Citations

4073 Background: Durvalumab and tremelimumab, investigational monoclonal antibodies against PD-L1 and CTLA-4 immune checkpoints, respectively, have shown efficacy in monotherapy and offer promise in combination for patients (pts) with HCC. This is a phase I/II, open-label, randomized study of durvalumab combined with tremelimumab in unresectable HCC. Methods: Phase I part of this study is a safety run-in cohort treated at the recommended phase II doses of the durvalumab/tremelimumab combination (20 and 1 mg/kg IV Q4W respectively for 4 doses followed by 20 mg/kg Q4W durvalumab alone) in pts with unresectable HCC with or without concomitant HBV or HCV infection who progress on, are intolerant to, or have refused sorafenib therapy. Secondary objectives include evaluation of antitumor activity. Here we present results of a preplanned analysis from the completed phase I part of the study. Results: As of 10 January 2017, 40 pts have been enrolled (11 HBV+, 9 HCV+, 20 uninfected). 30% had no prior systemic therapy; 93% were Child Pugh Class A. 24 (60%) had ≥1 treatment-related AE; 20% had ≥1 grade ≥3 related AE. Most common (≥15%) treatment-related AEs: fatigue (20%), increased ALT (18%), pruritus (18%), and increased AST (15%). Most common grade ≥3 related AE was asymptomatic increased AST (10%). 24 pts have discontinued treatment: 3 due to treatment-related AEs (grade 3 pneumonitis, grade 3 colitis/diarrhea, asymptomatic grade 4 elevated AST and ALT), 16 due to progressive disease, 4 due to death unrelated to treatment (cardiac arrest, variceal bleed, progressive disease, probable HCC rupture), and 1 other (pt entered hospice care). 40 pts were evaluable for response at ≥16 weeks follow-up. Conclusions: No unexpected safety signals with durvalumab and tremelimumab were seen in this unresectable HCC population. Clinical activity observed predominantly in uninfected pts though interpretation limited by small subsets. Enrollment to the phase II portion of the study is ongoing. Clinical trial information: NCT02519348. [Table: see text]

AbstractAbsolute values of cortical porosity and trabecular density are used to estimate fracture risk, but these values are the net result of their growth‐related assembly and age‐related deterioration. Because bone loss affects both cortical and trabecular bone, we hypothesized that a surrogate measure of bone fragility should capture the age‐related deterioration of both traits, and should do so independently of their peak values. Accordingly, we developed a structural fragility score (SFS), which quantifies the increment in distal radial cortical porosity and decrement in trabecular density relative to their premenopausal mean values in 99 postmenopausal women with forearm fractures and 105 controls using HR‐pQCT. We expressed the results as odds ratios (ORs; 95% CI). Cortical porosity was associated with fractures in the presence of deteriorated trabecular density (OR 2.30; 95% CI, 1.30 to 4.05; p = 0.004), but not if trabecular deterioration was absent (OR 0.96; 95% CI, 0.50 to 1.86; p = 0.91). Likewise, trabecular density was associated with fractures in the presence of high cortical porosity (OR 3.35; 95% CI, 1.85 to 6.07; p < 0.0001), but not in its absence (OR 1.60; 95% CI, 0.78 to 3.28; p = 0.20). The SFS, which captures coexisting cortical and trabecular deterioration, was associated with fractures (OR 4.52; 95% CI, 2.17 to 9.45; p < 0.0001). BMD was associated with fracture before accounting for the SFS (OR 5.79; 95% CI, 1.24 to 27.1; p = 0.026), not after (OR 4.38; 95% CI, 0.48 to 39.9; p = 0.19). The SFS was associated with fracture before (OR 4.67; 95% CI, 2.21 to 9.88) and after (OR 3.94; 95% CI, 1.80 to 8.6) accounting for BMD (both ps < 0.0001). The disease of bone fragility is captured by cortical and trabecular deterioration: A measurement of coexisting cortical and trabecular deterioration is likely to identify women at risk for fracture more robustly than absolute values of cortical porosity, trabecular density, or BMD. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research

