Molecular Cancer Therapeutics最新文献

Radiation-induced fibrosis (RIF) is a progressive pathology deleteriously impacting cancer survivorship. CXCL12 is an immune-stromal signal implicated in fibrosis and innate response. We hypothesised that modulation of CXCL12 would phenotypically mitigate RIF. CXCL12 expression was characterised in a rodent model of RIF and its expression modulated by the intravascular delivery of lentiviral vectors encoding small hairpin RNA to silence (LVShCXCL12) or overexpress (LVOeCXCL12) CXCL12. Multi-modal fibrotic outcomes were quantified, flow cytometry and Y-chromosome lineage-tracking studies performed to examine cellular recruitment and activation post-radiotherapy (post-RT). Whole-tissue RNA-seq was used to examine matrisomal response. MATBIII tumours were engrafted within tissues with differing levels of CXCL12 expression and tumoral response to RT evaluated. CXCL12 was upregulated in irradiated fibroblasts demonstrating DNA-damage post-RT and led to the recruitment of CD68+ macrophages. Silencing Cxcl12 with LVShCXCL12 demonstrated reduced RIF phenotype as a result of decreased macrophage recruitment. Transcriptomic profiling identified osteopontin (SPP1) as being highly differentially expressed in LVShCXCL12-treated tissues. Tumours growing in tissues devoid of CXCL12 expression responded better following RT due to reductions in peri-tumoural fibrosis as a result of decreased CXCL12 and OPN expression at the tumour/normal tissue interface. This was also associated with greater CD8+ T cell infiltration in tumours with less fibrosis. Antibody-mediated OPN blockade slowed tumour growth by increased intra-tumoral CD8+ T cell activation. The CXCL12/OPN axis is an important node of immune/matrisomal cross-talk in the development of fibrosis. Therapeutic manipulation of this axis may offer greater anti-tumour efficacy whilst also reducing adverse effects.

Murine double minute 2 (MDM2) is an E3 ligase that inhibits the tumor suppressor protein p53. Clinical trials employing small-molecule MDM2/p53 interaction inhibitors (SMIs) have demonstrated limited activity, underscoring an unmet need for a better approach to target MDM2. KT 253 is a highly potent and selective heterobifunctional degrader that overcomes the MDM2 feedback loop seen with SMIs and induces apoptosis in a range of hematologic and solid tumor lines. A single intravenous dose of KT 253 triggered rapid apoptosis and sustained tumor regression in p53 wild-type acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) xenograft models. Additionally, a single intravenous dose of KT 253 in combination with standard-of-care (SoC) venetoclax, overcame venetoclax resistance in an AML xenograft model. The data herein define the therapeutic potential of KT-253 and support its clinical development in a range of hematologic and solid p53 wild-type (WT) malignancies, as a monotherapy and in combination with SoC agents.

Src homology-2 domain-containing phosphatase 2 (SHP2) promotes RAS-MAPK signaling and tumorigenesis and is a promising therapeutic target for multiple solid tumors. Migoprotafib is a potent and highly selective SHP2 inhibitor designed for the treatment of RAS-MAPK driven cancers, particularly in combination with other targeted agents. Here we report first-in-human study results of single agent migoprotafib in advanced solid tumor patients. We conducted a phase 1a, open-label, multi-center, dose-escalation and expansion study in adult patients with locally advanced or metastatic solid tumors. The key objectives were to evaluate safety, pharmacokinetics, pharmacodynamics (peripheral blood pERK) and preliminary anti-tumor activity. Fifty-six heavily pre-treated patients were treated with migoprotafib (10-150 mg QD). Migoprotafib had a rapid absorption rate (~0.5-2 hours) with dose-dependent increases in exposure and pathway modulation (pERK changes). The maximum tolerated dose was 100 mg and the recommended phase 2 dose (RP2D) was 60 mg daily (QD) based on safety, pharmacokinetics (PK), pharmacodynamics, and anti-tumor activity. Migoprotafib was generally well tolerated with the most frequent adverse events of diarrhea, peripheral edema, dyspnea, anemia, constipation, fatigue, AST increase and platelet count decrease. Stable disease was observed in 10 patients (18%). Migoprotafib had predictable, dose-dependent PK with an effective half-life that supports QD dosing and demonstrated promising safety, tolerability, and clinical activity at the RP2D. Further clinical testing of migoprotafib in combination with other targeted agents is warranted.

Lurbinectedin is a selective inhibitor of oncogenic transcription approved for the treatment of adult patients with metastatic small cell lung cancer (SCLC) with disease progression on or after platinum-based chemotherapy. Preclinical data provide evidence for lurbinectedin exerting its actions in a unique manner that involves oncogenic transcription inhibition, DNA damage, reshaping of the tumor microenvironment, and inducing anticancer immunity. Understanding the mechanism of action (MoA) has facilitated the rational combination of lurbinectedin and anticancer therapies with complementary modes of action, in order to obtain synergistic effects that could potentially lead to improved efficacy. This review evaluates the MoA for lurbinectedin and provides an overview of the therapeutic landscape with regards to lurbinectedin combination therapies for the treatment of SCLC based on data from preclinical and clinical studies.

