Abstract PD6-02: A randomized, controlled trial of high dose vs. standard dose vitamin D for aromatase inhibitor-induced arthralgia in breast cancer survivors

Background: Approximately half of women on aromatase inihbitor (AI) therapy develop AI-induced arthralgia (AIA), and many discontinue the medication because of this common side effect. While Vitamin D has been studied as a treatment for AIA, trial results have been conflicting thus far.

Patients and Methods: All subjects were post menopausal women who were beginning adjuvant AI therapy for stage I-III hormone receptor positive breast cancer. Patients were randomized 1:1 to receive standard dose vitamin D3 (800 IU daily for 52 weeks) or high dose vitamin D3 (50,000 IU weekly for 12 weeks, followed by 2000 IU daily for 40 weeks). All patients also took oral calcium 600 mg daily. The primary endpoint was development of AIA, as defined by pre-specified changes in the Health Assessment Questionnaire II (HAQ-II). Secondary endpoints include compliance with AI therapy, and correlation between grip strength and development of AIA. Exploratory endpoint was measurement of inflammatory cytokine reduction in each arm. The trial was designed to enroll 184 patients, but this futility analysis was performed after 93 patients were enrolled. The futility boundary for stopping the trial early was calculated as p = 0.47.

Results: All 93 patients (46 in the high dose arm, and 47 in the standard dose arm) enrolled in the study at the time of the interim analysis were evaluable. The HAQ-II was completed at 12 weeks in 76% on the high dose arm, and 68% in the standard dose arm. Subjects who did not complete the questionnaire were deemed as study failures (i.e. development of AIA was assumed). In the high dose arm, 25 patients (54%) developed AIA, compared to 27 patients (57%) in the standard dose arm. The one-tailed p value is 0.3818, and the Z-score is 0.3, yielding only a 38% conditional power that that study would find a significant difference between the two arms. Thus, the study was terminated early for futility. There was no significant difference between the two arms in adherence to AI therapy. The grip strength and inflammatory cytokine data are pending at this time. They will be ready by the time of the conference.

Conclusions: There was no significant signal for benefit of high dose vitamin D supplementation, as compared to standard dose vitamin D, for AIA prevention in post menopausal women taking adjuvant AI therapy. These results further characterize the role of Vitamin D in AIA, and they inform future clinical trials in this arena. Further research is necessary, as this remains an important cause of non-adherence to this highly effective therapy.

Citation Format: Niravath P, Wang T, Hilsenbeck SG, Lipscomb K, Pavlick A, Jiralerspong S, Nangia J, Ellis M, Ademuyiwa F, Cherian M, Frith A, Ma C, Park H, Rigden C, Suresh R, Osborne CK, Rimawi MF. A randomized, controlled trial of high dose vs. standard dose vitamin D for aromatase inhibitor-induced arthralgia in breast cancer survivors [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-02.

A BRCA1-Like, 25-Gene Assay Predicts for Anthracycline-Chemosensitivity in Sporadic Triple-Negative Breast Cancer

Background Studies have shown higher chemosensitivity to anthracyclines in BRCA1-associated breast cancer (BABC) when compared to sporadic triple-negative breast cancers (TNBC), possibly due to differences in DNA repair function. We hypothesized that a subset of TNBC with acquired BRCA1 deficiency and defective DNA repair function will benefit most from DNA-damaging agents, such as anthracyclines. Methods We applied a previously published BRCA1 gene expression signature that differentiates BABC from sporadic TNBC to three datasets of sporadic TNBC from Baylor College of Medicine (BCM, n=68), GSE2034 (n=49), and the Netherlands Cancer Institute (NKI2, n=40). The signature separated the sporadic TNBC samples into those with a gene expression profile similar to BABC, or BRCA1-like, versus those with an expression pattern similar to sporadic TNBC, nonBRCA1-like. A list of 92 genes was obtained from the overlap of the most differentially expressed genes between the BRCA1-like samples and nonBRCA1-like samples in each of the three datasets. We then confirmed a subset of the 25 most differentially expressed genes by quantitative RTPCR. We validated the predictive value of this BRCA1-based, 25-gene assay in anthracycline response in three neoadjuvant studies of fluorouracil, epirubicin, and cyclophosphamide (FEC 6 cycles, n=53), doxorubicin and cyclophosphamide (AC 4 cycles, n=12), and T-FAC (paclitaxel-FAC, n=16). Results We determined gene expression of the 92 candidate genes by RT-PCR on 30 available samples of the BCM database. 25 genes were found to have the highest correlation between the microarray and RTQPCR gene expression. Gene expression profile using these 25-gene assay was obtained for three databases which included neoadjuvant anthracycline response data. The 25-gene assay predicted for anthracycline response in sporadic triple-negative breast cancers. In a neoadjuvant FEC study, this assay predicted for pathologic complete response (pCR) in 14/25 patients with BRCA1-like pattern, vs. 7/25 with sporadic-like pattern, p<0.05. In the AC study, 6/9 patients in the BRCA1-like group achieved pCR, vs. 0/3 in nonBRCA1-like group, p<0.05. Finally, in the T-FAC study, 5/7 patients in the BRCA1-like group achieved pCR vs. 3/9 patients in the nonBRCA1-like group, p=0.15. Analysis of the microarray data of triple negative breast cancer revealed higher PARP1 expression levels in the BRCA1-like group when compared to nonBRCA1-like group. Conclusion We present a promising BRCA1-based 25-gene assay that can be used on formalin-fixed paraffin-embedded tissue that may guide therapy in triple- negative breast cancer. The assay differentiates TNBC that are very sensitive to anthracyclines, and it should now be tested and validated prospectively in clinical trials with anthracyclines, other DNA-damaging agents, and PARP1 inhibitors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 110.

