR) in solid tumors. The extent of EPR and its variability in human tumors is highly debated and has been proposed as an explanation for variable responses to therapeutic nanoparticles in clinical studies. We assessed the EPR effect in patients using a Cu-labeled nanoparticle, Cu-MM-302 (Cu-labeled HER2-targeted PEGylated liposomal doxorubicin), and imaging by PET/CT.

HERMIONE: a randomized Phase 2 trial of MM-302 plus trastuzumab versus chemotherapy of physician's choice plus trastuzumab in patients with previously treated, anthracycline-naïve, HER2-positive, locally advanced/metastatic breast cancer.

Background: Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is a particularly aggressive form of the disease, and ultimately progresses in patients with metastases on standard therapies. Anthracyclines, such as doxorubicin, are an effective treatment for HER2-positive breast cancer, particularly when administered in combination with trastuzumab - however, doxorubicin-related cardiotoxicity has limited its use. Many patients are therefore never treated with anthracyclines, even upon disease progression, despite the potential for benefit.

Dual HER2 Targeting with Trastuzumab and Liposomal-Encapsulated Doxorubicin (MM-302) Demonstrates Synergistic Antitumor Activity in Breast and Gastric Cancer.

Trastuzumab is the standard of care for HER2-positive breast cancer patients, markedly improving disease-free and overall survival. Combined with chemotherapy, it enhances patient outcomes, but cardiotoxicity due to the trastuzumab treatment poses a serious adverse effect. MM-302 is a HER2-targeted PEGylated liposome that encapsulates doxorubicin to facilitate its delivery to HER2-overexpressing tumor cells while limiting exposure to nontarget tissues, including the heart.

Cyclophosphamide-Mediated Tumor Priming for Enhanced Delivery and Antitumor Activity of HER2-Targeted Liposomal Doxorubicin (MM-302).

Given the bulky nature of nanotherapeutics relative to small molecules, it is hypothesized that effective tumor delivery and penetration are critical barriers to their clinical activity. HER2-targeted PEGylated liposomal doxorubicin (MM-302, HER2-tPLD) is an antibody-liposomal drug conjugate designed to deliver doxorubicin to HER2-overexpressing cancer cells while limiting uptake into nontarget cells. In this work, we demonstrate that the administration and appropriate dose sequencing of cyclophosphamide can improve subsequent MM-302 delivery and enhance antitumor activity in preclinical models without negatively affecting nontarget tissues, such as the heart and skin.

Whole-body organ-level and kidney micro-dosimetric evaluations of (64)Cu-loaded HER2/ErbB2-targeted liposomal doxorubicin ((64)Cu-MM-302) in rodents and primates.

Background: Features of the tumor microenvironment influence the efficacy of cancer nanotherapeutics. The ability to directly radiolabel nanotherapeutics offers a valuable translational tool to obtain biodistribution and tumor deposition data, testing the hypothesis that the extent of delivery predicts therapeutic outcome. In support of a first in-human clinical trial with (64)Cu-labeled HER2-targeted liposomal doxorubicin ((64)Cu-MM-302), a preclinical dosimetric analysis was performed.

A gradient-loadable (64)Cu-chelator for quantifying tumor deposition kinetics of nanoliposomal therapeutics by positron emission tomography.

Effective drug delivery to tumors is a barrier to treatment with nanomedicines. Non-invasively tracking liposome biodistribution and tumor deposition in patients may provide insight into identifying patients that are well-suited for liposomal therapies. We describe a novel gradient-loadable chelator, 4-DEAP-ATSC, for incorporating (64)Cu into liposomal therapeutics for positron emission tomographic (PET).

Single-cell quantitative HER2 measurement identifies heterogeneity and distinct subgroups within traditionally defined HER2-positive patients.

Human epidermal growth factor receptor 2 (HER2) is an important biomarker for breast and gastric cancer prognosis and patient treatment decisions. HER2 positivity, as defined by IHC or fluorescent in situ hybridization testing, remains an imprecise predictor of patient response to HER2-targeted therapies. Challenges to correct HER2 assessment and patient stratification include intratumoral heterogeneity, lack of quantitative and/or objective assays, and differences between measuring HER2 amplification at the protein versus gene level.

Impact of tumor HER2/ERBB2 expression level on HER2-targeted liposomal doxorubicin-mediated drug delivery: multiple low-affinity interactions lead to a threshold effect.

Numerous targeted nanotherapeutics have been described for potential treatment of solid tumors. Although attention has focused on antigen selection and molecular design of these systems, there has been comparatively little study of how cellular heterogeneity influences interaction of targeted nanoparticles with tumor cells. Antigens, such as HER2/ERBB2, are heterogeneously expressed across different indications, across patients, and within individual tumors.

HER2-targeted liposomal doxorubicin displays enhanced anti-tumorigenic effects without associated cardiotoxicity.

Anthracycline-based regimens are a mainstay of early breast cancer therapy, however their use is limited by cardiac toxicity. The potential for cardiotoxicity is a major consideration in the design and development of combinatorial therapies incorporating anthracyclines and agents that target the HER2-mediated signaling pathway, such as trastuzumab. In this regard, HER2-targeted liposomal doxorubicin was developed to provide clinical benefit by both reducing the cardiotoxicity observed with anthracyclines and enhancing the therapeutic potential of HER2-based therapies that are currently available for HER2-overexpressing cancers.

Experimental treatment of ovarian cancers by adenovirus vectors combining receptor targeting and selective expression of tumor necrosis factor.

