Joseph A. Fontana

190 Background: Addition of abiraterone or docetaxel has overall survival (OS) benefit in metastatic hormone sensitive prostate cancer (mHSPC). The clinical outcomes with early enzalutamide in mHSPC are unknown. We compared the combinations of enzalutamide (Arm A) or bicalutamide (Arm B) each with LHRH analogue therapy in mHSPC. Methods: The primary endpoint was PSA nadir < 4 ng/ml after 7 months of therapy, as this has been recognized as a powerful surrogate for overall survival (OS) outcomes. A minimum of 29 African American (AA) patients were required to be enrolled to evaluate the effect of race on the primary endpoint. Secondary endpoints were toxicities, biochemical and radiologic progression free survival (PFS), and OS. Stratification was by presence of bone pain and race; AA or other. PSA was monitored monthly for first 7 months and then every 3 months. The target sample size was 82 evaluable patients but the study was stopped when early abiraterone showed OS benefit in mHSPC. Metastatic site biopsies were mandatory pretherapy and optional post therapy. Results: 71 men; 29 black, 41 white and 1 Asian were enrolled. The median age was 67 years (range 46-87 years) and median baseline PSA was 56.3 ng/ml in Arm A (4.2-10,431 ng/ml) and 60 (4.9-12,030 ng/ml) in Arm B. 27 pts (38.5%) had bone pain and 13 had visceral metastases. No seizures were noted in either arm. Grade 3+ AE’s on Arm A were: Hypertension (13%), infection (7%), and Snycope (7%) and on Arm B were: Hypertension (21%), Fatigue (7%), and Hematuria (7%). By intent to treat PSA nadir < 4ng/ml at month 7 was achieved in 96.3% pts in arm A and 66.7% pts in arm B and in 71.7% of AA men and 89.7% of Caucasians. The 6-month PSA remission duration rates after month 7 on Arms A and B were 86% and 79%, respectively. 53 (75%) biopsy samples had tumor tissue available. Tmprss2-Erg fusion gene expression and androgen biosynthetic enzyme levels were determined in metastatic biopsies and will be correlated with clinical endpoints. Conclusions: Early enzalutamide use in mHSPC has the potential to improve PSA remission rates and subsequently improve PFS and OS outcomes. Clinical trial information: NCT02058706.

453 Background: Immune checkpoint inhibitors (ICI) have been approved in genitourinary cancers (GU) such as renal cell carcinoma (RCC) and urothelial carcinoma (UC). There is an unmet need to determine factors predictive of response, to guide therapeutic selection in these cancers. We evaluated NLR as a predictor of response, progression free survival (PFS), and overall survival (OS) in patients treated with ICI. Other known prognostic clinical factors assessed were age, race, and smoking status and for RCC the prognostic score per MSKCC (Memorial Sloan Kettering) and Heng criteria. Methods: Regulatory approval was obtained. A retrospective chart review of RCC and URC patients at Karmanos Cancer Institute, treated with ICI based therapy was conducted. Data was collected on demographics, smoking status, prognostic scoring, NLR pretherapy, and post 4 doses of ICI. Correlation with clinical PFS and OS was conducted by univariable and multivariable analyses. Log-rank test was used to compare PFS and OS. Results: 57 pts were evaluated with median age 62 yrs (range, 24-85). 11 (19%) were African American (AA) and 31 (54%) were smokers. Pretherapy NLR 1 VEGF therapy and 24(57%) pt were treated for > 6 mths and 14/15 UC pts were pretreated. RCC pts treated with > 6 mths and > 12 mths of VEGF therapy had a shorter PFS (HR =2.31, p= 0.028; HR = 2.075, p= 0.051 respectively). AA had shorter PFS and OS with ICI in RCC but not in UC (HR=3.72, p=0.001; HR= 40.8; p=0.001; HR=0.49, p=0.5; HR=0.85, p=0.88, respectively). Conclusions: Pretherapy NLR ≥4 was a statistically significant predictor of shorter PFS and OS with ICI therapy in RCC. NLR is an easily applicable clinical predictive factor that can help guide therapy, after validation of these findings in a larger population dataset. [Table: see text]

