Multi-Omic Characterization of Single Cells and Cell-Free Components Detected in the Cerebrospinal Fluid of Patients with Leptomeningeal Disease.

Background/objectives: Up to 30% of patients with breast cancers will develop brain or leptomeningeal metastases, and this risk is especially high with HER2-positive cancers. For patients with central nervous system metastases, cerebrospinal fluid (CSF) liquid biopsies are a promising opportunity to monitor disease, inform treatment, and predict prognosis. This pilot study investigated CSF liquid biopsy analytes from three patients diagnosed with central nervous system metastases based on imaging but not confirmed via clinical cytology.

Nonsignaling extracellular spacer regulates tumor antigen selectivity of CAR T cells.

Advancing chimeric antigen receptor (CAR)-engineered T cells for the treatment of solid tumors is a major focus in the field of cellular immunotherapy. Several hurdles have hindered similar CAR T cell clinical responses in solid tumors as seen in hematological malignancies. These challenges include on-target off-tumor toxicities, which have inspired efforts to optimize CARs for improved tumor antigen selectivity and overall safety.

PSCA-CAR T cell therapy in metastatic castration-resistant prostate cancer: a phase 1 trial.

Despite recent therapeutic advances, metastatic castration-resistant prostate cancer (mCRPC) remains lethal. Chimeric antigen receptor (CAR) T cell therapies have demonstrated durable remissions in hematological malignancies. We report results from a phase 1, first-in-human study of prostate stem cell antigen (PSCA)-directed CAR T cells in men with mCRPC.

Regulation of nuclear transcription by mitochondrial RNA in endothelial cells.

Chromatin-associated RNAs (caRNAs) form a relatively poorly recognized layer of the epigenome. The caRNAs reported to date are transcribed from the nuclear genome. Here, leveraging a recently developed assay for detection of caRNAs and their genomic association, we report that mitochondrial RNAs (mtRNAs) are attached to the nuclear genome and constitute a subset of caRNA, thus termed mt-caRNA.

Using Oncolytic Virus to Retask CD19-Chimeric Antigen Receptor T Cells for Treatment of Pancreatic Cancer: Toward a Universal Chimeric Antigen Receptor T-Cell Strategy for Solid Tumor.

Background: Chimeric antigen receptor (CAR) T cells targeting the B-cell antigen CD19 are standard therapy for relapsed or refractory B-cell lymphoma and leukemia. CAR T cell therapy in solid tumors is limited due to an immunosuppressive tumor microenvironment and a lack of tumor-restricted antigens. We recently engineered an oncolytic virus (CF33) with high solid tumor affinity and specificity to deliver a nonsignaling truncated CD19 antigen (CD19t), allowing targeting by CD19-CAR T cells.

Dexamethasone potentiates chimeric antigen receptor T cell persistence and function by enhancing IL-7Rα expression.

Dexamethasone (dex) is a glucocorticoid that is a mainstay for the treatment of inflammatory pathologies, including immunotherapy-associated toxicities, yet the specific impact of dex on the activity of CAR T cells is not fully understood. We assessed whether dex treatment given ex vivo or as an adjuvant in vivo with CAR T cells impacted the phenotype or function of CAR T cells. We demonstrated that CAR T cell expansion and function were not inhibited by dex.

Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting.

Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumors. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies. Here, we describe CAR T cells targeting tumor-associated glycoprotein-72 (TAG72), utilizing the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFNγ secretion.

Targeting advanced prostate cancer with STEAP1 chimeric antigen receptor T cell and tumor-localized IL-12 immunotherapy.

Six transmembrane epithelial antigen of the prostate 1 (STEAP1) is a cell surface antigen for therapeutic targeting in prostate cancer. Here, we report broad expression of STEAP1 relative to prostate-specific membrane antigen (PSMA) in lethal metastatic prostate cancers and the development of a STEAP1-directed chimeric antigen receptor (CAR) T cell therapy. STEAP1 CAR T cells demonstrate reactivity in low antigen density, antitumor activity across metastatic prostate cancer models, and safety in a human STEAP1 knock-in mouse model.

Antigen-dependent IL-12 signaling in CAR T cells promotes regional to systemic disease targeting.