Targeting Intrinsically-Resistant Breast Cancer Stem Cells with Gamma-Secretase Inhibitors

Background: We showed previously that tumorigenic, mammosphere-forming human breast cancer cells characterized by high CD44 and low or undetectable CD24 levels (CD44+/CD24-/low) are intrinsically resistant to conventional chemotherapy, and therefore may be responsible for cancer relapse. Our goal is identify novel drugs that selectively target these chemotherapy-resistant, tumor-initiating cells. Gene expression analysis of CD44+/CD24-/low cells vs. non-tumorigenic cells implicated the Notch, PI3K, and Hedgehog signaling pathways in regulating CD44+/CD24-/low cells. Thus, Notch, PI3K-AKT, and/or Hedgehog inhibitors may eliminate this unique subpopulation of cancer cells, either alone or in combination with chemotherapy, and could improve patient outcome. To test this hypothesis, we are carrying out a series of preclinical and clinical studies using a gamma-secretase inhibitor (GSI) to target the Notch pathway. Methods: For preclinical studies, stable xenograft lines were generated by transplantation of human tumor biopsy fragments into immunocompromised mice. Mice with tumors (n = 32, 150-300 mm3) were randomized to four treatment groups: 1) vehicle control, 2) chemotherapy: docetaxel 3) drug: GSI (MRK-003, Merck) or 4) combination: docetaxel + MRK-003. During treatment, mice were monitored for tumor volume and body weight. At the end of the treatment cycle, residual tumors were characterized by FACS for the percentage of CD44+/CD24-/low cells, as well as for mammosphere-forming efficiency (MSFE) and tumor-initiating capacity. In a complementary clinical trial, breast cancer biopsies taken before and after treatment with GSI (MK-0752, Merck) were characterized for expression of CD44, CD24, and ALDH by FACS and for MSFE. Results and Conclusions: In preclinical studies using two independent triple negative xenograft lines, Notch pathway inhibition reduced mammosphere formation but did not affect tumor volume, with no consistent change in marker expression by FACS. In patient samples, MSFE also declined after the first cycle of GSI/chemotherapy and remained low after subsequent cycles. This response corresponded with a stasis of metastatic growth during five cycles of treatment, but metastatic burden began to increase coincident with the sixth cycle of treatment. Marker analysis suggests that GSI treatment chemo-sensitizes a significant proportion of the otherwise chemo-resistant CD44+/CD24-/low cell population indicating that they are dependent on the Notch pathway for survival. The decrease of MSFE in both preclinical and clinical studies suggests that inhibition of the Notch pathway by GSI may reduce the number of tumorigenic cancer cells that would otherwise remain after chemotherapy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 48.

Prospective analysis of predictors of survival in melanoma patients with brain metastases

9074

Background: Melanoma patients (pts) with brain metastases (BM) have limited survival, and BM remains an exclusion criterion in most clinical trials. A recent retrospective analysis at Memorial Sloan Kettering Cancer Center (MSKCC) identified 4 clinical variables that were associated with worse post BM survival (Raizer J et al, Neuro Oncol 2008). In this study, we investigated whether primary tumor features could improve the predictability of post BM survival and examined the reproducibility of the variables identified in MSKCC study. Methods: Melanoma pts with BM prospectively enrolled in an interdisciplinary database at NYU Medical Center from 2002 to 2008 were studied. Six primary tumor characteristics, 21 clinical variables, and treatments were examined. Univariate associations were analyzed using Kaplan Meier survival analysis and the independent effect of identified predictors was assessed by multivariate cox proportional hazards regression analysis. Results: Eighty-nine pts (36 F, 53 M, median age 57) were identified. Median post BM survival was 5.75 months. Median follow-up time based on survivors was 4.2 months. Ulceration and mitotic index ≥3/field were univariately associated with worse post BM survival (p=0.004, p=0.009 respectively). Age >65, ≥3 BM lesions, presence of neurological symptoms, and extracranial metastases were also univariately associated with worse post BM survival (the same 4 variables identified in MSKCC retrospective study). An additional 4 clinical parameters were significant by univariate analysis: frontal lobe location (p=0.01), bilateral lesions (p=0.01), ≥2 neurological symptoms (p=0.005), and weakness/fatigue (p<0.0001). After reproducing the significance of the 4 MSKCC variables in a multivariate model, ulceration of the primary tumor was also an independent predictor of post BM survival (hazard ratio [HR] = 2.75; 95% CI = 1.30, 5.83; p=0.008) whereas mitotic index ≥3/field was not (HR=1.24; 95% CI = 0.57, 2.71; p=0.59). Conclusions: Data suggest that ulceration of the primary melanoma might indicate an adverse biologic behavior that impacts post BM survival. Our data also lend independent support for the predictive model of post BM survival.

No significant financial relationships to disclose.

