Management of Metastatic Renal Clear Cell Cancer: ASCO Guideline Rapid Recommendation Update

ASCO Rapid Recommendation Updates highlight revisions to select ASCO guideline recommendations as a response to the emergence of new and practice-changing data. The rapid updates are supported by an evidence review and follow the guideline development processes outlined in the ASCO Guideline Methodology Manual. The goal of these articles is to disseminate updated recommendations, in a timely manner, to better inform health practitioners and the public on the best available cancer care options. See the Appendix for disclaimers and other important information (Appendix 1 and Appendix 2, online only).

DNA Methyltransferase 1 Targeting Using Guadecitabine Inhibits Prostate Cancer Growth by an Apoptosis-Independent Pathway

Epigenetic alterations such as DNA methylation and histone modifications are implicated in repressing several tumor suppressor genes in prostate cancer progression. In this study, we determined the anti-prostate cancer effect of a small molecule drug guadecitabine (gDEC) that inhibits/depletes the DNA methylation writer DNA methyltransferase 1 (DNMT1). gDEC inhibited prostate cancer cell growth and proliferation in vitro without activating the apoptotic cascade. Molecular studies confirmed DNMT1 depletion and modulated epithelial-mesenchymal transition markers E-cadherin and β-catenin in several prostate cancer cell lines (LNCaP, 22Rv1, and MDA PCa 2b). gDEC treatment also significantly inhibited prostate tumor growth in vivo in mice (22Rv1, MDA PCa 2b, and PC-3 xenografts) without any observed toxicities. gDEC did not impact the expression of androgen receptor (AR) or AR-variant 7 (AR-V7) nor sensitize the prostate cancer cells to the anti-androgen enzalutamide in vitro. In further investigating the mechanism of cytoreduction by gDEC, a PCR array analyses of 84 chromatin modifying enzymes demonstrated upregulation of several lysine-specific methyltransferases (KMTs: KMT2A, KMT2C, KMT2E, KMT2H, KMT5A), confirmed by additional expression analyses in vitro and of harvested xenografts. Moreover, gDEC treatment increased global histone 3 lysine 4 mono-and di-methylation (H3K4me1 and H3K4me2). In sum, gDEC, in addition to directly depleting the corepressor DNMT1, upregulated KMT activating epigenetic enzymes, activating terminal epithelial program activation, and prostate cancer cell cycling exits independent of apoptosis.

Diet and Health-related Quality of Life Among Men on Active Surveillance for Early-stage Prostate Cancer: The Men's Eating and Living Study (Cancer and Leukemia Group 70807 [Alliance])

BACKGROUND

Health-related quality of life (HRQoL) among patients with localized prostate cancer (PC) on active surveillance (AS) and whether it may be improved through lifestyle-focused interventions remain underdefined.

OBJECTIVE

To assess longitudinal changes in HRQoL in patients who received and those who did not receive a behavioral intervention that increased vegetable intake.

DESIGN, SETTING, AND PARTICIPANTS

A secondary analysis of participants in the Men's Eating and Living (MEAL) study (Cancer and Leukemia Group 70807 [Alliance]), a randomized trial of vegetable consumption in patients on AS, was conducted.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Patient-reported outcomes (PROs) included the Memorial Anxiety Scale for Prostate Cancer (MAX-PC), the Expanded Prostate Cancer Index Composite 26 (EPIC-26), and the Functional Assessment of Cancer Therapy Scale-Prostate (FACT-P). Areas under the curves (AUCs) were used to summarize serial HRQoL.

RESULTS AND LIMITATIONS

PROs were completed in 87% (n = 387) of the intention-to-collect population. Baseline characteristics of patients completing HRQoL measures did not differ significantly from the entire study population or between groups. Baseline scores were high for all PROs and remained stable over 24 mo, with no significant differences from baseline at any time point. In adjusted analyses, there were no significant differences in summary AUC measures comparing control with intervention for the total MAX-PC score (p = 0.173); EPIC-26 domains of urinary incontinence (p = 0.210), urinary obstruction (p = 0.062), bowel health (p = 0.607), sexual health (p = 0.398), and vitality (p = 0.363); and total FACT-P scores (p = 0.471).

CONCLUSIONS

Among men with localized PC on AS enrolled in a randomized trial, HRQoL was high across multiple domains at baseline, remained high during follow-up, and did not change in response to a behavioral intervention that increased vegetable intake.

PATIENT SUMMARY

Patients with localized prostate cancer enrolled on active surveillance experience minimal cancer-associated anxiety, suffer low levels of cancer-associated symptoms, and perceive high physical and emotional well-being.

Management of Metastatic Clear Cell Renal Cell Carcinoma: ASCO Guideline

PURPOSE

To provide recommendations for the management of patients with metastatic clear cell renal cell carcinoma (ccRCC).

METHODS

An Expert Panel conducted a systematic literature review to obtain evidence to guide treatment recommendations.

RESULTS

The panel considered peer-reviewed reports published in English.

RECOMMENDATIONS

The diagnosis of metastatic ccRCC should be made using tissue biopsy of the primary tumor or a metastatic site with the inclusion of markers and/or stains to support the diagnosis. The International Metastatic RCC Database Consortium risk criteria should be used to inform treatment. Cytoreductive nephrectomy may be offered to select patients with kidney-in-place and favorable- or intermediate-risk disease. For those who have already had a nephrectomy, an initial period of active surveillance may be offered if they are asymptomatic with a low burden of disease. Patients with favorable-risk disease who need systemic therapy may be offered an immune checkpoint inhibitor (ICI) in combination with a vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor (TKI); patients with intermediate or poor risk should be offered a doublet regimen (no recommendation was provided between ICIs or an ICI in combination with a VEGFR TKI). For select patients, monotherapy with either an ICI or a VEGFR TKI may be offered on the basis of comorbidities. Interleukin-2 remains an option, although selection criteria could not be identified. Recommendations are also provided for second- and subsequent-line therapy as well as the treatment of bone metastases, brain metastases, or the presence of sarcomatoid features. Participation in clinical trials is highly encouraged for patients with metastatic ccRCC.Additional information is available at www.asco.org/genitourinary-cancer-guidelines.

A phase 2 study of cabozantinib in combination with atezolizumab as neoadjuvant treatment for muscle-invasive bladder cancer (HCRN GU18-343) ABATE study

TPS4618

Background: ABACUS and PURE-01 trials demonstrated the activity of single agent atezolizumab and pembrolizumab respectively as neoadjuvant therapy for muscle invasive bladder carcinoma (MIBC). However, downstaging to non-muscle invasive disease was noted in only 50 percent of patients. Resistance to programmed death (PD)- 1/L1 antibodies is likely to include factors such as impaired dendritic cell maturation/function, infiltration of T-Regs and myeloid derived suppressor cells, impaired T-cell priming and T-cell trafficking in tumors. Cabozantinib is a tyrosine kinase inhibitor which targets MET, AXL, MER, Tyro3 and VEGFR2. Cabozantinib has a unique immunomodulatory profile and has demonstrated clinical activity as monotherapy and in combination with PD-1/L1 antibodies in various solid tumors including urothelial cancer (UC), renal cell, castrate- resistant prostate and non-small cell lung cancer. We hypothesize that the combination of cabozantinib and atezolizumab as neoadjuvant therapy for MIBC would improve rates of pathologic downstaging compared to single-agent checkpoint inhibitors. Methods: ABATE is an open-label, single arm, multi-center study to assess the efficacy and safety of cabozantinib with atezolizumab as neoadjuvant therapy for cT2-T4aN0/xM0 MIBC. An estimated 42 patients will be enrolled to obtain 38 evaluable patients, and the study will have over 80% power to declare the investigational combination to be successful using a Bayesian evaluation at 90% posterior probability cutoff, if the response probability is 59%, i.e., 20% higher than the 39% response rate with the single agent atezolizumab. Eligible patients will receive cabozantinib 40 mg PO daily with atezolizumab 1200mg every 3 weeks for a total duration of 9 weeks (3 cycles) followed by radical cystectomy. Adults (≥18 years) with resectable MIBC who are either cisplatin-ineligible or decline cisplatin-based chemotherapy are eligible. Patients are required to have an ECOG PS of 0-2 and provide tumor tissue for PD-L1 expression analysis. UC should be predominant component (≥ 50%). Previous systemic anticancer therapies for MIBC are not permitted. CT/MRI will be performed before investigational therapy and cystectomy. Primary endpoint is pathologic response rate defined as the absence of residual muscle-invasive cancer in the surgical specimen (< pT2). Secondary endpoints are safety and toxicity, pathologic complete response rate and event-free survival. Exploratory end points include patient-reported outcomes and outcome associations with biomarkers. Accrual began May 2020. Clinical trial information: NCT04289779.

Nivolumab plus ipilimumab in patients with advanced non-clear cell renal cell carcinoma (nccRCC): Safety and efficacy from CheckMate 920