Abstract Introduction. VSV-IFNβ-NIS is an oncolytic vesicular stomatitis virus (VSV; Rhabdovirus family) with rapid replication kinetics and potent antitumor activity. VSV-IFNβ-NIS encodes the human interferon beta (IFNβ) gene as a STING agonist and the human sodium iodide symporter (NIS) as a reporter gene for tracking the pharmacokinetics (PK) of virus replication in infected tumors. VSV replicates selectively in cancer cells and has promising preclinical antitumor activity across a broad spectrum of cancer types. We report here the safety and correlative data from an FIH trial of intravenous (IV) administration of VSV-IFNβ-NIS in patients with stage IV or recurrent endometrial cancer (EC). Methods. There are two ongoing IV FIH trials using VSV-IFN-NIS, in patients with EC (NCT03120624) and one in patients with hematological malignancies (NCT03017820). In EC, it is a classical 3+3 phase I trial, starting at 5x109 TCID50 through 5x1011 TCID50, given as a single IV dose. The primary objective is safety and tolerability; secondary objectives include monitoring the PK of viral replication through SPECT/CT imaging with NIS gene, viremia, virus shedding, preliminary efficacy, changes in the immune profile of peripheral blood leukocytes, and immunohistochemistry for immune cell infiltrates in tumors. Results. Nine patients have received IV VSV-IFNβ-NIS to date; three with EC and six with hematologic malignancies. The highest dose administered to date is 1.7x1010 TCID50 and dose escalation is ongoing. No DLTs have been observed. Patients experienced the expected infusion related AEs including rigors, chills, nausea, fever, hypotension, and hot flashes. Multiple cytokines increased at 4h post infusion of virus, but most returned to baseline levels by 24h. Viremia was detectable in all patients at the end of infusion, and to varying levels at 30 mins, 1, 2, 4, 24, 48h or 72 hours post virus infusion. No persistent viremia was observed. No infectious virus was recovered in buccal swabs or urine and neutralizing anti-VSV antibodies were present by day 29. Extensive immune phenotyping for T cells, NK, MSDC, myeloid cells performed on peripheral blood cells collected at baseline and at day 3, 8, 15 and 29 post virus infusion showed a trend towards increased PD-1 expression on CD8+ cells. Early IHC data suggests an increase in CD3+ and CD8+ cells in tumor biopsies at day 29 and 3 months in patients with EC treated at the first dose level. Elispot assays for shared EC antigens are pending. Conclusions. IV administration of VSV-IFNβ-NIS up to doses of 1.7x1010 is safe and well tolerated. There is evidence of T cell activation with increased PD-1 expression in CD8+ T cells in the peripheral blood and increased in CD3+ and CD8+ cells in tumor biopsies. Updated results for the EC study will be reported. Citation Format: Jamie Bakkum-Gamez, Matthew S. Block, Nanda Packiriswamy, Bethany A. Brunton, Upreti Deepak, Jonathan M. Mitchell, Lukkana Suksanpaisan, Pamela Atherton, Amylou Dueck, Stephen J. Russell, Martha Q. Lacy, Kah-Whye Peng. First in human (FIH) dose escalation studies of intravenous administration of VSV-IFNβ-NIS (Voyager-V1™) in Stage IV or recurrent endometrial cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT072.

Abstract Introduction Voyager-V1TM is derived from VSV, a bullet-shaped negative sense RNA virus with very low human seroprevalence; it is engineered to selectively replicate in and kill human cancer cells. Voyager-V1 encodes the human IFNβ gene to boost antitumoral immune responses and the thyroidal sodium iodide symporter NIS gene to permit noninvasive imaging of virus spread. FIH studies are underway via both IV and IT routes. Here we report safety and preliminary correlative data from the FIH IT study. Methods and objectives This is a classical 3+3 phase 1 design, using escalating single IT viral doses from 3 x 106 to 3 x 109 TCID50 into one target lesion. The primary objective is safety and tolerability, monitored by committee. Other objectives include PK by RT-PCR for viral genomes, serum IFNβ levels, Tc-99m SPECT/CT imaging to monitor virus infection in injected lesions, peripheral blood immunophenotyping with 11-color flow cytometry for activation markers on T cells, T-regs, NK cells, and MDSCs, and serial biopsies to assess the tumor microenvironment (TME). IHC was performed on tumor biopsies for CD3, CD8, CD4, FoxP3, CD68, PD-1 and PDL-1 pre and post treatment in non-injected and injected lesions. CD45 staining is ongoing. Results Dose level 3 is ongoing (n=8+). No DLTs have been observed to date. Most patients were male (75%), white (100%), with ECOG PS1 (75%) and a median of &gt;6 lines of prior systemic therapy. AEs (in 63% patients) reported as related to study drug were mild-moderate, short-lived, and consisted of G1 fever, chills, hot flashes, nausea, vomiting, hyperhidrosis and G2 fatigue. Most patients had some mild AEs (pain, bruising, subclinical pneumothorax) related to biopsy and IT injection procedures and one had an SAE related to biopsy (G2 pneumothorax). There was no difference in incidence, intensity or duration of related AEs between dose levels so far. In patients analyzed to date, at the first three dose levels of 3 x 106, 1 x 107 and 3 x 107 TCID50 (n=7), viremia and serum IFNβ were below levels of detection after IT injection. There is evidence in all patients of an increase in PD-1 expression on CD4 and CD8 T cells, suggesting T cell activation post- single virus injection. One patient at dose level 2 had increased CD4 and CD8 T cells in the peripheral blood. TME analysis revealed increased infiltration of CD3 and CD8 cells in tumors of some patients. In addition, there are changes in numbers of FoxP3 and CD68 positive cells in the injected lesions compared to the pre-treatment and non-injected lesion. Two patients at dose level 3, one with an injected adrenal metastasis of colorectal cancer and another with a chest wall lesion from a head of pancreas primary, have positive SPECT/CTs on days 3-15 showing viral replication in tumor plus concomitant lymphocyte/neutrophil trafficking in the periphery. Conclusions IT injection of a single dose of the novel oncolytic virotherapy Voyager-V1 has proven safe at doses up to 3 x 107 TCID50. There was evidence of T cell activation with increased PD-1 expression in peripheral blood lymphocytes after a single IT injection. Tumor biopsies indicate increased lymphocyte infiltration. Two patients at the highest dose tested show signs of viral replication in the injected lesion plus evidence of systemic impact on leukocyte populations. Citation Format: Steven Powell, Manish R. Patel, Jaime R. Merchan, Timothy P. Cripe, James Strauss, Rosa M. Diaz, Nandakumar Packiriswamy, Bethany A. Brunton, Deepak Upreti, Rehan Khan, Lukkana Suksanpaisan, Rianna Vandergaast, Stephen J. Russell, Alice S. Bexon, Kah Whye Peng. Preliminary correlative and clinical data from a first-in-human (FIH) study of the intratumoral (IT) oncolytic virotherapy, Voyager-V1, in patients with solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT051.

