Nancy Chan

First-in-human Clinical Trial of Oral ONC201 in Patients with Refractory Solid Tumors

Purpose: ONC201 is a small-molecule selective antagonist of the G protein–coupled receptor DRD2 that is the founding member of the imipridone class of compounds. A first-in-human phase I study of ONC201 was conducted to determine its recommended phase II dose (RP2D). Experimental Design: This open-label study treated 10 patients during dose escalation with histologically confirmed advanced solid tumors. Patients received ONC201 orally once every 3 weeks, defined as one cycle, at doses from 125 to 625 mg using an accelerated titration design. An additional 18 patients were treated at the RP2D in an expansion phase to collect additional safety, pharmacokinetic, and pharmacodynamic information. Results: No grade >1 drug-related adverse events occurred, and the RP2D was defined as 625 mg. Pharmacokinetic analysis revealed a Cmax of 1.5 to 7.5 μg/mL (∼3.9–19.4 μmol/L), mean half-life of 11.3 hours, and mean AUC of 37.7 h·μg/L. Pharmacodynamic assays demonstrated induction of caspase-cleaved keratin 18 and prolactin as serum biomarkers of apoptosis and DRD2 antagonism, respectively. No objective responses by RECIST were achieved; however, radiographic regression of several individual metastatic lesions was observed along with prolonged stable disease (>9 cycles) in prostate and endometrial cancer patients. Conclusions: ONC201 is a selective DRD2 antagonist that is well tolerated, achieves micromolar plasma concentrations, and is biologically active in advanced cancer patients when orally administered at 625 mg every 3 weeks. Clin Cancer Res; 23(15); 4163–9. ©2017 AACR.

Immune Activation and Benefit From Avelumab in EBV-Positive Gastric Cancer

Response to immune checkpoint therapy can be associated with a high mutation burden, but other mechanisms are also likely to be important. We identified a patient with metastatic gastric cancer with meaningful clinical benefit from treatment with the anti-programmed death-ligand 1 (PD-L1) antibody avelumab. This tumor showed no evidence of high mutation burden or mismatch repair defect but was strongly positive for presence of Epstein-Barr virus (EBV) encoded RNA. Analysis of The Cancer Genome Atlas gastric cancer data (25 EBV+, 80 microsatellite-instable [MSI], 310 microsatellite-stable [MSS]) showed that EBV-positive tumors were MSS. Two-sided Wilcoxon rank-sum tests showed that: 1) EBV-positive tumors had low mutation burden (median = 2.07 vs 3.13 in log10 scale, P < 10-12) but stronger evidence of immune infiltration (median ImmuneScore 2212 vs 1295, P < 10-4; log2 fold-change of CD8A = 1.85, P < 10-6) compared with MSI tumors, and 2) EBV-positive tumors had higher expression of immune checkpoint pathway (PD-1, CTLA-4 pathway) genes in RNA-seq data (log2 fold-changes: PD-1 = 1.85, PD-L1 = 1.93, PD-L2 = 1.50, CTLA-4 = 1.31, CD80 = 0.89, CD86 = 1.31, P < 10-4 each), and higher lymphocytic infiltration by histology (median tumor-infiltrating lymphocyte score = 3 vs 2, P < .001) compared with MSS tumors. These data suggest that EBV-positive low-mutation burden gastric cancers are a subset of MSS gastric cancers that may respond to immune checkpoint therapy.

Influencing the Tumor Microenvironment: A Phase II Study of Copper Depletion Using Tetrathiomolybdate in Patients with Breast Cancer at High Risk for Recurrence and in Preclinical Models of Lung Metastases

