Improved Anti-Tumor Response of Chimeric Antigen Receptor T Cell (CART) Therapy after GM-CSF Inhibition Is Mechanistically Supported By a Novel Direct Interaction of GM-CSF with Activated Carts
Despite the remarkable activity of CD19 directed chimeric antigen receptor T cell (CART19) therapy in the treatment of B cell malignancies, the therapy is limited by the development of severe life-threatening complications such as neurotoxicity (NT) and cytokine release syndrome (CRS). Additionally, durable efficacy following CART19 therapy is not optimal. Emerging literature suggests that inhibitory myeloid cells and their cytokines play an important role in inducing CAR-T cell toxicities and also contribute to the inhibition of their effector functions. Specifically, GM-CSF was identified as a critical cytokine in the development of NT and CRS after CART19 therapy. Neutralization of GM-CSF in preclinical models has been shown to prevent CRS and enhance CART anti-tumor activity through modulation of myeloid cell behavior, resulting in reduction of tumor associated macrophages. In addition to the predominant effect of GM-CSF on myeloid cells, there appears to be a direct effect on CART19 cells. In this study, we aimed to evaluate the direct effect of GM-CSF on CART cells. Our initial finding of enhanced anti-tumor activity of CART19 cells after GM-CSF inhibition suggested a direct effect of GM-CSF on CART cells (Sterner et al. 2019, Blood). In these experiments, a guide RNA (gRNA) targeting exon 3 of GM-CSF in a CRISPR-Cas9 lentiviral vector was used to knock out GM-CSF during CART cell manufacturing. This resulted in a disruption efficiency of approximately 70% of the GM-CSF gene. Using a high tumor burden xenograft model for relapsed acute lymphoblastic leukemia established through the engraftment of the CD19+ luciferase+ NALM6 cell line (1x106 cells intravenously) in immunocompromised NOD-SCID-γ-/- mice, treatment with low doses of GM-CSFk/o CART19 resulted in improved anti-tumor activity and overall survival compared to GM-CSFwt CART19. The lack of myeloid cells in this model pointed to an intrinsic effect of GM-CSF on CAR-T cells. To ensure that this was not related to an off-target effect of the gRNA, whole exome sequencing (WES) of the modified cells was performed. There was no difference in the single nucleotide variants or indel counts between GM-CSFk/o CART19 and GM-CSFwt CART19 (Figure 1A). WES was significant for only two alterations in the exon 3 targeted by the gRNA (Figure 1B). The high efficiency and accuracy of targeting exon 3 of GM-CSF indicated that the improvement in CART function is unlikely related to an off-target effect of the gRNA and suggested the possibility of a direct interaction between GM-CSF and CART cells as a potential mechanism behind the improved anti-tumor activity. To investigate this interaction, we first assessed the expression of GM-CSF receptors on CART cells. While resting CART cells do not express any GM-CSF receptors, our analysis robustly indicates that activated CART cells significantly upregulate both α and β subunits of the GM-CSF receptor. This finding was significant both when CART cells are activated through their T cell receptor with CD3/CD28 beads (Figure 1C) or through the CAR with irradiated NALM6 cells (Figure 1D). Additionally, activated GM-CSFk/o CART19 cells also upregulated GM-CSF receptors, indicating this upregulation is induced by T cell stimulation. These results suggest a direct interaction between GM-CSF and upregulated GM-CSFR on activated CART cells. Having demonstrated that 1) GM-CSF depletion enhances CART19 efficacy in xenograft models in the absence of monocytes and 2) T cell activation increases GM-CSF receptor expression, we sought to uncover the downstream changes resulting from this effect. Transcriptome interrogation of GM-CSFk/o CART19 revealed a distinct signature including a significant inhibition of the Fas death pathway, a known critical pathway in inducing CART cell apoptosis. This suggests a potential mechanism for enhanced CART19 activity following GM-CSF depletion (Figure 1E). In summary, our results strongly indicate that CART cells increase expression of GM-CSF receptor subunits when activated, resulting in modulation of CART cell functions. Furthermore, GM-CSFk/o CART19 revealed a distinct transcriptome signature compared to GM-CSFwt CART19. These results illuminate a novel mechanism for a direct modulatory effect of GM-CSF on activated CART cells. Disclosures Cox: Humanigen: Patents & Royalties. Sterner:Humanigen: Patents & Royalties. Sakemura:Humanigen: Patents & Royalties. Ahmed:Humanigen: Employment. Chappell:Humanigen: Employment. Durrant:Humanigen: Employment. Parikh:Acerta Pharma: Research Funding; MorphoSys: Research Funding; AbbVie: Honoraria, Research Funding; Genentech: Honoraria; Janssen: Research Funding; AstraZeneca: Honoraria, Research Funding; Pharmacyclics: Honoraria, Research Funding; Ascentage Pharma: Research Funding. Kay:MorphoSys: Other: Data Safety Monitoring Board; Infinity Pharmaceuticals: Other: DSMB; Celgene: Other: Data Safety Monitoring Board; Agios: Other: DSMB. Kenderian:Novartis: Patents & Royalties, Research Funding; Tolero: Research Funding; Lentigen: Research Funding; Humanigen: Other: Scientific advisory board , Patents & Royalties, Research Funding; Kite/Gilead: Research Funding; Morphosys: Research Funding.