309

Background: The long-term efficacy and tolerability of nivolumab (NIVO) 3 mg/kg + ipilimumab (IPI) 1 mg/kg Q3W × 4 doses followed by NIVO 3 mg/kg Q2W for previously untreated advanced RCC (aRCC) demonstrated in the registrational CheckMate 214 clinical trial was based on patients (pts) with a predominantly clear cell component. CheckMate 920 (NCT02982954) is a US community-based, multi-arm, phase IIIb/IV clinical trial of NIVO+IPI treatment in pts with previously untreated aRCC and clinical features mostly excluded from phase III trials. Here, we present the safety and efficacy results for the cohort of pts with nccRCC from CheckMate 920, a patient population with a poor prognosis and without a definitive effective treatment. Methods: Pts with previously untreated advanced/metastatic nccRCC, Karnofsky performance status ≥ 70%, and any International Metastatic Renal Cell Database Consortium risk received NIVO 3 mg/kg + IPI 1 mg/kg (NIVO3+IPI1) Q3W × 4 doses followed by NIVO 480 mg Q4W for ≤ 2 years or until disease progression/unacceptable toxicity. The primary endpoint was incidence of any-causality grade ≥ 3 immune-mediated adverse events (imAEs) within 100 days of last dose of study drug. Key secondary endpoints: progression-free survival (PFS) and objective response rate (ORR) by RECIST v1.1 (both per investigator), duration of response (DOR), and time to response (TTR). Exploratory endpoints included overall survival (OS). Results: Of 52 treated pts with nccRCC, 69.2% were men; median age was 64 years (range, 23–86), and 28.8% had sarcomatoid features. Histological subtypes were papillary (34.6%), chromophobe (13.5%), translocation associated (3.8%), collecting duct (3.8%), renal medullary (1.9%), or unclassified (42.3%). With 24.1 months minimum follow-up, median duration of therapy (range) was 3.5 months (0.0–25.8) for NIVO and 2.1 months (0.0–3.9) for IPI. Median (range) number of doses received was 4.5 (1–28) for NIVO and 4.0 (1–4) for IPI. No grade 5 imAEs occurred. Grade 3–4 imAEs (n = 52) by category were diarrhea/colitis (7.7%), rash (5.8%), nephritis and renal dysfunction (3.8%), hepatitis (1.9%), adrenal insufficiency (1.9%), and hypophysitis (1.9%). ORR (n = 46) was 19.6% (95% CI, 9.4–33.9). Two pts achieved complete response (papillary, n = 1; unclassified pathology, n = 1), 7 achieved partial response (papillary, n = 4; unclassified pathology, n = 3), and 17 pts had stable disease. Median TTR was 2.8 months (range, 2.1–4.8). Median DOR was not reached (range, 0.03+–27.8+); 8 of 9 responders remain without reported progression. Median PFS (n = 52) was 3.7 months (95% CI, 2.7–4.6). Median OS (n = 52) was 21.2 months (95% CI, 16.6–not reached). Conclusions: In pts with previously untreated nccRCC, a population with high unmet medical need, treatment with NIVO3+IPI1 Q3W followed by NIVO 480 mg Q4W showed no new safety signals, and encouraging antitumor activity. Clinical trial information: NCT02982954 .

A phase II, multicenter, single-arm trial of CV301 plus atezolizumab (Atezo) in locally advanced (unresectable) or metastatic urothelial cancer (UC)

TPS494

Background: Anti-PD1/PD-L1 can achieve durable responses in advanced UC but most patients (pts) do not respond. Combination strategies with agents that “prime” the immune system may improve outcomes. CV301 comprises two recombinant poxviruses, Modified Vaccinia Ankara (MVA) and Fowlpox (FPV), encoding the human transgenes for CEA, MUC-1, and a Triad of Co-stimulatory Molecules (TRICOM: ICAM-1, LFA-3, and B7-1). MVA-CV301 is used for priming doses and FPV-CV301 is used for booster doses to achieve a heterologous prime boost regimen. In preclinical studies, BN-platform vaccine plus PD1/PD-L1 inhibitors exhibited synergistic anti-tumor efficacy, T-cell infiltration, and PD-L1 upregulation in tumors. CEA and MUC-1 are expressed, in 41-90% and 55-91% of any stage UC, respectively, and in ~100% of metastatic UC. An ongoing Phase Ib trial of CV301 plus anti-PD-1 agent has demonstrated a similar safety profile to anti-PD-1 monotherapy with only mild vaccine-related adverse events (AEs). Methods: This is a Phase 2, single-arm, multi-institutional trial designed to study CV301 plus atezo as 1st-line treatment in pts with advanced UC ineligible for cisplatin-based chemotherapy regardless of PD-L1 (Cohort 1) and as salvage treatment in pts with UC progressing after platinum-based chemotherapy (Cohort 2). MVA-CV301 is given subcutaneously (SC) on Days 1 and 22 and FPV-CV301 SC every 21 days for 4 doses, then every 6 weeks until 6 months, then every 12 weeks until 2 years. Atezo 1200mg is given every 21 days. Primary endpoint is objective response rate (ORR; RECIST 1.1). Secondary endpoints: immune response, OS, PFS, response duration, AEs. Tumor and serial blood samples will be collected for biomarker analyses; 1-sided α is 0.025/cohort in this design. With a 2-stage design, success criteria are based on historic ORR (H0) and alternative ORR (H1) with ≥70% power. For Cohort 1, assuming H0 = 0.23, H1 = 0.43, then Cohort 1 sample size N1= 14, responders required at stage 1 to continue R1≥3, total accrual goal N = 33, total responders to reject H0, R≥13. For Cohort 2, assuming H0 = 0.15, H1 = 0.33, then N1= 13, R1≥2, N = 35, R≥10. Accrual has begun; completion is expected within 1 year. Clinical trial information: NCT03628716.

Patient-reported outcomes for patients with metastatic castration-resistant prostate cancer receiving docetaxel and Atrasentan versus docetaxel and placebo in a randomized phase III clinical trial (SWOG S0421)

Background

SWOG S0421 was a large randomized trial comparing docetaxel/prednisone plus placebo (DPP) to docetaxel/prednisone plus atrasentan over 12 cycles for patients with metastatic castration-resistant prostate cancer (mCRPC). The current report presents the PRO results for this trial, an important secondary endpoint.

Methods

The trial specified two primary PRO endpoints. Palliation of worst pain was based on the Brief Pain Inventory (BPI), where a 2 point difference is defined as clinically meaningful. Improvement of functional status was based on the Functional Assessment of Cancer Therapy – Prostate Cancer Trial Outcome Index (FACT-P TOI); a 5-point difference has been defined as clinically meaningful. We compared rates by arm using chi-square tests. Longitudinal analyses using linear mixed models addressed changes by arm over time.

Results

Four-hundred eighty-nine patients on each arm were evaluable for PRO endpoint data. There were no differences by arm in clinically meaningful pain palliation (41.7% for DPP vs. 44.0% for DPA, p = .70) or functional status (24.2% for DPP vs. 28.7% for DPA, p = .13). Longitudinal comparisons indicated no differences over time by arm for BPI Worst Pain scores (0.13 points, p = .23). Patients on the DPA arm had improved functional status of 1.78 points on average, a statistically significant (p = .02) but not clinically meaningful difference.

Conclusions

The SWOG S0421 PRO data showed little evidence of clinically meaningful differences by arm in either pain palliation or functional status.

Electronic supplementary material

The online version of this article (10.1186/s41687-018-0054-5) contains supplementary material, which is available to authorized users.

Validation of the Association of RECIST Changes With Survival in Men With Metastatic Castration-Resistant Prostate Cancer Treated on SWOG Study S0421

BACKGROUND

Phase 2 trials evaluating new agents for metastatic castration-resistant prostate cancer (mCRPC) have relied on bone scan and prostate-specific antigen changes to assess activity. Given the increasing detection of measurable disease, Response Evaluation Criteria in Solid Tumors (RECIST) changes warrant consideration to evaluate activity. We validated the association of RECIST 1.0 changes with survival in men with mCRPC receiving docetaxel.

PATIENTS AND METHODS

Data for men with measurable disease from the Southwest Oncology Group (SWOG) S0421, a phase 3 trial in men with mCRPC receiving docetaxel and prednisone plus placebo or atrasentan, were used. Cox proportional hazards regression was used to evaluate the association of RECIST 1.0 outcomes within 120 days, ie, unconfirmed partial response (uPR), stable disease, and progressive disease (PD), with overall survival (OS) from day 120, adjusted for prognostic factors.

RESULTS

Overall, 326 men were evaluable for landmark analysis, of whom 23 had PD, 230 stable disease, and 73 uPR. OS beyond day 120 was significantly different (P = .004) among these subgroups, with median (95% confidence interval) OS of 7.1 (3.5-8.8), 13.4 (11.4-15.6), and 16.3 (10.0-19.6) months for those with PD, stable disease, and uPR, respectively. In a multivariable model, the hazard ratio (95% confidence interval) for patients with PD was 2.47 (1.42-4.29) compared to patients with an uPR (P = .002).

CONCLUSION

The association of RECIST 1.0 changes with OS in men with mCRPC receiving docetaxel was validated. Given limitations of bone scan and prostate-specific antigen alterations, improvements in objective RECIST 1.0 changes should be reported in phase 2 trials before launching phase 3 trials.

Impact Study: MK-0646 (Dalotuzumab), Insulin Growth Factor 1 Receptor Antibody Combined with Pemetrexed and Cisplatin in Stage IV Metastatic Non-squamous Lung Cancer

BACKGROUND

Insulin-like growth factor 1 receptor (IGF-1R) regulates cell growth, proliferation, and apoptosis. Adenocarcinoma and never-smokers have a higher expression of IGF-1R, which is associated with worse overall survival. Dalotuzumab-MK0646 (D) is a humanized monoclonal antibody that targets IGF-1R. Pemetrexed (P) has higher activity in non-squamous lung cancer (NSQL). We initiated a randomized phase II trial to test the combination of P and Cisplatin (C) ± D in NSQL.

METHODS

Eligibility criteria were untreated NSQL stage IV, ECOG 0 or 1, measurable disease, adequate renal, hepatic and hematologic function, and no other intercurrent illness. P at 500 mg/m(2) and C at 75 mg/m(2) IV were given every 3 weeks. D was given at 10 mg/kg IV weekly on days 1, 8, and 15 of every 3-week cycle in the experimental group. The patients had a radiographic assessment after every two cycles and were treated for a maximum of six cycles if there was a response or stable disease. The primary objective of the study was to compare the clinical response rates of PC vs. PC + D.

RESULTS

From 1/2009 to 2/2011, the study accrued 26 subjects: 16 male and 10 female, with a median age of 59; 14 were treated with PC and 12 were treated with PC + D. We observed two partial responses (PR), seven stable disease (SD), three progressive disease (PD), and two not evaluable (NE) in the PC arm. In comparison, for the PC + D arm, there were three PR, four SD, four PD, and one NE. The hematologic toxicity was similar in both groups. There was higher incidence of hyperglycemia in the experimental group; four cases with grade 3 and one case with grade 4.

CONCLUSION

PC + D had a similar response rate compared to PC, with a higher rate of hyperglycemia. Identification of responders using predictive markers would be key to continuing the study of D in NSQL.

TRIAL REGISTRATION

NCT00799240, clinicaltrials.gov.

Prostate-specific antigen and prostate-specific antigen velocity as threshold indicators in 11C-acetate PET/CTAC scanning for prostate cancer recurrence

PURPOSE

The aim of this study was to identify which patient characteristics are associated with the highest likelihood of positive findings on 11C-acetate PET/computed tomography attenuation correction (CTAC) (PET/CTAC) scan when imaging for recurrent prostate cancer.