Purpose: Bone marrow–derived progenitor cells, including VEGFR2+ endothelial progenitor cells (EPCs) and copper-dependent pathways, model the tumor microenvironment. We hypothesized that copper depletion using tetrathiomolybdate would reduce EPCs in high risk for patients with breast cancer who have relapsed. We investigated the effect of tetrathiomolybdate on the tumor microenvironment in preclinical models. Experimental Design: Patients with stage II triple-negative breast cancer (TNBC), stage III and stage IV without any evidence of disease (NED), received oral tetrathiomolybdate to maintain ceruloplasmin (Cp) between 8 and 17 mg/dL for 2 years or until relapse. Endpoints were effect on EPCs and other biomarkers, safety, event-free (EFS), and overall survival (OS). For laboratory studies, MDA-LM2-luciferase cells were implanted into CB17-SCID mice and treated with tetrathiomolybdate or water. Tumor progression was quantified by bioluminescence imaging (BLI), copper depletion status by Cp oxidase levels, lysyl oxidase (LOX) activity by ELISA, and collagen deposition. Results: Seventy-five patients enrolled; 51 patients completed 2 years (1,396 cycles). Most common grade 3/4 toxicity was neutropenia (3.7%). Lower Cp levels correlated with reduced EPCs (P = 0.002) and LOXL-2 (P < 0.001). Two-year EFS for patients with stage II–III and stage IV NED was 91% and 67%, respectively. For patients with TNBC, EFS was 90% (adjuvant patients) and 50% (stage IV NED patients) at a median follow-up of 6.3 years, respectively. In preclinical models, tetrathiomolybdate decreased metastases to lungs (P = 0.04), LOX activity (P = 0.03), and collagen crosslinking (P = 0.012). Conclusions: Tetrathiomolybdate is safe, well tolerated, and affects copper-dependent components of the tumor microenvironment. Biomarker-driven clinical trials in high risk for patients with recurrent breast cancer are warranted. Clin Cancer Res; 23(3); 666–76. ©2016 AACR.

The Antibody-Drug Conjugate Glembatumumab Vedotin (CDX-011) and Its Use in Treatment of Breast Cancer

Breast cancer is the most common malignancy in women and significant cause of cancer-related deaths, second only to lung cancer. Amongst different subtypes of breast cancers, triple-negative breast cancer (TNBC) is especially challenging due to fewer treatment options and more aggressive clinical course. Therefore, the development of molecularly targeted therapies for TNBC is crucial. Glycoprotein nonmetastatic B (GPNMB) is overexpressed in many malignancies, including TNBC, and is associated with poor prognosis. The antibody—drug conjugate (ADC) glembatumumab vedotin (CDX-011) selectively target GPNMB, and is being investigated for its efficacy in metastatic breast cancer. This chapter reviews the mechanisms of action, preclinical, and phase I/II results of glembatumumab vedotin, and ongoing studies of its role in the treatment of breast cancer.

Inference of Germline Mutational Status and Evaluation of Loss of Heterozygosity in High-Depth, Tumor-Only Sequencing Data

PURPOSE Inherited germline defects are implicated in up to 10% of human tumors, with particularly well-known roles in breast and ovarian cancers that harbor BRCA1/2-mutated genes. There is also increasing evidence for the role of germline alterations in other malignancies such as colon and pancreatic cancers. Mutations in familial cancer genes can be detected by high throughput sequencing (HTS), when applied to formalin-fixed paraffin-embedded (FFPE) tumor specimens. However, due to often lack of patient-matched control normal DNA and/or low tumor purity, there is limited ability to determine the genomic status of these alterations (germline versus somatic) and to assess the presence of loss of heterozygosity (LOH). These analyses, especially when applied to genes such as BRCA1/2, can have significant clinical implications for patient care. METHODS LOHGIC (LOH-Germline Inference Calculator) is a statistical model selection method to determine somatic-versus-germline status and predict LOH for mutations identified via clinical grade, high-depth, hybrid-capture tumor-only sequencing. LOHGIC incorporates statistical uncertainties inherent to HTS as well as specimen biases in tumor purity estimates, which we use to assess BRCA1/2 mutations in 1,636 specimens sequenced at Rutgers Cancer Institute of New Jersey. RESULTS Evaluation of LOHGIC with available germline sequencing from BRCA1/2 testing, demonstrates 93% accuracy, 100% precision, and 96% recall. This analysis highlights a differential tumor spectrum associated with BRCA1/2 mutations. CONCLUSION LOHGIC can assess LOH status for both germline and somatic mutations. It also can be applied to any gene with candidate, inherited mutations. This approach demonstrates the clinical utility of targeted sequencing in both identifying patients with potential germline alterations in tumor suppressor genes as well as estimating LOH occurrence in cancer cells, which may confer therapeutic relevance.

