HA-high Tumors Research Articles

Tumor hyaluronan as a novel biomarker in non-small cell lung cancer: A retrospective study.

Hyaluronan (HA) accumulation is associated with tumorigenesis and aggressive tumor behavior. We investigated the biomarker potential of HA in non-small cell lung cancer (NSCLC). HA levels were scored using affinity histochemistry in 137 NSCLC samples stratified by HA score ≤10, 11-20, 21-30, and >30 with HA-high defined as ≥25% expression in the extracellular matrix (ECM) of the tumor surface area. Overall survival (OS) and time to progression from initiation of taxane therapy (TTP) were compared using log-rank tests based on HA score. Of 122 patients with recurrent/metastatic NSCLC, 93 had mean HA scores that were not significantly different across clinicopathologic variables. Frequency of HA-high tumors did not differ by histology (34/68 adenocarcinomas vs. 12/25 squamous tumors, Fisher's p = 1.0000). Median OS for recurrent/metastatic adenocarcinoma was 35.5 months (95%, 23.6-50.3) vs. 17.9 months for squamous (95%, 12.7-37.0, log-rank test, p = 0.0165). OS was not significantly different by HA quartiles, high or low (<25) HA score and tumor histology, and HA biopsy site (all p > 0.05). Median TTP (n = 98) significantly differed by HA quartile (2.8 months for HA score ≤10; 5.0 months for 11-20; 7.9 months for 21-30; 3.9 months for >30, p = 0.0265). Improved TTP trended in HA-high over HA-low tumors (n = 98, p = 0.0911). In this NSCLC cohort, tumor HA level represents a potential biomarker for TTP, which remains a cornerstone of NSCLC therapy. Further validation is warranted to identify the HA accumulation threshold associated with clinical benefit.

Blood-based extracellular matrix biomarkers as predictors of survival in patients with metastatic pancreatic ductal adenocarcinoma receiving pegvorhyaluronidase alfa

BackgroundExtensive extracellular matrix (ECM) remodeling is a hallmark of metastatic pancreatic ductal adenocarcinoma (mPDA). We investigated fragments of collagen types III (C3M, PRO-C3), VI (PRO-C6), and VIII (C8-C), and versican (VCANM) in plasma as biomarkers for predicting progression-free survival (PFS) and overall survival (OS) in patients with mPDA treated with pegvorhyaluronidase alfa, a biologic that degrades the ECM component hyaluronan (HA), in a randomized phase 2 study (HALO109-202).MethodsHALO109-202 comprised a discovery cohort (Stage 1, n = 94) and a validation cohort (Stage 2, n = 95). Plasma ECM biomarkers were analyzed by ELISAs. Univariate Cox regression analysis and Kaplan–Meier plots evaluated predictive associations between biomarkers, PFS and OS in patients treated with pegvorhyaluronidase alfa plus nab-paclitaxel/gemcitabine (PAG) versus nab-paclitaxel/gemcitabine (AG) alone.ResultsPFS was improved with PAG vs. AG in Stage 1 patients with high C3M/PRO-C3 ratio (median cut-off): median PFS (mPFS) 8.0 vs. 5.3 months, P = 0.031; HR = 0.40; 95% CI 0.17–0.92). High C3M/PRO-C3 ratio was validated in Stage 2 patients by predicting a PFS benefit of PAG vs. AG (mPFS: 8.8 vs. 3.4 months, P = 0.046; HR = 0.46; 95% CI 0.21–0.98). OS was also improved in patients with high C3M/PRO-C3 ratio treated with PAG vs. AG (mOS 13.8 vs 8.5 months, P = 0.009; HR = 0.35; 95% CI 0.16–0.77). Interestingly, high C3M/PRO-C3 ratio predicted for a PFS benefit to PAG vs. AG both in patients with HA-low tumors (HR = 0.36; 95% CI 0.17–0.79) and HA-high tumors (HR = 0.20; 95% CI 0.06–0.69).ConclusionsThe C3M/PRO-C3 ratio measuring type III collagen turnover in plasma has potential as a blood-based predictive biomarker in patients with mPDA and provides additional value to a HA biopsy when applied for patient selection.Trial registration: NCT01839487. Registered 25 April 2016

Exposure-response (E-R) analysis of efficacy of pegvorhyaluronidase alfa (PEGPH20) in combination with nab-paclitaxel + gemcitabine (AG) in patients (Pts) with metastatic pancreatic ductal adenocarcinoma.

e15746 Background: PEGPH20 depolymerizes extracellular matrix hyaluronan (HA) and is an investigational agent for the treatment of pts with HA-accumulating tumors. HALO-109-202 (260 pts) was conducted to evaluate the effect of PEGPH20 + AG in pts with mPDA. Methods: E-R models were developed to evaluate the relationship between PEGPH20 exposure and efficacy, including time to PFS, time to OS, and overall response (OR). Results: The final E-R PFS model was a Cox proportional hazards model that included effects of PEGPH20 Cmax and baseline tumor biopsy HA (high or low). Higher PEGPH20 Cmax was associated with a lower risk of radiological progression. Pts with baseline HA≥ 50% (HA-high) tumor biopsy were at a lower risk of radiological progression with PEGPH20 treatment. A similar E-R model evaluated the effect of PEGPH20 on OS, including effects of dose-adjusted PEGPH20 concentration 7 days postdose (D7 Conc), liver metastases, and baseline tumor burden. The model-predicted influence of PEGPH20 D7 Conc on risk of death indicated that with increasing PEGPH20 D7 Conc, the predicted risk of death decreases. Pts with liver metastases and higher baseline tumor burden were predicted to have a higher risk of death. The final E-R efficacy model for OR probability was a linear function of dose-adjusted PEGPH20 AUC in Cycle 1, where increasing exposure was related to a higher predicted OR probability. Conclusions: The E-R analyses demonstrate that improvements in PFS and OS with PEGPH20 + AG is PEGPH20 exposure-dependent, supporting 3 µg/kg as an appropriate dose for further development and emphasizing the need for sufficient PEGPH20 exposure for improved therapeutic effect. Clinical trial information: NCT01839487. [Table: see text]

Parallel Accumulation of Tumor Hyaluronan, Collagen, and Other Drivers of Tumor Progression.

