We identified genetic mutations in CD19 and loss of heterozygosity at the time of CD19
relapse to chimeric antigen receptor (CAR) therapy. The mutations are present in the vast majority of resistant ...tumor cells and are predicted to lead to a truncated protein with a nonfunctional or absent transmembrane domain and consequently to a loss of surface antigen. This irreversible loss of CD19 advocates for an alternative targeting or combination CAR approach.
Background Thymic stromal lymphopoietin (TSLP) pathway blockade is a potential strategy for asthma treatment because the main activities of TSLP are activation of myeloid dendritic cells (mDCs) and ...modulation of cytokine production by mast cells. TSLP-activated mDCs prime the differentiation of naive T cells into inflammatory TH 2 cells. Objective We sought to investigate mechanisms underlying the development of allergic lung inflammation in cynomolgus monkeys using gene expression profiling and to assess the effect of thymic stromal lymphopoietin receptor (TSLPR) blockade in this model. Methods An mAb against human TSLPR was generated and confirmed to be cross-reactive to cynomolgus monkey. Animals were dosed weekly with either vehicle or anti–TSLPR mAb for 6 weeks, and their responses to allergen challenge at baseline, week 2, and week 6 were assessed. Results After 6 weeks of treatment, anti-TSLPR mAb–treated animals showed reduced bronchoalveolar lavage (BAL) fluid eosinophil counts, reduced airway resistance in response to allergen challenge, and reduced IL-13 cytokine levels in BAL fluid compared with values seen in vehicle-treated animals. Expression profiling of BAL fluid cells collected before and after challenge showed a group of genes upregulated by allergen challenge that strongly overlapped with 11 genes upregulated in dendritic cells (DCs) when in vitro stimulated by TSLP (TSLP-DC gene signature). The number of genes differentially expressed in response to challenge was reduced in antibody-treated animals after 6 weeks relative to vehicle-treated animals. Expression of the TSLP-DC gene signature was also significantly reduced in antibody-treated animals. Conclusion These results demonstrate promising efficacy for TSLPR blockade in an allergic lung inflammation model in which TSLP activation of mDCs might play a key role.
2594 Background: Transforming growth factor (TGF)-β signaling has been shown to induce an immunosuppressive tumor microenvironment (TME) and promote tumor progression. Targeting key immune cells ...involved in this mechanism, including regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and M2 macrophages, by altering their function/depleting them is an important strategy in cancer therapeutics. Glycoprotein A repetitions predominant (GARP) is a membrane-bound receptor that complexes with latent TGF-β1 and plays a vital role in the immunosuppressive function of Tregs (1). In addition to Tregs, GARP–TGF-β1 is also expressed on other cells such as macrophages and tumor cells (2). Data from mouse models demonstrated that combined targeting of GARP–TGF-β1 and PD-1 improved antitumor effects compared with anti–PD-1 alone (3). Livmoniplimab (livmo), a first-in-class mAb, targets and stabilizes the GARP–TGF-β1 complex, sequestering TGF-β in its inactive form. Livmo is in clinical trials in combination with the anti–PD-1 mAb budigalimab (budi) (NCT03821935, NCT05822752). Methods: Recently, fresh human tumor-derived tissue culture platforms, which retain autologous TME and immune cell content, have emerged as powerful tools to address the gap between clinical data and preclinical models. To better understand the MOA of livmo + budi, we procured fresh tumors from patients (pts) undergoing surgical resection, minced and cultured them for 48h in the presence of livmo ± budi. The functional activity of livmo and budi was determined by assessing tumor cell viability, T-cell effector function, and modulation of immune-suppressive cells. Results: In tumor explant models from 10 pt samples from various indications (NSCLC: n=2; stomach cancer: n=3; HNSCC: n=2; pancreatic cancer: n=1; bladder cancer: n=1; RCC: n=1), treatment with livmo alone led to reduction of tumor cell viability, increase in T-cell effector function, and decrease in immune-suppressive myeloid cells. This effect was further enhanced in combination with budi. Specifically, within the immune cell components, livmo + budi treatment led to no change in the number of Tregs but a 40% reduction in MDSCs and macrophages, both of which depend on TGF-β1 for sustenance and survival. Furthermore, this decrease corresponded with a 50% increase in secretion of granzyme B/IFNγ antitumor T-cell effector functions. Conclusions: These data demonstrate that livmo induces decrease in tumor cell viability, increased antitumor immune cell activation, and remodeling of the immune-suppressive TME, which is further enhanced in combination with budi. These results support the hypothesis that pts would benefit from therapeutic intervention with livmo + budi. 1. Stockis et al. Mol Biosyst 2017;13:1925-35. 2. Zimmer et al. Front Immunol 2022;13:928450. 3. de Streel et al. Nat Commun 2020;11:4545.
