Targeted therapy with small molecules directed at essential survival pathways in leukemia represents a major advance, including the phosphatidylinositol-3'-kinase (PI3K) p110δ inhibitor idelalisib. ...Here, we found that genetic inactivation of p110δ (p110δD910A/D910A) in the Eμ-TCL1 murine chronic lymphocytic leukemia (CLL) model impaired B cell receptor signaling and B cell migration, and significantly delayed leukemia pathogenesis. Regardless of TCL1 expression, p110δ inactivation led to rectal prolapse in mice resembling autoimmune colitis in patients receiving idelalisib. Moreover, we showed that p110δ inactivation in the microenvironment protected against CLL and acute myeloid leukemia. After receiving higher numbers of TCL1 leukemia cells, half of p110δD910A/D910A mice spontaneously recovered from high disease burden and resisted leukemia rechallenge. Despite disease resistance, p110δD910A/D910A mice exhibited compromised CD4+ and CD8+ T cell response, and depletion of CD4+ or CD8+ T cells restored leukemia. Interestingly, p110δD910A/D910A mice showed significantly impaired Treg expansion that associated with disease clearance. Reconstitution of p110δD910A/D910A mice with p110δWT/WT Tregs reversed leukemia resistance. Our findings suggest that p110δ inhibitors may have direct antileukemic and indirect immune-activating effects, further supporting that p110δ blockade may have a broader immune-modulatory role in types of leukemia that are not sensitive to p110δ inhibition.
The nuclear receptor (NR) superfamily is one of the major druggable gene families, representing targets of approximately 13.5% of approved drugs. Certain NRs, such as estrogen receptor and androgen ...receptor, have been well demonstrated to be functionally involved in cancer and serve as informative biomarkers and therapeutic targets in oncology. However, the spectrum of NR dysregulation across cancers remains to be comprehensively characterized. Through computational integration of genetic, genomic, and pharmacologic profiles, we characterized the expression, recurrent genomic alterations, and cancer dependency of NRs at a large scale across primary tumor specimens and cancer cell lines. Expression levels of NRs were highly cancer-type specific and globally downregulated in tumors compared with corresponding normal tissue. Although the majority of NRs showed copy-number losses in cancer, both recurrent focal gains and losses were identified in select NRs. Recurrent mutations and transcript fusions of NRs were observed in a small portion of cancers, serving as actionable genomic alterations. Analysis of large-scale CRISPR and RNAi screening datasets identified 10 NRs as strongly selective essential genes for cancer cell growth. In a subpopulation of tumor cells, growth dependencies correlated significantly with expression or genomic alterations. Overall, our comprehensive characterization of NRs across cancers may facilitate the identification and prioritization of potential biomarkers and therapeutic targets, as well as the selection of patients for precision cancer treatment. SIGNIFICANCE: Computational analysis of nuclear receptors across multiple cancer types provides a series of biomarkers and therapeutic targets within this protein family.
Dysfunctional CD8
T cells, which have defective production of antitumor effectors, represent a major mediator of immunosuppression in the tumor microenvironment. Here, we show that SUSD2 is a ...negative regulator of CD8
T cell antitumor function. Susd2
effector CD8
T cells showed enhanced production of antitumor molecules, which consequently blunted tumor growth in multiple syngeneic mouse tumor models. Through a quantitative mass spectrometry assay, we found that SUSD2 interacted with interleukin (IL)-2 receptor α through sushi domain-dependent protein interactions and that this interaction suppressed the binding of IL-2, an essential cytokine for the effector functions of CD8
T cells, to IL-2 receptor α. SUSD2 was not expressed on regulatory CD4
T cells and did not affect the inhibitory function of these cells. Adoptive transfer of Susd2
chimeric antigen receptor T cells induced a robust antitumor response in mice, highlighting the potential of SUSD2 as an immunotherapy target for cancer.