Purpose: The tumor microenvironment (TME) evolves to support tumor progression. One marker of more aggressive malignancy is hyaluronan (HA) accumulation. Here, we characterize biological and physical changes associated with HA-accumulating (HA-high) tumors.Experimental Design: We used immunohistochemistry, in vivo imaging of tumor pH, and microdialysis to characterize the TME of HA-high tumors, including tumor vascular structure, hypoxia, tumor perfusion by doxorubicin, pH, content of collagen. and smooth muscle actin (α-SMA). A novel method was developed to measure real-time tumor-associated soluble cytokines and growth factors. We also evaluated biopsies of murine and pancreatic cancer patients to investigate HA and collagen content, important contributors to drug resistance.Results: In immunodeficient and immunocompetent mice, increasing tumor HA content is accompanied by increasing collagen content, vascular collapse, hypoxia, and increased metastatic potential, as reflected by increased α-SMA. In vivo treatment of HA-high tumors with PEGylated recombinant human hyaluronidase (PEGPH20) dramatically reversed these changes and depleted stores of VEGF-A165, suggesting that PEGPH20 may also diminish the angiogenic potential of the TME. Finally, we observed in xenografts and in pancreatic cancer patients a coordinated increase in HA and collagen tumor content.Conclusions: The accumulation of HA in tumors is associated with high tIP, vascular collapse, hypoxia, and drug resistance. These findings may partially explain why more aggressive malignancy is observed in the HA-high phenotype. We have shown that degradation of HA by PEGPH20 partially reverses this phenotype and leads to depletion of tumor-associated VEGF-A165. These results encourage further clinical investigation of PEGPH20. Clin Cancer Res; 24(19); 4798-807. ©2018 AACR.

260TiP - Phase 3, randomized, double-blind, placebo-controlled study of PEGylated recombinant human hyaluronidase PH20 (PEGPH20)+nab-paclitaxel/gemcitabine in patients with previously untreated, hyaluronan-high, stage IV pancreatic ductal adenocarcinoma (PDA)

Background: Poor outcome in PDA is associated with stromal hyaluronan (HA) accumulation, which may compromise treatment access. In animal models, PEGPH20 degrades tumor HA. Key data from a Phase 2 study showed that PEGPH20 plus chemotherapy improved efficacy over chemotherapy alone in tumors retrospectively identified to accumulate HA (“HA-High”). The objectives of this phase 3 study are to compare efficacy and safety of standard-dose nab-paclitaxel (NAB) and gemcitabine (GEM) combined with PEGPH20 or placebo in patients with HA-High, previously untreated, stage IV PDA. Primary endpoints are progression-free survival (PFS) and overall survival (OS). Secondary endpoints are objective response rate, duration of response, and safety. Trial design: 420 patients ≥18 years with untreated HA-High metastatic PDA, ECOG PS 0-1 are randomized (stratified by North America/Europe/other) 2:1 to NAB 125 mg/m2 + GEM 1000 mg/m2 + PEGPH20 3.0 μg/kg or to NAB + GEM + placebo, respectively. Patients with HA-High tumors are prospectively identified by the co-developed VENTANA HA RxDx Assay, which identifies HA in the extracellular matrix. HA-High status (indicating patients who may achieve clinical benefit) was determined by Halozyme to be ≥ 50% HA staining based on clinical outcome data from a Phase 2 study. Treatment is provided in 4-week cycles (Wk 1-3, Wk 4 rest) until disease progression, unacceptable toxicity, death, or consent withdrawal. PEGPH20 or placebo is given twice weekly (Cycle 1) then weekly (Cycles 2+), NAB + GEM once weekly for all cycles. Dexamethasone is given before and after PEGPH20 to reduce treatment-related musculoskeletal symptoms and enoxaparin is given to minimize thromboembolic events. Tumor response will be assessed by an independent central imaging vendor using RECIST v1.1. Adverse events will be graded per NCI CTCAE v4.03. An independent Data Monitoring Committee will evaluate safety and efficacy (PFS and OS) data. Trial initiated Q12016. Clinical trial indentification: EudraCT 2015-004068-13; NCT02715804. Legal entity responsible for the study: Halozyme Therapeutics Funding: Halozyme Therapeutics Disclosure: D-Y. Oh: Research funding from AstraZeneca, Array BioPharma. Y-J. Bang: Research funding: AstraZeneca, Novartis, Roche, MSD, Merck Serano, Bayer, GSK, BMS, Pfizer, Eli Lilly, Boeringer-Ingelheim, MacroGenics, Boston Biomedical, FivePrime, CKD, Ono, Otsuka, Taiho, Takeda, BeiGene, Hanmi, Green Cross, Curis Ad board member: AstraZeneca, Novartis, Roche, Genentech, MSD, Pfizer, Bayer, BMS, Eli Lilly, Merck Serano, FivePrime, Merrimack, Taiho, Ono, ADC Therapeutics, GreenCross, Samyang Biopharm. E. Van Cutsem: Research funding: Halozyme. A. Hendifar: Consulting or Advisory Role: Xbiotech, Novartis (self) Research Funding: Ipsen, Halozyme (institution). L. Zheng: Employment: Roche, Stock or Other Ownership: Roche, Honoraria: Roche, Travel, Accommodations, Expenses: Roche. M. Ducreux: Honoraria/Consultation Fees: Roche, Celgene, Merck Serono, Amgen, Novartis, Sanofi, Pfizer, Lilly, Servier, Halozyme; Grants/Research funding: Roche, Chugai, Pfizer Spouse: Head of BU, Sandoz. W. Harris: Consulting or Advisory Role: Neotherma Oncology, Bayer (self); Research Funding: Halozyme, BMS, Exelixis, Arqule, Polaris, Medimmune, BTG (institution). P. Corrie: Honoraria: Roche, Novartis, Bristol Myers Squibb, Merck Sharpe & Dohme, Pierre Fabre Research funding: Celgene; Ad hoc honoraria for lectures/meeting presentations: Novartis, Celgene, Merck Sharpe & Dohme. T. Seery: Consulting or Advisory Role: Bayer (self) Speakers' Bureau: Ipsen, Bayer (self). D. Chondros: Employment: Halozyme (self) Leadership: Halozyme (self) Stock or Other Ownership: Halozyme, Roche (self) Travel Accommodations, Expenses: Halozyme, Roche/Genentech (self). A. Bullock: Consulting or advisory board participation support: Halozyme, Celgene, and EMD Serono (self). All other authors have declared no conflicts of interest.

