Citations

Abstract Abstract 750 Background: DKK1 is a negative regulator of the Wnt signaling pathway in bone that is overexpressed in a subset of newly-diagnosed MM patients with osteolytic lesions as well as in refractory and relapsed patients. Expression also correlates with the number of osteolytic lesions in untreated MM patients. BHQ880 is a novel anti-DKK1 human monoclonal antibody. Alleviation of DKK1 inhibition by BHQ880 results in activation of the Wnt signaling pathway, leading to increased bone mass mediated via upregulation of osteoblasts in mice and monkeys. In murine models of MM bone disease; this anabolic activity of BHQ880 increased trabecular and cortical bone density. Lytic bone disease in MM is caused by osteoclast activation and osteoblast inhibition. Current approved therapies for the treatment of MM bone disease are focused on osteoclast inhibition (e.g., bisphosphonates) and BHQ880 therapy may be able to reverse the effects of DKK1-induced osteoblast inhibition. Therefore, dual therapy with zoledronic acid to decrease bone resorption and BHQ880 to increase new bone formation may provide an effective treatment strategy for MM bone disease. Methods: In the phase I portion of this phase I/II study, patients with relapsed or refractory MM with prior skeletal-related event (SRE) were treated with BHQ880 as an IV infusion Q28 days. Patients also received Zol (4 mg) and approved MM Tx (bortezomib not allowed). Bone markers and total DKK1 levels along with bone mineral density are being measured. Full PK profiles were collected during the first and second cycle, after which predose (trough) samples were collected to assess accumulation. Results: Ten pts (6:M, 4:F), median age: 66.5 yrs (range 41- 70), performance status-0(5 pts), 1(4 pts), 2 (1 pts) have been enrolled in the following dose levels (mg/kg) 3 (2 pts), 10 (starting dose level -4 pts), 20 (4 pts) and have been on treatment for 1 day to 5 28-day cycles. No BHQ880-related AE's have been observed to date. Bone mineral density (BMD) data from the first two patients treated at 10 mg show the following: a.) Pt 1 (hip +5.8%, spine N/A due to surgery, wrist -1.8%); b.) Pt 2 (hip -0.2%, spine +6.1%, wrist not done). The biomarker data from these patients show: a.) Pt 1 shows a maximal +98% change over baseline in PINP at day 15 post-treatment, while osteocalcin (OC) changes +17% at day 15, reaching a +56% change over baseline at cycle 4 day 1; uNTx/Cr changes – 43 % at cycle 2 day 15. b) Partial data from Pt 2 suggests a -44 % change in PINP and –73 % change in OC and a +73% change in uNTx/Cr. Baseline total DKK1 levels on 3 patients ranged from 8.8 to 21.5 ng/mL. Preliminary PK analysis is available in 1 out of 3 patients treated at 10mg/kg. The Cmax achieved after the first infusion was 165 ug/mL and 201 ug/mL after the second infusion. Calculated t1/2 was 188 hours after the first infusion and 254 hours after the second infusion. Regarding overall exposure, AUC0-672 hours after first infusion was 36081 hr*ng/mL and 48533 hr*ng/mL after the second infusion. Conclusion: BHQ880 given IV Q28 days appears to be well tolerated in combination with Zol and chosen MM Tx. Once safety of 40 mg/kg BHQ880 or the MTD dose has been determined, pts will be enrolled in the phase II portion to assess activity on a SRE endpoint. Updated safety, efficacy, bone density and biomarker data will be presented on all patients at the upcoming ASH meeting. Disclosures: Padmanabhan: Genentech: Consultancy, Honoraria; GSK: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau. Off Label Use: BHQ880, a novel osteoblast activating, anti-DKK1 antibody. Dzik-Jurasz:Novartis: Employment, Equity Ownership. Gangolli:Novartis: Employment, Equity Ownership. Ettenberg:Novartis: Employment, Equity Ownership. Miner:Novartis: Employment, Equity Ownership. Bilic:Novartis: Employment, Equity Ownership. Whyte:Novartis: Employment, Equity Ownership. Mehdi:Novartis: Employment, Equity Ownership. Chiang:Novartis: Employment, Equity Ownership. Rae:Novartis: Employment, Equity Ownership. Shah:Novartis: Consultancy, Speakers Bureau; Celgene: Consultancy, Speakers Bureau; Millenium: Research Funding, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Elan: Consultancy. Giles:Novartis: Consultancy, Research Funding; BMS: Research Funding; Merck: Research Funding; Clavis: Research Funding. Stewart:Novartis: Consultancy; Amgen: Consultancy; Millenium: Consultancy, Research Funding; Proteolix: Consultancy; Celgene: Honoraria.