Outcomes and Complications in the Management of Distal Radial Fractures in the Elderly
Background: The purpose of the present study was to identify trends in management and to compare the outcomes and complications following nonoperative and operative management (including external fixation, closed reduction and percutaneous pinning, and open reduction and internal fixation) for distal radial fractures in patients ≥65 years of age. Methods: We performed a retrospective analysis, with use of the OptumLabs Data Warehouse database, of patients ≥65 years of age who had been managed for a distal radial fracture between 2009 and 2014 (as indicated by diagnosis codes according to the International Classification of Diseases, Ninth Revision, Clinical Modification). Ninety-day and 1-year complication rates per 1,000 fractures were analyzed overall and by treatment modality. Results: Thirteen thousand, seven hundred and thirteen distal radial fractures were analyzed. The overall 90-day complication rate was 36.5 per 1,000 fractures, and the 1-year upper-extremity-specific complication rate was 236.2 and 307.5 per 1,000 fractures for nonoperative and operative management, respectively. Overall, post-injury stiffness was the most common 1-year upper-extremity-specific complication (incidence, 11.5%). There was no significant difference between operative and nonoperative management in terms of 90-day complication rates. However, operative management had a higher 1-year complication rate than nonoperative management (307.5 versus 236.2 per 1,000 fractures). Overall, the 5 most common upper-extremity-specific complications following operative treatment of distal radial fracture were stiffness (16.0%), chronic regional pain syndrome (9.9%), median neuropathy (8.0%), implant-related complications (3.8%), and tendon-related complications (2.8%). Stiffness was significantly more frequent following operative management (16.0% versus 9.8%; p < 0.01). Conclusions: Operative management of a distal radial fracture should be carefully considered when discussing treatment options with patients ≥65 years of age. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
Variation in treatment practices for subclinical hypothyroidism in pregnancy: US national assessment
The Journal of Clinical Endocrinology & Metabolism | April 24, 2019 | Volume: No volume available | Issue: No issue available | Pages: No page available
Objectives/HypothesisTo evaluate trends, outcomes, and healthcare utilization following medialization laryngoplasty (ML) with or without arytenoid adduction (AA) over 10 years.Study DesignRetrospective observational study.MethodsUsing OptumLabs Data Warehouse, trends, outcomes, and healthcare utilization from 2006 to 2015 were examined with a focus on discharge type (same day or not). Predictors of postoperative emergency department (ED) use and hospitalization were determined by multivariable logistic regression.ResultsOverall rate of ML was 1.09 per 100 thousand enrollees per year. Of these, 7.8% ML were combined with an AA. Outpatient same‐day discharge represented 62.0% (1,142 of 1,843) of total patients, steadily increasing over the 10‐year period (P < 0.01). There was a 5.9% revision ML rate and 1.0% rate of tracheotomy within 1 day of ML. A total of 5.6% visited an ED, and 5.4% were admitted to a hospital following initial discharge within 30 days. Same‐day discharge was found to be a predictor of hospitalization within 30 days after ML (odds ratio [OR] 1.74, P = 0.0452), along with Elixhauser comorbidity index of 4 + (OR 5.74, P = 0.0001). Pulmonary embolism, pulmonary hypertension, and weight loss were top predictors of ED visit or hospitalization.ConclusionTo our knowledge, this is the first search evaluating national claims data for ML with or without AA. Overall rate of ML is low, and same‐day discharge has become more common over a 10‐year period, with an associated higher 30‐day hospital admission risk. Correct patient selection criteria for disposition status cannot be fully determined based on current data, but a high Elixhauser comorbidity index clearly carries increased risk for hospitalization after initial discharge.Level of Evidence4 Laryngoscope, 129:952–960, 2019