Introduction:T cell engaging bispecific antibodies (T-BsAb) redirect cytotoxic T cells to tumor associated antigen (TAA)-positive target cells, leading to T-cell activation and lysis of target cells. ...Blinatumomab is the only T-BsAb approved by FDA. Numerous T-BsAb are undergoing clinical trials, targeting both hematological malignancies (e.g. BCMA, CD123 and CD33) and solid tumors (e.g. CEA, EpCAM, and GPC3). While these T-BsAbs represent a promising novel therapeutic approach, their efficacy remains modest. Ibrutinib is an irreversible inhibitor of Bruton's tyrosine kinase (BTK) and induces durable remissions in chronic lymphocytic leukemia (CLL). Our group has reported that ibrutinib has favorable immunomodulatory effects due to inhibition of interleukin-2 inducible T-cell kinase (ITK). Ibrutinib decreased key immunosuppressive checkpoint molecules and the frequency of regulatory T cells (Treg)(Long, Beckwith et al. 2017). Moreover, Ibrutinib significantly increased the number of the activated T cells by rescuing them from activation induced cell death (AICD). However, the function of ibrutinib ‘rescued’ T cells and their ability to mediate T-BsAb redirected cytotoxicity is unknown. Therefore we proceeded to study how ibrutinib treatment affects the functional competency of T cells by measuring their capability to mediate Blinatumomab redirected cytotoxicity.
To examine T cell function post ibrutinib treatment, T cells were isolated from pre and post treatment PBMC samples by fluorescence activated cell sorting (FACS), and used as effector cells with pre-treatment CLL B-cells as target cells. Blinatumomab redirected T-cell cytotoxicity against tumor cells and T cell survival were assayed by flow cytometry based methods. Effector cells (T cells) were labeled with CFSE. Target (CLL) cells were labeled with CellTrace Violet. They were co-cultured at an E:T ratio of 4:1 with Blinatumomab for 24 hours. Effector cells and target cells can be distinguished by different fluorescence labels. Apoptosis and cell death were evaluated by Annexin-V and PI staining. The number of viable target cells and effector cells were calculated by Countbright counting bead.
Results: We observed that post-ibrutinib T cells demonstrated significantly superior cytotoxicity against autologous CLL cells in the presence of blinatumomab in three independent patient samples. Numbers of viable CLL cells co-cultured with post-ibrutinib T cells were lower when compared to those co-cultured with pre-ibrutinib T cells (33.6%, 68% and 55.1% reduction in viable CLL cells for the three patient samples, respectively). We also found that Treg depletion (by depleting CD25high/CD127low CD4+ T cells) further enhanced cytotoxicity for both pre and post-ibrutinib treatment T cells, with the numbers of viable CLL cells reduced another 30-40%. Moreover, compared to pre-ibrutinib T cells, post-ibrutinib treatment T cells again demonstrated superior cytotoxicity when Treg cells were depleted, with decreased numbers of viable CLL cells at the end of co-culture (43%, 69% and 49.4% reduction, respectively). We also observed that the numbers of viable T cells from pre-ibrutinib samples were much lower than post-ibrutinib samples (52.5%, 77.9% and 74% reduction in viable T cells, respectively).
Conclusions: Our findings suggest that ibrutinib-rescued T cells are functionally competent. CLL patients' T cells post ibrutinib treatment demonstrated superior cytotoxicity against autologous leukemia cells compared to T cells from treatment baseline. Moreover, we show that increased T cell activity is not solely due to ibrutinib-related Treg depletion. Treg depletion in our experiments further enhanced the cytotoxicity of both post and pre-ibrutinib treatment T cells while post-ibrutinib T cells still demonstrated superior cytotoxicity (Fig 1). Lastly, T cells isolated from post-ibrutinib samples demonstrated significantly improved viability after in-vitro stimulation with blinatumomab, which is likely a result of reduced AICD.