212 Background: Cabozantinib (C) is a c-met and vascular endothelial growth factor receptor inhibitor that demonstrated remarkable responses on bone scan, but failed to demonstrate overall survival benefit. We studied the dynamics of biomarker changes with imaging and biopsies pre- and post-therapy with C to explore predictors of efficacy. Methods: Eligibility included mCRPC patients (pts) with normal organ function and performance status 0-2. C 60 mg orally was administered daily. Pretherapy and 2 weeks post, ^99mTc-labeled bone scans (BS), positron emission tomography with ¹⁸F-sodium fluoride (NaF-PET) and ¹⁸F-(1-(2′-deoxy-2′-fluoro-β-D-arabinofuranosyl) thymine (FMAU-PET) scans were conducted. The maximum tumor standardized uptake values (SUVmax) were measured for the 5 most active lesions in at least 3 skeletal areas with each tracer. Tumor biopsies were conducted, and bone markers were measured. Results: 20 evaluable pts, 5 African American and 15 Caucasian were enrolled. Median age was 69 years, 11 had received prior chemotherapy. 16 had received prior abiraterone/enzalutamide or both.5 pts had visceral disease. 11 and 6 pts required dose reduction to the 40 mg and 20 mg daily dose respectively.8 patients had a PSA decline, of which 2 had a decline > 50%. Median PFS and OS for all 20 pts were 4.1 and 11.2 months, respectively and 3 pts were on therapy for 8, 10 and 13 months. Circulating tumor cell count changes did not correlate with PFS or OS. The NaF-PET demonstrated a median change in SUVmax of -56% (range -85 to -5%, n = 11) and -41% (range -60 to -25%, n = 9) for the pts who were clinically stable and remained on therapy for ≥ 4 or < 4 cycles, respectively. The FMAU-PET demonstrated a median change in SUVmax of -44% (-60 to -14%) and -42% (-63 to -23%) for these groups. A 50% decrease in serum BSAP was associated with a hazard ratio (HR) for progression of 0.91 (90% confidence interval [CI]: 0.71 – 1.16). For serum NTx and urine NTx, the analogous HR’s were 0.79 (90% CI: 0.61 – 1.01) and 1.07 (90% CI: 0.66 – 1.73), respectively. Conclusions: Early changes in imaging and bone markers were not predictive of clinical benefit with C. Tissue C-met testing is in process and will be correlated with PFS and OS.

Aberrant regulation of microRNA expression in pancreatic cancers has been shown to play an important role in its inherent poor prognosis and malignant potential. MicroRNAs have also been shown to inhibit translation of genes by targeting the 3'-untranslated region (3-UTR) of mRNAs resulting in the inhibition of translation and often destruction of the mRNA. In the present study we investigated the role of the microRNA miR-202 in the apoptotic pathways of pancreatic cancer cells. The adamantyl-related molecule, 3-Cl-AHPC down-regulated expression of miR-202 and miR-578 resulting in the increased expression of mRNA and protein expression of their target genes, Max dimerization protein 1 (Mxd1/Mad1) and the Sin3A associated protein 18 (SAP18). Overexpression of pre-miR-202 led to diminished levels of Mxd1 and blocked the 3-Cl-AHPC-mediated increase in Mxd1 mRNA expression. The addition of the microRNA inhibitor 2'-O-methylated miR-202 enhanced the 3-Cl-AHPC-mediated increase of Mxd1 mRNA levels as well as 3-CI-AHPC-mediated apoptosis. We found increased Mxd1 bound to the Sin3A repressor protein complex through its increased binding with HDAC-2 and subsequently enhanced transcriptional repression in cells as evidenced by increased HDAC activity. Mxd1 also repressed human telomerase reverse transcriptase (hTERT) mRNA expression through its increased binding to the hTERT promoter site and resulted in decreased telomerase activity in cells. Our results demonstrate that down regulation of miR-202 increased the expression of its target Mxd1, followed by Mxd1 recruitment to the Sin3A repressor complex and through its dimerization with Max, and increased repression of Myc-Max target proteins.

Transcription factor NF-κB promotes cell proliferation in response to cell injury. Increasing evidence, however, suggests that NF-κB can also play an apoptotic role depending on the stimulus and cell type. We have previously demonstrated that novel retinoid 4-[3-Cl-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC)-mediated apoptosis in breast carcinoma cells requires activation of canonical and non-canonical NF-κB pathways. The mechanism NF-κB uses to induce apoptosis remains largely unknown. NF-κB subunit p65 (RelA) was identified as one potent transcriptional activator in 3-Cl-AHPC-mediated apoptosis in cells. Here we used ChIP-on-chip to identify NF-κB p65 genes activated in 3-Cl-AHPC mediated apoptosis. This paper focuses on one hit: pro-apoptotic protein programmed cell death 5 (PDCD5). 3-Cl-AHPC mediated apoptosis in MDA-MB-468 had three related effects on PDCD5: NF-κB p65 binding to the PDCD5 gene, enhanced PDCD5 promoter activity, and increased PDCD5 protein expression. Furthermore, 3-Cl-AHPC increased orphan nuclear receptor small heterodimer partner (SHP) mRNA expression, increased SHP protein bound to NF-κB p65, and found the SHP/NF-κB p65 complex attached to the PDCD5 gene. PDCD5 triggered apoptosis through increased Bax protein and release of cytochrome C from mitochondria to cytosol. Lastly, knockdown of PDCD5 protein expression blocked 3-Cl-AHPC mediated apoptosis, while over-expression of PDCD5 enhanced apoptosis, suggesting PDCD5 is necessary and sufficient for NF-κB p65 mediated apoptosis. Our results demonstrate a novel pathway for NF-κB p65 in regulating apoptosis through SHP and PDCD5.