Abstract
Introduction: Multiple myeloma (MM) is a plasma cell disorder characterized by clonal expansion and accumulation of immature undifferentiated neoplastic cells in the bone marrow (BM). Recent ...advances in fluorochrome chemistries, flow cytometry (FACS) instrumentation and rapid tissue preservation methodologies have created opportunities for broader adoption of FACS in the clinical management of multiple myeloma patients.
Methods: We have developed a 10 color, 2 tube FACS assay based on recommendations made by the European Myeloma Network for phenotyping plasma cell gammopathies to identify abnormal blasts in multiple myeloma patient bone marrow aspirates. The assay includes essential plasma cell markers CD138, CD38, CD56 and CD19 to differentiate abnormal blasts from reactive plasma cells. Use of a multi epitope fluorochrome conjugated anti-CD38 antibody enables CD38 detection in patients on anti-CD38 therapy.
Results: Quantification of cell surface HLA-A2 and intracellular survivin protein was made possible using fluorochrome conjugated antibodies in combination with bead standards. The SmartTube™ proteomic stabilizer system for rapid preservation was used to freeze BM aspirate specimens for later analysis at locations with appropriate FACS equipment and trained staff. Consistent with previously published literature, patient survivin levels were elevated on abnormal MM blasts in comparison to survivin levels on non-blast immune cells.
Conclusion: We have developed a robust FACS methodology that would be easy to implement in the clinical trial and development setting with minimal training. The assay can consistently identify abnormal blasts in BM samples of multiple myeloma patients and quantify intracellular and cell surface biomarkers related to MM disease or disease treatment responses.
Citation Format: Tejaswini Hardas, Hyun-Jeong Ra, James Sheridan, Maria Kovalenko, Catherine Tribouley. Quantification of cell surface HLA-A2 and intracellular Survivin protein levels for tumor blasts and non-blast immune cells in multiple myeloma bone marrow aspirates using a rapid sample preservation methodology followed by 10-color FACS assay abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 408.
Inhaled allergen challenge is a validated disease model of allergic asthma offering useful pharmacodynamic assessment of pharmacotherapeutic effects in a limited number of subjects.
To evaluate ...whether an RNA signature can be identified from induced sputum following an inhaled allergen challenge, whether a RNA signature could be modulated by limited doses of inhaled fluticasone, and whether these gene expression profiles would correlate with the clinical endpoints measured in this study.
Thirteen non-smoking, allergic subjects with mild-to-moderate asthma participated in a randomised, placebo-controlled, 2-period cross-over study following a single-blind placebo run-in period. Each period consisted of three consecutive days, separated by a wash-out period of at least 3 weeks. Subjects randomly received inhaled fluticasone ((FP) MDI; 500 mcg BID×5 doses in total) or placebo. On day 2, house dust mite extract was inhaled and airway response was measured by FEV1 at predefined time points until 7 h post-allergen. Sputum was induced by NaCl 4.5%, processed and analysed at 24 h pre-allergen and 7 and 24 h post-allergen. RNA was isolated from eligible sputum cell pellets (<80% squamous of 500 cells), amplified according to NuGEN technology, and profiled on Affymetrix arrays. Gene expression changes from baseline and fluticasone treatment effects were evaluated using a mixed effects ANCOVA model at 7 and at 24 h post-allergen challenge.