Pharmacokinetics (PK) of CR011-vcMMAE, an antibody-drug conjugate (ADC), in a phase (Ph) I study of patients (pts) with advanced melanoma

9063

Background: CR011-vcMMAE, an ADC of fully-human monoclonal anti-GPNMB antibody (Ab) with monomethylauristatin E (MMAE), is in Ph I/II trials in pts with melanoma and breast cancer. We report PK and toxicity data from a Ph I study in melanoma pts treated every (q) 3 weeks (w), qw, or 2 of 3w. Methods: Enzyme-linked immunosorbent assays were used to measure ADC, total Ab (TA), soluble GPNMB (sGPNMB), and anti-ADC Ab in pt samples. Free MMAE was measured by liquid chromatography/mass spectrometry. Results: Initially, 32 pts were treated in 9 cohorts of 0.03 to 2.63 mg/kg iv q3w using standard 3+3 dose escalation. Noncompartmental PK analysis showed dose-proportional TA, ADC and free MMAE levels. As previously reported, maximum tolerated dose (MTD) was 1.88 mg/kg iv q3w; dose limiting toxicity (DLT) was rash. At MTD (n=15), terminal phase half life (T½) of TA was 41 ± 25h and T½ of ADC was 29 ± 13h. Mean maximum plasma concentrations of free MMAE was 1.3–2.9% of TA concentration across all doses. Mean sGPNMB at baseline was 12 ng/ml (range 1.3–32 ng/ml), corresponding to 0.024 % of TA concentration at MTD. Anti-ADC Ab were detectible in 8/240 (3.3%) samples (n=54). Based on the T½, two additional dose schedules (qw and 2 out of 3w) were initiated (n=14). Pts received 0.75 mg/kg (n=3) and 1.0 mg/kg (n=5) in the qw schedule and 1.25 mg/kg (n=3) and 1.5 mg/kg (n=3) in 2 of 3w. The most common adverse events (AEs) were rash (n=6), pruritus (n=5) and fatigue (n=4). 1 DLT (Gr 3 rash) was observed at 1.0 mg/kg qw. Enrollment is ongoing in both schedules. Conclusions: The relatively short T½ of CR011-vcMMAE (∼40h) does not appear to be due to immunogenicity or sGPNMB-mediated clearance. Preliminary data suggest that weekly dosing is tolerated at higher per-cycle cumulative doses than the q3w schedule.

[Table: see text]

Developing genetic markers for melanoma risk assessment

9046

Background: Risk assessment for melanoma is currently based on phenotype, family and exposure history. This approach is subject to recall bias and excludes at-risk groups such as those with darker skin pigmentation. Poorly stratified risk pools also result in unnecessary dermatologist visits and biopsies for those at lower risk. Use of genetic markers may improve risk assessment; however few susceptibility markers have been developed to date. There have been a number of reports of association between melanoma and genetic markers though few have been replicated or validated. In addition, these studies frequently utilized specific coding region variants as markers and failed to test the entire gene. We have therefore assembled a case-control cohort in which to search for potential biomarkers for melanoma risk by interrogating genes using recently developed tools for genetic analysis. A pilot study was performed to test the utility of our cohort. Methods: A cohort of 326 individuals diagnosed with melanoma and treated at the New York University Langone Medical Center and 400 controls obtained from the New York Cancer project was assembled. Candidate genes were selected based on involvement in determining melanoma predisposition factors (skin pigmentation and DNA repair capability) and previous studies showing association. Three genes, ERCC1, ERCC4 (DNA repair) and MATP (skin pigmentation) were selected. Tag Single Nucleotide Polymorphisms (tSNPs) were selected using Haploview (Hapmap.org) and DNA genotyped (Sequenom Inc, San Diego, CA). Odds ratios and confidence intervals were computed for each SNP. Results: An association was found between SNP rs11615 at the ERCC1 locus and melanoma (Odds ratio = 1.718, 95% Confidence interval: 1.259 - 2.343 for TT vs TC/CC). Conclusions: A tSNP approach is thus useful in identifying associations in our melanoma case-control cohort. Sequence variation at the ERCC1 locus contributes to melanoma risk and the gene will now be screened for clinically useful susceptibility biomarkers. Additional DNA repair and pigmentation genes will also be interrogated using this approach. Genes found to be associated with melanoma will be screened by high- density SNP analysis to identify the most appropriate biomarker/s for use in risk assessment.

No significant financial relationships to disclose.

Randomized phase II study of the safety and efficacy of a human anti-αv integrin monoclonal antibody (CNTO 95) alone and in combination with dacarbazine in patients with stage IV metastatic melanoma: 12-month results

