Markovic, Svetomir N.

8041 Background: ABT-510 is a synthetic peptide analog of thrombospondin-1 demonstrating inhibition of VEGF/bFGF mediated human endothelial cell migration, proliferation, tube formation, cornea-neovascularization as well as inhibition of tumor growth in vivo (B16F10 melanoma). Having been found to be safe in phase I testing, ABT-510 has entered phase II trials. Presented are the results of a phase II study using ABT-510 for the treatment of stage IV melanoma. Methods: A two stage phase II clinical trial was conducted to assess the anti-tumor activity, safety profile and pharmacodynamics of ABT510 in patients with stage IV melanoma. Patients self-administered 100mg of ABT-510 subcutaneously twice/day. Therapy was continued in the absence of excessive toxicity or tumor progression. Primary endpoint was 18 week progression free survival rate. Enrolled were patients at least 18 years of age with measurable (RECIST) metastatic melanoma, ECOG performance status of 0–2 and normal pre-registration blood tests. Exclusion criteria included: cancer therapy less than 4 weeks prior to registration; failure to recover from prior therapy; brain metastases; significant recent bleeding; uncontrolled hypertension; and ongoing anti-coagulation. Pregnant or nursing women were not eligible. Results: Twenty-one patients (67% male) were enrolled with a median age of 55 years. Most patients had M1c disease (80%) and 62% had prior chemotherapy for stage IV melanoma. None of the patients were ineligible/canceled participation. After the first stage of the trial was complete, only 3 of the first 20 patients enrolled were progression-free at 18 weeks. Having not met the minimal clinical efficacy requirement (at least 7 of the first 20 patients progression-free at 18 weeks) the trial was closed to further accrual. Correlative laboratory studies suggested decreases in some of the measured parameters of angiogenesis (VEGFC, circulating endothelial cells) with no impact on immune homeostasis. Conclusions: Single agent ABT-510 therapy administered at 100mg twice/day to patients with previously treated metastatic melanoma did not demonstrate significant clinical efficacy. However, changes in measured parameters of angiogenesis suggest possible clinical efficacy with higher dosing or in combination with cytotoxic therapy. [Table: see text]

e20046 Background: The immune system and VEGF may play a role in melanoma behavior. We prospectively collected data in 10 stage III and 22 stage IV melanoma patients to observe factors influencing outcomes. Methods: We assessed median survival (MS), LDH, BRAF, VEGF, Th1/Th2 ratio, regulatory T cells (Tregs) and CD4/CD8 ratio, which were measured upon enrollment. LDH and BRAF were measured in standard commercial labs; VEGF via ELISA at LVHN; Th1/Th2 ratio and CD4/CD8 ratio via flow cytometry at Mayo Clinic. Stage III patients were treated with resection and interferon or observation. Stage IV patients were treated with some or all of the following: resection +/- GM-CSF, IL-2, ipilimumab, vemurafenib, carboplatin/paclitaxel/bevacizumab and temazolamide. Results: MS for stage IV patients was 48 months using a Kaplan-Meier survival curve. The only variable associated with survival was LDH, (HR=1.0017, 95%CI: 1.0003-1.0032, p=0.02). In stage IV patients, there was a positive correlation between VEGF and Tregs (r=.485, n=22 p=0.022) and a negative correlation between Tregs and Th1/Th2 (r=-.470, n=22, p=0.027). In stage III/IV patients who were alive at study completion, there was a positive correlation between CD4/CD8 and VEGF (r=.792, n=10, p=0.006). In patients who died, there was a negative correlation between Tregs and Th1/Th2 (r=-.660, n=12, p=0.02). 7 of the stage IV patients are currently disease free, including 5 of the 10 who received IL-2 +/- metastectomy. Conclusions: While a median survival of 48 months was provocative for stage IV patients, it may reflect referral selection at an IL-2 center. Recent advances such as ipilimumab (which lowers Tregs), BRAF inhibitors, and immunotherapy/aggressive resection as initial therapy may have impacted survival. The literature suggests that an elevated CD4/CD8 ratio predicts better outcomes. Higher VEGF levels have also been associated with lower overall survival in patients treated with IL-2. We found an association between higher VEGF levels and increased Tregs in deceased patients but not in living patients. In patients still alive, higher VEGF was balanced by a higher CD4/CD8 ratio. We did not find a correlation between baseline VEGF and survival.

