Cooperative Armoring of CAR and TCR T Cells by T Cell-Restricted IL15 and IL21 Universally Enhances Solid Tumor Efficacy

PURPOSE

Chimeric antigen receptor (CAR) and T-cell receptor (TCR) T-cell therapies are effective in a subset of patients with solid tumors, but new approaches are needed to universally improve patient outcomes. Here, we developed a technology to leverage the cooperative effects of IL15 and IL21, two common cytokine-receptor gamma chain family members with distinct, pleiotropic effects on T cells and other lymphocytes, to enhance the efficacy of adoptive T cells.

EXPERIMENTAL DESIGN

We designed vectors that induce the constitutive expression of either membrane-tethered IL15, IL21, or IL15/IL21. We used clinically relevant preclinical models of transgenic CARs and TCRs against pediatric and adult solid tumors to determine the effect of the membrane-tethered cytokines on engineered T cells for human administration.

RESULTS

We found that self-delivery of these cytokines by CAR or TCR T cells prevents functional exhaustion by repeated stimulation and limits the emergence of dysfunctional natural killer (NK)-like T cells. Across different preclinical murine solid tumor models, we observed enhanced regression with each individual cytokine but the greatest antitumor efficacy when T cells were armored with both.

CONCLUSIONS

The coexpression of membrane-tethered IL15 and IL21 represents a technology to enhance the resilience and function of engineered T cells against solid tumors and could be applicable to multiple therapy platforms and diseases. See related commentary by Ruffin et al., p. 1431.

Managing leukapheresis in adult and pediatric patients eligible for chimeric antigen receptor T-cell therapy: suggestions from an Italian Expert Panel

Chimeric antigen receptor (CAR) T-cell therapy relies on T cells engineered to target specific tumor antigens such as CD-19 in B-cell malignancies. In this setting, the commercially available products have offered a potential long-term cure for both pediatric and adult patients. Yet manufacturing CAR T cells is a cumbersome, multistep process, the success of which strictly depends on the characteristics of the starting material, i.e., lymphocyte collection yield and composition. These, in turn, might be affected by patient factors such as age, performance status, comorbidities, and previous therapies. Ideally, CAR T-cell therapies are a one-off treatment; therefore, optimization and the possible standardization of the leukapheresis procedure is critical, also in view of the novel CAR T cells currently under investigation for hematological malignancies and solid tumors. The most recent Best Practice recommendations for the management of children and adults undergoing CAR T-cell therapy provide a comprehensive guide to their use. However, their application in local practice is not straightforward and some grey areas remain. An Italian Expert Panel of apheresis specialists and hematologists from the centers authorized to administer CAR T-cell therapy took part in a detailed discussion on the following: 1) pre-apheresis patient evaluation; 2) management of the leukapheresis procedure, also in special situations represented by low lymphocyte count, peripheral blastosis, pediatric population <25 kg, and the COVID-19 outbreak; and 3) release and cryopreservation of the apheresis unit. This article presents some of the important challenges that must be faced to optimize the leukapheresis procedure and offers suggestions as to how to improve it, some of which are specific to the Italian setting.

CD19-Targeted Chimeric Antigen Receptor T-cell Therapy for Concomitant Diffuse Large B-cell Lymphoma and Multiple Myeloma

Multiple myeloma (MM) and diffuse large B-cell lymphoma (DLBCL) comprise a large fraction of hematologic malignancies diagnosed each year. However, the co-occurrence of these conditions in the same patient is rare. CD19- and B-cell maturation antigen-targeted chimeric antigen receptor (CAR) T-cell therapies have been approved in recent years with promising responses. Here, we present a patient who presented following a bone marrow biopsy that revealed MM with 20% lambda-restricted plasma cells with no evidence of lymphoma involvement in the marrow. A subsequent lymph node biopsy of a right thigh mass was done and revealed DLBCL. The patient received CD19-targeted CAR T-cell therapy and has no detectable MM or DLBCL. To our knowledge, this is the first case report in the literature describing a patient with concomitant MM and DLBCL who received CD19-targeted CAR T-cell therapy.