743P - Tumor hyaluronan (HA) is a novel biomarker: Results of the randomized phase 2 HALO 202 study of PEGPH20 plus nab-paclitaxel/gemcitabine (PAG) vs AG in previously untreated, metastatic pancreatic ductal adenocarcinoma (mPDA)

Background: PEGPH20 (P) degrades HA in the tumor microenvironment to increase access and therapeutic index of anticancer agents. In Stage 1 of this study, Halozyme Therapeutics, Inc. and Ventana Medical Systems, Inc., co-developed a novel HA assay, scoring algorithm, and cut-point, and showed improved progression-free survival (PFS) and objective response rate (ORR) in HA-High patients (pts) with PAG vs AG. Due to an imbalance in thromboembolic (TE) events in the PAG arm, the protocol was amended to add enoxaparin and exclude pts at high risk for TE events in Stage 2, which prospectively validated the algorithm and cut-point for the VENTANA HA RxDx assay. Methods: In Stage 2, pts with mPDA were randomized 2:1 to PAG (P 3 µg/kg IV 2x/wk x 3 wk [C1], then 1x/wk x 3 wk [C2+] + AG) vs AG every 28 days. Endpoints were: primary—PFS and TE events; secondary—PFS by HA level, ORR; OS by HA level was exploratory. Tumor HA was evaluated using the VENTANA HA RxDx assay and algorithm; HA-High was defined by HA staining in the extracellular matrix ≥50% of the entire tumor surface at any intensity. Results: 133 pts were enrolled; 125 pts were treated. As of December 16, 2016, an improvement in median PFS (91%) and median OS (50%) was observed in HA-High pts treated with PAG vs AG (Table), supporting tumor HA as a predictive marker for PEGPH20 efficacy. Among AG-treated pts, those with HA-High tumors showed poorer median PFS and median OS outcomes, suggesting that targeting tumor HA with PEGPH20 may improve the standard of care in mPDA.Table743PPAGAGHR (95% CI)HA-Highn = 24n = 11PFS, months8.64.50.63 (0.21-1.93)OS, months11.77.80.52 (0.22-1.23)HA-Lown = 53n = 23PFS, months6.07.21.21 (0.63-2.30)OS, months11.910.20.69 (0.38-1.23) Open table in a new tab Conclusions: This is the first randomized Phase 2 study evaluating and supporting tumor HA as a potential predictive biomarker informing patient selection for PEGPH20 treatment, based on improvement in both PFS and OS in HA-High pts. The results provide support for the ongoing phase 3 HALO 109-301 study with co-primary endpoints of PFS and OS. NCT01839487. Clinical trial identification: NCT01839487 Legal entity responsible for the study: Halozyme Therapeutics, Inc. Funding: Halozyme Therapeutics, Inc. Disclosure: A. Hendifar: Consulting or advisory role: Genentech, Novartis, Ipsen, Perthera. Travel, accommodations, expenses: Halozyme. A. Bullock: Consulting or advisory board participation support: Halozyme, Celgene, EMD Serono. T. Seery: Consulting or advisory role: Bayer. Speakers' Bureau: Ipsen, Bayer. L. Zheng: Consultancy or advisory role: Merrimack. Patents, royalties, other intellectual property: GVAX. Licensed to Aduro Biotech. Stock and other ownership: Z&L Medical Intl. Research funding: Bristol-Myers Squibb, Amgen, Iteos Therap, Gradalis, Merck, Halozyme. D. Sigal: Stock or other ownership: Novartis, BMS, Ignyta, Halozyme. Honoraria: Novartis, Serond, Halozyme. Speakers' Bureau: Novartis, Celgene, Bayer. Research funding: Halozyme. F.S. Braiteh: Author has disclosures to report for: Honoraria, Consulting or Advisory Role,Speaker's Bureau,Travels, Accommodation, Expenses. M. Zalupski: Research funding: Halozyme, OncoMed, Newlink Genetics. N. Bahary: Consulting or advisory role: Bayer/Onyx, EMD Serono. Research funding: New Links Genetics. W. Harris: Consulting or advisory role: Neotherma Oncology, Bayer. Research funding: Halozyme, BMS, Exelixis, Argule, Polaris, Medimmune, BTG. J. Pu: Employment: Roche; Research funding: Roche. Patents, royalties, other intellectual property: Roche (for author and institution). F. Lian: Stock or other ownership: Merck (Immediate Family Member). J. Zhu: Employment: Roche. Stock or other ownership: Roche. Honoraria: Roche. Travel, accommodations, expenses: Roche. W. Wu: Employment: Halozyme. Stock or other ownership: Halozyme. D. Chondros: Employee of Halozyme Therapeutics. P. Jiang: Employment: Halozyme. Stock or other ownership: Halozyme Therapeutics Inc. Patents, royalties, other intellectual property: Halozyme Therapeutics Inc. S.R. Hingorani: Consulting or advisory role: Halozyme, Aduro Biotech. Research funding to institution: Halozyme. All other authors have declared no conflicts of interest.

Abstract CT066: Global phase 3, randomized, double-blind, placebo-controlled study evaluating PEGylated recombinant human hyaluronidase PH20 (PEGPH20) plus nab-paclitaxel and gemcitabine in patients with previously untreated, hyaluronan (HA)-high, stage IV pancreatic ductal adenocarcinoma

Abstract Background: Poor outcome in pancreatic ductal adenocarcinoma (PDA) is associated partly with stromal hyaluronan (HA) accumulation, which may compromise chemotherapy access to tumors. In animal models, PEGPH20 degrades HA in tumors. Key endpoint data from a phase 2 study showed that PEGPH20 plus chemotherapy improved efficacy over chemotherapy alone in tumors retrospectively identified to accumulate HA (“HA-High”). The objectives of this phase 3 study are to compare efficacy and safety of standard-dose nab-paclitaxel (NAB) and gemcitabine (GEM) combined with either PEGPH20 or placebo in patients with HA-High, previously untreated, Stage IV PDA. Primary endpoints are progression-free survival (PFS) and overall survival (OS). Secondary endpoints are objective response rate, duration of response, and safety. Methods: 420 patients ≥18 years with untreated HA-High metastatic PDA, ECOG PS 0-1 will be randomized (stratified by geographic region: North America/Europe/Other) 2:1 to NAB 125 mg/m2 + GEM 1000 mg/m2 + PEGPH20 3.0 μg/kg or to placebo. Patients with HA-High tumors will be prospectively identified by the co-developed VENTANA HA RxDx Assay, which indicates HA in the extracellular matrix. HA-High status (indicating patients who may achieve clinical benefit) was determined by Halozyme to be ≥50% staining based on clinical outcome data from a phase 2 study. Treatment will be provided in 4 week cycles (Wk 13, Wk 4 rest) until disease progression, unacceptable toxicity, death, or consent withdrawal. PEGPH20 or placebo will be given twice weekly (Cycle 1) then weekly (Cycles 2+), NAB + GEM once weekly for all cycles. Dexamethasone will be given before and after PEGPH20 administrations to reduce treatment related musculoskeletal symptoms and enoxaparin will be given to minimize thromboembolic events. Tumor response will be assessed by an independent central imaging vendor using RECIST v1.1. Adverse events will be graded per NCI CTCAE v4.03. An independent Data Monitoring Committee will evaluate safety and data for PFS and OS. Trial initiated Q12016 (EudraCT 2015-004068-13; NCT02715804). Citation Format: Lei Zheng, Andrew E. Hendifar, Michele Reni, William P. Harris, Michel Ducreux, Andrea J. Bullock, Pippa G. Corrie, Tara Seery, Dimitrios Chondros, Eric Van Cutsem. Global phase 3, randomized, double-blind, placebo-controlled study evaluating PEGylated recombinant human hyaluronidase PH20 (PEGPH20) plus nab-paclitaxel and gemcitabine in patients with previously untreated, hyaluronan (HA)-high, stage IV pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT066. doi:10.1158/1538-7445.AM2017-CT066