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Bhat:Pharmacyclics: Consultancy; Janssen: Consultancy. Rogers:Janssen: Research Funding; AbbVie: Research Funding; Genentech: Research Funding; Acerta Pharma: Consultancy. Woyach:Janssen: Consultancy, Research Funding; Pharmacyclics LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding; Karyopharm: Research Funding; Loxo: Research Funding; Morphosys: Research Funding; Verastem: Research Funding. Muthusamy:Ohio State University: Patents & Royalties: OSU-2S. Byrd:Novartis: Other: Travel Expenses, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; BeiGene: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Genentech: Research Funding; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Acerta: Research Funding; Ohio State University: Patents & Royalties: OSU-2S; BeiGene: Research Funding; Novartis: Other: Travel Expenses, Speakers Bureau; TG Therapeutics: Other: Travel Expenses, Research Funding, Speakers Bureau; Janssen: Consultancy, Other: Travel Expenses, Research Funding, Speakers Bureau; Genentech: Research Funding; Pharmacyclics LLC, an AbbVie Company: Other: Travel Expenses, Research Funding, Speakers Bureau; Gilead: Other: Travel Expenses, Research Funding, Speakers Bureau.
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Background: AMV564 is a novel bivalent, bispecific (2:2) CD33/CD3 T-cell engager that binds CD33 on target cells and CD3 on T-cells leading to T-cell-directed lysis of CD33+ leukemic blasts and ...myeloid derived suppressor cells (MDSCs), as well as T-cell expansion, differentiation and proliferation. By design, AMV564 has reduced clearance and therefore has a longer half-life (t1/2) than monovalent, bispecific T-cell engagers. In preclinical investigations using both leukemic cell lines and primary cells from AML patients, AMV564 eliminated myeloid blasts with picomolar potency and broad activity independent of cytogenetic or molecular abnormalities, CD33 expression level, and disease stage, with no nonspecific activation of T cells (Reusch U et al. Clin Cancer Res. 2016;22:5829-38).
Methods: This is an ongoing Phase 1 study with a 3+3 dose-escalation design (NCT03144245). The primary objectives of this study are to characterize the safety, tolerability, and preliminary anti-leukemic activity of AMV564. Evaluation of pharmacokinetics (PK), cytokine changes, and immunophenotyping are secondary objectives. Key inclusion/exclusion criteria are: adults with relapsed/refractory AML after 1-2 prior induction regimens (with a standard anthracycline-based regimen or hypomethylating agent) and no more than 2 prior salvage regimens. AMV564 is administered by continuous intravenous infusion (CIV) for 14 consecutive days over a 28 day cycle, with prophylactic antiemetics, antipyretics, and antihistamines. AMV564 and cytokine (IL2, IL4, IL6, IL8, IL10, TNF-α, and IFN-γ) concentrations were measured by validated immunoassays. T-cell activation was measured using flow cytometry to quantify T cells expressing CD25, CD38, CD69, or HLA-DR.
Results: To date, 36 patients (20 male/16 female) with a median age of 71 years (range 24-85 years) have been enrolled in 10 dose cohorts from 0.5 to 300 mcg/day. Twenty-four patients (67%) had secondary AML and/or adverse cytogenetics, including 9 patients (25%) with a TP53 mutation. Fourteen patients (39%) had received at least 1 prior salvage regimen and 23 (64%) had received prior intensive chemotherapy, including 13 patients (36%) who had received a high-dose (≥ 1 g/m2) cytarabine-based regimen and 1 patient (3%) with prior allogeneic stem cell transplant. At the time of this analysis, 36 patients were evaluable for safety and 35 patients were evaluable for activity. No dose-limiting toxicities were reported. Median duration of treatment was 20 days (range 3-204 days). Using a lead-in dose escalation schedule, no Grade 3 or higher cytokine release syndrome has been observed. The most common Grade ≥3 treatment-emergent AE has been anemia, reported in 4 (11%) patients. No patient has died within 30 days of treatment initiation. Bone marrow blast reductions have been observed in 17 (49%) of 35 efficacy evaluable patients. Objective responses have been observed including 1 complete response (CR) during cycle 1 at the 200 mcg/day assigned dose, 1 CRi (CR with incomplete hematologic recovery) during cycle 2 at the 150 mcg/day assigned dose, and 1 partial response (PR) during cycle 1 at the 100 mcg/day assigned dose. In addition, 3 patients had hematologic improvement in neutrophil counts. AMV564 PK was dose proportional through the 100 mcg/day dose level with a terminal half-life of 2-3 days. Serum concentrations increased gradually, with times to steady-state concentration of 3-7 days. T-cell redistribution from the periphery upon initiation of dosing (consistent with T-cell activation) was observed, as was evidence of increased bone marrow T-cells with repeated cycles of treatment.