METHODS

From 2007 to 2011, 250 11C-acetate PET/CTAC scans were performed at a single institution on patients with prostate cancer recurrence after surgery, brachytherapy, or external beam radiation. Of these patients, 120 met our inclusion criteria. Logistic regression analysis was used to examine the relationship between predictability of positive findings and patients' characteristics, such as prostate-specific antigen (PSA) level at the time of scan, PSA kinetics, Gleason score, staging, and type of treatment before scan.

RESULTS

In total, 68.3% of the 120 11C-acetate PET/CTAC scans were positive. The percentage of positive scans and PSA at the time of scanning and PSA velocity (PSAV) had positive correlations. The putative sensitivity and specificity were 86.6% and 65.8%, respectively, when a PSA level greater than 1.24 ng/mL was used as the threshold for scanning. The putative sensitivity and specificity were 74% and 75%, respectively, when a PSAV level greater than 1.32 ng/mL/y was used as the threshold. No significant associations were found between scan positivity and age, PSA doubling time, Gleason score, staging, or type of treatment before scanning.

CONCLUSIONS

This retrospective study suggests that threshold models of PSA greater than 1.24 ng/mL or PSAV greater than 1.32 ng/mL per year are independent predictors of positive findings in 11C-acetate PET/CTAC imaging of recurrent prostate cancer.

Abstract 2430: Treatment sequence and molecular biomarker in EGFR mutant lung cancer cells

Introduction

Lung cancer is the leading cause of cancer related death in the US. A subset of patients with lung cancer has a mutation in the Epidermal Growth Factor Receptor (EGFR) which makes them extremely responsive to EGFR tyrosine kinase inhibitor (TKI) erlotinib. The emergence of EGFR TKI resistance is new challenge in the management of these patients. We conducted a study to determine the best treatment sequence after resistance to EGFR TKI, testing the use of chemotherapy Pemetrexed (P), Afatinib (A), Rociletinib (R) and the combination of these agents in lung cancer cell lines with EGFR mutation that were pretreated with erlotinib.

Material and methods

Lung cancer cell lines with EGFR mutation CRL-2868 (E746 - A750 deletion) and CRL-2871 (L747 - E749 deletion, A750P) mutation were treated with 5 nM erlotinib for 24h and 72 h.

The erlotinib resistance cells were then treated with 10nM of A or 10nM of P, or 21.5 nM of R, or the combination AP or the combination of RP. As control, we used lung cancer HTB-177 which does not have EGFR mutation. MTT proliferation assay was performed after 24, 48, 72 and 144h after the treatment. microRNA profiling was done by real time PCR in all cells after erlotinib treatment to find potential biomarkers as hallmark of erlotinib resistance cells.

Results

Rociletinib induced the maximum inhibition of cell proliferation at 144h in both cell lines with EGFR mutation. The RP also induced decreased cell proliferation in both cell lines with EGFR mutation. RP combination was more effective then R alone in CRL 2871. The use of A alone, P alone or AP combination was not different in CRL2871 but P had antagonistic effect when combined with A or R in CRL 2868. microRNA 10b, 27a and 27b were upregulated in the erlotinib resistant cells.

Conclusion.

EGFR resistance arises after treatment with erlotinib in lung cancer cell lines with EGFR mutation. Treatment with R and the combination of RP induced greater inhibition of proliferation compared to A, P alone. The combination of AP was antagonistic. This may have implications in the management of patients resistant to EGFR TKI. microRNA analysis showed up-regulation of several microRNA that should be tested in clinical setting.

Citation Format: Hannah Motes, Emma Borrego-Diaz Reyes, Jared Kevern, Chao H. Huang, Peter J. Van Veldhuizen. Treatment sequence and molecular biomarker in EGFR mutant lung cancer cells. [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 2430. doi:10.1158/1538-7445.AM2015-2430

A multicenter pilot study examining the role of circulating tumor cells as a blood-based tumor marker in patients with extensive small-cell lung cancer

Background: Small-cell lung cancer (SCLC), a variant of lung cancer marked by early metastases, accounts for 13% of all lung cancers diagnosed in US. Despite high response rates to treatment, it is an aggressive disease with a median survival of 9–11 months for patients with extensive stage (EX-SCLC). Detection of circulating tumor cells (CTCs) is a novel laboratory technique currently in use to determine response to therapy and to predict prognosis in breast, colorectal, and prostate cancer. We initiated a pilot study to analyze the role of CTCs as a biomarker of response and relapse in patients with EX-SCLC.

Methods: We collected blood samples from chemotherapy naïve patients with EX-SCLC prior to initiation of therapy, after completion of systemic therapy, and follow-up every 6–8 weeks and at relapse. The number of CTCs was determined using the cell search system in a central laboratory. The study was conducted in four different sites, and it was reviewed and approved by respective research review committees and IRBs.

Results: We enrolled 26 patients with EX-SCLC, 1 was excluded due to ineligibility, all were treated with platinum and etoposide. We observed partial response in 16 patients, stable disease in 3 patients, 1 patient with disease progression, and 6 patients were not assessed (5 deceased, 1 not available). The overall median number of CTCs in 24 patients measured at baseline and post-tx was 75 (range 0–3430) and 2 (range 0–526), respectively. A significant reduction in CTCs from baseline to post-treatment was identified for 15 subjects; the median reduction was 97.4% (range −100 to +100%, p < 0.001). Higher baseline CTCs and percentage change in post-treatment CTCs were associated with decreased survival.

Conclusion: We demonstrated that it is feasible to detect CTCs in EX-SCLC. If validated in other prospective studies, CTCs could be a useful biomarker in the management of EX-SCLC by predicting patients’ clinical responses to therapy.

Circulating tumor cell telomerase activity as a prognostic marker for overall survival in SWOG 0421: a phase III metastatic castration resistant prostate cancer trial

Circulating tumor cells (CTC) are promising biomarkers in metastatic castration resistant prostate cancer (mCRPC), and telomerase activity (TA) is a recognized cancer marker. Therefore, we hypothesized that CTC TA may be prognostic of overall survival (OS) in mCRPC. To test this, we used a novel Parylene-C slot microfilter to measure live CTC TA in S0421, a phase III SWOG-led therapeutic trial. Blood samples underwent CTC capture and TA measurement by microfilter, as well as parallel enumeration by CellSearch (Janssen/J&J). Cox regression was used to assess baseline (pre-treatment) TA versus OS, and recursive partitioning was used to explore potential prognostic subgroups and to generate Kaplan-Meier (KM) OS curves. Samples were obtained from 263 patients and generated 215 TA measures. In patients with baseline CTC count ≥5 (47% of patients), higher CTC TA was associated with hazard ratio 1.14 (p = 0.001) for OS after adjusting for other clinical covariates including CTC counts and serum PSA at study entry. Recursive partitioning identified new candidate risk groups with KM OS curve separation based on CTC counts and TA. Notably, in men with an intermediate range baseline CTC count (6-54 CTCs/7.5 ml), low versus high CTC TA was associated with median survival of 19 versus 12 months, respectively (p = 0.009). Baseline telomerase activity from CTCs live-captured on a new slot microfilter is the first CTC-derived candidate biomarker prognostic of OS in a large patient subgroup in a prospective clinical trial. CTC telomerase activity thus merits further study and validation as a step towards molecular CTC-based precision cancer management.

Circulating tumor cell counts are prognostic of overall survival in SWOG S0421: a phase III trial of docetaxel with or without atrasentan for metastatic castration-resistant prostate cancer

PURPOSE

Circulating tumor cell (CTC) enumeration has not been prospectively validated in standard first-line docetaxel treatment for metastatic castration-resistant prostate cancer. We assessed the prognostic value of CTCs for overall survival (OS) and disease response in S0421, a phase III trial of docetaxel plus prednisone with or without atrasentan.

PATIENTS AND METHODS

CTCs were enumerated at baseline (day 0) and before cycle two (day 21) using CellSearch. Baseline counts and changes in counts from day 0 to 21 were evaluated for association with OS, prostate-specific antigen (PSA), and RECIST response using Cox regression as well as receiver operator characteristic (ROC) curves, integrated discrimination improvement (IDI) analysis, and regression trees.

RESULTS

Median day-0 CTC count was five cells per 7.5 mL, and CTCs < versus ≥ five per 7.5 mL were significantly associated with baseline PSA, bone pain, liver disease, hemoglobin, alkaline phosphatase, and subsequent PSA and RECIST response. Median OS was 26 months for < five versus 13 months for ≥ five CTCs per 7.5 mL at day 0 (hazard ratio [HR], 2.74 [adjusting for covariates]). ROC curves had higher areas under the curve for day-0 CTCs than for PSA, and IDI analysis showed that adding day-0 CTCs to baseline PSA and other covariates increased predictive accuracy for survival by 8% to 10%. Regression trees yielded new prognostic subgroups, and rising CTC count from day 0 to 21 was associated with shorter OS (HR, 2.55).

CONCLUSION

These data validate the prognostic utility of CTC enumeration in a large docetaxel-based prospective cohort. Baseline CTC counts were prognostic, and rising CTCs at 3 weeks heralded significantly worse OS, potentially serving as an early metric to help redirect and optimize therapy in this clinical setting.

In vitro efficacy of MAGMAS inhibition in prostate cancer

281

Background: Prostate cancer is the second most common cancer worldwide in males. The initial treatment in advanced cases is medical or surgical castration. The outlook declines when prostate cancer advances independently, despite the aforementioned castration. Within the last ten years, a handful of new agents have proven effective in this castration-resistant phase, but finding more effective, novel ways of treating advanced prostate cancer is warranted. MAGMAS (mitochondria-associated, granulocyte-macrophage colony stimulating factor (GM-CSF) signaling molecule) is a protein ubiquitously expressed in eukaryotic cells that plays a key role in embryonal development in a variety of species. Overexpression of MAGMAS has anti-apoptotic effects, as GM-CSF is a growth factor essential for survival, proliferation and differentiation of cells. MAGMAS and GM-CSF receptor levels have been shown to be overexpressed in prostate cancer, but do not correlate with pathological grade or clinical stage. The purpose of our study was to evaluate the efficacy of a MAGMAS inhibitor, synthesized by Dr Bhaskar Das, in androgen-dependent and androgen-independent prostate cancer cell lines, as well as in a normal prostate cell line as another control. Methods: The different cell lines were treated with MAGMAS inhibitor at various concentrations in vitro. For analysis, we used MTT Cell Proliferation assay at 24 and 48 hours, per manufacturer’s protocol. We tested MAGMAS inhibitor effect on apoptosis/necrosis, cell migration and microtubule destabilization as well. Results: After prostate cancer cell lines were treated with MAGMAS inhibitor in vitro, cell proliferation and migration decreased, apoptosis and necrosis were induced, and microtubules were destabilized, all showing more impressive results in the androgen-independent cells. MAGMAS inhibition did not affect cell proliferation in the normal prostate cells. Conclusions: In vitro studies show MAGMAS inhibition proves efficacious in both androgen-dependent and androgen-independent prostate cancer cell lines. This will be evaluated further in a xenograft mouse model.

