Tolerance to self-antigens prevents the elimination of cancer by the immune system1,2. We used synthetic chimeric antigen receptors (CARs) to overcome immunological tolerance and mediate tumor rejection in patients with chronic lymphocytic leukemia (CLL). Remission was induced in a subset of subjects, but most did not respond. Comprehensive assessment of patient-derived CAR T cells to identify mechanisms of therapeutic success and failure has not been explored. We performed genomic, phenotypic and functional evaluations to identify determinants of response. Transcriptomic profiling revealed that CAR T cells from complete-responding patients with CLL were enriched in memory-related genes, including IL-6/STAT3 signatures, whereas T cells from nonresponders upregulated programs involved in effector differentiation, glycolysis, exhaustion and apoptosis. Sustained remission was associated with an elevated frequency of CD27+CD45RO- CD8+ T cells before CAR T cell generation, and these lymphocytes possessed memory-like characteristics. Highly functional CAR T cells from patients produced STAT3-related cytokines, and serum IL-6 correlated with CAR T cell expansion. IL-6/STAT3 blockade diminished CAR T cell proliferation. Furthermore, a mechanistically relevant population of CD27+PD-1CD8+ CAR T cells expressing high levels of the IL-6 receptor predicts therapeutic response and is responsible for tumor control. These findings uncover new features of CAR T cell biology and underscore the potential of using pretreatment biomarkers of response to advance immunotherapies.

Type 1 diabetes (T1D) is an autoimmune disorder characterized by the destruction of insulin-producing pancreatic β cells. Immune modulators have achieved some success in modifying the course of disease progression in T1D. However, there are parallel declines in C-peptide levels in treated and control groups after initial responses. In this review, we discuss mechanisms of β cell death in T1D that involve necrosis and apoptosis. New technologies are being developed to enable visualization of insulitis and β cell mass involving positron emission transmission that identifies β cell ligands and magnetic resonance imaging that can identify vascular leakage. Molecular signatures that identify β cell derived insulin DNA that is released from dying cells have been described and applied to clinical settings. We also consider changes in β cells that occur during disease progression including the induction of DNA methyltransferases that may affect the function and differentiation of β cells. Our findings from newer data suggest that the model of chronic long standing β cell killing should be reconsidered. These studies indicate that the pathophysiology is accelerated in the peridiagnosis period and manifest by increased rates of β cell killing and insulin secretory impairments over a shorter period than previously thought. Finally, we consider cellular explanations to account for the ongoing loss of insulin production despite continued immune therapy that may identify potential targets for treatment. The progressive decline in β cell function raises the question as to whether β cell failure that is independent of immune attack may be involved.

In both cardiovascular disease and cancer, there are established sex-based differences in prevalence and outcomes. Males and females may also differ in terms of risk of cardiotoxicity following cancer therapy, including heart failure, cardiomyopathy, atherosclerosis, thromboembolism, arrhythmias, and myocarditis. Here, we describe sex-based differences in the epidemiology and pathophysiology of cardiotoxicity associated with anthracyclines, hematopoietic stem cell transplant (HCT), hormone therapy and immune therapy. Relative to males, the risk of anthracycline-induced cardiotoxicity is higher in prepubertal females, lower in premenopausal females, and similar in postmenopausal females. For autologous hematopoietic cell transplant, several studies suggest an increased risk of late heart failure in female lymphoma patients, but sex-based differences have not been shown for allogeneic hematopoietic cell transplant. Hormone therapies including GnRH (gonadotropin-releasing hormone) modulators, androgen receptor antagonists, selective estrogen receptor modulators, and aromatase inhibitors are associated with cardiotoxicity, including arrhythmia and venous thromboembolism. However, sex-based differences have not yet been elucidated. Evaluation of sex differences in cardiotoxicity related to immune therapy is limited, in part, due to low participation of females in relevant clinical trials. However, some studies suggest that females are at increased risk of immune checkpoint inhibitor myocarditis, although this has not been consistently demonstrated. For each of the aforementioned cancer therapies, we consider sex-based differences according to cardiotoxicity management. We identify knowledge gaps to guide future mechanistic and prospective clinical studies. Furthering our understanding of sex-based differences in cancer therapy cardiotoxicity can advance the development of targeted preventive and therapeutic cardioprotective strategies.