9029

Objectives: Evaluate the safety and efficacy of CNTO 95, a human anti-αv integrin monoclonal antibody, when administered alone or in combination with dacarbazine (DTIC). Methods: Patients with Stage IV metastatic melanoma were randomized 1:1:1:1 to receive 5 or 10mg/kg CNTO 95 alone, or DTIC (1000mg/m2) + either 10mg/kg CNTO 95 or placebo administered intravenously once every 3 weeks for 8 cycles in the absence of disease progression or unacceptable toxicity. DTIC arms were blinded; single-agent arms were open-label. The primary endpoint was progression free survival (PFS); secondary endpoints included partial response (PR), complete response (CR), stable disease (SD) and overall survival (OS). Major safety endpoints included the incidence of adverse events (AEs) and serious AEs (SAEs). Results: Patients were randomized to receive 5mg/kg CNTO 95 (n=32), 10mg/kg CNTO 95 (n=33), CNTO 95+DTIC (n=32), or placebo+DTIC (n=32). Baseline demographics were similar across groups. The median PFS for CNTO 95+DTIC was 75 days, placebo+DTIC was 54 days and both CNTO 95 alone arms were 42 days. Six patients achieved PR (2–10mg/kg CNTO 95, 1-CNTO 95+DTIC, 3-placebo+DTIC); one patient achieved CR (CNTO 95+DTIC). A higher proportion (43.3%) of patients achieved SD ≥ 12 wks in the CNTO 95+DTIC group compared with the other 3 groups (<20.0%). The median survival was 11.0 months for the patients in the CNTO 95+DTIC arm, 9.8 months and 14.9 months for the 5mg/kg and 10mg/kg arms, and 8.0 months for those in the DTIC control arm. The most common AEs were headache, nausea, fatigue, pyrexia, vomiting and transient uveitic reactions. Three patients (1–5mg/kg, 2-CNTO 95+DTIC) discontinued treatment due to AEs. A higher proportion of patients experienced SAEs in the placebo+DTIC group (29.0%) than in the 5mg/kg (12.9%), 10mg/kg (16.2%) or CNTO 95+DTIC (18.8%) groups. Conclusions: CNTO 95 alone or combined with DTIC was generally well tolerated. In patients with Stage IV metastatic melanoma, a trend toward improvement in PFS, OS and disease control was demonstrated with CNTO 95+DTIC.

Centocor, Centocor Research and Development, Inc.

Centocor Research and Development, Inc.

Johnson & Johnson

Centocor Research and Development, Inc.

No significant financial relationships to disclose.

Detection of BRAF kinase mutations in melanoma, ovarian, and prostate carcinomas: Evidence for tumor heterogeneity in clinical samples

11031

Background: Several studies have provided evidence that solid tumors are polyclonal malignancies, an observation which may contribute to difficulties in achieving durable treatment responses. In some patients, molecularly targeted therapies may be compromised due to heterogeneity among tumor subclones. In this study we compared conventional DNA sequencing with a fluorescent-based mutant-specific PCR (MS-PCR) assay to detect the BRAF hotspot mutation V600E in a large panel of patient tumors, including paired primary and metastatic tumors from individual patients. Methods: BRAF MS-PCR and conventional sequencing were performed on DNA from 304 tumors (112 melanoma, 110 ovarian, 82 prostate) to determine the presence of the BRAFV600E hot-spot mutation. Among the melanomas were 18 matched primary and metastatic specimens, and 40 metastatic specimens from 19 patients, each of whom had 2 or more metastases. Results: DNA sequencing detected mutations in 5/110 (4.5%) ovarian tumors, 1/82 (1.2%) prostate tumors, and 36/112 (32%) melanomas. In contrast, the MS-PCR assay detected mutations in 12/110 (11%) ovarian tumors, 15/82 (18%) prostate tumors and 85/112 (76%) melanomas. The presence of contaminating normal tissue was scored for each melanoma sample, but excess normal tissue did not influence the results using either methodology. In all cases mutations detected by sequencing were also detected by MSPCR. Among 18 patients with matched primary and metastatic melanoma, 8/18 (44%) had discordant results including 2 patients with mutant primary tumors and wild-type metastases; among the 19 patients with multiple metastases 5/19 (26%) had discordant (both wild-type and mutant) tumors. Conclusions: Using a highly sensitive BRAF mutation detection method, we observed substantial evidence for heterogeneity within clinical tumor specimens. This was especially true in melanoma samples, where multiple specimens from individual patients differed with respect to the presence of the mutant BRAF allele. These results suggest that failures of molecularly targeted therapies, such as those directed against mutant BRAF, may be due in part to a lack of clonality among the tumors under treatment.

No significant financial relationships to disclose.

Effect of mebendazole on melanoma xenograft growth through targeting of bcl-2

9075

Background: Defects in apoptosis are thought to contribute to melanoma chemoresistance, making the anti-apoptotic protein Bcl-2 an attractive therapeutic target. We identified mebendazole (MBZ), a microtubule binding agent, as an inducer of melanoma cytotoxicity via a Bcl-2 dependent mechanism in vitro (Mol Cancer Res, Aug 2008). In the present study, we assessed the effect of MBZ on human melanoma tumor growth and progression in a mouse xenograft model and compared the ability of MBZ to inhibit growth of cultured melanoma cells to that of oblimersen (OBL), an antisense drug targeting Bcl-2. Methods: Growth of human M-14 melanoma xenografts in mice administered MBZ orally at doses from 0.1 to 2 mg were compared to tumor growth in mice receiving 100mg/kg intraperitoneal temozolomide (TMZ) or vehicle alone. Tumor diameter, volume, histopathology, and immunohistochemical staining of caspase 3 and Ki67 were assessed. Bcl-2 phosphorylation was determined by immunoblotting. MBZ and OBL-induced melanoma growth inhibition was analyzed by MTT assay. Results: Anti-melanoma effects of MBZ were dose- dependent up to 1 mg which displayed a 72% reduction in tumor volume compared to vehicle treated mice. This reduction in volume was accompanied by a 46% decrease in proliferating cells and an 81% increase in apoptotic cells. Moreover, 1 mg MBZ inhibited tumor growth as effectively as high dose TMZ, the current melanoma standard of care. Orally administered MBZ treatment resulted in Bcl-2 phosphorylation in vivo, further confirming its mechanism of action. MBZ inhibited growth of melanoma cells in culture more effectively than OBL with GI50 values of 0.32 uM and 7.45 uM, respectively. Conclusions: MBZ safely and effectively inhibits melanoma growth and progression in a xenograft model. A phase II clinical trial investigating MBZ's utility as adjuvant therapy in patients with stage IV, resected melanoma is planned.