Melanoma is an aggressive cancer in dogs involving skin and mucosa similar to people. Anchored immunotherapeutics offer a novel approach to increase intratumoral retention of therapeutic payloads while decreasing systemic exposure, and this strategy can be critically evaluated through a comparative oncology approach. JEN-101 is an anchored canine interleukin-12 (IL-12) tethered to aluminum hydroxide administered by local injection. A Phase I study was conducted to determine the tolerability, activity, and immune responses of JEN-101 in dogs with advanced melanoma. A 3+3 dose escalation design was used to evaluate intratumoral injection of JEN-101 at 1, 3, 10, or 20 μg/kg every three weeks for four cycles. A second course was allowable in the absence of disease progression or toxicity. Peripheral blood, serum, and tumor biopsies were collected at baseline and at pre-specified timepoints for pharmacokinetic and immune analyses, which included serum cytokines, immunohistochemistry, and gene expression assessment. JEN-101 was well tolerated with adverse events being fever, lethargy, and isolated elevated liver enzymes. Five dogs experienced grade 3 events and no grade 4 events were observed. Pharmacokinetic analysis showed a trend towards dose-related Cmax within 8 hours of injection. Responding dogs demonstrated increased systemic interferon-γ and IL-10 AUC levels and local recruitment of CD3+ T cells. Increased pro-inflammatory and antigen processing gene expressions were identified in responding lesions. JEN-101 was well tolerated with evidence of biologic and therapeutic activities. Anchored IL-12 immunotherapy merits further investigation in dogs with melanoma and our approach represents an immune competent model to inform human clinical trials.

Various combination therapies have been investigated to overcome the limitations of using immune checkpoint inhibitors. However, determining the optimal combination therapy remains challenging. To overcome the therapeutical limitation, we conducted a translational research to elucidate the mechanisms by which AXL inhibition enhances the anti-tumor effects when combined with anti-PD-1 antibody therapy. Herein, we demonstrated improved antitumor effects through combination treatment with denfivontinib and pembrolizumab which resulted in enhanced differentiation into effector CD4+ and CD8+ memory T cells, accompanied by an increase in IFN-γ expression in the YHIM-2004 xenograft model derived from patients with NSCLC. Concurrently, a reduction in the number of immunosuppressive M2 macrophages and myeloid-derived suppressor cells was observed. Mechanistically, denfivontinib potentiated the NOD-like receptor pathway, thereby facilitating the NLRP3 inflammasome formation. This leads to macrophage activation via the NF-kB signaling pathway activation. We have confirmed that the positive interaction between macrophages and T cells arises from the enhanced antigen-presenting machinery of activated macrophages. Furthermore, the observed tumor effects in AXL knock-out mice confirmed that AXL inhibition by denfivontinib enhances the anti-tumor effects, thus opening new avenues for therapeutic interventions aimed at overcoming limitations in immunotherapy. To demonstrate the extent to which our findings reflect clinical results, we analyzed bulk-RNA sequencing data from 21 NSCLC patients undergoing anti-PD-1 immunotherapy. The NLRP3 inflammasome score influenced enhanced immune responses in patient data undergoing anti-PD-1 immunotherapy, suggesting a role for NLRP3 inflammasome in activating immune responses during treatment.

Proteasomes generate antigenic peptides that are presented on the tumor surface to cytotoxic T-lymphocytes. Immunoproteasomes are highly specialized proteasome variants that are expressed at higher levels in antigen-presenting cells and contain replacements of the three constitutive proteasome catalytic subunits to generate peptides with a hydrophobic C-terminus that fit within the groove of MHC class I (MHC-I) molecules. A hallmark of cancer is the ability to evade immunosurveillance by disrupting the antigen presentation machinery and downregulating MHC-I antigen presentation. High-throughput screening was performed to identify compound A, a novel molecule that selectively increased immunoproteasome activity and expanded the number and diversity of MHC-I-bound peptides presented on multiple myeloma cells. Compound A increased the presentation of individual MHC-I-bound peptides by >100-fold and unmasked tumor-specific neoantigens on myeloma cells. Global proteomic integral stability assays determined that compound A binds to the proteasome structural subunit PSMA1 and promotes association of the proteasome activator PA28α/β (PSME1/PSME2) with immunoproteasomes. CRISPR/Cas9 silencing of PSMA1, PSME1, or PSME2 as well as treatment with immunoproteasome-specific suicide inhibitors abolished the effects of compound A on antigen presentation. Treatment of multiple myeloma cell lines and patient bone marrow-derived CD138+ cells with compound A increased the anti-myeloma activity of allogenic and autologous T cells. Compound A was well-tolerated in vivo and co-treatment with allogeneic T cells reduced the growth of myeloma xenotransplants in NOD/SCID gamma mice. Taken together, our results demonstrate the paradigm shifting impact of immunoproteasome activators to diversify the antigenic landscape, expand the immunopeptidome, potentiate T-cell-directed therapy, and reveal actionable neoantigens for personalized T-cell immunotherapy.