Abstract CT032: A Phase 1b study of PEGPH20 plus pembrolizumab in patients with selected hyaluronan-high solid tumors

Abstract Background: Hyaluronan (HA) accumulation in the tumor microenvironment increases tumor interstitial fluid pressure, promoting vascular collapse and limiting access of chemotherapy and immune cells to tumor sites. In animal models, HA-High tumors exhibit increased growth and metastasis, treatment resistance, and reduced survival. PEGPH20 is a PEGylated recombinant human hyaluronidase that enzymatically degrades tumor HA. Pembrolizumab (PEM) is a humanized monoclonal antibody targeting PD-1, demonstrating tolerability and activity in patients (pts) with non-small cell lung cancer (NSCLC). This study evaluates the safety and activity of PEGPH20 plus PEM in pts with NSCLC or gastric cancer. Methods: This Phase 1b study comprises dose escalation (up to 30 pts regardless of HA status) and cohort expansion (up to 51 pts with tumors accumulating high levels of HA). HA staining is performed using the VENTANA HA RxDX Assay, which indicates HA in the extracellular matrix. HA-High status (ie, patients who may achieve clinical benefit) was determined by Halozyme to be ≥50% staining based on clinical outcome data from a phase 2 study. For dose escalation, eligible pts (ECOG 0-1) had stage IIIB/IV NSCLC failing ≥1 prior platinum-based regimen or locally advanced or metastatic gastric adenocarcinoma failing ≥1 previous chemotherapy regimen. NSCLC pts known to be epidermal growth factor receptor (EGFR)- or anaplastic lymphoma kinase (ALK)-positive must have received an EGFR inhibitor or ALK inhibitor, respectively. For cohort expansion, previously treated or untreated NSCLC is allowed; gastric cancer pts must have failed 1-2 prior treatments. PEGPH20 (1.6, 2.2, 2.6, 3.0, 4.0 µg/kg) is administered IV on D1, 8, 15 of each 21-day cycle followed by PEM 200 mg IV on D1, 4 to 6 hours after PEGPH20. Due to increased thromboembolic risk in gastric cancer, these pts receive prophylactic enoxaparin. Additional prophylaxis with piroxicam (possible musculoskeletal events) and proton pump inhibitors are given to all patients. The primary endpoint for dose escalation is the recommended Phase 2 dose for PEGPH20 in combination with PEM. The primary endpoint for cohort expansion is objective response rate per RECIST v1.1. Secondary endpoints are duration of response, disease control rate, progression-free survival per RECIST and immune-related response criteria, pharmacokinetics, and adverse events. Exploratory endpoints include secondary efficacy endpoints by PD-LI status, plasma and tumor HA levels, and imaging parameters of tumor blood flow (dynamic contrast-enhanced magnetic resonance imaging [DCE-MRI]) and tumor metabolic activity (positron emission tomography/computed tomography [PET/CT] scans). ClinicalTrials.gov Identifier: NCT02563548. Citation Format: Lyudmila Bazhenova, Philip J. Gold, R. Donald Harvey, Alexander I. Spira, John Nemunaitis, Joaquina C. Baranda, Shirish Gadgeel. A Phase 1b study of PEGPH20 plus pembrolizumab in patients with selected hyaluronan-high solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT032. doi:10.1158/1538-7445.AM2017-CT032

Abstract LB-198: Combination of PEGylated recombinant hyaluronidase PH20 (PEGPH20) with live-attenuated, double-deleted (LADD) Listeria enhances tumor infiltrating CD8+ T cell response and antitumor efficacy in mice

Abstract Successful immunotherapy is highly dependent on inducing an efficient CD8+ T cell-mediated antitumor immune response. The trafficking and activation of these effector CD8+ T cells are often inhibited by various immunosuppressive mechanisms in the tumor microenvironment (TME). Hyaluronan (HA), a glycosaminoglycan that accumulates in the TME of many solid tumors, is associated with rapid tumor progression, poor prognosis and increased immunosuppression. We have previously demonstrated in nonclinical models that enzymatic degradation of TME HA by intravenous PEGylated recombinant human hyaluronidase PH20 (PEGPH20) facilitates delivery of chemotherapeutics to tumors and enhances checkpoint inhibitor efficacy. Based on these observations we hypothesized that PEGPH20 may improve current cancer immunotherapies by increasing immune cell infiltration into tumors. To test this hypothesis we used CT26/HAS3 tumors, CT26 murine colon carcinoma cells engineered to over-express hyaluronan synthase-3, and treated them with PEGPH20 in combination with recombinant live-attenuated double-deleted strains of Listeria monocytogenes expressing AH1 (gp70423-431, SPSYVYHQF), the immunodominant CD8+ T cell epitope of CT26 (LADD-AH1). PEGPH20 (1mpk), which results in nearly complete removal of HA at 24hrs, was administered 24hrs prior to LADD-AH1. In this model, LADD-AH1 alone inhibited tumor growth which correlated with an increase in IFNγ+ (p=0.0019) and granzyme B+ CD8+ tumor infiltrating lymphocytes (TILs) (p=0.0006). Tumor-associated macrophages (TAMs) from LADD-AH1 treated tumors were more immunostimulatory with a decrease in MHCIIlow (p=0.0205) and CD206+ TAMs (p=0.0003). Moreover, the combination of PEGPH20 and LADD-AH1 resulted in enhanced anti-tumor activity compared to either PEGPH20 (p=0.0047) or LADD-AH1 alone (p=0.0002). Significant TME changes were observed in the combination treatment with an increase in CD8+ TILs (p=0.0200, of which 88% were granzyme B+), NK cells (p=0.0205) and an increase in CD8:Treg ratio (p=0.0007).These findings were corroborated by immunohistochemical analysis demonstrating an increase in CD3+ T cells with PEGPH20 treatment. Taken together, these data suggest that HA accumulation in tumors may act as a barrier to immune cell access and that reduction of HA by PEGPH20 facilitates increased accumulation of tumor antigen-specific CD8+ effector T cells induced by LADD immunotherapy. Our findings reveal a benefit of PEGPH20 in enhancing tumor infiltration of cytotoxic CD8+ T cells induced by LADD that translate into a significant improvement in efficacy in a murine model of HA-high tumors. Citation Format: Jisook Lee, Meredith Leong, Yujun Huang, Benjamin J. Thompson, Sanna Rosengren, Barbara Blouw, Dirk G. Brockstedt, Curtis B. Thompson. Combination of PEGylated recombinant hyaluronidase PH20 (PEGPH20) with live-attenuated, double-deleted (LADD) Listeria enhances tumor infiltrating CD8+ T cell response and antitumor efficacy in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-198. doi:10.1158/1538-7445.AM2017-LB-198