Abstract Background The dearth of relevant tumor models reflecting the heterogeneity of human central nervous system metastasis (CM) has hindered development of novel therapies. Methods We established 39 CM patient-derived xenograft (PDX) models representing the histological spectrum, and performed phenotypic and multi-omic characterization of PDXs and their original patient tumors. PDX clonal evolution was also reconstructed using allele-specific copy number and somatic variants. Results PDXs retained their metastatic potential, with flank-implanted PDXs forming spontaneous metastases in multiple organs, including brain, and CM subsequent to intracardiac injection. PDXs also retained the histological and molecular profiles of the original patient tumors, including retention of genomic aberrations and signaling pathways. Novel modes of clonal evolution involving rapid expansion by a minor clone were identified in 2 PDXs, including CM13, which was highly aggressive in vivo forming multiple spontaneous metastases, including to brain. These PDXs had little molecular resemblance to the patient donor tumor, including reversion to a copy number neutral genome, no shared nonsynonymous mutations, and no correlation by gene expression. Conclusions We generated a diverse and novel repertoire of PDXs that provides a new set of tools to enhance our knowledge of CM biology and improve preclinical testing. Furthermore, our study suggests that minor clone succession may confer tumor aggressiveness and potentiate brain metastasis.

Participation refers to a state of health in which a person is able to fully engage in roles and life situations. Adults living with and beyond cancer often report persistent participation restrictions that affect their productivity and quality of life. The American Occupational Therapy Foundation convened a group of scientists from seven different disciplines in a Planning Grant Collective (PGC) to stimulate research to identify scalable ways to preserve and optimize participation among cancer survivors. Participants identified challenges, prioritized solutions, and generated novel research questions that move beyond symptom and impairment mitigation as outcomes to identify interventions that improve participation in roles and life situations. This article summarizes the PGC discussion and recommendations regarding three challenges: (a) the dynamic and multi-faceted nature of participation, (b) a need to integrate the concept of participation within the culture of oncology, and (c) identification of priority areas in which new lines of research regarding participation would be most impactful.

Abstract Despite recent advances in cancer therapy, options for central nervous system metastasis (CM) remain limited and patient outcomes are dismal. The lack of tumor models that reflect the heterogeneity and complexity of human CM tumors is a barrier to understanding the underlying biology and to developing novel therapies. Here, we report the development and characterization of 39 patient derived xenograft (PDX) models of CM tumors with histological subtypes representing the disease spectrum. The PDX models successfully grew both in the flank and brains of mice, and retained their histology regardless of the site of implantation. Brain metastasis also formed in 5/12 models after intra-cardiac injection. Multi-omic analysis of the PDX tumor and the patient-matched CM tumor showed that PDXs largely retained the molecular profiles of the tumor from which they were derived, including the retention of aberrations in key driver genes and signaling pathways. PDXs differed primarily from the ungrafted patient tumors by a downregulation in immunity-related pathways, which was expected due to the use of an immuno-compromised host, arguing for the validity of using the flank as a site of implantation. Integrated analysis of mutations and gene expression changes in CM revealed an upregulation of neuronal signaling and DNA damage response, and downregulation of calcium signaling and inflammation. We also assessed the clonal evolution of the PDX from the original patient CM by tracing variant allele frequencies in copy number neutral regions. We found that the PDX tumors were heterogeneous and comprised of multiple tumor clones that were either unique or in common with the original tumor, and displayed evidence of clonal expansion. Two PDXs that underwent phylogeny assessment showed evidence of minor clone expansion. One such PDX was a tumor from a Her2+ breast cancer (CM13), which largely did not molecularly resemble its matched patient tumor but was confirmed to have some shared expressed variants. The PDX was nearly copy number neutral, which included loss of the Her2 amplicon, and had few mutations compared with its parent tumor. Most noteworthy, is that CM13 displayed unique molecular patterns, aggressive growth and was highly metastatic in vivo. From the flank, it led to multiple metastases, including micrometastasis in the brain. This suggests that minor clone takeover may confer tumor aggressiveness and potentiate brain metastasis. The large and diverse repertoire of PDXs developed and characterized in this study provides a new set of tools that will help deepen our understanding of CM and improve preclinical testing for CM therapies. Our data also show that expansion of minor clones could confer aggressive tumor behavior and may be important in tumor evolution in PDX models and human cancers. Citation Format: Ben Yi Tew, Christophe Legendre, Tim Triche, Gerald C. Gooden, Kyle N. Johnson, Rae Anne Martinez, Emanuel F. Petricoin, Mariaelena Pierobon, Joyce O'Shaughnessy, Cindy Osborne, Mark A. Schroeder, Daniel J. Ma, Mark Bernstein, Jann N. Sarkaria, Steven A. Toms, Bodour Salhia. Development and characterization of patient derived xenografts from central nervous system metastasis reveal minor clone expansion linked with aggressive tumor behavior [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 991.