MicroRNAs have been implicated in many critical cellular processes including apoptosis. We have previously found that apoptosis in pancreatic cancer cells was induced by adamantyl retinoid-related (ARR) molecule 3-Cl-AHPC. Here we report that 3-Cl-AHPC-dependent apoptosis involves regulating a number of microRNAs including miR-150* and miR-630. 3-Cl-AHPC stimulated miR-150* expression and caused decreased expression of c-Myb and IGF-1R in the pancreatic cancer cells. 3-Cl-AHPC-mediated reduction of c-Myb resulted in diminished binding of c-Myb with IGF-1R and Bcl-2 promoters, thereby causing repression of their transcription and protein expression. Over-expression of miR-150* also resulted in diminished levels of c-Myb and Bcl-2 proteins. Furthermore, the addition of the miRNA inhibitor 2′-O-methylated miR-150 blocked 3-Cl-AHPC-mediated increase in miR-150* levels and abrogated loss of c-Myb protein. Knockdown of c-Myb in PANC-1 cells resulted in enhanced apoptosis both in the presence or absence of 3-Cl-AHPC confirming the anti-apoptotic property of c-Myb. Overexpression of miR-630 also induced apoptosis in the pancreatic cancer cells and inhibited target protein IGF-1R mRNA and protein expression. Together these results implicate key roles for miR-150* and miR-630 and their targeting of IGF-1R to promote apoptosis in pancreatic cancer cells.

Introduction/Background. Nonmetastatic castrate resistant prostate cancer (CRPC) is a challenging disease state. The objective of this study was to evaluate the efficacy and tolerability of bevacizumab in nonmetastatic CRPC patients. Patients. Patients with prostate cancer who developed PSA recurrence after local therapy were included if they had absence of bone or visceral metastases and PSA progression despite androgen deprivation therapy. Methods. Bevacizumab 10 mg/kg intravenously was administered every 14 days until PSA progression, development of metastasis, or unacceptable toxicity. Results. 15 patients were enrolled and treated with bevacizumab for a median duration of 3.1 months. Median baseline PSA was 27 ng/mL, and seven patients had Gleason Score ≥8. Five patients had declined in PSA during the treatment. Median PSA doubling time was prolonged from 4.7 months pretreatment to 6.5 months. Median time to PSA progression and new metastasis were 2.8 and 7.9 months, respectively. There were three grade 3 adverse events (one proteinuria and two hypertension) and one pulmonary embolism. There was no treatment-related mortality. Conclusion. Bevacizumab therapy had minimal impact on the disease course of nonmetastatic CRPC, and investigation of novel strategies is needed.

415 Background: Pazopanib is an oral tyrosine kinase inhibitor and is currently approved for treatment of patients with advanced or mRCC in the first-line, or second-line setting, after progression on cytokine therapy. No reports of efficacy and safety are available post targeted therapy. We conducted a retrospective analysis of cases receiving pazopanib after failure of other targeted agents. Methods: The study was reviewed and approved by our Institutional Review Board. Review of medical records of advanced renal cancer patients, treated with second-line pazopanib from April 2010 to August 2011 at Karmanos Cancer Center was performed. The Common Terminology Criteria for Adverse Events version 4.0 was used to grade the severity of definitely treatment-related adverse events (AEs). Results: 14 patients are included to date in this ongoing data collection and analysis study. Median age was 58 years, 8 were Caucasian, 4 African American, and 2 other races. By the MSKCC criteria, 1 patient was favorable, 6 were intermediate and 7 poor risk. Pazopanib was utilized as second line in 4 patients, third line in 5, and even later in 5. Prior line targeted therapies included sunitinib (8), temsirolimus (9), everolimus (4), sorafenib (1), bevacizumab (1) and axitinib (1). Nine of 14 patients to date were treated with pazopanib for at least 2 months and were assessed for response by imaging studies. One achieved partial remission; 5 had stable disease, and 3 had progression. The median time to progression after starting pazopanib was 4.0 months. The predominant AEs were grade 1 or 2, which included fatigue (4), liver enzyme elevation (3), diarrhea (2), hypertension (2), skin rash (1), depression (1) and hyponatremia (1). No grade 3 or 4 AEs, or definitely treatment-related deaths were observed. Conclusions: Pazopanib appears to maintain efficacy and tolerability in mRCC even after failure of other targeted therapies. Further investigations of larger patient cohorts in this setting are recommended.