Abstract A261: NPV-LDE-225 (Erismodegib) inhibits human prostate cancer stem cell growth in NOD/SCID IL2γnull mice by regulating Bmi-1 and microRNA-128

Prostate cancer stem cells (CSCs) are defined by their extensive self-renewal, differentiation, and tumor initiation properties. It is now clear that CSCs are involved in tumor growth and recurrence, and resistance to conventional treatments. Thus, the strategy that suppresses stemness and consequently tumorigenic potential of CSCs could be considered for the management of prostate cancer. The objectives of this study were to examine the molecular mechanisms by which NPV-LDE-225 / Erismodegib (smoothened inhibitor) regulates stem cell characteristics in prostate cancer. Effects of NPV-LDE-225 on CSC's viability, sphere formation, apoptosis, transcriptional activity, and epithelial-mesenchymal transition (EMT) were measured. NPV-LDE-225 inhibited cell viability and spheroid formation, and induced apoptosis by activation of caspase-3 and cleavage of PARP. NPV-LDE-225 induced expression of Bax and Bak, and inhibited the expression of Bcl-2, Bcl-XL, XIAP, cIAP1, cIAP2 and survivin. NPV-LDE-225 inhibited Gli transcriptional activity, Gli-DNA interaction, and the expression of Gli1, Gli2, Patched1 and Patched 2 in prostate CSCs. Interestingly, NPV-LDE-225 induced PDCD4 and apoptosis and inhibited cell viability by suppressing miR-21. Furthermore, NPV-LDE-225 inhibited pluripotency maintaining factors Nanog, Oct4, cMyc and Sox-2. The inhibition of Bmi-1 by NPV-LDE-225 was regulated by up-regulation of miR-128. NPV-LDE-225 suppressed EMT by up-regulating E-cadherin and inhibiting N-cadherin, Snail, Slug and Zeb1 through regulating miR-200 family. Finally, NPV-LDE-225 inhibited CSC tumor growth which was associated with the suppression of Gli1, Gli2, Patched-1, Patched-2, Cyclin D1 and PCNA, and cleaved caspase-3 and PARP in tumor tissues derived from NOD/SCID IL2Rϒnull mice. Overall, our findings suggest that inhibition of the Shh signaling pathway in CSCs is a potential therapeutic strategy for prostate cancer.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A261.

Citation Format: Rajesh Nanta, Daniel Meeker, Mariana Rodova, Peter J. Van Veldhuizen, Sharmila Shankar, Rakesh K. Srivastava. NPV-LDE-225 (Erismodegib) inhibits human prostate cancer stem cell growth in NOD/SCID IL2γnull mice by regulating Bmi-1 and microRNA-128. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A261.

Docetaxel and atrasentan versus docetaxel and placebo for men with advanced castration-resistant prostate cancer (SWOG S0421): a randomised phase 3 trial

BACKGROUND

The endothelin pathway has a role in bone metastases, which are characteristic of advanced prostate cancer. Atrasentan, an endothelin receptor antagonist, has shown activity in prostate cancer. We therefore assessed its effect on survival in patients with castration-resistant prostate cancer with bone metastases.

METHODS

In a double-blind phase 3 trial, men with metastatic castration-resistant prostate cancer, stratified for progression type (prostate-specific antigen or radiological), baseline pain, extraskeletal metastases, and bisphosphonate use, were randomly assigned in a 1:1 ratio to docetaxel (75 mg/m(2) every 21 days, intravenously) with atrasentan (10 mg/day, orally) or placebo for up to 12 cycles and treated until disease progression or unacceptable toxicity. Patients who did not progress on treatment were permitted to continue atrasentan or placebo for up to 52 weeks. Coprimary endpoints were progression-free survival (PFS) and overall survival. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00134056.

FINDINGS

498 patients were randomly assigned to the atrasentan group and 496 to the placebo group. The trial was halted early for futility in April, 2011, after a planned interim analysis. Median PFS was 9·2 months (95% CI 8·5-9·9) in the atrasentan group and 9·1 months (8·4-10·2) in the placebo group (hazard ratio 1·02, 0·89-1·16; p=0·81). Median overall survival was 17·8 months (16·4-19·8) in the atrasentan group versus 17·6 months (16·4-20·1) in the placebo group (1·04, 0·90-1·19; p=0·64). 278 (57%) of 492 patients in the atrasentan group had grade 3 and greater toxicity compared with 294 (60%) of 486 in the placebo group (p=0·22). Three deaths in the atrasentan group and seven in the placebo group were judged to be possibly or probably due to protocol treatment.

INTERPRETATION

Atrasentan, when added to docetaxel, does not improve overall survival or PFS in men with castration-resistant prostate cancer and bone metastases; therefore, single-agent docetaxel should remain as one of the standard treatments.

FUNDED

National Cancer Institute, Sanofi-Aventis, and Abbott Laboratories.

Circulating tumor cells (CTC) as a biomarker of response in patients with extensive-stage small cell lung cancer (EX-SCLC)

e22048

Background: SCLC, a variant of lung cancer marked by early metastases, accounts for 13% of all lung cancers diagnosed in US. Despite high response rates to treatment, it is an aggressive disease with a median survival of 9-11 months for patients with EX-SCLC. Detection of CTCs is a novel laboratory technique currently in use to determine response to therapy and to predict prognosis in breast, colorectal and prostate cancer. We initiated a study to study the role of CTC as a biomarker of response and relapse in patients with EX-SCLC. Methods: We collected blood sample from chemotherapy naïve patients with EX-SCLC prior to initiation of therapy, following completion of systemic therapy, follow up every 6-8 weeks and at relapse. The CTC was determined using the Cell Search system in a central laboratory. The study was conducted in 4 different sites and it was reviewed and approved by respective Research Review Committee and IRBs. Results: We enrolled 27 patients with EX-SCLC, 1 was excluded due ineligibility, all patients were treated with platinum and etoposide. We observed partial response in 16 patients (61%), stable disease in 3 patients, 1 with progression of disease and not assessed in 7 patients (5 deceased, 2 not available); the baseline CTC of 2 patient were not measured (one due instrument failure and one due insufficient blood). The overall median number of CTCs in 24 patients measured at baseline and post-tx was 75 (range 0 to 3430) and 2 (range 0 to 526), respectively. A significant reduction in CTCs from baseline to post-tx was identified; for the 14 subjects with pre and post treatment CTC, the median reduction was 51.5% (51.5% decrease, range -2904% to +5%, p< 0.001). Conclusions: We were able to demonstrate feasibility of using CTC as a biomarker of response in patients with EX-SCLC in clinical setting. CTC could be a useful biomarker in the management of SCLC to predict response to therapy.

A phase ii study of gemcitabine and capecitabine in patients with advanced renal cell cancer: Southwest Oncology Group Study S0312

OBJECTIVES

Gemcitabine plus capecitabine has moderate efficacy in patients with advanced renal cell cancer (RCC) but has considerable toxicity. We evaluated the efficacy and toxicity of a modified dose-schedule of this doublet in patients with metastatic RCC.

METHODS

Chemotherapy-naive patients were treated with gemcitabine at 900 mg/m2 on days 1, 8, and 15 and with capecitabine at 625 mg/m2 twice daily on days 1 through 21, and every 28 days thereafter. The primary end point was response rate (RR). No further evaluation of this regimen would be pursued if the RR was ≤ 5%. In an exploratory analysis, we also evaluated potential markers of prognosis and treatment response, including thymidylate synthase, PTEN, pAKT, pmTOR, XRCC1, and ERCC1.

RESULTS

Of 43 patients, 1 was ineligible and 2 were not analyzable. There was 1 complete response and 3 partial responses, for an overall RR of 10% (95% CI = 3, 24). Nineteen patients (48%) had stable disease. The 6-month freedom-from-treatment-failure and overall survival rates were 20% (95% CI = 8, 32) and 75% (95% CI = 62, 88), respectively. Median survival time was 23 months (95% CI = 10, 37). One patient each experienced grade 4 neutropenia, fatigue, thrombocytopenia, and hemolysis with renal failure. The most common grade 3 toxicities were neutropenia (12 patients), fatigue (5), and leucopenia (4). Patients with a best response of stable disease or better were more likely to have decreased expression of PTEN and increased expression of pmTOR.

CONCLUSIONS

Gemcitabine plus capecitabine at this reduced dose-schedule benefits a small percentage of patients with RCC with an acceptable toxicity profile.

NPV-LDE-225 (Erismodegib) inhibits epithelial mesenchymal transition and self-renewal of glioblastoma initiating cells by regulating miR-21, miR-128, and miR-200

BACKGROUND

Glioblastoma multiforme is the most common form of primary brain tumor, often characterized by poor survival. Glioblastoma initiating cells (GICs) regulate self-renewal, differentiation, and tumor initiation properties and are involved in tumor growth, recurrence, and resistance to conventional treatments. The sonic hedgehog (SHH) signaling pathway is essential for normal development and embryonic morphogenesis. The objectives of this study were to examine the molecular mechanisms by which GIC characteristics are regulated by NPV-LDE-225 (Smoothened inhibitor; (2,2'-[[dihydro-2-(4-pyridinyl)-1,3(2H,4H)-pyrimidinediyl]bis(methylene)]bis[N,N-dimethylbenzenamine).