P3.02c-011 A Phase 1b Open-Label Study of PEGPH20 Combined with Pembrolizumab in Patients with Selected Hyaluronan-High Solid Tumors: Topic: Targeted Therapy

Hyaluronan (HA) is a megadalton polysaccharide found in the tumor microenvironment (TME). HA accumulation in the TME increases tumor interstitial pressure, which promotes vascular collapse and limits access of chemotherapy and immune cells to tumor sites. In animal models, HA-High tumors exhibit increased growth and metastasis, treatment resistance, and reduced survival. PEGPH20 is a pegylated recombinant human hyaluronidase that enzymatically degrades tumor HA. Pembrolizumab (PEM) is a humanized monoclonal antibody targeting PD-1 and demonstrating tolerability and activity in patients with non-small cell lung cancer (NSCLC). This study evaluates the safety and activity of PEGPH20 plus PEM in patients with HA-High tumors. This is a Phase 1b study comprising a dose escalation portion (up to 30 patients without regard to HA status) followed by a cohort expansion portion in up to 51 patients with HA-High tumors, determined using a companion diagnostic assay developed in collaboration with Ventana Medical Systems. Eligible patients are ≥18 years, ECOG PS 0-1, with either relapsed/refractory stage IIIB/IV NSCLC who failed ≥1 previous platinum-based chemotherapy regimen or relapsed/refractory locally advanced or metastatic gastric adenocarcinoma who failed ≥1 previous chemotherapy regimen. Patients with NSCLC known to be epidermal growth factor receptor (EGFR)- or anaplastic lymphoma kinase (ALK)-positive must have received an EGFR inhibitor or ALK inhibitor, respectively. PEGPH20 (1.6, 2.2, 2.6, 3.0, 4.0 μg/kg) is administered intravenously (IV) over 10 minutes on days 1, 8, and 15 of each 21-day cycle followed by PEM 2 mg/kg IV on day 1, 4 to 6 hours after PEGPH20 is completed. Piroxicam will be given prophylactically for possible musculoskeletal events. Prophylactic proton pump inhibitors will be given to all patients. The primary endpoint for the dose escalation portion is the recommended Phase 2 dose for PEGPH20 in combination with PEM. In the cohort expansion portion, the primary endpoint is objective response rate per RECIST v1.1. Secondary endpoints are duration of response, disease control rate, progression-free survival per RECIST and immune-related response criteria, pharmacokinetics, and adverse events. Exploratory endpoints in patients with HA-High NSCLC include HA levels in plasma and tumor tissue and imaging parameters of tumor blood flow (dynamic contrast-enhanced magnetic resonance imaging [DCE-MRI]) and tumor metabolic activity (positron emission tomography/computed tomography [PET/CT] scans). ClinicalTrials.gov Identifier: NCT02563548. Section not applicable. Section not applicable.

PUB031 PRIMAL: A Phase 1b Study of PEGPH20 plus Docetaxel in Patients with Previously Treated Hyaluronan (HA)-High Advanced NSCLC

Hyaluronan (HA) is a megadalton polysaccharide found in the tumor microenvironment (TME). HA accumulation in the TME increases tumor interstitial pressure which promotes vascular collapse and limits access of chemotherapy and immune cells to tumor sites. In animal models, HA-High tumors exhibit increased growth and metastasis, treatment resistance, and reduced survival. PEGylated recombinant human hyaluronidase (PEGPH20) enzymatically degrades tumor HA. Preclinical studies in non-small cell lung cancer (NSCLC) patient-derived xenografts showed that PEGPH20 enhanced the effect of docetaxel (Doc) in HA-High tumors by increasing tumor growth inhibition and prolonging survival. This Phase 1b study will evaluate the safety and activity of PEGPH20 plus Doc in patients with NSCLC in dose escalation and cohort expansion periods. Eligible patients are ≥18 years, ECOG PS 0-1 with stage IIIB/IV NSCLC, and have failed 1 previous platinum-based chemotherapy regimen (plus EGFR/ALK inhibitor treatment where indicated). Patients with brain metastases are eligible if clinically stable and not receiving corticosteroids. During dose escalation, up to 30 patients (regardless of HA status) receive PEGPH20 (1.6, 2.2, 2.8 μg/kg IV over 10 minutes) on day 1, followed 24 hours later by Doc (75 mg/m2 IV over 60 minutes) on Day 2 of each 21-day cycle. In the cohort expansion period, PEGPH20 will be administered at the recommended Phase 2 dose (RP2D) in up to 50 patients with HA-High tumors determined using a companion diagnostic assay currently being developed in collaboration with Ventana Medical Systems. During both periods, dexamethasone (8 mg orally BID) will be given for possible musculoskeletal events. Patients with a history of deep vein thrombosis will receive enoxaparin. Primary endpoints include the RP2D and safety and tolerability of the study combination. Secondary endpoints are objective response rate, duration of response, disease control rate, progression-free survival, and pharmacokinetic profiles of the study drugs. Exploratory endpoints include change in plasma HA levels, potential prognostic/predictive markers, and correlation between plasma/tumor biomarkers and clinical outcomes. Clinical trial identifier: NCT02346370. Section not applicable Section not applicable

Interim results of a randomized phase II study of PEGPH20 added to nab-paclitaxel/gemcitabine in patients with stage IV previously untreated pancreatic cancer.

439 Background: Poor outcome in pancreatic cancer (PDA) is associated partly with stromal hyaluronan (HA) accumulation, which compromises chemotherapy perfusion. PEGPH20, PEGylated recombinant human hyaluronidase, potentiates chemotherapy by depleting HA in tumors. Methods: In an ongoing, phase II, open-label, randomized study of PEGPH20+nab-paclitaxel (Nab)+Gemcitabine (Gem) (PAG) vs Nab+Gem (AG) in previously untreated stage IV PDA, pts receive PEGPH20 3 µg/kg twice weekly (C1), then weekly (C2+) with standard AG dosing. HA status was tested retrospectively. After a temporary clinical hold (Apr-Jul 2014) for an imbalance in thromboembolic (TE) events (29% PAG vs 15% AG), the protocol was amended to exclude high-TE-risk pts and add enoxaparin (LMWH) prophylaxis. Endpoints are PFS and TE events (primary); PFS and ORR by HA level and OS (secondary). Efficacy and safety data through Dec 2014 are for pts enrolled up to clinical hold (Stage 1); TE data are through Sep 2015 (Stage 2). Results: 135 pts were treated (74 PAG, 61 AG). PFS results are shown below (median follow-up 7 mo). In HA-high pts receiving PAG vs AG, ORR was 52% (1 CR) vs 24% (P=.038); ORR was 37% vs 38% in HA-low pts. OS was 12 mo vs 9 mo (HR=0.62) despite 12/23 PAG pts discontinuing PEGPH20 at clinical hold. Common ADRs (PAG vs AG) included peripheral edema (58% vs 31%), muscle spasms (55% vs 1.6%), and neutropenia (32% vs 18%). TE events were: Stage 1 42% vs 25% (no LMWH); Stage 2 (with LMWH; 40 mg/d or 40 mg/d increased to 1 mg/kg/d) 28% vs 29%; (1 mg/kg/d) 5% vs 6%; overall (40 mg/d or 1 mg/kg/d) 13% each arm (to be updated). Conclusions: Pts with HA-high tumors receiving PAG, vs AG, showed significant improvements in PFS and ORR and a trend toward improved OS. PAG was well tolerated, with TE events reduced with LMWH prophylaxis. A global phase III trial of PAG will initiate Q1 2016. Clinical Trial Information: NCT01839487. Clinical trial information: NCT01839487. [Table: see text]