Chimeric antigen receptor (CAR) T cell therapeutic responses are hampered by limited T cell trafficking, persistence, and durable anti-tumor activity in solid tumor microenvironments. However, these challenges can be largely overcome by relatively unconstrained synthetic engineering strategies, which are being harnessed to improve solid tumor CAR T cell therapies. Here, we describe fully optimized CAR T cells targeting tumor-associated glycoprotein-72 (TAG72) for the treatment of solid tumors, identifying the CD28 transmembrane domain upstream of the 4-1BB co-stimulatory domain as a driver of potent anti-tumor activity and IFNγ secretion.

Hyperthermic Intraperitoneal Chemotherapy-Induced Molecular Changes in Humans Validate Preclinical Data in Ovarian Cancer.

Purpose: Hyperthermic intraperitoneal chemotherapy (HIPEC) confers a survival benefit in epithelial ovarian cancer (EOC) and in preclinical models. However, the molecular changes induced by HIPEC have not been corroborated in humans.

Patients And Methods: A feasibility trial evaluated clinical and safety outcomes of HIPEC with cisplatin during optimal cytoreductive surgery (CRS) in patients with EOC diagnosed with stage III, IV, or recurrent EOC.

Off-the-Shelf Prostate Stem Cell Antigen-Directed Chimeric Antigen Receptor Natural Killer Cell Therapy to Treat Pancreatic Cancer.

Background & Aims: Pancreatic cancer (PC) is the third leading cause of cancer-related death with a 5-year survival rate of approximately 10%. It typically presents as a late-stage incurable cancer and chemotherapy provides modest benefit. Here, we demonstrate the feasibility, safety, and potency of a novel human natural killer (NK) cell-based immunotherapy to treat PC.

Novel Redirected T-Cell Immunotherapies for Advanced Prostate Cancer.

Immunotherapy has failed to achieve durable remissions in advanced prostate cancer patients. More potent T-cell-redirecting strategies may be needed to overcome the immunologically exclusive and suppressive tumor microenvironment. Clinical trials are underway, seeking to define the optimal target for T-cell redirection, such as PSMA, PSCA, or STEAP-1, as well as the optimal strategy, with CAR or bispecific antibodies.

Enhanced intratumoural activity of CAR T cells engineered to produce immunomodulators under photothermal control.

Treating solid malignancies with chimeric antigen receptor (CAR) T cells typically results in poor responses. Immunomodulatory biologics delivered systemically can augment the cells' activity, but off-target toxicity narrows the therapeutic window. Here we show that the activity of intratumoural CAR T cells can be controlled photothermally via synthetic gene switches that trigger the expression of transgenes in response to mild temperature elevations (to 40-42 °C).

Pre-conditioning modifies the TME to enhance solid tumor CAR T cell efficacy and endogenous protective immunity.

Chimeric antigen receptor (CAR) T cell therapy has led to impressive clinical responses in patients with hematological malignancies; however, its effectiveness in patients with solid tumors has been limited. While CAR T cells for the treatment of advanced prostate and pancreas cancer, including those targeting prostate stem cell antigen (PSCA), are being clinically evaluated and are anticipated to show bioactivity, their safety and the impact of the immunosuppressive tumor microenvironment (TME) have not been faithfully explored preclinically. Using a novel human PSCA knockin (hPSCA-KI) immunocompetent mouse model, we evaluated the safety and therapeutic efficacy of PSCA-CAR T cells.

Recombinant Orthopoxvirus Primes Colon Cancer for Checkpoint Inhibitor and Cross-Primes T Cells for Antitumor and Antiviral Immunity.

Although it is known that oncolytic viruses can inflame and recruit immune cells to otherwise immunosuppressed tumor microenvironments, the influence of the antiviral immune response on antitumor immunity is less clear across viral platforms and tumor types. CF33 is a recombinant orthopoxvirus backbone effective against colon cancer. We tested derivatives of CF33 with and without immune-checkpoint inhibition (anti-PD-L1) in mouse models of colon cancer.

The Cerebroventricular Environment Modifies CAR T Cells for Potent Activity against Both Central Nervous System and Systemic Lymphoma.

Lymphomas with central nervous system (CNS) involvement confer a worse prognosis than those without CNS involvement, and patients currently have limited treatment options. T cells genetically engineered with CD19-targeted chimeric antigen receptors (CAR) are effective against B-cell malignancies and show tremendous potential in the treatment of systemic lymphoma. We aimed to leverage this strategy toward a more effective therapy for patients with lymphoma with CNS disease.