Abstract P4-22-21: NCI9782: A phase 1 study of talazoparib in combination with carboplatin and paclitaxel in patients with advanced solid tumors

Background: Poly(ADP-ribose) polymerase (PARP) enzymes are involved in DNA repair and activated by DNA strand breaks. DNA damage from carboplatin is associated with activation of PARP. Preclinical data indicate that PARP inhibition potentiates the anti-tumor effect of platinum chemotherapy. Talazoparib (T) is an oral, selective PARP inhibitor with a single agent maximum tolerated dose (MTD) of 1mg orally qd. Primary dose-limiting toxicity (DLT) was thrombocytopenia. This phase I study combines T with the commonly used chemotherapy regimen of carboplatin (C) and paclitaxel (P). Methods: Two dosing schedules are being investigated. In both schedules, C is administered on day 1 and P on days 1, 8, and 15 of a 21-day cycle. T (100-1000mcg) is dosed once daily for days 1-7 (schedule A) or days 1-3 (schedule B) starting on day 1. A 3+3 design is used for dose escalation. Key eligibility criteria include age 318 with a measurable or evaluable solid incurable malignancy. Patients (pts) must have tumor type that is expected to respond to C + P or have BRCA germline or somatic mutation. Stable, treated brain metastases are allowed. No prior C for metastatic disease is allowed. Pts must have platelets>150 and no need for anticoagulation. After 4-6 cycles of combination therapy, pts may continue the combination, change to C and intermittent T without P or change to T alone with continuous daily dosing. Each schedule will have a 6 subject dose expansion at the MTD. The starting dose level for schedule B will be the MTD from schedule A. Results: Schedule A cohort results are reported: 11 pts (median age 59 [range 39-68]; 8 female; 3 male) have been enrolled. Pts had breast (6), ovarian (2), pancreatic (1), and SCC of oropharynx (1) and concurrent ovarian and pancreatic (1). Five pts are BRCA2+ and 3 pts are BRCA1+. Dose level 3 on schedule A (T 350mcg with C AUC 6 and P 80mg/m2) exceeded the MTD with 2 of 3 pts experiencing hematologic dose limiting toxicities (DLTs) including 1 pt with grade (gr) 3 neutropenic fever and gr 4 thrombocytopenia and another pt with grade 3/4 neutropenia lasting > 7 days. Most common AEs include neutropenia (grade 3-4: 7), anemia (grade 3-4: 3), and thrombocytopenia (grade 3-4: 4). Results from expansion of dose level 2 (T 250mcg with C AUC 6 and T 80mg/m2) will be presented. The 11 pts were on study a median of 9 weeks (range 9-36+). Four pts have discontinued study therapy: 1 due to need for anticoagulation for PE, 1 for prolonged cytopenias, and 2 for disease progression. Of the 8 pts with measurable disease evaluated for response to date, 4 had SD, 1 had a cPR, 1 had radiographic CR, and 2 with PD. A pt with BRCA 1+ triple negative breast cancer has maintained a prolonged PR (36+ weeks) even after dose reductions to T 100mcg with C AUC 3. One pt with ovarian cancer (BRCA WT) has radiographic CR (CA 125 remains mildly elevated) after 15+ weeks of therapy. Conclusion: PARP inhibition with talazoparib days 1-7 in combination with carboplatin and paclitaxel leads to DLT of myelosuppression. However, clinical responses are seen even with lower dose combinations. Citation Format: Turk A, Chan N, Leal T, O9Regan R, Tevaarwerk A, Rice L, Campbell T, Barroilhet L, Mehnert J, Eickhoff J, Kolesar J, Liu G, Wisinski K. NCI9782: A phase 1 study of talazoparib in combination with carboplatin and paclitaxel in patients with advanced solid tumors [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 P4-22-21.