Inhaled allergen-induced statistically significant gene expression changes in sputum, which were effectively blunted by fluticasone (adjusted p<0.025). Forty-seven RNA signatures were selected from these responses for correlation analyses and further validation. This included Th2 mRNA levels for cytokines, chemokines, high-affinity IgE receptor FCER1A, histamine receptor HRH4, and enzymes and receptors in the arachidonic pathway. Individual messengers from the 47 RNA signatures correlated significantly with lung function and sputum eosinophil counts.
Our RNA extraction and profiling protocols allowed reproducible assessments of inflammatory signatures in sputum including quantification of drug effects on this response in allergic asthmatics. This approach offers novel possibilities for the development of pharmacodynamic (PD) biomarkers in asthma.
The TNF family is involved in the regulation of the immune system, and its members have been implicated in a variety of biological events such as apoptosis, cell proliferation, differentiation and ...survival. Here we present a new member of the TNF family, tumor necrosis factor super family member 20 (TNFSF20) that we have identified from the expressed sequence tag (EST) database and characterized. The human protein is a 285 amino acid long type II transmembrane protein and is 19% homologous to TNF in its extra-cellular domain. TNFSF20 is expressed at the surface of antigen presenting cells such as cells of the macrophagemonocyte lineage and dendritic cells. After treatment with bacterial lipopolysaccharide (LPS), TNFSF20 expression is downregulated at the surface of the expresssing cells, suggesting that the membrane-bound protein gets cleaved, and that a soluble factor is released in the extra-cellular compartment. The soluble form of the recombinant TNFSF20 induces proliferation of resting peripheral blood monocytes (PBMC) and cell death of activated lymphocytes. TNFSF20 might therefore play a critical role in the regulation of cell-mediated immune responses.
Treatment with a tyrosine kinase inhibitor (TKI) targeting BCR-ABL1 is currently the standard of care for patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP). In this study, we ...present results of the ENESTchina (Evaluating Nilotinib Efficacy and Safety in Clinical Trials–China) that was conducted to investigate nilotinib 300 mg twice daily vs imatinib 400 mg once daily in a Chinese population. ENESTchina met its primary end point with a statistically significant higher rate of major molecular response (MMR; BCR-ABL1 ≤0.1% on the International Scale) at 12 months in the nilotinib arm vs the imatinib arm (52.2% vs 27.8%; P < .0001), and MMR rates remained higher with nilotinib vs imatinib throughout the follow-up period. Rates of complete cytogenetic response (0% Philadelphia chromosome–positive Ph+ metaphases by standard cytogenetics) were comparable and ≥80% by 24 months in both arms. The estimated rate of freedom from progression to accelerated phase/blast crisis at 24 months was 95.4% in each arm. The safety profiles of both drugs were similar to those from previous studies. In conclusion, rates of MMR at 12 months were superior with nilotinib vs imatinib in Chinese patients with newly diagnosed Ph+ CML-CP. This trial was registered at www.clinicaltrials.gov as #NCT01275196.
•Chinese patients with newly diagnosed CML-CP achieved higher rates of MMR with nilotinib vs imatinib.•Nilotinib was well tolerated, and no new safety signals were observed.