Effective combination immunotherapy using oncolytic viruses to deliver CAR targets to solid tumors.

Chimeric antigen receptor (CAR)-engineered T cell therapy for solid tumors is limited by the lack of both tumor-restricted and homogeneously expressed tumor antigens. Therefore, we engineered an oncolytic virus to express a nonsignaling, truncated CD19 (CD19t) protein for tumor-selective delivery, enabling targeting by CD19-CAR T cells. Infecting tumor cells with an oncolytic vaccinia virus coding for CD19t (OV19t) produced de novo CD19 at the cell surface before virus-mediated tumor lysis.

CAR T Cell Therapy Progress and Challenges for Solid Tumors.

The past two decades have marked the beginning of an unprecedented success story for cancer therapy through redirecting antitumor immunity [1]. While the mechanisms that control the initial and ongoing immune responses against tumors remain a strong research focus, the clinical development of technologies that engage the immune system to target and kill cancer cells has become a translational research priority. Early attempts documented in the late 1800s aimed at sparking immunity with cancer vaccines were difficult to interpret but demonstrated an opportunity that more than 100 years later has blossomed into the current field of cancer immunotherapy.

Precision Medicine-Enabled Cancer Immunotherapy.

Repairing defects in anti-tumor immunity has been a longstanding challenge in cancer therapy, and in recent years, immunotherapy has emerged as a promising approach for treating advanced disease. While the interactions between the immune system and cancer have been studied for more than a century, only in recent years has the field realized the tremendous potential in stimulating the immune system to eradicate cancer. From early investigations by William Coley in using bacteria to treat cancer patients to more recent work in adoptively transferred engineered T cells to identify and kill cancer cells has opened up an entire field dedicated to re-educating the immune system in a cancer patient.

Effective Targeting of TAG72 Peritoneal Ovarian Tumors via Regional Delivery of CAR-Engineered T Cells.

Impressive clinical efficacy of chimeric antigen receptor (CAR)-engineered T cell therapy for hematological malignancies have prompted significant efforts in achieving similar responses in solid tumors. The lack of truly restricted and uniform expression of tumor-associated antigens, as well as limited T cell persistence and/or tumor trafficking pose major challenges for successful translation of CAR T cell therapy in solid tumors. Recent studies have demonstrated that aberrantly glycosylated cell surface proteins on tumor cells are amenable CAR targets.

PET of Adoptively Transferred Chimeric Antigen Receptor T Cells with Zr-Oxine.

Chimeric antigen receptor (CAR) T cell therapy is a promising clinical approach for reducing tumor progression and prolonging patient survival. However, improvements in both the safety and the potency of CAR T cell therapy demand quantitative imaging techniques to determine the distribution of cells after adoptive transfer. The purpose of this study was to optimize Zr-oxine labeling of CAR T cells and evaluate PET as a platform for imaging adoptively transferred CAR T cells.

Co-stimulatory signaling determines tumor antigen sensitivity and persistence of CAR T cells targeting PSCA+ metastatic prostate cancer.

Advancing chimeric antigen receptor (CAR)-engineered adoptive T cells for the treatment of solid cancers is a major focus in the field of immunotherapy, given impressive recent clinical responses in hematological malignancies. Prostate cancer may be amenable to T cell-based immunotherapy since several tumor antigens, including prostate stem-cell antigen (PSCA), are widely over-expressed in metastatic disease. While antigen selectivity of CARs for solid cancers is crucial, it is problematic due to the absence of truly restricted tumor antigen expression and potential safety concerns with "on-target off-tumor" activity.

Regional Delivery of Chimeric Antigen Receptor-Engineered T Cells Effectively Targets HER2 Breast Cancer Metastasis to the Brain.

Metastasis to the brain from breast cancer remains a significant clinical challenge, and may be targeted with CAR-based immunotherapy. CAR design optimization for solid tumors is crucial due to the absence of truly restricted antigen expression and potential safety concerns with "on-target off-tumor" activity. Here, we have optimized HER2-CAR T cells for the treatment of breast to brain metastases, and determined optimal second-generation CAR design and route of administration for xenograft mouse models of breast metastatic brain tumors, including multifocal and leptomeningeal disease.