Abstract C137: First-in-human dose escalation study of oral ONC201 in advanced solid tumors

Background: ONC201 is an orally active first-in-class small molecule with strong antitumor activity in preclinical models of advanced cancers. In cancer cell lines and patient samples ONC201 induces activation of the integrated stress response (Ishizawa et al ASH, 2014) resulting in upregulation of ATF4 and CHOP which in turn regulates several proapoptotic genes namely DR5. ONC201 also causes late-stage inactivation of Akt and ERK, which also results in downstream activation of the apoptotic TRAIL pathway as part of innate immune surveillance (Allen J et al, Sci Trans Med, 2013). Activity of ONC201 is independent of p53 status and mutation agnostic. ONC201 is well tolerated at efficacious doses in animal models, crosses the blood brain barrier, is particularly effective in refractory tumors, depletes cancer stem cells (Ishizawa et al, ASH 2014; Prabhu et al, Blood 2014; Zhao et al, ASCO 2014), and is effective with infrequent dosing preclinically. Based on the compelling efficacy and safety profile of ONC201 as well as the engagement of signaling pathways critical for many cancers, the clinical introduction ONC201 in advanced cancer patients is warranted. Methods: The first-in-human study of ONC201 (NCT02250781) began in January 2015 as an open-label single-site phase I trial enrolling adult patients with refractory advanced solid tumors and glioblastoma (GBM). Patients with symptomatic brain metastases or prior bevacizumab for treatment of GBM are excluded. The primary endpoint is determination of the recommended phase II dose (RP2D) of single agent ONC201 given orally once every 3 weeks (1 cycle). Secondary endpoints include assessment of pharmacodynamics using select biomarkers for ONC201 (Allen et al, 2015), pharmacokinetics, toxicity, and efficacy. The study employs an accelerated, single patient per cohort, dose escalation design with expansion to a standard 3+3 design if a subject has grade > / = grade 2 toxicity or dose limiting toxicity within cycle 1. The maximum tolerated dose is the highest dose level in which 6 patients have been treated with Results: Single patient dose escalation was completed in cohorts 1 to 4 and 6 patients completed at least 3 weeks of level 5 without any > / = grade 2 drug related toxicity. At DL 6, Mean T1/2 = 7.91hours (7.01-9.42); Mean Cmax = 8.58 ug/mL (3.95 - 19.15) Mean AUC(0-24) = 28057 (15293 - 50597) hr-ng/mL. Ongoing radiographic stable disease is noted in a patient with metastatic castrate resistant prostate cancer. Conclusions: The RP2D of ONC201 is 625mg on a once every 3 week schedule. Evaluation of PD markers of response and enrollment to a dose expansion safety cohort are ongoing. Citation Format: Mark N. Stein, Rebecca Moss, Tina Mayer, Ann W. Silk, Nancy Chan, Ling Zheng, Yasmeen Beckett, Noelle Tenpenny, Edward Bentlyewski, Robert DiPaola, Rohinton Tarapore, Joshua Allen, Janice Mehnert. First-in-human dose escalation study of oral ONC201 in advanced solid tumors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C137.

Abstract CT309: Influencing the tumor microenvironment: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with breast cancer (BC) at high risk for recurrence