Breaching the Castle Walls: Hyaluronan Depletion as a Therapeutic Approach to Cancer Therapy.

Hyaluronan (HA) has many functions in the extracellular milieu of normal and diseased tissues. Disease-associated HA accumulation has been shown to predict a worsened prognosis in cancer patients, with tumors having a high-extracellular HA content (HA-high) being more aggressive than their HA-low counterparts. HA-high tumor aggressiveness is derived from the specialized biomechanical and molecular properties of the HA-based assembly of HA binding proteins and the growth-promoting factors that accumulate in it. Biophysical characteristics of an HA-high tumor microenvironment include high tumor interstitial pressure, compression of tumor vasculature, and resulting tumor hypoxia. Within the tumor cell membrane, HA receptors, primarily CD44 and RHAMM, anchor the HA-high extracellular network. HA–CD44 association on the tumor cell surface enhances receptor tyrosine kinase activity to drive tumor progression and treatment resistance. Together, malignant cells in this HA-high matrix may evolve dependency on it for growth. This yields the hypothesis that depleting HA in HA-high tumors may be associated with a therapeutic benefit. A pegylated form of recombinant human hyaluronidase PH20 (PEGPH20) has been deployed as a potential cancer therapeutic in HA-high tumors. PEGPH20 can collapse this matrix by degrading the HA-assembled tumor extracellular framework, leading to tumor growth inhibition, preferentially in HA-high tumors. Enzymatic depletion of HA by PEGPH20 results in re-expansion of the tumor vasculature, reduction in tumor hypoxia, and increased penetration of therapeutic molecules into the tumor. Finally, HA-depletion results in reduced signaling via CD44/RHAMM. Taken together, HA-depletion strategies accomplish their antitumor effects by multiple mechanisms that include targeting both biophysical and molecular signaling pathways. Ongoing clinical trials are examining the potential of PEGPH20 in combination with partner therapeutics in several cancers.

Abstract 982: Hyaluronan (HA) depletion increases tumor accessibility of T cell and therapeutic PD-L1 monoclonal antibody in HAhigh tumors

Abstract Tumor initiation and progression is a complex interaction between host and tumor. One of the essential elements for tumor progression is evasion of the host immune system. Among the mechanisms important for host immune cell evasion is the amplification of receptor tyrosine kinases, and tumor secretion of immune suppressive cytokines, like TGF-β, suppression of activated T cells by various intrinsic immune response regulatory mechanisms 1-3. Additionally, tumor cells evolve to express cell-associated programmed death 1 (PD1) ligands (PD-L1 or LD-L2), which promotes tumor cell growth by inactivating PD1 expressing activated T cells 3-4. Recent reports suggest a role of the tumor microenvironment (TME) as an immunosuppressive environment by accumulating hyaluronan (HA)5-7, which then results in accumulation of water and resulting high interstitial fluid pressure and sequelae, including blood vessel compression, and decreased perfusion8-10. Hyaluronan depletion from solid tumors with high levels of HA (HAhigh) reverses these physiological effects, resulting in increased chemotherapeutic drug penetration and tumor growth inhibition in preclinical animal models 8-10. In this report we investigated whether increasing the access of therapeutic immune checkpoint monoclonal antibodies and effector T cells into the HAhigh tumor can enhance activated T cell-mediated tumor cell lysis. We have generated human hyaluronan synthase and PD-L1 overexpressing tumor cell lines to study (i) the role of HA in PD-1 and PD-L1 interaction in HAhigh tumor cells, and (ii) whether HA depletion increases the efficacy of tumor cell killing by PD-1 positive cytotoxic T lymphocytes in the presence of PD-L1 blocking monoclonal antibody. Our data show that HAhigh tumor cells form an HA-rich barrier that restricts T cell access to tumor cell and HA depletion by PEGPH20, a pegylated PH20, allowed T cells to access tumor cell. HA depletion increases HAhigh PD-L1 positive tumor cells killing by activated T cell in the presence of anti-human PD-L1 monoclonal antibody (MAb). Furthermore, HA depletion by PEGPH20 increased the access of T cell and anti-human PD-L1 MAb in HAhigh xenograft tumors, suggesting that PEGPH20 may enhance efficacy of immune check point blocking therapeutic PD-L1 MAb in HAhigh tumors.

Abstract 2547: PEGPH20 enhances chemotherapy in patient-derived and traditional cell-derived xenograft NSCLC models