Type I Interferon Signaling via the EGR2 Transcriptional Regulator Potentiates CAR T Cell-Intrinsic Dysfunction

Chimeric antigen receptor (CAR) T cell therapy has shown promise in treating hematologic cancers, but resistance is common and efficacy is limited in solid tumors. We found that CAR T cells autonomously propagate epigenetically programmed type I interferon signaling through chronic stimulation, which hampers antitumor function. EGR2 transcriptional regulator knockout not only blocks this type I interferon-mediated inhibitory program but also independently expands early memory CAR T cells with improved efficacy against liquid and solid tumors. The protective effect of EGR2 deletion in CAR T cells against chronic antigen-induced exhaustion can be overridden by interferon-β exposure, suggesting that EGR2 ablation suppresses dysfunction by inhibiting type I interferon signaling. Finally, a refined EGR2 gene signature is a biomarker for type I interferon-associated CAR T cell failure and shorter patient survival. These findings connect prolonged CAR T cell activation with deleterious immunoinflammatory signaling and point to an EGR2-type I interferon axis as a therapeutically amenable biological system.

SIGNIFICANCE

To improve CAR T cell therapy outcomes, modulating molecular determinants of CAR T cell-intrinsic resistance is crucial. Editing the gene encoding the EGR2 transcriptional regulator renders CAR T cells impervious to type I interferon pathway-induced dysfunction and improves memory differentiation, thereby addressing major barriers to progress for this emerging class of cancer immunotherapies. This article is highlighted in the In This Issue feature, p. 1501.

Development of Engineered CAR T Cells Targeting Tumor-Associated Glycoforms of MUC1 for the Treatment of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a common malignancy arising from the liver with limited 5-year survival. Thus, there is an urgency to explore new treatment methods. Chimeric antigen receptor T (CAR T) cell therapy is a very promising cancer treatment. Though, several groups have investigated CAR T cells targeting MUC1 in solid cancer models, Tn-MUC1-targeted CAR T cells have not yet to be reported in ICC. In this study, we confirmed Tn-MUC1 as a potential therapeutic target for ICC and demonstrated that its expression level was positively correlated with the poor prognosis of ICC patients. More importantly, we successfully developed effective CAR T cells to target Tn-MUC1-positive ICC tumors and explored their antitumor activities. Our results suggest the CAR T cells could specifically eliminate Tn-MUC1-positive ICC cells, but not Tn-MUC1-negative ICC cells, in vitro and in vivo. Therefore, our study is expected to provide new therapeutic strategies and ideas for the treatment of ICC.

Immunotherapy - Strategies for Expanding Its Role in the Treatment of All Major Tumor Sites

Immunotherapy is widely regarded to have the ability to transform the treatment of cancer, with immune checkpoint inhibitors already in use for cancers such as advanced melanoma and non-small cell lung cancer (NSCLC). However, despite its potential, the widespread adoption of immunotherapy for the treatment of other cancers has been largely limited. This can be partly attributed to additional immunosuppressive mechanisms in the tumor microenvironment that help promote and maintain a state of T cell exhaustion. As such, the exploration of combinatory immunotherapies is an active area of research and includes the combination of immune checkpoint inhibitors with cytotoxic therapies, cancer vaccines and monoclonal antibodies against other co-inhibitory and co-stimulatory receptors. Strategies are also being employed to improve the homing, extravasation and survival of chimeric antigen receptor (CAR)-T cells in the tumor microenvironment. Furthermore, the development of immunotherapies targeted to one or multiple neoantigens unique to a specific tumor may act to enhance anti-tumor immunity, as well as reduce immune-related adverse events (irAEs). As immunotherapy evolves to become a mainstay treatment for cancer, it is imperative that optimum treatment regimens that maximize efficacy and limit toxicity are developed. Foremost, appropriate biomarkers must be identified to help tailor combinatory immunotherapies to the individual patient and hence pave the way to a new era of personalized medicine. 