No significant financial relationships to disclose.

Skp2, a prognostic marker and potential therapeutic target in metastatic melanoma

11034

Background: Skp2, a known oncogene, is overexpressed in several types of tumors and is associated with worse recurrence rate and overall survival in primary melanoma patients. Moreover, the anti-proliferative effects of Skp2 siRNA on various tumor cell lines have prompted the preclinical testing of Skp2 small molecule inhibitors. In this study, we assessed the clinical relevance and molecular mechanism(s) underlying Skp2 overexpression in metastatic melanoma patients. Methods: Skp2 protein levels were measured in 122 metastatic melanoma specimens using immunohistochemistry (IHC), and the association between Skp2 overexpression and post-recurrence survival was examined. Moreover, 22 cell lines (2 normal primary melanocytes, 2 primary immortal melanocytes, 4 primary melanoma cell lines, and 18 metastatic melanoma cell lines) were evaluated for Skp2 genomic amplification using Single Nucleotide Polymorphism (SNP) arrays (Affymetrix 6.0) and Skp2 gene expression using mRNA arrays (Affymetrix U133A 2.0) and quantitative RT-PCR. We also screened 18 cell lines for Skp2 mutation by sequencing. Results: Skp2 overexpression, defined as >25% tumor cells, was associated with shorter 3-yr post-recurrence survival (37%) compared to Skp2 expression ≤25% (55%) (HR=1.89, 95%, CI= 1.04, 3.42, p=0.04). Skp2 overexpression was significantly associated with the site of melanoma metastasis: visceral (n= 12; 89%), lymph node (n=49; 36%), brain (n=15; 14%), and soft-tissue (n=36; 6%) (p<0.001). SNP array revealed genomic amplification at the Skp2 locus in 6 (33%) metastatic cell lines and one primary melanoma cell line. Skp2 genomic amplification was associated with increased transcript expression. No Skp2 mutations were identified. Conclusions: Skp2 protein overexpression is associated with worse prognosis in metastasis in melanoma. Our results also support that gene amplification, rather than a Skp2 gene mutation, may be the major mechanism responsible for Skp2 aberrant expression in metastatic melanoma.

No significant financial relationships to disclose.

A phase I/II study of CR011-vcMMAE, an antibody-drug conjugate (ADC) targeting glycoprotein NMB (GPNMB) in patients (pts) with advanced melanoma

9032

Background: GPNMB is expressed on melanoma cells and represents a potential target for ADCs. CR011-vcMMAE is a fully-human monoclonal antibody to GPNMB conjugated to the tubulin inhibitor monomethylauristatin E (MMAE). Dose limiting toxicity in Phase I (n=32) was rash; tumor shrinkage including one partial response (PR) was observed. We now report Phase II data at the maximum tolerated dose of 1.88 mg/kg iv q3w. Methods: Eligible pts had unresectable stage III or stage IV melanoma and had received no more than 1 prior cytotoxic regimen but any number of other therapies. Pts received CR011-vcMMAE until disease progression (PD) or intolerable toxicity. The primary endpoint was overall response (ORR) by RECIST using a minimax two-stage design (p0=0.5; p1=0.2, α=β=0.1) with 18 patients in the first stage and a total of 32 pts. Secondary endpoints included progression free survival (PFS) and duration of response. Results: 36 pts (median age 67 years [range 37–79]; 94% stage IV; 68% M1c) were treated for a median of 2.4 months (m)(range 0.5–7.5m). 18 pts discontinued (14 PD, 2 consent, 1 adverse event [AE], 1 stable disease [SD]) and 18 pts were ongoing. The study met the criteria for advancement to the second stage; 4 PRs (1 unconfirmed) and 19 SD (range 1.7–7.5 mo) have been observed; final ORR is pending. The unconfirmed PR was in a pt with 96% tumor reduction and PD 6 weeks later. Median PFS was 4m. The most common AEs were rash (81%), fatigue (72%), alopecia (63%) and pruritus (56%). The most common grade 3/4 AEs were neutropenia (22%) and rash (19%). Grade 2 or higher rash was associated with longer PFS. Conclusions: CR011-vcMMAE is active and well-tolerated in heavily pretreated pts with advanced melanoma. Rash may be a useful biomarker for activity. More frequent dosing is being explored.