The effects of melatonin on ionic conductances in a cultured mouse lens epithelial cell line (α-TN4) and in cultured human trabecular meshwork (HTM) cells were measured using the amphotericin perforated patch whole cell voltage-clamp technique. Melatonin stimulated a voltage-dependent Na+-selective current in lens epithelial cells and trabecular meshwork cells. The effects of melatonin were observed at 50 pM and were maximal at 100 μM. Melatonin enhanced activation and inactivation kinetics, but no change was observed in the voltage dependence of activation. The results are consistent with an increase in the total number of ion channels available for activation by membrane depolarization. Melatonin was also found to stimulate a K+-selective current at high doses (1 mM). Melatonin did not affect the inwardly rectifying K+ current or the delayed rectifier type K+ current that has been described in cultured mouse lens epithelial cells. The results show that melatonin specifically stimulated the TTX-insensitive voltage-dependent Na+ current by an apparently novel mechanism.

Carbon monoxide (CO) has been postulated to be a messenger in the gastrointestinal tract. The aims of this study were to determine the distribution of heme oxygenase (HO), the source for endogenous CO in the canine jejunum, and to determine the effects of CO on jejunal circular smooth muscle cells. HO-2 isoform was present in a population of myenteric and submucosal neuronal cell bodies, in nerve fibers innervating the muscle layers, and in smooth muscle cells. HO-1 isozyme was not detected in the canine jejunum. Exogenous CO increased whole cell current by 285 ± 86%, hyperpolarized the membrane potential by 8.5 ± 2.9 mV, and increased guanosine 3′,5′-cyclic monophosphate (cGMP) levels in smooth muscle cells. 8-Bromo- cGMP also increased the whole cell current. The data suggest that endogenous activity of HO-2 may be a source of CO in the canine jejunum and that exogenously applied CO can modulate intestinal smooth muscle electrical activity. It is therefore reasonable to suggest a role for endogenously produced CO as a messenger in the canine jejunum.

Thirty-eight cells, freshly isolated from circular smooth muscle of normal human jejunum obtained from nine patients undergoing weight-reduction surgery for morbid obesity, were patch clamped using a perforated patch-clamp technique. A highly potassium-selective voltage-dependent outward current was present in all cells. The current was carried by a 220-pS channel that activated near -75 mV and reached unit open probability at about +10 mV. Blockade of the current by quinidine (50 microM) and tetraethylammonium (25 mM) was accompanied by membrane depolarization to 0 to -3 mV, suggesting that this current was the major determinant of the membrane potential. Flufenamic and mefenamic acid at concentrations comparable with blood levels reached when these drugs are used in clinical therapy as nonsteroidal anti-inflammatory agents, activated the potassium outward current and hyperpolarized the membrane potential. The shift in the membrane potential for 250 microM flufenamic acid was -36 +/- 24 (SD) mV. Activation was rapid (seconds) and reversible. It was concluded that normal human jejunal circular smooth muscle cells have a highly potassium-selective outward current, which is the major determinant of the membrane potential and which is activated by fenamates.