METHODS

Cell viability and apoptosis were measured by XTT and annexin V-propidium iodide assay, respectively. Gli translocation and transcriptional activities were measured by immunofluorescence and luciferase assay, respectively. Gene and protein expressions were measured by quantitative real-time PCR and Western blot analyses, respectively.

RESULTS AND CONCLUSION

NPV-LDE-225 inhibited cell viability, neurosphere formation, and Gli transcriptional activity and induced apoptosis by activation of caspase-3 and cleavage of poly(ADP-ribose) polymerase. NPV-LDE-225 increased the expression of tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-R1/DR4, TRAIL-R2/DR5, and Fas and decreased the expression of platelet derived growth factor receptor-α and Bcl2, and these effects were abrogated by Gli1 plus Gli2 short hairpin RNAs. NPV-LDE-225 enhanced the therapeutic potential of FasL and TRAIL by upregulating Fas and DR4/5, respectively. Interestingly, NPV-LDE-225 induced expression of programmed cell death 4 and apoptosis and inhibited cell viability by suppressing micro RNA (miR)-21. Furthermore, NPV-LDE-225 inhibited pluripotency-maintaining factors Nanog, Oct4, Sox2, and cMyc. The inhibition of Bmi1 by NPV-LDE-225 was regulated by induction of miR-128. Finally, NPV-LDE-225 suppressed epithelial-mesenchymal transition by upregulating E-cadherin and inhibiting N-cadherin, Snail, Slug, and Zeb1 through modulating the miR-200 family. Our data highlight the importance of the SHH pathway for self-renewal and early metastasis of GICs.

A second-generation 2-Methoxyestradiol prodrug is effective against Barrett's adenocarcinoma in a mouse xenograft model

2-Methoxyestradiol (2-ME2) is an endogenous metabolite of estradiol. In preclinical models, 2-ME2 is effective against different types of tumors. Unfortunately, only low systemic concentrations of 2-ME2 can be achieved following oral administration, even after very high doses are administered to patients. In an effort to solve this problem, we have now synthesized and tested a new prodrug of 2-ME2 that is water-soluble due to a bioreversible hydrophilic group added at the 3-position and that more effectively resists metabolic inactivation due to an ester moiety added to mask the 17-position alcohol. We are reporting here for the first time that this double prodrug of 2-ME2 is effective as an antiproliferative and anticancer agent for both in vitro and in vivo studies against Barrett esophageal adenocarcinoma (BEAC) and provided greater potency than 2-ME2 in inhibiting the growth of BEAC xenografts. Finally, studies indicate that, like 2-ME2, the 2-ME2-PD1 exhibits anticancer effect through possible disruption of microtubule network.

Circulating tumor cell (CTC) counts and CTC telomerase activity (TA) as prognotic markers of overall survival (OS) in SWOG S0421: Docetaxel with or without atrasentan for metastatic castration-resistant prostate cancer (mCRPC)

1

Background: CTCs are promising biomarkers in mCRPC, and telomerase activity (TA) is a recognized cancer marker. In this phase III trial we analyzed CTCs using 2 methods: CellSearch for fixed cell enumeration, and a novel Parylene-C slot filter for live CTC capture and TA measurement. Methods: Blood samples (7.5 ml) were drawn at baseline (d1) and pre-cycle 2 (d21) of Rx and shipped overnight for central processing. For CellSearch enumeration, Cox regression was used to evaluate the association between OS, baseline CTC counts, and CTC dynamics (d1 to d21). For TA, filter-trapped cells were lysed and assayed for TA using qPCR-based telomeric repeat amplification. Cox regression evaluated the association between OS and TA overall and within subgroups characterized by good vs. poor (<5 vs. >=5) prognosis baseline CTC counts. For all measurements, receiver operator characteristic (ROC) analysis and characteristics and regression trees (CART) were used to explore further prognostic cutpoints. Results: Samples were obtained from 263 men. Median d1 CTC count was 5, and there was a significant difference in OS for d1 CTC < vs. >=5, hazard ratio (HR) 2.92 (p<0.001) after adjustment for other factors. D1 CTC and OS had ROC AUC of 0.781. In men with low d1 CTC (< 5), an increase in CTC was associated with shorter OS, HR 4.04 (p=0.004); in men with high d1 CTC (>=5), a >=2-fold decrease in CTC was associated with longer OS, HR 0.45 (p=0.012); adjusting for risk factors. For TA, men with baseline CTC >=5 (41% of cohort) who had high CTC TA had HR 1.14 (p<0.005) for OS after adjustment for other factors including CTC counts. CART identified additional risk subgroups based on CTC counts and TA. Conclusions: In this phase III trial, d1 CTC and d1 to d21 CTC dynamics were prognostic of OS after risk factor adjustment, comprising the largest docetaxel-based prospective cohort to date which validates a 5 CTC prognostic threshold and identifies new potentially useful enumeration subgroups. In men with CTCs >=5, TA from cells live-captured on a new slot filter constitutes the first CTC-derived biomarker prognostic of OS in a prospective clinical trial.

Effect of sequential docetaxel followed by mTOR inhibitor temsirolimus on suppression of PI3K overactivation resistance mechanism

88

Background: Mammalian target of rapamycin (mTOR) is a downstream regulatory protein of the PI3K/Akt signal transduction pathway. This is a common pathway for a several cell surface receptors including IGFR (Insulin-like Growth Factor Receptor) and EGFR (Epidermal Growth Factor Receptor). The activation of these receptors through PI3K/Akt pathway is essential in cell proliferation, angiogenesis, and anti-apoptosis process. The upregulation of PI3K could be a mechanism of resistance of mTOR inhibitors. Docetaxel (D) is commonly used in the treatment of lung cancer. We demonstrated previously that the sequence of D followed by mTOR inhibitor temsirolimus (T) in lung cancer cell lines (LCCL) had synergistic effect in suppressing cell proliferation compared with T→D. The exact mechanism of this effect is unknown. We studied the expression of mTOR and PI3K in these cell lines treated in different time points to investigate the activity of this pathway when using these sequences of drug treatment. Methods: Adenocarcinoma LCCL H2122 and H1437 were plated and exposed to temsirolimus 1000nM and docetaxel 100nM. The cell viability was measured by optical density (OD) at 24, 48, and 72h. We tested effect of drugs D and T alone as well as the sequence of D treated for 24h followed by addition of T and the reverse in both LCCL. We then prepared cell lysate at 24h, 48h, and 72h time points and studied the expression of phospho mTOR (pmTOR) and PI3K by western blot using antibody obtained from cell signaling. Results: The use of T alone increased the expression of PI3K in both H2122 and H1437 cell lines at 48h time point. The use of D had a variable response: absent in H1437 and present in H2122 at 48 H. The sequence of D→T suppressed the expression of pmTOR and PI3K at 48 and 72 h compared with the opposite sequence of T→D. Conclusions: The combination of D → T is synergistic in suppression of pmTOR and inhibited the overactivation of upstream PI3K in both LCCL compared with opposite sequence. Therefore, the sequential treatment of D followed by T is able to overcome the PI3K overactivation mechanism of resistance in lung cancer cell line when treated with T. This would have implications in the use of these agents in treatment of lung cancer.

Circulating tumor cell counts (CTC) as prognostic of overall survival (OS) in SWOG S0421-docetaxel with or without atrasentan for metastatic castration resistant prostate cancer (mCRPC)

10503

Background: CTC are promising biomarkers in mCRPC but have not been prospectively validated for docetaxel treatment (Rx). Using CellSearch technology (J&J), we enumerated CTC in this Phase 3 trial & assessed prognostic value for OS. The aim of this correlative study nested within 0421 was to compare CTC via CellSearch technology to newer microfilter technologies (Cote & Goldkorn PIs RO1 CA141077). Comparative data analysis is ongoing. Methods: CTC were drawn at baseline (d1) & pre-cycle 2 (d21) of Rx & shipped overnight to a central site for enumeration (CTC/7.5 ml). Cox regression evaluated the association between OS and (i) baseline CTC counts & (ii) CTC dynamics (d1 to d21) in pts with good (<5) vs. poor (>=5) baseline CTC counts. Receiver operator characteristic (ROC) analysis and Characteristics & Regression Trees (CART) were used to explore further prognostic CTC cutpoints for 2-yr survival. Results: Of 263 patients (pts) consented, 238 were evaluable at d1 & 232 at d21. At d1 median CTC was 5 (range 0-5916) & d1 CTC < vs. >= 5 was associated with baseline PSA (mean 99 vs. 320 ng/ml, p=0.004) and worse bone pain (36% vs. 51%, p=0.03). There was a significant difference in OS for d1 CTC < vs. >=5, with a hazard ratio (HR) of 2.92 (95% CI 1.92-4.43, p<0.001) after adjustment for PSA & other factors. In pts with low d1 CTC (< 5), an increase in CTC was associated with shorter OS, HR 4.04 (95%CI 1.56-10.44, p=0.004); in pts with high d1 CTC (>=5), a >=2-fold decrease in CTC was associated with longer OS, HR 0.45 (95%CI 0.24-0.84, p=0.012); adjusting for risk factors. D1 CTC and 2-year survival had ROC AUC of 0.781. CART analysis identified prognostic subgroups based on CTC of 0, 1-5, 6-53, and >53: (HR 0.36, 0.77,1.3 and 2.8). Conclusions: In this phase 3 trial, d1 CTC was prognostic of OS after risk factor adjustment. CTC dynamics from d1 to d21 were also prognostic of OS. These data are an exploratory subset analysis of the overall study. Yet, they comprise the largest docetaxel-based prospective cohort to date, which validates a 5 CTC prognostic threshold for OS & identifies new potential prognostic subgroups that may extend the clinical utility of CTC enumeration in mCRPC.