Background: Bone marrow derived endothelial progenitor cells (EPCs) and copper-dependent angiogenic pathways are critical to the metastatic process. Copper depletion (CD) therapy inhibits tumor metastases in preclinical models. We hypothesized that TM-associated CD would reduce EPCs in pts at high risk for BC recurrence, and we explored the relationship between CD and its effects on the tumor microenvironment in pre-clinical models. Methods: In this single arm, phase II study, BC pts at high risk for recurrence, defined as node positive triple negative (TN), stage 3 and 4 with no evidence of disease (NED) were enrolled on a trial of CD with TM. We CD’d to maintain ceruloplasmin (Cp) between 5-17 mg/dl for 2 years or until relapse. The primary endpoint was change in EPCs measured before and during treatment with TM. Secondary endpoints included tolerability, safety, and efficacy of CD. Laboratory studies: MDA-LM2-luciferase cells were implanted into CB17-SCID mice gavaged with water or TM. The tumors were quantified by bioluminescence images (BLI). We measured Cp oxidase to determine copper status. Western blots were used to assess LOX activity, and IHC was used to quantify collagen cross-linking and CD11b+ macrophage infiltration. Results: We enrolled 43 pts. Treatment duration was 24 cycles (each cycle is 28 days) for the primary study. A total of 752 cycles were completed in 2 years. The mean age was 49 (range 29-66). Mean Cp level decreased from 29 at baseline to 16 (p Citation Format: Nancy Chan, Naomi Kornhauser, Maureen Ward, Amy Willis, Tessa Cigler, Ellen Chuang, Anne Moore, Diana Donovan, Sarah E. Schneider, Christina Lam, David J. Warren, Anna Rubinchik, Sandra Hurtado Rua, Sharrell Lee, Maureen Lane, Vivek Mittal, Linda Vahdat. Influencing the tumor microenvironment: A phase II study of copper-depletion using tetrathiomolybdate (TM) in patients (pts) with breast cancer (BC) at high risk for recurrence. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT309. doi:10.1158/1538-7445.AM2014-CT309

Abstract 2888: Computational analysis of microtubule dynamics for personalized cancer therapy.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Metastatic prostate cancer (PC) is treated primarily by means of taxane-based chemotherapy with one of the clinically used taxanes: paclitaxel, docetaxel and cabazitaxel. At the cellular level, the taxanes bind microtubules (MTs), inhibit MT dynamics and alter the spatial organization of the MT network. Thereby the taxanes inhibit the intracellular trafficking of transcription factors critical for tumor survival. In PC, taxanes are the only chemotherapy class shown to improve survival, however, the emergence of clinical taxane resistance hampers their clinical efficacy. In addition, patients resistant to one taxane often respond to another, yet, currently we do not have the ability to match individual patients to a specific taxane. In cells, different taxanes have differential effects on microtubule dynamics which may ultimately pre-determine their efficacy for each individual patient. Thus, we hypothesized that the particular pattern of dynamic behavior of the MT cytoskeleton in individual patients could be exploited therapeutically. Therefore, we looked into dissecting the concrete effects of each of the taxanes for several PC cells lines. Preliminary unpublished data have revealed that PC cells expressing the TMPRSS2-ERG fusion protein exhibit taxane resistance. In addition, we have recently shown that the androgen receptor (AR) binds MTs in order to traffic to the nucleus and that taxane-mediated inhibition of AR nuclear accumulation correlates with patient clinical response to taxane therapy. Moreover, we have shown that the two clinically relevant AR splice variants, ARv567 and ARv7, show differential response to taxane therapy. Therefore, we set out to investigate the hypothesis that ERG fusion and/or AR variants might modulate endogenous microtubule dynamics in a way that determines cellular response to taxane treatment. Xenografts PC models expressing the ARv7 variant exhibit reduced sensitivity to docetaxel treatment. In addition, docetaxels ability to induce MT stabilization is significantly impaired in ERG+ cells. We have recently established isogenic PC cell line series with inducible ERG (DU145 ERG+ and ERG-), as well as M12 cells without endogenous AR that stably express, wt-AR, ARv567 and ARv7. We then tested in a systematic way endogenous MT dynamics using live cell confocal microscopy of labeled MT tips following EGFP-EB1 lentiviral transduction. We use computer vision algorithms to obtain statistically representative results for the effects of ERG or AR on microtubule homeostasis following treatment with each of the three taxanes. We measure changes in MT behavior as statistically significant shifts in different parameters of MT dynamics measured from >20,000 MTs for each condition. Our preliminary results revealed that the presence of ERG fusion a correlation between MT dynamics and AR variant expression in PC cell lines. Citation Format: Alexandre Matov, Dragi Kimovski, Giuseppe Galletti, Nancy Chan, Benet Pera, William T. Harkcom, David S. Rickman, Paraskevi Giannakakou. Computational analysis of microtubule dynamics for personalized cancer therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2888. doi:10.1158/1538-7445.AM2013-2888