9073 Background: An accumulating body of evidence suggests that the outcome of early-stage melanoma is influenced by endocrine and menopausal status. However, it remains controversial as to whether the superior female melanoma-specific survival (MSS) is restricted to early stage disease or if it also pertains to patients with metastatic melanoma (MM). Methods: We analyzed data from the 13 registries that participate in the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program. We identified all cases of primary invasive melanoma diagnosed between 1992 and 2009; none of the patients had a prior history of another cancer. MSS was compared between males and females, stratified by stage of disease. Age groups were defined as 18-45y, 46-54y, 55-64y, 65+y as a proxy of female menopausal status. Results: The study population included 87,165primary invasive melanoma cases (unstaged n=2834). MSS was significantly poorer for males compared to females for localized (n=72,456) and regional (n=8,945) disease for all age groups (Hazard ratio (HR) ranging from 1.21 to 2.09, all p<0.001). MSS was not significantly different between males and females for patients with distant disease at diagnosis (n= 2930; HR 0.99, 0.92, 1.11, 1.07 for each age group) and remained non-significant after adjusting for Breslow thickness, histologic subtype, anatomic site, and age group (adjusted HR 1.04 males vs. females; 95% CI 0.95-1.14; p=0.41). Conclusions: While our results were consistent with earlier reports that women have higher MSS rates compared to men for early (stage I-III) melanoma, the intriguing finding of this study was that the female survival advantage does not vary with age or menopausal status as compared to men, which is contrary to previously published reports. Furthermore, we found that the difference in survival was no longer significant for patients with MM, suggesting that sex may influence local and regional, but not distant cancer progression.

7041 Background: Prognostic factors for diffuse large B-cell lymphoma (DLBCL) at day 100 post-autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT) have not been evaluated. We previously reported that absolute monocyte (AMC)/lymphocyte count (ALC) prognostic score (AMLCPS) at diagnosis of DLBCL patients is a prognostic factor of survival, stratifying patients into three risk groups: low- (AMC<630/μL and ALC>1000/μL), intermediate- (AMC ≥ 630/μL or ALC ≤ 1000/μL) and high-risk (AMC ≥ 630/μL and ALC ≤ 1000/μL) (Leukemia 25: 1502-9, 2011). Therefore, we evaluated day 100 AMLCPS as a prognostic factor of survival by landmark analysis from day 100 post-APBHSCT in DLBCL patients. Methods: DLBCL patients that achieved complete response by day 100 post-APBHSCT qualified for the study. From 2000 to 2007, 134 consecutive DLBCL patients were evaluated. Overall survival (OS) and progression free survival (PFS) were calculated using Kaplan-Meier analysis. Results: The median follow up from day 100 for the cohort was 5.5 years (range: 0.17-12.17 years) and for living patients (N=93) was 6.9 years (range: 2.5-12.17 years). Day 100 AMLCPS was able to stratify patients into three risk groups low-, intermediate-, and high-risk for OS [low: median OS = not reached, 5-year survival rate = 94% (95%CI 83.3%-98.1%); intermediate: median OS = not reached, 5-year survival rate = 70% (95%CI 58.0%-79.8%); high: median OS = 2.2 years, 5-year survival rate = 13% (95%CI 3.4%-40.5%); p<0.0001] and PFS [low: median PFS = not reached, 5-year progression free rate = 87% (95%CI 74.5%-94.3%); intermediate: median PFS = 10.9 years, 5-year progression free rate = 67% (95%CI 55.4%-77.5%); high: median PFS = 1 year, 5-year progression free rate = 13% (95%CI 3.4%-40.5%); p<0.0001]. The day 100 AMLCPS was balanced in relation to the International Prognostic Index (IPI; p=0.22), infused CD34+ stem cells (p=0.92), and disease status pre-APBHSCT (complete remission versus partial response; p=0.11). Conclusions: The day 100 AMLCPS is a simple biomarker that can help identify DLBCL patients post-APBHSCT with poor clinical outcomes.

3037 Background: Tumor immunotherapies directed towards enhancing natural or endogenous anti-tumor T-cell immunity in patients with advanced malignancies are currently being implemented in clinic with promising results. In order to optimize therapeutic protocols and monitor the effectiveness of such therapies, a reliable T-cell marker is needed. Methods: We utilized CD11a (LFA-1, lymphocyte functional-associated antigen 1), an integrin up-regulated on effector and memory CD8 T-cells, and PD-1 (programmed death-1), an immunoregulatory receptor expressed by activated T cells, as biomarkers to identify, quantitate and monitor endogenous tumor-reactive cytotoxic lymphocytes (CTLs) in two mouse tumor models and the peripheral blood (PB) of 12 patients with stage IV melanoma. Results: High expression of CD11a and PD-1 was identified among CD8 T-cells residing within primary and metastatic murine tumor sites, as well as in spontaneous murine breast cancer tissues. In the PB of melanoma patients, tumor antigen-specific CD8 T cells were associated with a population of CD11a high CD8 T-cells which co-expressed high levels of PD-1, as opposed to eleven healthy donors who had a much lower frequency of PD-1+ CD11a high CD8 T-cells (p <0.0001). Phenotypic analysis showed that CD11a high CD8 T-cells are proliferating (Ki67 positive) activated (CD62L low, CD69 high) T-cells. Increased CD11a high CD8 T-cells and delayed tumor growth were observed in PD-1 deficient mice, suggesting that the antitumor effector function of CD8 T cells is compromised by co-expression of elevated levels of PD-1. Conclusions: CD11a high CD8 T-cell population expresses high levels of PD-1 and is likely the cellular target of PD-1 blockade therapy. High expression of CD11a (LFA-1) and PD-1 (CD279) by CD8 T-cells may represent a novel biomarker to identify and monitor endogenous tumor-reactive CTLs. This may not only provide an immunological readout for evaluating the efficacy of therapy, but also contribute to the selection of patients with solid malignancies likely to benefit from anti-PD-1 therapy.