MK-0646 (MK), insulin growth factor 1 receptor (IGF-1R) antibody combined with pemetrexed (P) and cisplatin (C) in stage IIIb or IV metastatic nonsquamous lung cancer (NSQL)

e13551

Background: IGF-1R regulates cell growth, proliferation and apoptosis. Adenocarcinoma and never smokers have higher expression of IGF-1R and it is associated with worse survival. MK is a humanized monoclonal antibody that targets IGF-1R. P has higher activity in NSQL. We initiated a randomized phase II trial to evaluate the combination of P and C +/- MK in NSQL. Methods: Eligibility criteria: untreated NSQL stage IIIB or IV, ECOG 0 or 1, measurable disease, adequate organ function and no other intercurrent illness. Standard B12 and folic acid were given. P at 500mg/m2 and C at 75mg/m2 IV were given every 3 weeks. MK was given at the dose of 10mg/kg IV weekly on days 1, 8 and 15 of every 3 week cycle in the experimental group. The patients had radiographic assessment after every 2 cycles and treated for a maximum of 6 cycles if there was either response or stable disease. The primary objective of the study was to estimate the individual response rate of standard and experimental arm. IRB reviewed and approved the study at participating institutions. Results: From 1/2009 to 2/2011, the study accrued 26 patients, 16 male, 10 female, median age 59 yo. 14 patients were treated with PC and 12 patients were treated with PC +MK. In the PC arm we observed 2 partial responses (PR), 7 stable disease (SD), 3 had progression (PD) and 2 were not evaluable (NE). In the MK arm there were 3 PRs, 4 SD, 4 PD and 1 NE. In both arms, hematologic adverse events(AE) observed were: grade 3 neutropenia(5), hemoglobin (3), febrile neutropenia (2), platelet (2) leukopenia (1), lymphopenia (1); grade 4 platelet (2), hemoglobin (1); Grade 3 non-hematological AE were: hyperglycemia (4) and 1 occurrence each of hearing deficit, pain in extremity, hyponatremia, urinary tract infection, fatigue, dyspnea, laboratory, hypokalemia, esophageal stenosis, hypoxia, dysphagia and muscle weakness; Grade 4 hypoxia and hyperglycemia. The study was closed due to termination of funding. Conclusions: PC with MK had a similar response rate to PC. There was a higher rate of hyperglycemia in the MK group. Identification of a response predictive marker would be critical in order to continue the study of this agent.

SWOG S0421: Phase III study of docetaxel (D) and atrasentan (A) versus docetaxel and placebo (P) for men with advanced castrate resistant prostate cancer (CRPC)

4511

Background: The endothelin pathway has a mechanistic role in bone metastases (mets). Atrasentan (A), an endothelin receptor antagonist, has reported activity in CRPC. This trial tested the survival impact of A + docetaxel (D) vs. D+ placebo (P) in CRPC pts with bone mets. Methods: Eligible CRPC pts, stratified for progression type, baseline pain index (BPI), extraskeletal mets and bisphosphonate (BisP) use, were randomized 1:1 to D+A vs. D+P for 12 3-wk cycles. Non-progressors could continue blinded drug alone for 16 more wks. Co-primary endpoints: overall (OS) and progression-free survival (PFS). 930 pts were needed to detect a 25% increase in med OS with D+A (1-sided log-rank, α=0.025, 87% power). Results: 991/1,038 pts were eligible: med age 69, 16% non-white, 61% on BisP, 31% prior prostatectomy, 42% worst pain by BPI ≥ 4, 20% PSA only progression and 56% extraskeletal mets. Multivariate analysis of baseline prognostic factors predicting worse OS were: measurable or evaluable disease progression, high BPI and extraskeletal mets (all p<0.02). No differences in median OS, PFS, or response between arms. Toxicities were similar between arms. Most common toxicities were fatigue, dyspnea, neutropenia and anemia. Addition of A trended to worse OS in pts with visceral mets (HR=1.13 p=0.21) and better OS in those without: bone only (HR=0.86, p=0.20). 357 pts continued A or P up to 52 weeks, no OS difference was seen post-chemo for this subset (p=0.92). Conclusions: This phase III study found no benefit for the addition of A to D in CRPC. Unless specific biomarkers can stratify a population for benefit, endothelin modulators have limited future use in advanced CRPC. Further analyses will test putative surrogacy effects of PSA, serum bone markers and circulating tumor cell kinetics for OS. [Table: see text]

Results of telomerase activity measurements from live circulating tumor cells captured on a slot microfilter in a phase III SWOG-coordinated prostate cancer trial (S0421)

4663

Background: Analysis of circulating tumor cells (CTC) is a promising biomarker strategy in advanced prostate cancer, and telomerase activity (TA) is a recognized cancer marker. To test whether CTC TA is prognostic for survival (OS), we developed a novel Parylene-C slot microfilter capable of capturing live CTC and used it to measure CTC TA as part of a Phase III SWOG-coordinated therapeutic trial in metastatic castration resistant prostate cancer (S0421). Methods: Blood samples were drawn into EDTA tubes and shipped overnight to a central processing site. After Ficoll centrifugation, low constant pressure was used to pass the mononuclear cell layer through two slot microfilters in series as published previously (filter1 captures CTC + background white blood cells; filter2 captures only background white blood cells). Filter-trapped cells were lysed in CHAPS buffer and assayed for TA using qPCR-based telomeric repeat amplification. In parallel, CTC were enumerated using CellSearch (J&J). Cox regression was used to evaluate the association between baseline (pre-treatment) TA and OS overall, and within subgroups characterized by good prognosis (<5) vs. poor prognosis (>=5) baseline CTC counts. CART regression was used to explore potential prognostic subgroups based on baseline PSA, CTC, and TA cutpoints. Results: Samples were obtained from 263 patients. While no association was observed between TA and OS overall, in patients with baseline CTC >=5 (108 of 263 or 41% of patients), TAfilter2 – TAfilter1 representing high CTC TA relative to background blood cells was associated with a hazard ratio (HR) of 1.14 (95% CI 1.05-1.23, p<0.001) for OS after adjusting for risk factors and remained significant when also adjusting for CTC: HR 1.14 (95% CI 1.04-1.23; p=0.005). Exploratory CART regression assessing baseline PSA, CTC, and TA identified risk groups based only on CTC and TA values. Conclusions: Baseline TA from CTC live-captured on a new slot microfilter is the first CTC biomarker shown to be prognostic of OS in men with CTC counts >=5 in a prospective clinical trial. CTC TA may be useful for further identifying prognostic groups in this population.

Phase I pharmacokinetic study of dasatinib (BMS-354825) in patients with advanced malignancies and varying levels of liver dysfunction: S0711, a SWOG early therapeutics committee study

3078

Background: Dasatinib (D) is a first in class Src kinase inhibitor, and inhibits BCR-Abl, c-Kit, PDGFR-beta, EPHA2 and Src family kinases including Src, Lck, Yes, Fyn at nanomolar concentrations. Initially FDA approved for use in imatinib resistant CML. It is a small molecule targeted therapy hepatically metabolized primarily by CYP3A4. We conducted a phase I study to determine maximum tolerated dose (MTD) and pharmacokinetics (PK) of D in patients (pts) with liver dysfunction (LD). Methods: Pts with advanced solid tumors or lymphoma, Zubrod ≤2, no baseline ascites or pleural effusions, adequate renal and bone marrow function, received PO D daily. Cycles q28 days. Pts stratified into 4 LD groups: normal, mild, moderate, severe, using Child-Pugh classification (CPC). Data also collected for NCI ODWG Organ Dysfunction Working GroupCriteria. D dose was escalated in sequential cohorts of pts within each LD category. Blood analysis for D concentrations were determined during cycle 1 using a validated LC-MC/MS assay. Study objectives included characterizing safety, tolerability, PK, identifying the MTD and obtaining preliminary evidence of efficacy. Results: 54 registered pts, 51 pts received 51 cycles of D at doses starting at 100 mg in mild LD (50-140 mg). Median age 60, male 55%, Zubrod 1 70%. CRC 27%. Groups: normal-17, mild-20, moderate-13, severe-1 pt(s). Related AEs include fatigue 35%, diarrhea 27%, anemia 27%, nausea 25%, vomiting 21%, lymphopenia 13%, rash 13%, pleural effusion 8%. 1 DLT of increased CK in a pt in moderate LD with past history of similar episode with previous sorafenib. Previous linear PK disposition, and no accumulation. No apparent PK differences between normal and mild groups. Cycle 1 Day 1 D 140 mg Normal Group: Cmax 129 ng/mL. Mild Group 140mg: Cmax 157 ng/mL. Prolonged disease stabilization (≥4 cycles) in 6 pts, 3 CRC (4,5,8); 1 Pancreas, HCC, Bladder (4,5,6). Conclusions: Recommended dose for Dasatinib given PO QD for pts with mild, moderate, or severe LD using clinical criteria with CPC and no baseline ascites, are 140 mg, 70 mg, insufficient pts, respectively. Dose adjustment not necessary in pts with mild LD.

Docetaxel followed by temsirolimus in suppression of mTOR pathway

e13535

Background: Mammalian target of rapamicin(mTOR) is a downstream regulatory protein of the PI3K/Akt signal transduction pathway. This is a common pathway for a several cell surface receptors including IGFR (Insulin-like Growth Factor Receptor) and EGFR (Epidermal Growth Factor Receptor). The activation of these receptors through PI3K/Akt pathway is essential in cell proliferation, angiogenesis and anti-apoptosis process. Several therapeutic agents that inhibit these receptors have shown to be active in the treatment of diverse types of cancers. Docetaxel (D) is commonly used in the treatment of lung cancer. We demonstrated previously that the sequence of D followed by mTOR inhibition using temsirolimus (T) in lung cancer cell lines (LCCL) had synergistic effect in suppressing cell proliferation compared with T→D. The exact mechanism of this effect is unknown. We studied the expression of mTOR, Raptor and PI3K in these cell lines treated in different time points to investigate the activity of this pathway when using these sequences of drug treatment. Methods: Adenocarcinoma LCCL H2122 and H1437 were plated and exposed to temsirolimus 1000nM and docetaxel 100nM. The cell viability was measured by optical density (OD) at 24, 48 and 72h. We tested the sequence of D treated for 24h followed by addition of T and the reverse in both LCCL. We then prepared cell lysate at 24h, 48h and 72h time points and studied the expression of mTOR, Raptor and PI3K by western blot using antibody obtained from Cell Signaling. Results: The sequence of D→T had increased suppression of mTOR, Raptor and PI3K at 48 and 72 hours compared with the opposite sequence of T→D. Conclusions: The combination of D → T seems to have synergistic suppression of mTOR and PI3K pathway in 2 LCCL compared with opposite sequence. Further studies in animal models using this sequence and confirmation of mTOR suppression may help determine if this is a feasible combination in the treatment of lung cancer.