[Table: see text]

Use of gene expression profile and mitotic index of metastatic melanoma lesions as an adjunct to TNM staging in predicting patient survival

9014

Background: Although remission rates for metastatic melanoma are generally very poor, some patients can survive for prolonged periods following metastasis. We used gene expression profiling of metastatic lesions to search for a molecular basis for this observation, and to develop improved methods for predicting patient survival. Methods: We analyzed gene expression profiles of 44 metastatic melanoma specimens collected from 38 patients (median follow-up of 20 months after surgery). We used the False Discovery Rate (FDR) approach to identify genes significantly associated with post-recurrence survival. We then evaluated matching H&E stained tissue samples for the presence of tumor-infiltrating leukocytes (TILs) and mitotic index, (MI). Support vector machines and multi-variable Cox regression analysis was used to examine the relative ability of the pre-validated gene expression predictor, TILs, MI and TNM staging to predict survival. Results: We identified a group of approximately 300 genes associated with survival. Genes associated with immune response (ICOS, CD3d, ZAP70, TRAT1, TARP, GZMK, LCK, CD2, CXCL13, CCL19, CCR7, VCAM1 etc.) or with cell proliferation (PDE4D, CDK2, GREF1, NUSAP1, SPC24 etc.) were highly represented .Prolonged survival was associated with the elevated expression of immune response genes and decreased expression of genes associated with proliferation. Furthermore, any of the three additional parameters (pre-validated gene expression signature, TILs or MI) improved the ability of TNM staging to predict post-recurrence survival; MI was the most significant contributor (HR = 2.65, p = 0.003) followed by the gene expression signature (HR = 2.71, p = 0.05). Conclusions: Gene expression profiling and MI of metastatic lesions can both be utilized to improve upon current staging of metastatic melanoma to predict patient survival. Gene expression signature and analysis of TILs indicate immune surveillance as a mechanism for prolonged survival in these patients.

No significant financial relationships to disclose.

BRCA1 gene expression signature predicts for anthracycline-chemosensitivity in triple-negative breast cancer

Abstract #6039

Background: We used a previously published gene expression signature that can identify tumors from BRCA1 mutation carriers to evaluate its predictive value in triple-negative breast cancer as a marker for chemosensitivity to anthracycline-based chemotherapy. We proposed that based on preclinical evidence suggesting that BRCA1-deficient breast cancer cells are sensitive to DNA damaging drugs such as cisplatin and anthracyclines this gene expression profile may identify tumors with anthracycline chemosensitivity. Two previously published studies defined a gene expression signature associated with BRCA1 germline mutation.(1,2) In these studies, sporadic tumors were misclassified as BRCA1 tumors and further analysis revealed methylation of the BRCA1 promoter region and decreased BRCA1 gene expression. This finding suggests the possibility of identifying sporadic tumors with decreased BRCA1 activity.&#x2028; Methods: We selected from our database of a locally advanced breast cancer neoadjuvant trial all cases of triple negative breast cancer that received 4 cycles of doxorubicin/cyclophosphamide(AC, 60/200 mg/m2, every 3 weeks) prior to surgery. Pathologic response to chemotherapy was disappearance of all invasive cancer or microscopic residual disease. Tumoral gene expression profile previously obtained using Affymetrix U133A Chip was analyzed for an optimal set of 100 most differentially expressed genes distinguishing BRCA1 and sporadic triple negative tumors according to the previously identified gene signature by van't Veer et al.1 We performed unsupervised clustering to determine if this signature could classify a subtype of triple-negative tumors with "BRCAness" and to test our hypothesis that BRCA1-like tumors are more sensitive to AC. We then performed a supervised analysis to determine the most differentially expressed genes that could prospectively identify triple-negative sporadic tumors with “BRCAness” and tumors from BRCA1 germline carriers that are sensitive to anthracyclines.&#x2028; Results: Of the 66 patients enrolled in our neoadjuvant trial, 12 patient's tumors were triple negative and received preoperative AC. By unsupervised clustering, the gene expression pattern associated with BRCA1 cancers subdivided these sporadic cancers in to two groups: Group A(6/7 pathologic responders), and group B(5/5 non-pathologic responders). By supervised analysis, the most differentially overexpressed gene from the BRCA1 profile for AC sensitivity was YWHAH(14-3-3 eta polypeptide), while DKK3(Inhibitor of Wnt and Notch signaling pathway) and RPL23A were most overexpressed in all cases with adriamycin-resistance(p&lt;0.01).&#x2028; Discussion: Triple negative sporadic breast cancer displaying “BRCAness” appear to be sensitive to AC chemotherapy. YWHAH, DKK3, and RPL23A are differentially expressed in anthracycline-sensitive versus resistant tumors. These three genes can potentially identify triple-negative breast cancers that exhibit “BRCAness” and sensitivity to DNA-damaging chemotherapy such as cisplatin, anthracycline, or PARP inhibitors.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6039.