Abstract
Background: Programmed cell death 1 (PD-1) is a receptor upregulated on activated lymphocytes that mediates a dominant-negative checkpoint signal limiting antigen receptor-driven cellular ...activation. PD-1 immune checkpoint inhibitors have shown durable clinical responses in patients with non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC). Budigalimab (formerly ABBV-181) is a blocking humanized recombinant anti-PD-1 monoclonal antibody, currently under evaluation in multiple studies such as phase 1 clinical trial (NCT03000257) in patients with solid tumors including HNSCC and NSCLC. Multiple clinical biomarker assessments have been incorporated into this study to accommodate pharmacodynamic (PD) and predictive analyses. Methods: Patients with previously treated, advanced HNSCC (n=41) or NSCLC (n=40) that were PD-1 inhibitor naïve received budigalimab IV at 250 mg every two weeks or 500 mg every four weeks to progression, with responses assessed every 8 weeks. Archival tumor FFPE specimens from patients with HNSCC (n=37) and NSCLC (N=33) were evaluated for CD8 infiltration and tumor PD-L1 expression by Dako 28-8 IHC assay, with remaining samples processed for RNA sequencing and whole-exome sequencing. Serum (for soluble biomarkers) and whole blood (for flow cytometric analysis of T cell biomarkers) were taken at baseline and selected on-treatment time points. Univariate analysis of biomarkers associated with the best overall response (BOR) and progression-free survival was conducted. Results: As of July 2019, responses per response evaluation criteria in solid tumors (RECIST) v1.1 or iRECIST were observed at the expected rates for a PD-1 inhibitor (BOR of partial or complete response of 15% in HNSCC and 19% in NSCLC), with responses in PD-L1+ and PD-L1- tumors in both groups. Budigalimab dosing was associated with rapid complete PD-1 receptor saturation, transient decreases in circulating lymphocytes, upregulation of proliferation (Ki67) biomarkers in T cells, and upregulation of multiple soluble biomarkers, including IFNγ-induced chemokines. Differential neoantigen burden and lymphocyte-associated gene expression in tumors were observed in responders versus non-responders. Preliminary univariate analysis of biomarkers found that baseline tumor size, serum IL-6, and T cell counts were significantly associated with outcomes. Conclusions: Our biomarker analysis of budigalimab-treated HNSCC and NSCLC patients has identified early PD biomarkers consistent with PD-1 inhibitor activity as well as pre-treatment tumor and peripheral biomarkers associated with observed clinical responses. These findings confirm that budigalimab is a biologically active PD-1 inhibitor.
Citation Format: Stacie Lambert, Chun Zhang, Stefan Englert, Claire Guo, Tolga Turan, Catherine Tribouley, David Masica, Robert T. McLaughlin, Gregory S. Vosganian, Daniel E. Afar. Pharmacodynamic and predictive biomarkers of clinical responses to PD-1 inhibitor budigalimab from the first-in-human clinical trial abstract. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4464.
Budigalimab, a novel anti-PD-1 monoclonal antibody, demonstrated efficacy and biomarker pharmacodynamics in patients with head and neck squamous cell carcinoma (HNSCC) or non-small cell lung cancer ...(NSCLC) consistent with those reported by other PD-1 inhibitors. Herein are presented additional outcomes of biomarker analyses from the phase 1 study of budigalimab monotherapy in patients with HNSCC and NSCLC (NCT03000257). PD-1 inhibitor naive patients with advanced HNSCC (n=41) or NSCLC (n=40) received budigalimab intravenously at 250 mg every 2 weeks (Q2W) or 500 mg Q4W until progression. Archival tumor specimens were evaluated by immunohistochemistry for CD8 and tumor PD-1 ligand 1 (PD-L1) expression, RNA, and whole-exome sequencing. Serum and whole blood samples were acquired at baseline and at select on-treatment time points. As of October 2019, best overall response of 15% in HNSCC and 18% in NSCLC was observed in all treated patients; both cohorts reported responses in PD-L1+ and PD-L1- tumors. Treatment with budigalimab was associated with increases in multiple soluble biomarkers including interferon gamma-induced chemokines. Expanded overall T-cell counts, total CD8 T-cell counts, and percentages of CD8+CD45RA-CD62L- effector memory T cells were observed at cycle 1, day 15 in responders. Univariate analysis demonstrated an association between prolonged progression-free survival and higher tumor mutational burden/neoantigen load, smaller tumor size, lower platelet-lymphocyte ratios, lower CCL23, lower colony-stimulating factor 1, and lower interleukin-6 levels at baseline. The biomarker analysis presented herein identified additional early pharmacodynamic biomarkers associated with anti-PD-1 activity and improved clinical responses to budigalimab in patients with advanced HNSCC and NSCLC.
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