Effect of denosumab on prolonging bone-metastasis-free survival (BMFS) in men with nonmetastatic castrate-resistant prostate cancer (CRPC) presenting with aggressive PSA kinetics

6

Background: Denosumab, an anti-RANK-ligand monoclonal antibody, has been shown to prolong BMFS by a median 4.2 months and with a 15% risk reduction vs. placebo in men with non-metastatic CRPC and baseline PSA value ≥ 8.0 ng/mL and/or PSA doubling time (DT) ≤ 10.0 months. To determine the efficacy of denosumab in men at greatest risk for bone metastases, we evaluated BMFS in a subset of men with PSADT < 6 months, a cutoff based on a previous report (Smith MR, et al: J Clin Oncol. 23:2918-2925, 2005).

Methods: 1432 men with non-metastatic CRPC (baseline [median] PSA: 12.3 ng/mL, PSADT: 5.1 months, ADT duration: 47.1 months) were randomized 1:1 to receive monthly subcutaneous denosumab 120 mg or placebo. The first patient enrolled February 2006; primary analysis cut-off was July 2010, when > 660 men had developed bone metastasis or died. The primary endpoint was BMFS (time to first bone metastasis or death from any cause). BMFS results are presented for men with baseline PSADT < 6 months.

Results: Median BMFS in the placebo group of men with PSADT < 6 months was 6.5 months shorter than for the placebo group in the full population (18.7 months vs. 25.2 months), indicating that these men are at particularly high risk. In this group of men with PSADT < 6 months, denosumab prolonged BMFS by a median of 7.2 months and with a 23% reduction in risk compared with placebo (Table).

Conclusions: Patients with shortened PSADT are at higher risk of developing bone metastasis and denosumab is markedly effective at prolonging BMFS in this subset of patients.

[Table: see text]

Abstract 1684: 2-Methoxyestradiol reverses the epithelial-mesenchymal transition in Barrett's adenocarcinoma cells

2-Methoxyestradiol (2-ME2) is a novel anti-cancer agent because of its ability to potentiate apoptotic cell death and inhibit cancer cell growth and angiogenesis. In our study, we have investigated whether 2-ME2 is able to modulate epithelial-mesenchymal transition (EMT) in Barrett's esophageal adenocarcinoma cell (OE33), which has been postulated as an absolute requirement for tumor invasion and metastasis. Expression of epithelial (E-cadherin, β-catenin, Keratin-19) and mesenchymal markers (Oct-4, Vimentin) and stem cell markers (CD44, CD24) were studied at mRNA and protein levels in OE33 cells that were treated with 5µmolar/L of 2-ME2 for 24 h and 48 h. Our results indicate expression of β-catenin and E-cadherin is activated in a 2-ME2 dependent fashion in OE33 cells. Expression of Vimentin and Oct-4 is significantly down-regulated in 2-ME2 treated OE33 cells. Altogether, these results provide new insights into the role of 2-ME2 in EMT modulation, which may facilitate development of new therapeutic strategies to prevent the tumor invasion and metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1684. doi:10.1158/1538-7445.AM2011-1684

Phase II evaluation of early oral estramustine, oral etoposide, and intravenous paclitaxel combined with hormonal therapy in patients with high-risk metastatic prostate adenocarcinoma: Southwest Oncology Group S0032

OBJECTIVES

To assess the efficacy of a multiagent taxane-based chemotherapy combined with hormonal therapy in men with metastatic androgen-dependent prostate cancer in a multicenter, cooperative group, single-arm trial.

METHODS

A total of 41 patients with newly diagnosed metastatic prostate cancer involving both the axial and the appendicular skeletons or viscera were enrolled. Of the 41 patients, 35 were treated with combined androgen blockade and ≤4 cycles of oral estramustine (280 mg orally 3 times daily) and etoposide (50 mg/m(2) daily) for 14 days of each 21-day cycle, with paclitaxel (135 mg/m(2) intravenously within 1 hour) on day 2 of each cycle. Chemotherapy was started within 30 days of the initiation of hormonal therapy. The patients were followed up to determine the progression-free survival.

RESULTS

The 35 patients received a total of 126 cycles of chemotherapy, with 30 receiving all 4 cycles. The median progression-free survival for the evaluable population was 13 months (95% confidence interval 10-16), with a median overall survival of 38 months (95% confidence interval 28-49). The main toxicities were myelosuppression, with 9 patients experiencing grade 3 or greater neutropenia and 1 developing grade 4 thrombocytopenia. One patient died of neutropenic infection. Thrombosis embolism occurred 4 times (3 of grade 4 and 1 of grade 3), with 1 episode of grade 4 cardiac ischemia.

CONCLUSIONS

The results of our study have shown that the administration of chemotherapy to this population is feasible, with moderate toxicity. Taxane-based chemotherapy did not demonstrate significant efficacy in this high-risk population of patients with a poor prognosis.

Cyr61/CCN1 signaling is critical for epithelial-mesenchymal transition and stemness and promotes pancreatic carcinogenesis

BACKGROUND

Despite recent advances in outlining the mechanisms involved in pancreatic carcinogenesis, precise molecular pathways and cellular lineage specification remains incompletely understood.

RESULTS

We show here that Cyr61/CCN1 play a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. Cyr61 mRNA and protein were detected in the early precursor lesions and their expression intensified with disease progression. Cyr61/CCN1 expression was also detected in different pancreatic cancer cell lines. The aggressive cell lines, in which the expressions of mesenchymal/stem cell molecular markers are predominant; exhibit more Cyr61/CCN1 expression. Cyr61 expression is exorbitantly higher in cancer stem/tumor initiating Panc-1-side-population (SP) cells. Upon Cyr61/CCN1 silencing, the aggressive behaviors are reduced by obliterating interlinking pathobiological events such as reversing the EMT, blocking the expression of stem-cell-like traits and inhibiting migration. In contrast, addition of Cyr61 protein in culture medium augments EMT and stemness features in relatively less aggressive BxPC3 pancreatic cancer cells. Using a xenograft model we demonstrated that cyr61/CCN1 silencing in Panc-1-SP cells reverses the stemness features and tumor initiating potency of these cells. Moreover, our results imply a miRNA-based mechanism for the regulation of aggressive behaviors of pancreatic cancer cells by Cyr61/CCN1.

CONCLUSIONS

In conclusion, the discovery of the involvement of Cyr61/CCN1 in pancreatic carcinogenesis may represent an important marker for PDAC and suggests Cyr61/CCN1 can be a potential cancer therapeutic target.

Tumor cell-derived PDGF-B potentiates mouse mesenchymal stem cells-pericytes transition and recruitment through an interaction with NRP-1

Background

New blood vessel formation, or angiogenic switch, is an essential event in the development of solid tumors and their metastatic growth. Tumor blood vessel formation and remodeling is a complex and multi-step processes. The differentiation and recruitment of mural cells including vascular smooth muscle cells and pericytes are essential steps in tumor angiogenesis. However, the role of tumor cells in differentiation and recruitment of mural cells has not yet been fully elucidated. This study focuses on the role of human tumor cells in governing the differentiation of mouse mesenchymal stem cells (MSCs) to pericytes and their recruitment in the tumor angiogenesis process.

Results

We show that C3H/10T1/2 mouse embryonic mesenchymal stem cells, under the influence of different tumor cell-derived conditioned media, differentiate into mature pericytes. These differentiated pericytes, in turn, are recruited to bind with capillary-like networks formed by endothelial cells on the matrigel under in vitro conditions and recruited to bind with blood vessels on gel-foam under in vivo conditions. The degree of recruitment of pericytes into in vitro neo-angiogenesis is tumor cell phenotype specific. Interestingly, invasive cells recruit less pericytes as compared to non-invasive cells. We identified tumor cell-secreted platelet-derived growth factor-B (PDGF-B) as a crucial factor controlling the differentiation and recruitment processes through an interaction with neuropilin-1 (NRP-1) in mesenchymal stem cells.

Conclusion

These new insights into the roles of tumor cell-secreted PDGF-B-NRP-1 signaling in MSCs-fate determination may help to develop new antiangiogenic strategies to prevent the tumor growth and metastasis and result in more effective cancer therapies.

Interleukin-21: updated review of Phase I and II clinical trials in metastatic renal cell carcinoma, metastatic melanoma and relapsed/refractory indolent non-Hodgkin's lymphoma

IMPORTANCE TO THE FIELD

In advanced renal cell cancer and malignant melanoma, the current FDA approved immune modulators, such as IL-2, are the only agents which provide a durable complete remission. These responses, however, occur in < 10% of treated patients and their applicability is limited to selected patients because of their toxicity. The identification of new immunotherapeutic agents with an improved response rate and toxicity profile would represent a significant advancement in the treatment of these malignancies.

AREAS COVERED IN THIS REVIEW

This is a comprehensive review of IL-21 including its pharmacology and current developmental status. A literature review was performed using all PubMed listed publications involving IL-21, including original research articles, reviews and abstracts. It also includes a review of current ongoing trials and information from the official product website.

WHAT THE READER WILL GAIN

Recombinant IL-21 (rIL-21) is a new immune modulator currently undergoing Phase I and II testing. It is a cytokine with a four helix structure that has structural and sequence homology to IL-2 and -15, but also possesses many unique biological properties. In this review, we evaluate the development, pharmacologic properties, safety profile and current clinical efficacy of rIL-21.

TAKE HOME MESSAGE

rIL-21 has an acceptable safety profile and encouraging single agent activity in early phase renal cell carcinoma and melanoma clinical trials.

Clinical and correlative results of SWOG S0354: a phase II trial of CNTO328 (siltuximab), a monoclonal antibody against interleukin-6, in chemotherapy-pretreated patients with castration-resistant prostate cancer

PURPOSE

Interleukin-6 (IL-6) facilitates cancer cell survival via pleotrophic effects. We conducted a multicenter phase II study of CNTO328 (siltuximab) as second-line therapy for men with castration-resistant prostate cancer.

EXPERIMENTAL DESIGN

Eligible men had castration-resistant prostate cancer treated with one prior chemotherapy. Subjects were treated with 6 mg/kg CNTO328 i.v. every 2 weeks for 12 cycles. Response was assessed after every three cycles. Primary end point was prostate-specific antigen (PSA) response rate defined as a 50% reduction. Accrual was planned in two stages, with 20 eligible patients in the first stage and 40 overall. Plasma cytokines and growth factors were measured by Luminex.