Imiquimod: A TLR-7 agonist as adjuvant for a recombinant protein cancer vaccine

8545

Purpose: This clinical trial evaluates the safety and adjuvant activity of imiquimod, a toll-like receptor (TLR)-7 agonist, when given with a NY-ESO-1 protein vaccine. Imiquimod, by locally activating and recruiting dendritic cells (DCs) into the skin, is expected to stimulate antigen uptake by DCs, induce maturation and migration to draining lymph nodes, and to induce antigen-specific T and B cell immunity. Methods: Pilot study; 9 patients with resected stage 2B-3C malignant melanoma. Four 21 day cycles consisted of topical imiquimod cream (250 mg) on days 1–5 and id. injected NY-ESO-1 protein (100 mcg) into the site on day 3. Blood was drawn at several time points for immune monitoring; skin punch biopsies were obtained from control, imiquimod and vaccination sites 48 hours after the last vaccination. Results: The regimen was tolerated well, all patients completed four vaccinations. AEs were mild and transient and included injection site reactions (8/9 patients), fatigue (4/9 patients) and fever (2/9 patients). Significant levels of antigen-specific CD4+ or CD8+ T cell responses were not detected in ex-vivo ELISPOT assays. However, intracellular cytokine staining assays after in vitro pre-stimulation indicated that 6 of 8 subjects developed NY-ESO-1 CD4+ T cell responses. Humoral immunity was manifest by the induction of anti-NY-ESO-1 antibodies in 7/9 patients post-vaccination. Histochemistry of skin sections showed significant dermal mononuclear cell infiltrates in Imiquimod treated skin, whereas none were seen in untreated skin (p<0.01). IHC revealed markedly increased numbers of CD3+ (T-cells), CD68+ (macrophages/monocytes), CD123+ (plasmacytoid DCs) and DC-LAMP+ (mature myeloid DCs) immune cells in Imiquimod treated skin when compared with control skin of the same patients (p<0.05). Conclusion: Imiquimod, a topical immune response modifier, generated clear inflammatory infiltrates in the dermis, with significant increases in antigen-presenting cells and T cells. Imiquimod was well tolerated when used as an adjuvant to an NY-ESO-1 protein vaccine. Systemic immunity of both humoral and cellular types was induced in the majority of patients; however, responses were weak and the vaccine combination needs to be optimized in future studies.

No significant financial relationships to disclose.

Shedding of distinct cryptic epitope (HU177) in sera of melanoma patients

8550

Background: Our preclinical data suggest that a newly identified cryptic epitope HU177 within collagen regulates endothelial and tumor cell adhesion in-vitro and angiogenesis and tumor growth in-vivo. We investigated whether 1) HU177 shedding can be measured in melanoma patients’ sera, and 2) if HU177 concentration correlates with clinicopathological features, recurrence and survival. Methods: Sera from 291 melanoma patients (primary Stage I, n=140; II n=41; III n=29; recurrent/metastatic n=81) and 30 normal volunteers prospectively enrolled at the NYU School of Medicine were analyzed for HU177 epitope concentration (ng/ml) by ELISA. Microtiter plates were incubated overnight with monoclonal antibody (anti-HU177 epitope). Patients’ sera and standards (denatured type-IV collagen) were added in duplicate followed by dilutions of biotinylated anti-collagen type IV polyclonal and HRP-labeled anti-biotin antibodies with multiple washes after each incubation. Absorbance was monitored at 400 nm. Results: The mean concentration of anti-HU177 epitope was 5.8 ng/ml (range 0.1 to 139.8). Normal volunteers were 1.6±0.3 (mean ± SEM). A significant correlation was observed between HU177 concentration and tumor thickness in patients who presented with primary melanoma (=1.00 mm, n=113, 3.8±0.4; 1.01–3.99 mm, n=72, 8.9 ±2.1; =4.00 mm, n=22, 10.3±2.2; P=0.003 by ANOVA test) and nodular melanoma histological subtype (nodular, n=47, 10.5±3.1; superficial spreading, n=95, 4.4±0.5; others, n=68, 6.0±2.1; P=0.02, ANOVA). Multivariate analysis confirmed the independent correlation between higher HU177 concentration and nodular subtype after controlling for tumor thickness (P=0.04). Primary patients with ulcerated melanomas and those who developed recurrences both showed higher HU177 epitope levels, however, the difference was not significant (P>0.05). Conclusions: This is the first study on HU177 epitope shedding in melanoma patients. Data demonstrate the clinical feasibility of HU177 testing in melanoma patients’ sera and suggest that HU177 epitope shedding correlates with thicker primary melanomas. Longer follow-up is required to better define the prognostic value of HU177 epitope shedding in melanoma patients.

[Table: see text]

Differential expression of insulin like growth factor binding protein-4 (IGFBP4) in melanoma progression

8557

Background: Members of the IGFBP family are thought to regulate tumor progression through both IGF-dependent and independent mechanisms. Moreover, IGFBPs may exhibit distinct functions depending on whether they are present locally in tissue or systemically. Our preclinical data suggest that IGFBP4 serves as an endogenous inhibitor of angiogenesis and melanoma tumor growth. To examine the clinical validity of our observations, we compared IGFBP4 expression in tissue and sera in primary melanoma patients with a low risk of metastases versus patients with established metastatic disease. Methods: Eighty-nine melanoma patients (primary stage IA, n=57; metastatic, n=32; 44 M, 45 F; Median Age=56) prospectively enrolled in the Interdisciplinary Melanoma Cooperative Group at the NYU School of Medicine were studied. IGFBP4 protein expression in tumors was assessed in 83 patients using goat anti-human IGFBP4 antibody (R&D Systems) in an immunohistochemical assay. For each case, the percentage of tumor cells that stained positively was estimated. IGFBP4 concentration in the serum was measured in 64 patients by an ELISA assay (Diagnostic Systems Laboratories, Inc.). Fifty-eight patients had both sera and tumor specimens available for correlation. Results: The median IGFBP4 expression in tumor specimens from primary patients was 70% compared to 5% in metastatic patients (P=0.002, Wilcoxon rank-sum test). The median concentration of IGFBP4 in sera was 43.8 ng/ul in primary patients versus 41.0 ng/ul in metastatic patients (P=0.83). A weak association between IGFBP4 expression in tissue and IGFBP4 shedding in sera was observed (Spearman correlation coefficient=0.16, P=0.24) in the 58 cases with both sera and tissue available. Conclusions: Our data demonstrate that IGFBP4 expression in melanoma clinical specimens decreases in the progression from primary to metastatic melanoma, consistent with its potential role as an inhibitor of angiogenesis. Data also suggest that IGFBP4 tissue expression may be more clinically relevant than its sera shedding. Future studies using a larger sample size and extended follow up are needed to further define the role of IGFBP4 in melanoma progression.