Abstract Hyaluronan (HA) accumulates in the tumor microenvironment (TME) of many solid tumors, including prostate, colon, breast, stomach, ovary, pancreas and lung, and HA accumulation is associated with tumor progression and a negative clinical outcome. Accordingly, the HA degrading enzyme pegylated recombinant human hyaluronidase PH20 (PEGPH20) was developed to allow systemic therapy and enable treatment of HA-high tumors. Preclinical studies have demonstrated that PEGPH20-mediated HA removal from HA-rich xenograft tumors in mice decreases tumor interstitial fluid pressure and water content; resulting in decompression of tumor vasculature, increased tumor perfusion and enhanced chemotherapeutic (CTX) activity. As non-small cell lung cancer (NSCLC) is the most common cancer worldwide and is characterized by high levels of HA (∼30%), we aimed to evaluate PEGPH20 enhancement of anti-tumor activity of NSCLC CTXs. Specifically, using both cell derived xenograft (CDX) models, peritibial H2170/HAS3 human NSCLC xenografts, and patient derived xenograft (PDX) models, we investigated CTX tumor growth inhibition (TGI)+/- PEGPH20. Nude mice were inoculated with either H2170/HAS3 cells adjacent to the tibial periosteum or patient derived tumor fragments of human NSCLCs implanted subcutaneously, and tumor growth was monitored via ultrasonography or caliper, respectively. When tumors reached ∼400 mm3, mice were staged into four groups: (1) vehicle; (2) PEGPH20, (3) CTX(s), or (4) PEGPH20 + CTX(s). PEGPH20 alone depleted tumor HA in both CDX and PDX models. In CDX studies, PEGPH20 increased tumor perfusion, reduced hypoxia and decreased HIF-1α expression (p&amp;lt;0.05). A summary table of the TGI data is shown below. The average TGI for PEGPH20 plus CTX(s) was superior to all CTX(s) alone, suggesting that enzymatic depletion of TME HA increases tumor sensitivity to NSCLC CTXs, likely due to increased CTX access into the TME. PEGPH20 clinical trials in NSCLC are currently in development. Summary of TGIsGroup (n≥5/group)CDX%TGI w/ docetaxelCDX%TGI w/ nab-paclitaxel + carboplatinPDX%TGI w/ docetaxelPDX%TGI w/ gemcitabine + cisplatin(p-value vs. V)Vehicle (V)----PEGPH20 (P)28.5 (p&amp;lt;0.05)11.5 (p&amp;gt;0.05)44.4 (p&amp;lt;0.01)29.3 (p&amp;gt;0.05)CTX(s)19.8 (p&amp;gt;0.05)68.6 (p&amp;lt;0.0001)52.5 (p&amp;lt;0.001)38.4 (p&amp;gt;0.05)P + CTX56.1 (p&amp;lt;0.001)93.5 (p&amp;lt;0.0001)&amp;gt;100 (p&amp;lt;0.0001)76.6 (p&amp;lt;0.01) Citation Format: Jessica A. Cowell, Xiaoming Li, Ping Jiang, Susan Zimmerman, Rebecca Symons, H. Michael Shepard, Daniel C. Maneval, Curtis B. Thompson. PEGPH20 enhances chemotherapy in patient-derived and traditional cell-derived xenograft NSCLC models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2547. doi:10.1158/1538-7445.AM2015-2547

Abstract 3193: Expression analysis reveals candidate genes involved in highly invasive high-hyaluronan binding subpopulations of prostate cancer cell lines

Abstract Tumour heterogeneity is one of the hallmarks of aggressive cancers, which can be detected by differential gene expression, DNA mutation patterns, and ligand binding profiles. Hyaluronan (HA) is an extracellular matrix polysaccharide whose elevated accumulation is associated with tumour recurrence in colon and breast carcinomas. Previously, we reported that triple-negative breast cancer cell lines exhibit heterogeneous binding of HA, with high and low binding subpopulations showing differences in proliferation and invasion. Here we assessed whether or not a similar binding heterogeneity detects prostate cancer cell subsets with differential invasive capability. Flow cytometry HA-binding profiles reveal heterogeneous binding of a fluorescent HA probe to the PC3M-LN4 prostate cancer cell line. Fluorescence-activated cell sorting (FACS) was used to isolate low and high hyaluronan binding subpopulations. Sorted cells were cultured and, after one week of growth, were analyzed for cell proliferation and invasion using alamar blue, transwell invasion and gelatin degradation assays. Results confirmed that HAhigh tumor cells displayed reduced growth but increased invasion and degradation relative to HAlow subpopulations. We then employed human gene 2.0 expression arrays to assess transcriptome changes between these two subpopulations. The expression of 7 genes was significantly elevated or lowered in HAhigh vs. HAlow cells, and these were linked to inflammation, angiogenesis, MMP9 regulation and metastasis. These results identify a novel form of heterogeneity common to both breast and prostate cancer cell lines and suggest that subpopulations binding high levels of HA can be used as indicators of aggressive tumors. Citation Format: Sean J. Leith, Ann F. Chambers, James B. McCarthy, Joseph L. Chin, Eva A. Turley. Expression analysis reveals candidate genes involved in highly invasive high-hyaluronan binding subpopulations of prostate cancer cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3193. doi:10.1158/1538-7445.AM2015-3193

Abstract P5-04-02: Hyaluronan (HA) depletion sensitizes HAhigh tumors to antibody-dependent cell-mediated cytotoxicity

Abstract Therapeutic efficacy of monoclonal antibodies (MAbs) against solid tumor targets, like trastuzumab (anti-HER2) and cetuximab (anti-EGFR), have been used successfully to treat cancer, despite the many physical barriers impeding their access to the malignant cell surface1. For example, only about 50% of HER23+ patients have a durable response to therapy with trastuzumab2. Extracellular matrix (ECM)-mediated inhibition may be among the mechanisms of resistance to MAb therapy of solid tumors. Aberrant accumulation of hyaluronan (HA), a major component of the ECM in many tumors, is associated with poor prognosis and treatment-resistance in multiple malignancies3-5. We investigated HA-dependent pericellular matrix-mediated inhibition to ADCC in HAhigh human cancer cells in vitro and in vivo. We observed high levels of tumor associated HA (HA3+) in &amp;gt;50% of HER23+ breast adenocarcinoma and ∼40% of EGFR+ head and neck squamous cell carcinoma (HNSCC) primary tumors. Human hyaluronan synthase 2 (HAS2)-overexpressing breast cancer cells formed an HAhigh pericellular matrix, which inhibited both natural killer (NK) cell access to tumor cells and ADCC in vitro. Hyaluronan depletion by PEGPH20, a pegylated recombinant human PH20 hyaluronidase currently in clinical study for pancreatic cancer, increased NK cell access to HAS2-overexpressing breast cancer cells and greatly enhanced trastuzumab- or cetuximab-dependent ADCC. Trastuzumab and NK cell accessibility to HAS2-overexpressing tumors was enhanced following HA-depletion by PEGPH20. In an in vivo ADCC-based efficacy study, PEGPH20 treatment in combination with trastuzumab and NK cells enhanced tumor growth inhibition. This work describes a novel tumor microenvironment (TME)-dependent mechanism of inherent resistance to therapeutic antibody-mediated ADCC in vitro and in vivo, and furthermore shows that ADCC can be enhanced by hyaluronan depletion. These results may help to explain as to why tumors with high levels of HA are more aggressive, and suggest potential benefits of PEGPH20-mediated HA depletion in combination with therapeutic antibodies like trastuzumab or cetuximab in the treatment of HAhigh solid tumors.