Chimeric Antigen Receptor T-Cell Therapy: A Beacon of Hope in the Fight Against Cancer

Despite significant advancements, relapses, and persistent malignancies are still a major challenge faced by the oncologists. Immunotherapy has shown remarkable potential in induction of sustained remission in refractory malignancies. Chimeric antigen receptor T-cell (CAR-T) therapy is a newer treatment methodology approved by the Food and Drug Administration (FDA). The chimeric pairing of an antigen receptor with the T-cell receptor (TCR) intracellular signaling domain allows cluster of designation 8 (CD8) cytotoxic T-cells to target cell surface makers independent of major histocompatibility complex (MHC) activation. Another essential feature which contributes to the broad applicability of CARs and expanding their potential targets is their ability to bind not only to proteins but also to carbohydrate and glycolipid structures. Their antigen-specific and targeted immune responses have shown promising outcomes in clinical trials particularly involving B-cell malignancies and solid tumors. High remission rates and low percentages of relapses have caused a paradigm shift in the treatment of relapsed or refractory cancers. Challenges include side effects such as cytokine release syndrome, on-target off-tumor toxicities, and replication of its success in treating solid tumors. The burden of side effects and hefty cost of treatment are major obstacles which could hinder its progress globally. Nevertheless, ongoing research would only result in a maximized therapeutic potential in addition to more patient- and cost-friendly treatment. In this review, we aim to provide the readers an overview of chimeric antigen receptor T-cell therapy, a relatively new advancement in the world of immuno-oncology and thereby also discussing its advantages, side effects and future challenges.

Is Chimeric Antigen Receptor T-cell Therapy the Future of Autoimmunity Management?

Clinical trials with chimeric antigen receptor (CAR) T-cell therapy in oncology have been promising. The spectrum of this novel therapy is being expanded to include autoimmunity. It ensures "targeted treatment," resulting in more selective outcomes, fewer toxic effects, and a permanent restoration of immune system imbalance. The preliminary results of preclinical and clinical studies support the application of CAR therapy in autoimmunity, especially in regulating adverse autoimmune responses. This novel therapy should be considered for the treatment of autoimmune diseases and further clinical studies should be conducted to study all aspects of this treatment modality.

Cytokine Release Syndrome Grade as a Predictive Marker for Infections in Patients With Relapsed or Refractory B-Cell Acute Lymphoblastic Leukemia Treated With Chimeric Antigen Receptor T Cells

Background

Chimeric antigen receptor (CAR)-modified T cells that target the CD19 antigen present a novel promising therapy for the treatment of relapsed B-cell acute lymphoblastic leukemia (B-ALL). Although cytokine release syndrome (CRS) and neurotoxicity have emerged as predominant noninfectious complications of CD19 CAR T-cell therapy, infections associated with this treatment modality have not been well documented.

Methods

We analyzed infectious complications that followed CD19 CAR T-cell therapy in 53 adult patients with relapsed B-ALL enrolled in a phase I clinical trial at Memorial Sloan Kettering Cancer Center (NCT01044069).

Results

Overall, 22 patients (42%) experienced 26 infections (17 bacterial, 4 fungal, and 5 viral) within the first 30 days of CAR T-cell infusion. In 10 of 32 (31%) patients in whom complete remission was achieved, 15 infections developed between days 31 and 180; the majority of these late infections were due to respiratory viruses. In general, bacterial, fungal, and viral infections were detected at a median of 18, 23, and 48 days, respectively, after CAR T-cell infusion. CRS grade 3 or higher was independently associated with increased risk of subsequent infection (adjusted hazard ratio [HR], 2.67; P = .05) and in particular with bloodstream infection (adjusted HR, 19.97; P < .001). Three of 53 patients (6%) died of an infection-related cause.

Conclusions

Infections in adult patients with relapsed B-ALL are common after CD19 CAR T-cell therapy. Understanding the infectious complications that are temporally coincident with CD19 CAR T-cell therapy is critical for developing effective prophylactic and other supportive care measures to improve clinical outcomes.

Clinical Trials Registration

NCT01044069.