Conclusions: AMV564 is well-tolerated and demonstrates anti-leukemic activity through T-cell engagement.
Cortes:Sun Pharma: Research Funding; Forma Therapeutics: Consultancy, Honoraria, Research Funding; Merus: Consultancy, Honoraria, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; BiolineRx: Consultancy; Immunogen: Consultancy, Honoraria, Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Astellas Pharma: Consultancy, Honoraria, Research Funding; Jazz Pharmaceuticals: Consultancy, Research Funding; Biopath Holdings: Consultancy, Honoraria; Daiichi Sankyo: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding. Altman:Novartis: Consultancy; Cancer Expert Now: Consultancy; Agios: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Glycomimetics: Consultancy, Honoraria, Other: Data Safety and Monitoring Committee; Theradex: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; PeerView: Speakers Bureau; prIME Oncology: Speakers Bureau; France Foundation: Speakers Bureau; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Biosight: Other: US Lead. Oehler:Pfizer Inc.: Research Funding; Blueprint Medicines: Consultancy; NCCN: Consultancy. Gojo:Abbvie: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Merck: Research Funding; Juno: Research Funding; Amgen Inc: Consultancy, Honoraria, Research Funding; Amphivena: Research Funding. Guenot:Amphivena Therapeutics, Inc.: Employment. Chun:Amphivena Therapeutics, Inc: Employment. Roboz:Celltrion: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Astex: Consultancy, Membership on an entity's Board of Directors or advisory committees; Argenx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amphivena: Consultancy, Membership on an entity's Board of Directors or advisory committees; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Actinium: Consultancy, Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Eisai: Consultancy, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Orsenix: Consultancy, Membership on an entity's Board of Directors or advisory committees; Otsuka: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche/Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Sandoz: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; Trovagene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Daiichi Sankyo: Consultancy, Membership on an entity's Board of Directors or advisory committees.
By combining 6 druggable genome resources, we identify 6,083 genes as potential druggable genes (PDGs). We characterize their expression, recurrent genomic alterations, cancer dependencies, and ...therapeutic potentials by integrating genome, functionome, and druggome profiles across cancers. 81.5% of PDGs are reliably expressed in major adult cancers, 46.9% show selective expression patterns, and 39.1% exhibit at least one recurrent genomic alteration. We annotate a total of 784 PDGs as dependent genes for cancer cell growth. We further quantify 16 cancer-related features and estimate a PDG cancer drug target score (PCDT score). PDGs with higher PCDT scores are significantly enriched for genes encoding kinases and histone modification enzymes. Importantly, we find that a considerable portion of high PCDT score PDGs are understudied genes, providing unexplored opportunities for drug development in oncology. By integrating the druggable genome and the cancer genome, our study thus generates a comprehensive blueprint of potential druggable genes across cancers.
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•We combine 6 druggable genome resources and define 6,083 genes as PDGs•We characterize the expression, genomic alteration, and dependency of PDGs in cancers•We estimate a PDG cancer drug target score, including 16 cancer-related features•TCDA is developed and available to the public
Jiang et al. generate a comprehensive blueprint of potential druggable genes (PDGs) across cancers by a systematic integration of the druggable genome and the cancer genome. This resource is publicly available to the cancer research community in The Cancer Druggable Gene Atlas (TCDA) through the Functional Cancer Genome data portal.
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