Highlights of This Issue

The transmembrane receptor Notch3 may act as a tumor suppressor or as an oncogene in human cancers, depending upon the cellular context. To elucidate its role in medullary thyroid cancer (MTC), Jaskula-Sztul and colleagues created a gain-of-function model in a MTC cell line containing a doxycycline-inducible Notch3 intracellular domain and validated the function of Notch3 overexpression by exposure to a novel class I HDAC inhibitor, AB3. The forced expression of Notch3 in MTC altered malignant phenotype by triggering apoptosis and reducing neuroendocrine tumor markers. These studies document the tumor suppressor role of Notch3 in MTC and propose it as a potential therapeutic target.Double-strand break (DSB) repair pathways are emerging as a clinically relevant target for cancer therapy. However, previous drug screening campaigns have focused on single target proteins with in vitro assays. In this issue, Goglia and colleagues describe a cell-based, high-throughput small molecule screen for novel DSB repair inhibitors. They utilized a unique assay permitting the simultaneous analysis of two key DSB repair pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). The authors report numerous novel DSB repair inhibitors, many of which were FDA-approved compounds. One of their hits was subsequently translated into a Phase I trial as a glioma radiosensitizer.Vascular endothelial growth factor (VEGF) is critical for physiologic and pathological angiogenesis, particularly in cancer. To date, several antiangiogenic therapies neutralizing VEGF have been successfully developed for clinical use. Here, Lee and colleagues created a novel glycosylated VEGF decoy receptor, called VEGF-Grab. VEGF-Grab contains VEGFR1 D2-D3 domain, the positively charged patches of which are engineered to reduce the isoelectric point. VEGF-Grab exhibited more potent decoy activity against VEGF-A and placental growth factor (PlGF), and had prolonged pharmacokinetic profiles. These advancements lead to stronger and more durable antiangiogenic and antitumor efficacy, suggesting that VEGF-Grab is a promising therapeutic candidate for antiangiogenic cancer therapy.A complex network of hyaluronan (HA) and proteoglycans in a tumor microenvironment with high levels of HA (HAhigh) forms a physical barrier capable of inhibiting access of therapeutic monoclonal antibodies (mAbs) and immune cells to tumor cells, resulting in a more aggressive tumor phenotype in several solid tumor types. HA depletion by PEGPH20 removes this barrier, which allows increased access of mAb and immune cells to the tumor cell, resulting in efficient ADCC-dependent tumor cell killing. Microscopic live cell imaging shows that a physical barrier in HAhigh tumor cells restricts live human NK cells from accessing the tumor cells.

Final results of a phase Ib study of gemcitabine plus PEGPH20 in patients with stage IV previously untreated pancreatic cancer.

359 Background: Poor outcome in pancreatic cancer (PDA) has been associated with tumor stroma limiting access of chemotherapy drugs. PEGPH20 (PEG), PEGylated recombinant human hyaluronidase, which depletes hyaluronan (HA) in tumors, has demonstrated anti-tumor activity in preclinical PDA models. In a KPC model of PDA, PEG + gemcitabine (Gem) significantly prolonged survival compared to Gem alone. In Phase 1 PEG monotherapy studies, the MTD was 3µg/kg. The most common adverse events (AEs) were musculoskeletal events. Methods: This was a phase 1b study to determine the recommended phase 2 dose of PEG + Gem in patients (pts) with previously untreated Stage IV pancreatic cancer. PEG was given at 1, 1.6, or 3µg/kg IV twice weekly Wks 1–4 and weekly Wks 5–7, followed by 1 wk rest. Gem was given at 1000mg/m2IV once weekly for Wks 1–7, then 1 wk rest. Thereafter, PEG + Gem were given once weekly for 3 wks in 4-wk cycles. Dexamethasone was given pre and post PEG doses. Due to evolving SOC, the study was discontinued before initiation of the phase 2 randomization. Results: Twenty-eight pts were enrolled in the study. The majority of the patients (89%) had metastatic sites in the liver. Four, 4 and 20 pts received PEG at 1, 1.6 and 3µg/kg, respectively. The most common AEs related to PEG were muscle spasm (54%), myalgia (39%), arthralgia (29%), peripheral edema (29%), fatigue (25%), and extremity pain (18%). Median progression free survival (PFS) and overall survival (OS) were assessed and were 154 and 200 days, respectively. In an exploratory analysis, tumor biopsies from 17 pts were evaluated for HA levels (HAhigh or HAlow). 6 pts were determined to have HAhigh tumors and 11 pts had HAlow tumors. The median PFS and OS for HAhigh pts were 219 days (95% CI: 159-276) and 395 days (95% CI: 210-578). For HAlowpts median PFS and OS were 108 (95% CI: 14-163) and 174 days (95% CI: 34-293). Conclusions: PEG + Gem is generally well tolerated in advanced pancreatic cancer and shows promising clinical activity, especially in pts with HAhigh tumors. ClinicalTrials.gov Identifier: NCT01453153.

Exploratory biomarker results from early investigation of PEGPH20 in combination with gemcitabine (Gem) in patients with pancreatic cancer (PDA).

300 Background: PEGPH20 (PEG), a PEGylated recombinant human hyaluronidase, has anti-tumor activity as a single agent and in combination with chemotherapy in preclinical models. A Phase 1b study of PEG + Gem (P+G) in patients (pts) with advanced PDA showed good anti-tumor activity, particularly in pts with HAhigh tumors (ECCO 2013). In this study, we investigated pharmacodynamic (PD) markers including plasma(soluble) HA (sHA), dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and 18Fluorodeoxyglucose positron emission tomography (PET/CT) to explore additional correlates for PEG activity. Methods: 28 pts with stage IV PDA were treated with PEG at 1, 1.6, or 3µg/kg IV twice weekly for Wks 1-4 and Wks 5-7, followed by 1 wk rest, plus Gem at 1000 mg/m2 IV once weekly for Wks 1-7, then 1 wk rest. Thereafter, P+G was given once weekly for 3 wks in 4-wk cycles. Serial plasma samples were collected and analyzed in a quantitative assay for PEG and sHA. Exploratory imaging by DCE-MRI was performed on selection pts at baseline, 8hr, 24hr and end of cycle 1, PET/CT was performed at baseline and at the end of each cycle. Results: PEG pharmacokinetics was well-characterized by a 2-compartment PK model, peak plasma concentration increased in a dose-proportional manner after a single or repeat administration of PEG. Dose- and time-dependent increases in sHA were observed within 2-3 days after 1.0, 1.6, or 3.0 µg/kg of PEG administration. The median peak concentrations were 3,736; 48,150; and 74,950ng/mL, respectively, and increased with increasing doses. sHA reached steady state approximately 1 wk after repeated PEG administration, consistent with the expected hyaluronidase activity of PEG. Exploratory analysis with DCE-MRI from 6 pts showed an early increase (24hrs) in tumor perfusion (Ktrans) in target lesions. PET/CT from 5 pts showed an average reduction in the maximum standardized uptake value (SUVmax) of 37% at EOC1, and partial metabolic responses using EORTC criteria were achieved in 4 of 5 pts. These results suggest that P+G has measurable biological activity in metastatic PDA Conclusions: Plasma sHA concentration, DCE-MRI and PET/CT are PD markers for evaluation of P+G activity.