e21112 Background: Metastatic malignant melanoma is difficult to treat and has a poor prognosis. Systemic therapy for metastatic melanoma has had limited success and novel drug combinations need to be tested. To that end, we have combined anti-angiogenic therapy (bevacizumab) with chemotherapy in clinical trials and have shown some clinical efficacy. Vascular endothelial growth factor (VEGF) is increasingly seen as an immunosuppressive factor that hampers dendritic cell maturation and reduces antigen presentation. We have recently shown that tumor-derived VEGF plays a role in Th-2 driven systemic chronic inflammation seen in advanced melanoma patients. Therefore, our data suggest that blocking tumor derived VEGF with the monoclonal antibody bevacizumab may impact immunity in such a way that augments anti-tumor immunity enhancing clinical efficacy. Methods: In order to understand the immune status in metastatic melanoma patients on chemotherapy (n=55) or chemotherapy plus bevacizumab (n=73), we measured levels of 42 cytokines, chemokines and growth factors in plasma by a mulit-plex bead assay. Matched pairs analysis was performed to determine if the average responses of the measured cytokines were different between the patients that received chemotherapy with bevacizumab or chemotherapy alone. The pre-treatment levels were compared with levels drawn four weeks after the first treatment. Results: There were significant differences in IL-1a, IL-1ra, IL-6, IL-8 and IP-10 between patients treated with chemotherapy alone relative to patients treated with chemotherapy plus bevacizumab. In all cases of patients treated with chemotherapy plus bevacizumab, the levels of these cytokines all decreased relative to pre-treatment samples. In patients treated with chemotherapy alone the levels of these cytokines increased relative to pre-treatment samples. Conclusions: Our data suggest that treating patients with the anti-angiogenic drug bevacizumab may affect the plasma cytokine milieu by reducing the level of many key inflammatory cytokines. Therefore, the use of bevacizumab in combination with chemotherapy may augment host immunity and elicit a more effective anti-tumor immune response.

8600 Background: The prognosis of stage IV melanoma patients remains poor. Published results have suggested that components of the complete blood count have significant prognostic value in several malignancies. Among the most studied were the absolute lymphocyte count (ALC), and absolute monocyte count (AMC) on clinical outcomes of patients with lymphoid malignancies. Thus, we sought to investigate if the pre-operative ALC (ALC-PO), AMC (AMC-PO) and ALC/AMC ratio (ALC/AMC-PO) affects the risk of disease recurrence and survival after complete surgical resection of metastatic melanoma. Methods: We studied 66 stage IV, resected melanoma patients followed at Mayo Clinic from 2000 to 2010. Log rank chi-square analysis was used to determine the best cut-off values for each pre-operative variable, while proportional hazards models were used to compared survival. Results: The median follow-up of the cohort was 24 months (range: 2.3 – 117 months). ALC-PO, AMC-PO and ALC/AMC-PO, as continuous variables, were all identified as prognostic factors for both relapse-free survival (RFS) and overall survival (OS). The best cut-off values for ALC-PO, AMC-PO and ALC/AMC-PO were 1.9; 0.62; and 2.05, respectively. Using Kaplan-Meier analysis, patients with an ALC-PO ≥ 1.9 x 109/L experienced superior OS and RFS compared with ALC-PO < 1.9 x 109/L patients [median OS of 58 months vs. 34 months, p < 0.04; median RFS of 14 months vs. 5 months, p < 0.009]. Conversely, a low AMC-PO (<0.62 x 109/L) was associated with better OS and RFS compared with higher AMC-PO (≥ 0.62 x 109/L): [median OS of 47 months vs. 14 months, p < 0.007; median RFS of 9 months vs. 5 months, p < 0.02]. When the ALC-PO and AMC-PO were combined as an ALC/AMC ratio, the group with an ALC/AMC-PO ≥ 2.05 experienced a superior OS and RFS compared to patients with ALC/AMC-PO < 2.05: [median OS of 49 months vs. 12 months, p < 0.0001; median RFS of 10 months vs. 4 months, p < 0.0001]. Multivariate analysis showed ALC/AMC-PO to be an independent prognostic factor for RFS and OS (HR = 0.32, p < 0.003; HR = 0.23, p < 0.002). Conclusions: Our study showed, that ALC/AMC-PO ratio is an independent prognostic factor for RFS and OS in patients undergoing resection of metastatic (stage IV) melanoma.

