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Hyaluronan (HA) is a glycosaminoglycan polymer that often accumulates in malignancy. Megadalton complexes of HA with proteoglycans create a hydrated connective tissue matrix, which may play an important role in tumor stroma formation. Through its colloid osmotic effects, HA complexes contribute to tumor interstitial fluid pressure, limiting the effect of therapeutic molecules on malignant cells. The therapeutic potential of enzymatic remodeling of the tumor microenvironment through HA depletion was initially investigated using a recombinant human HA-degrading enzyme, rHuPH20, which removed HA-dependent tumor cell extracellular matrices in vitro. However, rHuPH20 showed a short serum half-life (t1/2 < 3 minutes), making depletion of tumor HA in vivo impractical. A pegylated variant of rHuPH20, PEGPH20, was therefore evaluated. Pegylation improved serum half-life (t1/2 = 10.3 hours), making it feasible to probe the effects of sustained HA depletion on tumor physiology. In high-HA prostate PC3 tumors, i.v. administration of PEGPH20 depleted tumor HA, decreased tumor interstitial fluid pressure by 84%, decreased water content by 7%, decompressed tumor vessels, and increased tumor vascular area >3-fold. Following repeat PEGPH20 administration, tumor growth was significantly inhibited (tumor growth inhibition, 70%). Furthermore, PEGPH20 enhanced both docetaxel and liposomal doxorubicin activity in PC3 tumors (P < 0.05) but did not significantly improve the activity of docetaxel in low-HA prostate DU145 tumors. The ability of PEGPH20 to enhance chemotherapy efficacy is likely due to increased drug perfusion combined with other tumor structural changes. These results support enzymatic remodeling of the tumor stroma with PEGPH20 to treat tumors characterized by the accumulation of HA. Mol Cancer Ther; 9(11); 3052–64. ©2010 AACR.

Video - 2-D ultrasound cine loop of post- vehicle tumor vascular area Vehicle at t = 8h; Mouse #413

Video Legend from Enzymatic Depletion of Tumor Hyaluronan Induces Antitumor Responses in Preclinical Animal Models

Video - 2-D ultrasound cine loop of post- PEGPH20 tumor vascular area 15 mg/kg PEGPH20 at t = 8h; Mouse #149

Video - 2-D ultrasound cine loop of pre- PEGPH20 tumor vascular area 15 mg/kg PEGPH20 at t = 0; Mouse #149

Hyaluronan (HA) is a glycosaminoglycan polymer that often accumulates in malignancy. Megadalton complexes of HA with proteoglycans create a hydrated connective tissue matrix, which may play an important role in tumor stroma formation. Through its colloid osmotic effects, HA complexes contribute to tumor interstitial fluid pressure, limiting the effect of therapeutic molecules on malignant cells. The therapeutic potential of enzymatic remodeling of the tumor microenvironment through HA depletion was initially investigated using a recombinant human HA-degrading enzyme, rHuPH20, which removed HA-dependent tumor cell extracellular matrices in vitro. However, rHuPH20 showed a short serum half-life (t1/2 < 3 minutes), making depletion of tumor HA in vivo impractical. A pegylated variant of rHuPH20, PEGPH20, was therefore evaluated. Pegylation improved serum half-life (t1/2 = 10.3 hours), making it feasible to probe the effects of sustained HA depletion on tumor physiology. In high-HA prostate PC3 tumors, i.v. administration of PEGPH20 depleted tumor HA, decreased tumor interstitial fluid pressure by 84%, decreased water content by 7%, decompressed tumor vessels, and increased tumor vascular area >3-fold. Following repeat PEGPH20 administration, tumor growth was significantly inhibited (tumor growth inhibition, 70%). Furthermore, PEGPH20 enhanced both docetaxel and liposomal doxorubicin activity in PC3 tumors (P < 0.05) but did not significantly improve the activity of docetaxel in low-HA prostate DU145 tumors. The ability of PEGPH20 to enhance chemotherapy efficacy is likely due to increased drug perfusion combined with other tumor structural changes. These results support enzymatic remodeling of the tumor stroma with PEGPH20 to treat tumors characterized by the accumulation of HA. Mol Cancer Ther; 9(11); 3052–64. ©2010 AACR.

AG-012986 is a multitargeted cyclin-dependent kinase (CDK) inhibitor active against CDK1, CDK2, CDK4/6, CDK5, and CDK9, with selectivity over a diverse panel of non-CDK kinases. Here, we report the potent antitumor efficacies of AG-012986 against multiple tumor lines in vitro and in vivo. AG-012986 showed antiproliferative activities in vitro with IC50s of 83.1%) in 10 of 11 human xenograft tumor models when administered at or near the maximum tolerated dose for 8 or 12 days. AG-012986 caused dose-dependent hypophosphorylation at Ser795 of the retinoblastoma protein, cell cycle arrest, and apoptosis in vitro. Colony-forming assays indicated that the potency of AG-012986 substantially decreased with treatment time of

The purpose of this study is to investigate whether the chemosensitivity of patient-derived primary tumor tissue when coupled with molecular characterization provides a stronger correlation to clinical outcomes than conventional preclinical anticancer drug testing. Current strategies for developing new anticancer drugs rely heavily on preclinical testing in cancer cell lines and their derived in vivo xenograft models. A significant limitation to current preclinical testing is the use of highly passaged cancer cell lines grown on plastic. Perhaps no aspect of life in a modern molecular biology lab is more ubiquitous, or more important than cell culture. The phenotype and behavior of a cell is significantly influenced by its microenvironment and an accumulating body of evidence highlights the importance and utility of 3D culture systems to better recapitulate the in vivo growth compartment. 3D models have emerged as a powerful method to interrogate the biological activities of cancer genes and oncogenic pathways. We have developed preclinical cancer models using patient-derived primary tumor cells (PTCs) grown in 3D cultures to conduct preclinical evaluation of molecularly targeted agents, identify sensitive and resistant subpopulations and design combinations based on the heterogeneity of the disease, and then explore these findings in vivo. We conducted a retrospective study in PTCs from solid tumor indications including breast, lung and melanoma and evaluated molecular targeted agents including lapatinib (Her2/EGF), trastuzumab (Her2), erlotinib (EFF), crizotinib (ALK/c-MET) and vemurafinib (B-RAF). We utilized a range of methods (PCR, FISH, IF, western blot) to determine the genetic and molecular features of the PTCs prior to performing drug treatments. We used high content imaging to evaluate colony segmentation, morphological features, proliferative and apoptotic endpoints to identify responder and non-responder populations. Our results indicate that 3D PTC models have predictive value and enable secondary interrogation beyond single agent antiproliferative activity to better profile the antitumor activity of targeted agents. Improved preclinical models are required to advance our understanding of the molecular aberrations that underpin cancer and are critical for developing and deploying targeted therapies that will improve patients' lives. Patient-derived primary tumor cell models grown in 3D culture conditions are essential for designing and conducting hypothesis driven studies as a foundation for subsequent in vivo studies from which data can make personalized medicine decisions actionable. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B123.