Metastatic castration-resistant prostate cancer (mCRPC) is an advanced disease in which patients ultimately fail standard-of-care androgen deprivation therapies and exhibit poor survival rates. The prostate-specific membrane antigen (PSMA) has been validated as an mCRPC tumor antigen with overexpression in tumors and low expression in healthy tissues. Using our proprietary technology for incorporating synthetic amino acids into proteins at selected sites, we have developed ARX517, an antibody-drug conjugate composed of a humanized anti-PSMA antibody site-specifically conjugated to a tubulin inhibitor at a drug-to-antibody ratio of 2. After binding PSMA, ARX517 is internalized and catabolized, leading to cytotoxic payload delivery and apoptosis. To minimize premature payload release and maximize delivery to tumor cells, ARX517 employs a noncleavable polyethylene glycol linker and stable oxime conjugation enabled via synthetic amino acid protein incorporation to ensure its overall stability. In vitro studies demonstrate that ARX517 selectively induces cytotoxicity of PSMA-expressing tumor cell lines. ARX517 exhibited a long terminal half-life and high serum exposure in mice and dose-dependent antitumor activity in both enzalutamide-sensitive and -resistant cell line-derived xenograft and patient-derived xenograft models of prostate cancer. Repeat-dose toxicokinetic studies in nonhuman primates demonstrated that ARX517 was tolerated at exposures well above therapeutic exposures in mouse pharmacology studies, indicating a wide therapeutic index. In summary, ARX517 inhibited tumor growth in diverse mCRPC models, demonstrated a tolerable safety profile in monkeys, and had a wide therapeutic index based on preclinical exposure data. Based on the encouraging preclinical data, ARX517 is currently being evaluated in a phase I clinical trial (NCT04662580).

The combination of CDK4/6 and MEK inhibition as a therapeutic strategy has shown promise in various cancer models, particularly in those harboring RAS mutations. An initial high-throughput drug screen identified high synergy between the CDK4/6 inhibitor palbociclib and the MEK inhibitor trametinib when used in combination in soft tissue sarcomas. In RAS mutant models, combination treatment with palbociclib and trametinib induced significant G1 cell cycle arrest, resulting in a marked reduction in cell proliferation and growth. CRISPR-mediated RB1 depletion resulted in a decreased response to CDK4/6 and MEK inhibition, which was validated in both cell culture and xenograft models. Beyond its cell cycle inhibitory effects, pathway enrichment analysis revealed the robust activation of interferon pathways upon CDK4/6 and MEK inhibition. This induction of gene expression was associated with the upregulation of retroviral elements. The TANK-binding kinase 1 inhibitor GSK8612 selectively blocked the induction of interferon-related genes induced by palbociclib and trametinib treatment and highlighted the separable epigenetic responses elicited by combined CDK4/6 and MEK inhibition. Together, these findings provide key mechanistic insights into the therapeutic potential of CDK4/6 and MEK inhibition in soft tissue sarcomas.

Glypican-3 (GPC3) is a proteoglycan with high sensitivity and specificity for hepatocellular carcinoma (HCC). We describe the integrated development and validation of a GPC3-targeting optical imaging probe and T cell-redirecting antibody (TRAB) as a theranostic strategy for the detection and treatment of HCC. A novel TRAB targeting GPC3 on HCC tumor cells and the CD3 T-cell receptor as well as a distinct GPC3-specific optical imaging probe were developed from a short peptide. The efficacy of GPC3/CD3 TRAB was evaluated in vitro using IFNγ release and calcein-AM assays. Patient-derived xenografts were used to assess the in vivo efficacy of GPC3/CD3 TRAB and the GPC3 imaging probe for the detection of GPC3+ HCC. GPC3/CD3 TRAB caused a dose-dependent escalation in IFNγ release from inactive peripheral blood T cells (P = 0.001) and higher tumor-cell lysis (P = 0.01) compared with controls in vitro. Intratumorally injected GPC3/CD3 TRAB resulted in significant prolongation of tumor doubling time in the GPC3+ tumors, with an associated reduction of tumor fluorescent signal from the HiLyte 488-conjugated GPC3-specific peptide on optical imaging. These data demonstrate that HCC cell targeting using a GPC3/CD3 TRAB derived from a small peptide enabled effective T-cell activation and induction of a cytotoxic response toward GPC3+ HCC tumor cells both in vitro and in vivo. GPC3-specific optical imaging enabled the detection of the GPC3+ HCC cells and noninvasive monitoring of tumor response to adoptive immunotherapy. The integrated development of a targeted therapeutic and molecular imaging probe provides a promising paradigm for the development of cancer theranostics.