Carbon monoxide (CO) is a low molecular weight oxide produced endogenously from fatty acids and heme protein. A physiological role for CO has been suggested for vascular smooth muscle, hemostasis, and olfactory neurons, but direct evidence is lacking. Heme oxygenase, which catalyzes the formation of CO from heme proteins, is present in small intestinal smooth muscle. The effect of 1% CO on whole cell currents in normal human jejunal circular muscle cells was studied with the use of a perforated patch-clamp technique. A 1% CO-containing Krebs solution caused an initial and transient increase in whole cell current in 20 of 22 cells tested (175 +/- 40%, mean +/- SE) and a transient hyperpolarization (15.6 +/- 3.6 mV, mean +/- SE) of the membrane potential. During prolonged recordings, 1% CO evoked ongoing cyclic increases and decreases in the whole cell current. Each current increase was accompanied by a sharp membrane hyperpolarization. These data suggest that CO may modulate whole cell potassium current and membrane potential.

Abstract BACKGROUND: Unique genes and pathways were identified for prognosis on tamoxifen (T, 5 yrs) and prediction on CAF-T vs T in S8814 using whole transcriptome RNA-Seq from archival FFPE tissue. (Albain, et al; Cherbavaz, et al; SABCS 2015) Discovery was robust for early DFS events but sparse for late. The aims of this new analysis were to 1) utilize a new endpoint BCSE for gene discovery of late events, prognosis and prediction and 2) add intronic counts to the previous exonic results to define whole genes impacting on late BCSE. METHODS: Charts of patients (pts) on CAF-T (212) vs T (142) were reviewed to define the BCSE endpoint (local/regional, contralateral, distant). Deaths without BC were treated as competing risks. BCSE models (including metagenes) of late prognosis and prediction used cumulative incidence functions. Consolidated intronic regions counts within genes were added to exonic regions counts. Using these “whole gene” (WG) counts, association of gene expression with time to BCSE was assessed by Cox regression. A multiple WG score (MWGS) for BCSE prognosis beyond 5 yrs (to 12.5 yrs) was constructed and evaluated for 1-3 and 4+ node (N) groups. False discovery rate was controlled at 10%. RESULTS: More exons and WG were discovered for prognosis on T alone over 12.5 yrs with the BCSE endpoint than DFS. For prognosis of late BCSE after 5 yrs, more genes were discovered using WG (n=111) than by exons (n=9). There were significantly fewer genes for late BCSE on CAF-T (8, WG; 0, exons). The functions of WG prognostic for late BCSE were: cell cycle/proliferation-26 genes, chromosome segregation/mitotic spindle-22, DNA repair/maintenance-10, transcriptional/translational control-5, cell adhesion/migration-4, immune-3, diverse/unknown-32 and growth factor/hormone receptor signaling-9 (this group was only found by WGs, not exons). Of these 111 WG, a MWGS prognostic for late BCSE on T used 57 previously discovered genes pre-specified for this analysis. Probability of BCSE beyond 5 yrs for low vs high MWGS was 8% vs 21% in N1-3+ and 17% vs 42% in N4+. Late prognosis on T differed by low vs high risk defined in a metagene model: cumulative BCSE at year 10 was 0% vs 47% (low vs high risk, p=0.001). Prediction of 10-yr incidence of BCSE varied by risk level by treatment in a metagene model: low risk- CAF-T=47%, T=0% (p=0.045); high risk- CAF-T=35%, T=45% (p=0.027). CONCLUSIONS: Gene discovery for prognosis of late BCSE is enhanced with a novel WG transcriptome expression approach. Use of chemotherapy (CT) before T significantly attenuated gene discovery, so that molecular tools for decisions on extending endocrine therapy (ET) may not be reliable in a setting of prior CT. Some pts on ET for 5 yrs may not require either longer ET or CT, given a N+ cohort was defined with no BCSE observed over 12.5 yrs. For prediction of CT benefit, CAF-T appeared to be inferior to T in a low risk metagene model for BCSE. In sum, these results add more evidence that ET alone may be sufficient (perhaps better) in select N+ settings. Validation in SWOG S1007 (RxPONDER) is planned. SUPPORT: NCI CA180888, 180819, 180821, 180820, 180863; in part, Genomic Health, Inc. Citation Format: Albain KS, Crager MR, Barlow WE, Baehner FL, Bergamaschi A, Rae JM, Ravdin PM, Tripathy D, Gralow JR, Livingston RB, Osborne CK, Ingle JN, Pritchard KI, Davidson NE, Carey LA, Cherbavaz DB, Sing AP, Shak S, Hortobagyi GN, Hayes DF. Discovery of molecular predictors of late breast cancer specific events (BCSE) in ER+, node+ breast cancer – new transcriptome expression whole gene analysis of the phase III adjuvant trial SWOG S8814 [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD7-07.