Dilpacimab (formerly ABT-165), a novel dual-variable domain immunoglobulin, targets both delta-like ligand 4 (DLL4) and VEGF pathways. Here, we present safety, pharmacokinetic (PK), pharmacodynamic (PD), and preliminary efficacy data from a phase I study (trial registration ID: NCT01946074) of dilpacimab in patients with advanced solid tumors. Eligible patients (≥18 years) received dilpacimab intravenously on days 1 and 15 in 28-day cycles at escalating dose levels (range, 1.
View Article and Find Full Text PDFTRAIL can activate cell surface death receptors, resulting in potent tumor cell death via induction of the extrinsic apoptosis pathway. Eftozanermin alfa (ABBV-621) is a second generation TRAIL receptor agonist engineered as an IgG1-Fc mutant backbone linked to two sets of trimeric native single-chain TRAIL receptor binding domain monomers. This hexavalent agonistic fusion protein binds to the death-inducing DR4 and DR5 receptors with nanomolar affinity to drive on-target biological activity with enhanced caspase-8 aggregation and death-inducing signaling complex formation independent of FcγR-mediated cross-linking, and without clinical signs or pathologic evidence of toxicity in nonrodent species.
View Article and Find Full Text PDFProgress in understanding tumor stromal biology has been constrained in part because cancer-associated fibroblasts (CAF) are a heterogeneous population with limited cell-type-specific protein markers. Using RNA expression profiling, we identified the membrane protein leucine-rich repeat containing 15 (LRRC15) as highly expressed in multiple solid tumor indications with limited normal tissue expression. LRRC15 was expressed on stromal fibroblasts in many solid tumors (e.
View Article and Find Full Text PDFAntiangiogenic therapy is a clinically validated modality in cancer treatment. To date, all approved antiangiogenic drugs primarily inhibit the VEGF pathway. Delta-like ligand 4 (DLL4) has been identified as a potential drug target in VEGF-independent angiogenesis and tumor-initiating cell (TIC) survival.
View Article and Find Full Text PDFRadiotherapy combined with chemotherapy is the treatment of choice for glioblastoma and locally advanced lung cancer, but radioresistance of these two types of cancer remains a significant therapeutic hindrance. To identify molecular target(s) for radiosensitization, we screened a small interfering RNA (siRNA) library targeting all protein kinases and E3 ubiquitin ligases in the human genome and identified tumor necrosis factor receptor-associated factor 2 (TRAF2). Silencing of TRAF2 using siRNA caused a significant growth suppression of glioblastoma U251 cells and moderately sensitized these radioresistant cells to radiation.
View Article and Find Full Text PDFTo identify new candidate cancer drug targets, we used RNAi as a tool to functionally evaluate genes that play a role in maintaining human tumor cell survival. We screened a small interfering RNA (siRNA) library directed against approximately 3,700 individual genes to assess the ability of siRNAs to induce cell death in an in vitro cell cytotoxicity assay. We found that siRNAs specifically targeting ras-related nuclear protein (Ran), targeting protein for Xenopus kinesin-like protein 2 (TPX2), and stearoyl-CoA desaturase 1 (SCD1), significantly reduced the survival of multiple human tumor cell lines.
View Article and Find Full Text PDFABT-737 is a novel and potent Bcl-2 antagonist with single-agent activity against small-cell lung cancer (SCLC) cell lines. Here, we evaluated the contribution of Bcl-2 family members to the in vitro cellular response of several SCLC cell lines to ABT-737. Relatively higher levels of Bcl-2, Bcl-X(L), Bim and Noxa, and lower levels of Mcl-1 characterized naïve SCLC cell lines that were sensitive to ABT-737.
View Article and Find Full Text PDFTo identify cancer-specific targets, we have conducted a synthetic lethal screen using a small interfering RNA (siRNA) library targeting approximately 4,000 individual genes for enhanced killing in the DLD-1 colon carcinoma cell line that expresses an activated copy of the K-Ras oncogene. We found that siRNAs targeting baculoviral inhibitor of apoptosis repeat-containing 5 (survivin) significantly reduced the survival of activated K-Ras-transformed cells compared with its normal isogenic counterpart in which the mutant K-Ras gene had been disrupted (DKS-8). In addition, survivin siRNA induced a transient G(2)-M arrest and marked polyploidy that was associated with increased caspase-3 activation in the activated K-Ras cells.
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