RESULTS

Fifty-three eligible subjects had all received prior taxane therapy. Two (3.8%; 95% CI, 0.5-13.0%) had PSA response. None of the 31 patients with measurable disease had a RECIST (Response Evaluation Criteria in Solid Tumors) response but 7 (23%) had stable disease. With median follow-up of 14.8 months, median progression-free survival was 1.6 months (95% CI, 1.6-1.7) and median overall survival was 11.6 months (95% CI, 7.5-19.0). Grade 3/4 toxicities included disseminated intravascular coagulation (1), central nervous system ischemia (1), elevated aspartate aminotransferase (1), gastritis/esophagitis (2), thrombocytopenia (2), pain (2), leukopenia (1), and neuropathy (2). Median baseline IL-6 levels were 12.5 pg/mL (interquartile range, 2.5-41.5). Patients with IL-6 >12.5 pg/mL had worse survival than those with levels <12.5 pg/mL (53% versus 94%; P = 0.02). After treatment, IL-6 levels were >250-fold higher. Thirty-two of 38 patients had a decline in C-reactive protein plasma levels at 6 weeks.

CONCLUSIONS

CNTO328 resulted in a PSA response rate of 3.8% and a RECIST stable disease rate of 23%. Declining C-reactive protein levels during treatment may reflect biological activity. Despite evidence of CNTO-mediated IL-6 inhibition, elevated baseline IL-6 levels portended a poor prognosis.

Abstract 1766: Effect of soy isoflavones on prostate cancer cell cycle regulation and apoptosis

Background: As many as one-third of all cancer deaths in the United States can be linked to diet. Significant epidemiological evidence suggests a role of a variety of dietary factors including the amount of dietary soy. In Asian countries where the average diet consists of 10 times the amount of soy products consumed compared to the average American diet there is a significantly lower incidence of prostate and breast cancer. Further supporting a dietary and environmental influence is the finding that Asian immigrants who have moved to the United States and adopt a Western diet have a prostate cancer incidence that approaches U.S. born males. These findings have been supported by other studies and, again, suggest that environmental factors such as dietary soy intake may be responsible for these differences in geographic incidence. Although there is this preclinical and epidemiological data suggesting that soy isoflavones decrease the risk of developing prostate cancer (PC), there is limited information regarding the in vivo effects of soy supplementation on human PC and benign prostate tissue. Methods: The primary objective of this study was to evaluate the molecular effects of soy isoflavones on human PC cell cycle regulation and apoptosis. Patients with histologically confirmed PC who had chosen radical prostatectomy (RRP) for treatment (without any other primary therapy) were randomized in double blind fashion to receive either soy supplementation or placebo. The patients in the treatment group received 4 capsules of a commercially available pure soy tablet (240 mg of total isoflavones) from time of enrollment until RRP. At the time of surgery, fresh tissue was collected from the tumor and adjacent normal tissue. Using these samples, we evaluated the status of genes essential for cell cycle regulation and apoptosis using cDNA microarray analyses. Results: In this preliminary analysis, multiple cell cycle and apoptotic genes were either down regulated or up regulated in the treatment samples compared to the placebo treated samples, including BAX, BCL-2, and Caspase-7. This effect was present in both tumor and adjacent normal tissue. Using samples from an additional four patients, we then further characterized these changes in gene expression using Western Blots analysis. Cleaved caspase-7 was up regulated in soy treated tumor and adjacent normal samples when compared to placebo, suggesting that soy mediates apoptosis though Caspace-7. The expression of BCL2L1 was down regulated in the treated compared to placebo tissue with this change being most marked in the adjacent normal samples. Conclusion: In total, our results suggest that soy isoflavones may exert a prostate cancer protective effect via a beneficial effect on cell cycle regulation and apoptosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1766.

S9511: a Southwest Oncology Group phase II study of trimetrexate, 5-fluorouracil, and leucovorin in unresectable or metastatic adenocarcinoma of the stomach

OBJECTIVE

The primary objective of this trial was to evaluate the response rate for trimetrexate in conjunction with 5-FU and leucovorin (LV) (= TFL) in the treatment of advanced gastric cancer in a phase II, cooperative group setting.

METHODS

Patients with locally advanced, unresectable, or metastatic adenocarcinoma of the stomach received trimetrexate 110 mg/m IV over 60 minutes day 1, followed by 5-FU 500 mg/m IV bolus and LV 200 mg/m IV over 60 minutes day 2, followed by oral LV 15 mg every 6 hours x 7 doses, all weekly for 6 weeks followed by 2 weeks of rest, continued until progression.

RESULTS

Characteristics for 37 eligible patients: median age 63 (range: 23-83); male/female: 69% of 31%; performance status 0/1/2 15/20/1. The confirmed response rate was 19%, and median overall survival was 6 months. Two patients died as a result of therapy, 1 because of infection without significant neutropenia, and 1 due to perforation of a responding gastric lesion. Seventy-two percent experienced grades 3 and 4 toxicity, most commonly diarrhea, fatigue, and lymphopenia.

CONCLUSIONS

This regimen achieves response rates comparable to other 5-FU-based regimens, when used in treatment of incurable gastric cancer. Toxicity appears manageable.

Intravenous zoledronic acid to prevent osteoporosis in a veteran population with multiple risk factors for bone loss on androgen deprivation therapy

PURPOSE

Androgen deprivation therapy for prostate cancer is associated with osteoporosis and increased fracture risk. Previous studies of zoledronic acid demonstrated bone loss prevention in patients initiating androgen deprivation therapy. There are limited data on patients on prolonged androgen deprivation therapy or in Veterans Affairs patients with multiple risk factors for osteoporosis.

METHODS

We randomized 93 patients with M0 prostate cancer in this placebo controlled trial in the Veterans Affairs health care system. Preplanned strata included 50 patients on androgen deprivation therapy for less than 1 year (stratum 1) and 43 on androgen deprivation therapy for greater than 1 year (stratum 2). In each stratum patients were randomized to 4 mg zoledronic acid intravenously every 3 months for 4 treatments or intravenous placebo. The primary end point was the percent change in bone mineral density at the lumbar spine at 12 months.

RESULTS

Age, race, body mass index and osteoporosis risk factors were similar for the 2 treatments. Most patients were former smokers, had moderate alcohol intake, were not on calcium/vitamin D supplements and were relatively sedentary at baseline. In stratum 1 spine bone mineral density increased 5.95% in the zoledronic acid arm and decreased 3.23% in the placebo arm (p = 0.0044). In stratum 2 spine bone mineral density increased 6.08% in the zoledronic acid arm and only increased 1.57% in the placebo arm (p = 0.0005). Treatment was well tolerated with minimal impact on renal function.

CONCLUSIONS

Zoledronic acid improved bone mineral density in patients with M0 prostate cancer on androgen deprivation therapy for 1 year or less, or greater than 1 year. This finding indicates that bisphosphonate therapy remains effective when initiated later in the course of androgen deprivation therapy and is efficacious in Veterans Affairs patients with multiple risk factors for osteoporosis.

Southwest Oncology Group phase II study of ispinesib in androgen-independent prostate cancer previously treated with taxanes

PURPOSE

The mitotic spindle has proven to be an effective therapeutic target in antineoplastic efforts. In this study, we sought to assess the efficacy of ispinesib, a mitotic kinesin spindle protein (KSP) inhibitor in androgen-independent prostate cancer progressing after docetaxel.

PATIENTS AND METHODS

Patients were treated with ispinesib 18 mg/m2 every 21 days and assessed for prostate-specific antigen (PSA) and measurable disease response at regular intervals. Kinesin spindle protein expression in archival tumors, population ispinesib pharmacokinetics, and pharmacodynamic assessments of circulating lymphocytes were included.

RESULTS

The study was terminated after first stage because no responses were seen in the first 21 patients. Median duration of PSA or clinical progression-free survival was 9 weeks. Plasma concentrations of ispinesib were comparable with those observed in previous phase I investigations. Immunohistochemical analysis of archival tumor specimens did not demonstrate significant KSP expression in most of the prostate cancer cases studied. Pharmacodynamic assessments of circulating lymphocytes from patients receiving ispinesib showed an absence of monopolar spindle formation, as would be expected if the drug were having its expected effects.

CONCLUSION

Ispinesib was inactive in this study of patients with androgen-independent, and largely docetaxelresistant, prostate cancer. The lack of efficacy might be explained by the low expression of the drug target seen in prostate cancer, whereas not detecting monopolar spindles in circulating lymphocytes with drug treatment likely reflects the lack of dividing cells in peripheral blood.

VEGF-A165 induces human aortic smooth muscle cell migration by activating neuropilin-1-VEGFR1-PI3K axis

Vascular smooth muscle cells (SMCs), one of the major cell types of the vascular wall, play a critical role in the process of angiogenesis under both physiological and pathophysiological conditions, including the cancer microenvironment. Previous studies have shown that VEGF-A 165 augments vascular SMC migration via VEGFR2 (KDR/Flk1) pathways. In this study, we found that VEGF-A 165 (recombinant protein or breast tumor cell-secreted) is also capable of inducing migration of VEGFR2-negative human aortic smooth muscle cells (hAOSMCs), and this induction is mediated through a molecular cross-talk of neuropilin-1 (NRP-1), VEGFR1 (Flt-1), and phosphoinositide 3-kinase (PI3K)/Akt signaling kinase. We found that VEGF-A 165 induces hAOSMC migration parallel with the induction of NRP-1 and VEGFR1 expressions and their associations along with the activation of PI3K/Akt. Neutralization of VEGF action by its antibody or inhibition of VEGF-induced PI3K/Akt kinase activation by wortmannin, a PI3K/Akt specific inhibitor, results in inhibition of VEGF-induced hAOSMC migration. Moreover, RNAi-mediated elimination of the NRP-1 expression or blocking of the activity of VEGFR1 by its antibody in hAOSMCs impairs the VEGF-A 165-induced migration of these cells as well as activation of PI3K/Akt kinase. Collectively, these results establish, for the first time, a mechanistic link among VEGF-A 165, NRP-1, VEGFR1, and PI3K/Akt in the regulation of migration of human vascular smooth muscle cells that eventually could be involved in the angiogenic switch.