Abstract Pancreatic ductal adenocarcinoma (PDAC) cell growth is dependent on altered biochemical and cellular activities that facilitate increased metabolic dependencies. We determined the role of mutationally activated KRAS, found in ~95% of PDAC, in supporting autophagy. Surprisingly, acute KRAS suppression, which blocks proliferation, was associated with increased rather than decreased autophagic flux. Similarly, KRAS transformation of immortalized human pancreatic epithelial cells showed decreased autophagic flux. Pharmacologic inhibition of ERK MAPK phenocopied the genetic silencing of KRAS and also increased autophagic flux. Addressing a mechanism for ERK suppression increased autophagy, we found increased AMPK activity, decreased mTOR activity, and increased expression of autophagic proteins. We speculated that increased autophagy may be a compensatory mechanism caused by the loss of KRAS- and ERK-dependent metabolic processes. To address this possibility, we performed RNA-seq analyses to monitor gene expression changes in response to ERK inhibition. We observed increased transcription of genes responsible for the metabolic processes of autophagy and β-oxidation, with concurrent decreased transcription of glycolysis and mitochondrial-associated genes. These changes were validated in metabolomic analyses following either genetic silencing of KRAS or ERK inhibition. Thus, the loss of ERK-driven metabolic processes may induce compensatory mechanisms to increase autophagy. We then addressed whether ERK inhibition increased PDAC dependence on autophagy. Supporting this possibility, we found that cotreatment with the autophagy inhibitor chloroquine synergistically enhanced ERK inhibitor mediated antiproliferative activity. Similarly, genetic or pharmacologic inhibition of specific regulators of autophagy also enhanced ERK inhibitor activity. We conclude that concurrent suppression of multiple metabolic processes, to block compensatory rebound activities, will be needed for effective PDAC treatment. Citation Format: Kirsten Bryant, Sen Peng, Andrey Tikunov, Mariaelena Pierobon, Venugopal Gunda, Garima Tomar, Pankaj Singh, Emanuel Petricoin, Jeffrey Macdonald, Nhan Tran, Alec Kimmelman, Channing Der. Inhibition of ERK MAPK signaling increases pancreatic cancer dependency on autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5492.

Abstract Glioblastoma Multiforme (GBM) is the most common malignant brain tumor in adults. Most GBM patients succumb to the disease less than one-year post diagnosis due to the highly invasive nature of the tumor, which prevents complete surgical resection and gives rise to tumor recurrence. The invasive phenotype also confers radio and chemoresistant properties to the tumor cells; therefore, there is a need to develop new therapeutics that target drivers of GBM invasion. Amplification of EGFR is observed in over 50% of GBM tumors, of which half concurrently overexpress the variant EGFRvIII, and expression of both receptors confers a worse prognosis. EGFR and EGFRvIII cooperate to promote tumor progression and invasion, in part, through activation of the Stat-signaling pathway. Here we report that EGFRvIII activates Stat5 and GBM invasion, in part, by inducing the expression of a previously established mediator of glioma cell invasion and survival, fibroblast growth factor-inducible 14 (Fn14). EGFRvIII-mediated induction of Fn14 expression is dependent upon Stat5 and requires activation of Src, whereas EGFR regulation of Fn14 is dependent upon MEK/ERK-Stat3 activation. Notably, treatment of EGFRvIII expressing GBM cells with the FDA approved Stat5 inhibitor pimozide blocked Stat5 phosphorylation, Fn14 expression, and cell migration. Since EGFR inhibitors display limited therapeutic efficacy in GBM patients, we hypothesize that the EGFRvIII-Stat5-Fn14 signaling pathway represents a node of vulnerability in the invasive GB cell population and that targeting critical effectors in this pathway will limit GBM tumor dispersion, mitigate therapeutic resistance, and increase survival. Citation Format: Alison Roos, Harshil D. Dhruv, Sen Peng, Landon J. Inge, Serdar Tuncali, Michael Pineda, Nghia Millard, Jeffrey A. Winkles, Joseph C. Loftus, Nhan L. Tran. EGFRvIII-Stat5 signaling enhances glioblastoma cell invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3462.