The adoptive transfer of autologous T cells genetically modified to express a CD19-specific, 4-1BB/CD3z-signaling CAR (CTL019) has shown remarkable activity and induce long-term remissions in a subset of patients with relapsed/refractory chronic lymphocytic leukemia (CLL). To date, little is known about predictive indicators of efficacy. This study was designed to evaluate biomarkers of clinical response to CTL019 in CLL. We studied forty-one patients with advanced, heavily pre-treated and high-risk CLL who received at least one dose of CTL019 cells. We show that in vivo expansion and persistence are key quality attributes of CTL019 cells in CLL patients who have complete responses to therapy; in 2 patients responses are sustained beyond five years and accompanied by the persistence of functional CTL019 cells. Furthermore, durable remissions were associated with transcriptomic signatures of early memory T cells, while T cells from non-responding patients were enriched in genes belonging to known pathways of terminal differentiation and exhaustion. Polychromatic flow cytometry also demonstrated a significantly higher level of T cell exhaustion markers on the infused CAR T cells and reduced CD27 expression in non-responding patients. Accordingly, the combined assessment of PD1 and CD27 expression on CD8+ CTL019 cells in the infusion product accurately predicted response to treatment. Restimulation of the infusion product through the CAR further demonstrated that CTL019 cells from complete responders secreted significantly higher levels of several cytokines, including CCL20, IL-21, IL-22, IL-17, and IL-6, suggesting that the STAT3 signaling pathway may play a role in potentiating the enhanced potency of CTL019 cells. To identify a phenotype of T cells that is predictive of response prior to CTL019 manufacturing, we initially retrospectively evaluated the proportions of naïve, stem cell memory, central memory, effector memory and effector cells at the time of leukapheresis and observed either marginally significant or no significant correlations with clinical outcome. A systematic, unbiased analysis of the same biomarker panel revealed that the frequency of CD27+CD45RO- cells in the CD8+ T cell population correlated significantly with complete and durable responses to this therapy. Analysis of the infusion products using the same flow cytometric panel showed that most (>95%) of T cells expressed CD45RO at the end of the manufacturing run; CD27 expression frequencies, however, were maintained at the same level as in the leukapheresis. Together, these findings suggest that intrinsic T cell fitness dictates both response and resistance to highly active engineered CAR T cells. Thus, enrichment of T cells with optimal differentiation potential and proliferative capacity by timing of collection or culture modification might potentiate the generation of maximally efficacious infusion products. These data and additional immunological biomarkers may be used to identify which patients are most likely to respond to adoptive transfer strategies, leading to an enhanced personalized approach to cellular therapy. Disclosures Fraietta: Novartis: Patents & Royalties: Novartis, Research Funding. Lacey:Novartis: Research Funding. Wilcox:Novartis: Research Funding. Bedoya:Novartis: Research Funding. Chen:Novartis: Research Funding. Orlando:Novartis: Employment. Brogdon:Novartis: Employment. Hwang:Novartis: Research Funding. Frey:Novartis: Research Funding; Amgen: Consultancy. Pequignot:Novartis: Research Funding. Ambrose:Novartis: Research Funding. Levine:Novartis: Patents & Royalties, Research Funding; GE Healthcare Bio-Sciences: Consultancy. Bitter:Novartis: Employment. Porter:Genentech: Employment; Novartis: Patents & Royalties, Research Funding. Xu:Novartis: Research Funding. June:Immune Design: Consultancy, Equity Ownership; University of Pennsylvania: Patents & Royalties; Celldex: Consultancy, Equity Ownership; Novartis: Honoraria, Patents & Royalties: Immunology, Research Funding; Tmunity: Equity Ownership, Other: Founder, stockholder ; Pfizer: Honoraria; Johnson & Johnson: Research Funding. Melenhorst:Novartis: Patents & Royalties: Novartis, Research Funding.

Friedreich ataxia is an autosomal recessive neurodegenerative disorder characterized by ataxia, dysarthria, and areflexia. We report the progress of a large international non-interventional cohort (n = 410), tracking the natural history of disease progression using the neurological exam-based Friedreich Ataxia Rating Scale. We analyzed the rate of progression with cross-sectional analysis and longitudinal analysis over a 2-year period. The Friedreich Ataxia Rating Scale captured disease progression when used at 1 and 2 years following initial evaluation, with a lower ratio of standard deviation of change to mean change over 2 years of evaluation. However, modeling of disease progression identified substantial ceiling effects in the Friedreich Ataxia Rating Scale, suggesting this measure is most useful in patients before maximal deficit is approached.