No significant financial relationships to disclose.

Continuous intravenous infusion (CIVI) topotecan may be safely combined with tipifarnib

2064

Background: Dose limiting (DL) myelosuppression occurred when topotecan 1.0 mg/m2/d × 5d was combined with tipifarnib (Proc ASCO, 2001, abst 321). We now report on a 3+3 cohort design to determine the safety and pharmacokinetics (PK) of this combination with topotecan given as CIVI in patients (pts) with refractory solid tumors. Methods: Pts were treated with escalating dose levels of topotecan (0.2–0.4 mg/m2/d) given as 21-day infusion in combination with tipifarnib 200 mg PO bid for 21 d every 28 d. Blood was drawn for topotecan PK and intracellular (PBMC) toposisomerase I on d 1 (baseline) and d 5 (tipifarnib omitted d1, cycle 1), and weekly × 8 for ras-farnesylation (membrane bound fraction). Plasma levels of the closed form of topotecan were determined by SPE and HPLC with fluorometric detection. Topoisomerase I in PBMCs was detected by Western blot. Results: 14 patients were accrued at 3 dose levels: topotecan 0.2 mg/m2/d (3 pts), 0.3 mg/m2/d (3), and 0.4 mg/m2/d (8), combined with tipifarnib. Median age was 50 years (33–62). 32 cycles (median 2) were given. Grade 1–3 fatigue, nausea, thrombocytopenia, neutropenia and anemia were common, and at dose level 3, two heavily-pretreated patients had DL myelosuppression. Six others had no significant toxicity over prolonged times. Of nine evaluable for response, a mucinous peritoneal cancer had a minor response for 5 m, an ovarian granulosa cell tumor had a mixed response in lung metastases for 15 m, and a PNET of bone had a minor response for 17 m; six had progression. Mean steady state (± SD) levels of topotecan for dose levels I, II and III were, respectively, 0.48 ± 08 (N = 3), 1.26 ± 0.32 (N = 3) and 1.47 ± 0.1 (N = 5) ng/ml, and were linear with respect to topotecan dose (r = 0.95). By the end of the 21 d infusion, 90% of baseline topoisomerase I signal was depleted in PBMCs. Conclusions: In contrast with bolus topotecan, CIVI topotecan may be combined at known effective doses with tipifarnib. Recommended phase II doses are 0.4 mg/m2/d × 21 days and 200 mg bid daily for those with limited prior therapy. Phase II studies in gynecologic and breast tumors are planned. Supported by UO1- 76642; CA 16087.

[Table: see text]

Clinical relevance of neutral endopeptidase overexpression in melanoma

8028

Background: Neutral Endopeptidase (NEP/CD10) is a cell surface peptidase expressed in a variety of normal and neoplastic tissue. Both loss of and overexpression of NEP have been reported in different types of tumors. Defining the role of NEP in the clinical progression of melanoma is particularly relevant given the availability of NEP inhibitors. Our aim was to determine if NEP expression correlated with clinicopathological parameters and survival. We also investigated the upregulation of NEP transcription as a possible mechanism of NEP overexpression. Methods: Eighty-four patients who were prospectively enrolled in the Interdisciplinary Melanoma Cooperative Group database at the New York University School of Medicine were studied. Ninety-three specimens from the 84 patients were examined for NEP protein expression using an immunohistochemical assay, including 33 primary melanoma (thickness <1mm, N=15; 1–4mm, N=15; >4mm, N=3) and 60 metastatic melanoma specimens. NEP overexpression was defined as either moderate or diffuse. NEP transcript expression was assessed using Affymetrix U133Plus2.0 GeneChips in 37 metastatic melanoma cases. NEP transcript upregulation was defined as >2 fold increase compared to NEP transcript expression in normal lymph node tissue. Results: A statistically significant difference was observed between NEP overexpression in primary [1/33 (3%)] versus metastatic disease [18/60 (30%)] (Fisher’s exact test, p=0.002). In addition, there was a statistically observed association between NEP transcript upregulation and NEP protein overexpression (p=0.002). Among patients with metastatic disease, median survival time was shorter for patients who overexpressed NEP compared to those who had normal NEP expression (10.2 yrs. versus 12.7 yrs., respectively); however this difference was not statistically significant (p=0.74 by log-rank test). Conclusions: Our data support a role for increased NEP expression in the progression of melanoma to metastatic disease. Functional studies are needed to better understand the role of NEP upregulation in melanoma pathogenesis and progression and to determine if there is a role for NEP inhibitors in the treatment of melanoma.

No significant financial relationships to disclose.