e14507 Background: Serious gastrointestinal injury (SGI) is a rare but documented side effect that can occur independently with agents that affect the vascular endothelial growth factor (VEGF) receptor or with stereotactic body radiotherapy (SBRT). The risk of SGI in patients treated with the combination of SBRT sequentially followed by a VEGF inhibitor (VEGF-i) is not yet quantified. We explored the incidence of SGI in patients treated with SBRT with or without VEGF-i therapy at a single institution. Methods: From May 2008 to August 2011, 76 patients with 84 primary or metastatic intraabdominal lesions underwent SBRT (median dose, 50 Gy in 5 fractions). Twenty of these patients (26%) received a VEGF-i within two years of completing SBRT (bevacizumab, n=14; sorafenib, n=4; pazopanib, n=1; sunitinib, n=1). The most common site treated with SBRT was the liver (n=43, 57%), and the most common histology was colorectal adenocarcinoma (n=18, 24%). Other common histologies included melanoma of the skin (n=14, 18%) and non-small cell lung cancer (n=10, 13%). The incidence of SGI (CTCAE v4.0 grade 3 to 5 ulceration or perforation) after SBRT was obtained, and the relationship between SGI and VEGF-i was examined. Other factors that could potentially contribute to SGI, such as radiotherapy dose to bowel, were also analyzed. Results: Seven patients (9%) experienced SGI at a median 4.6 months (range, 3-17 months) after SBRT. All seven had received a VEGF-i prior to SGI and within 13 months of completing SBRT, and five received the VEGF-i within three months of SBRT. The six-month estimate of SGI in patients receiving a VEGF-i within three months of SBRT was 38%. No SGI was noted in the 63 patients not receiving VEGF-i therapy after SBRT. The Log-Rank test showed a significant correlation between SGI and VEGF-i therapy within three months of SBRT (p=0.0006) but not between SGI and maximum radiotherapy bowel dose (p=0.20). Conclusions: The combination of SBRT and VEGF-i therapy results in a much higher risk of SGI than would be expected with either treatment given independently. Local therapies other than SBRT should be considered if a patient is likely to be treated with a VEGF-i in the future.

8599 Background: Chemotherapy resistance is a common, difficult problem for melanoma patients needing long term care and those suffering from recurrence. Neural growth factor receptor (NGFR), also known as CD271, is commonly expressed on mesenchymal stem cells and is important for development, survival and differentiation of cells. This has previously shown to be expressed on melanoma stem cells. We hypothesized that treatment with carboplatin enriches the population of tumor cells for cancer stem cells (CSC) as a mechanism of chemotherapy resistance. Methods: Core tumor samples from 118 patients with metastatic melanoma were obtained from formalin-fixed paraffin embedded specimens. Slides were stained using an anti-CD271 antibody for IHC. A375 melanoma cells were treated with increasing concentrations of carboplatin for approximately 1 year. WT, 6 mg/mL and 10 mg/mL resistant cells were tagged with CD271-PE antibody and run on a flow cytometer. These cells were then tested for gene expression by microarray using an Affymetrix human 133 plus 2.0 chip, and analyzed on Partek software. Pathway analysis of these carboplatin resistant cells was preformed using Ingenuity. Results: Virtually all melanoma tumor samples stained positively for CD271 by IHC, with a median of 50% cells within tumor samples expressing the cytoplasmic marker. Flow cytometry demonstrated an increase in the percentage of cells expressing CD271 as resistance to carboplatin increased. Wild type A375 cells contained 30% positive CD271, A375 6mg/mL resistant contained 42% positive and A375 10mg/mL resistant showed 66% positive. Microarray also exhibited a direct correlation between CD271 gene expression with increasing carboplatin resistance. Functional ontology enrichment revealed development and regulation of the EMT pathway as an important process impacted by our resistant cell line. Conclusions: The data suggests that as melanoma cells become resistant to certain chemotherapy drugs they essentially loose their differentiated phenotype and become more stem cell-like. Monitoring melanoma expression of CD271 could help individualize therapy and anticipate chemotherapeutic resistance in this high-risk group of patients.