Ovarian cancer is the fourth most common cancer among women and existing treatment is not routinely curative. One new strategy for cancer therapy is the selective delivery of TNFalpha to tumors via adenovirus vectors. We have tested the combination of two modifications to adenovirus vectors designed to limit delivery to tumors, capsid modification and expression control.

Epitopes expressed in different adenovirus capsid proteins induce different levels of epitope-specific immunity.

On the basis of the concept that the capsid proteins of adenovirus (Ad) gene transfer vectors can be genetically manipulated to enhance the immunogenicity of Ad-based vaccines, the present study compared the antiantigen immunogenicity of Ad vectors with a common epitope of the hemagglutinin (HA) protein of the influenza A virus incorporated into the outer Ad capsid protein hexon, penton base, fiber knob, or protein IX. Incorporation of the same epitope into the different capsid proteins provided insights into the correlation between epitope position and antiepitope immunity. Following immunization of three different strains of mice (C57BL/6, BALB/c, and CBA) with either an equal number of Ad particles (resulting in a different total HA copy number) or different Ad particle numbers (to achieve the same HA copy number), the highest primary (immunoglobulin M [IgM]) and secondary (IgG) anti-HA humoral and cellular CD4 gamma interferon and interleukin-4 responses against HA were always achieved with the Ad vector carrying the HA epitope in fiber knob.

Induction of leukemia-specific CD8+ cytotoxic T cells with autologous myeloid leukemic cells maturated with a fiber-modified adenovirus encoding TNF-alpha.

Acute myeloid leukemia (AML) cells can be differentiated into dendritic cells (DCs) using appropriate combinations of cytokines but generation of autologous antileukemic cytotoxic T cells using leukemic DCs remains difficult. Transduction by adenoviral vectors has been reported to induce efficient maturation of monocyte-derived DCs but AML cells are generally resistant to adenoviral gene transfer. In this study we tested the effects of adenoviral TNF-alpha gene transfer on maturation of AML cells using the fiber-modified AdTNF.

Protection against P. aeruginosa with an adenovirus vector containing an OprF epitope in the capsid.

Pseudomonas aeruginosa is an important opportunistic pathogen that can cause chronic and often life-threatening infections of the respiratory tract, particularly in individuals with cystic fibrosis (CF). Because infections with P. aeruginosa remain the major cause of the high morbidity and mortality of CF, a vaccine against P.

Histone deacetylase inhibitors upregulate expression of the coxsackie adenovirus receptor (CAR) preferentially in bladder cancer cells.

Studies on bladder cancer cell lines have shown that low adenoviral (Ad) infectivity is associated with low-level coxsackie adenovirus receptor (CAR) expression. Recently, we and others demonstrated a tumor stage- and grade-dependent downregulation of CAR expression in a large series of clinical bladder cancer specimens. Here, we demonstrate adenoviral gene transfer can be markedly enhanced in bladder cancer cells by upregulation of CAR through the use of certain differentiating agents, including the histone deacetylase inhibitors (HDACI) trichostatin A and sodium phenylbutyrate.

Modification to the capsid of the adenovirus vector that enhances dendritic cell infection and transgene-specific cellular immune responses.

Adenovirus (Ad) gene transfer vectors can be used to transfer and express antigens and function as strong adjuvants and thus are useful platforms for the development of genetic vaccines. Based on the hypothesis that Ad vectors with enhanced infectibility of dendritic cells (DC) may be able to evoke enhanced immune responses against antigens encoded by the vector in vivo, the present study analyzes the vaccine potential of an Ad vector expressing beta-galactosidase as a model antigen and genetically modified with RGD on the fiber knob [AdZ.F(RGD)] to more selectively infect DC and consequently enhance immunity against the beta-galactosidase antigen.

Ablating CAR and integrin binding in adenovirus vectors reduces nontarget organ transduction and permits sustained bloodstream persistence following intraperitoneal administration.

To create tumor-targeted Ad vectors, ablation of native CAR and integrin receptor binding is crucial to enhance the specificity of tumor transduction. Toward this aim, we have previously created base vectors in which binding to CAR (single-ablated) or to both CAR and integrins (double-ablated) has been ablated. In this study, the biodistribution of the conventional (CAR and integrin binding intact), single-ablated, and double-ablated vectors was evaluated following intraperitoneal administration.

Binding of adenoviral fiber knob to the coxsackievirus-adenovirus receptor is crucial for transduction of fetal muscle.

Adenoviral (Ad) infection involves attachment mediated by the Ad fiber protein binding to the coxsackievirus-adenovirus receptor (CAR) of a target cell and internalization facilitated by the interaction of the Ad penton base protein with alpha(v) integrins. To understand the relative importance of the Ad binding and internalization steps for the transduction of fetal skeletal muscle, we used a panel of genetically modified vectors that specifically ablate the fiber-CAR interaction (AdL.F*), the penton base-alpha(v) integrin interaction (AdL.

The role of capsid-endothelial interactions in the innate immune response to adenovirus vectors.

Adenovirus (Ad) vectors can produce inflammatory responses at high doses. Intravenous administration of an Ad vector expressing green fluorescent protein (AdGFP) to naive mice induced a biphasic pattern of liver cytokine/chemokine gene expression over 7 days. Tumor necrosis factor alpha (TNF-alpha), macrophage inflammatory protein 2 (MIP-2), and interferon gamma-inducible protein 10 (IP-10) genes were upregulated, with two distinct peaks of mRNA expression occurring at 6 hr and 5 days.