Activity In Renal Cell Carcinoma Research Articles

Abstract A255: Activity of VEGFR inhibitor tivozanib as a single agent or in combination with EGFR inhibitor erlotinib in engineered lung adenocarcinoma models

Abstract Tivozanib (AV-951 or KRN951) is an ATP competitive small molecule VEGFR antagonist that exhibits picomolar inhibitory activity against all three VEGF receptors. It has demonstrated robust clinical activity in renal cell carcinoma and is currently being evaluated in multiple clinical studies including a monotherapy phase 1b/2a trial in NSCLC. NSCLC is a highly heterogeneous disease, in which tumor histology and genetics have defined sensitivities and settings to targeted therapeutics. To model and explore potential clinical settings, we created genetically engineered lung adenocarcinoma models driven by EGFRL858R, EGFRL858R/T790M or KRAS G12V, propagated these models in vivo both subcutaneously and orthotopically and evaluated tumor inhibitory activity of tivozanib as a single agent or in combination with EGFR inhibitor erlotinib. To further explore activity of metastatic lesions to the lung, we also evaluated the activity of tivozanib using an engineered breast tumor metastatic model. Treatment of subcutaneous lung KRAS tumors or lung EGFRL858R/T790M tumors with tivozanib alone resulted in complete tumor growth inhibition. Histological analysis revealed substantial central necrosis with proliferating (Ki67+) tumor cells present only at the tumor periphery, typical of an anti-angiogenesis mechanism. When tivozanib was given to treat lung EGFRL858R+T790M tumors in an orthotopic setting in the lungs after tumors were well established, significant antiangiogenic and antitumor effects, as demonstrated by histology and extended survival period, were observed. However, the necrotic lung lesions showed no sign of resorption or elimination after 6 weeks of treatment. Similar results were also observed in a HER2 driven breast tumor lung metastatic model. This prompted us to further explore the activity of tivozanib in an orthotopic lung tumor minimal disease model. Tivozanib treatment in this setting did not alter tumor lesion numbers but effectively blocked the progression of micro pre-angiogenic lesions. Finally, we explored the combined activity of tivozanib and erlotinib in a model constructed to reflect the emergence of erlotinib resistance by implanting tumor material comprising both EGFRL858R and EGFRL858R/T790M tumor cells. In this setting, the combination of tivozanib and erlotinib resulted in significantly greater control of tumor progression than erlotinib alone. Our results suggest that tivozanib may have activity as a single agent in lung tumors with KRAS or EGFR L858R/T790M mutations and that combinations with other targeted lung cancer drugs such as erlotinib may provide meaningful clinical benefit. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A255.

Inhibition of telomerase activity in renal cell carcinoma cells by doxorubicin and anti-Fas monoclonal antibody

Telomerase, the ribonucleoprotein enzyme that maintains the telomeres of eukaryotic chromosomes, is an attractive target for a mechanism-based therapeutic approach as its activation has been associated with unlimited proliferation in most types of cancer cells. Here, we investigated the effect of chemotherapeutic or immunotherapeutic agents and anti-Fas monoclonal antibody (mAb) on telomerase activity in renal cell carcinoma (RCC) cells. Primary RCC cells were surgically obtained from 24 patients with RCC. Telomerase activity and cytotoxicity were determined by the telomeric repeat amplification protocol and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, respectively. Telomerase activity was positive in 20 (83.3%) of the 24 primary RCC cell cultures. Treatment of ACHN human RCC cells with anti-Fas mAb in combination with vinblastine, interferon-α or interferon-γ did not affect telomerase activity. However, a combination of anti-Fas mAb and doxorubicin resulted in marked down-regulation of telomerase activity in conjunction with a synergistic cytotoxicity. This inhibitory effect on telomerase activity was also observed in 16 telomerase-positive primary RCC cell cultures. These findings suggest that telomerase may be a promising molecular target for combination therapy using biological response modifiers and doxorubicin for RCC.

Advances in developing tris(8-quinolinolato)gallium(iii) as an anticancer drug: critical appraisal and prospects

Gallium-based anticancer chemotherapeutics are appreciably progressing in clinical studies. A steady interest of drug developers and clinicians in gallium compounds is due to a proven ability of gallium cations to inhibit tumour growth, on the one hand, and enhanced bioavailability and moderate toxicity provided by the conversion of gallium into chelate complexes, on the other. One of the complexes suitable for a more convenient oral administration is tris(8-quinolinolato)gallium(iii) (KP46). Nominated from a range of gallium complexes for the clinical stage of development, KP46 has finished phase I trials with the outcome of promising tolerability and evidence of clinical activity in renal cell carcinoma. Therefore, there is obviously a need to codify and critically evaluate the continuing advances in the emergence of KP46 as a lead-drug candidate. Additionally, many questions remain unanswered regarding the relevant biological reactivity, modes of delivery and action and potential cell target(s) of KP46. The timely publication of the present review is also an attempt to shed light on these pertinent drug assets and to accelerate research activities towards further clinical development of KP46.

Targeting Angiogenesis in Renal Cell Carcinoma

Angiogenesis is an important factor for cancer development and progression in humans. Hereditary and sporadic renal cell carcinoma are characterized by inactivation of the Von-Hippel Lindau (VHL) gene, which results in hyperactivity of the hypoxia-inducible factor-a (HIFa). As a consequence, there is a production of angiogenic factors, such as vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF). The activity of these factors is associated with oncogenesis, growth, and metastatic potential of renal-cell carcinoma. These data indicate that angiogenic factors are the promising therapeutic targets in this disease. Surgery can cure the patients with renal cancer if disease is diagnosed at an early stage. On the contrary, inoperable or metastatic disease is not curable. Until recently, the only drugs approved for the treatment of advanced disease were the cytokines, interferon, and interleukin. Nevertheless, only a minority of patients (about 15%) would benefited from this treatment, while the toxicity was considerable. During the last 5 years a new era of biological agents, with considerable activity has been developed and tested in clinical trials and (some of them) have been approved in USA and Europe. These agents are: Sunitinib, Bevacizumab, Sorafenib and Temserolimus. Bevacizumab is an anti-VEGF monoclonal antibody, Sunitinib and Sorafenib are multi- tyrosine kinase inhibitors (TKIs), while Temserolimus is a mTOR inhibitor. The common these in their development is the inhibition of angiogenesis, which may explain their significant activity in renal-cell carcinoma. All the agents have been proven more effective than the interferon as first or second-line treatment. This review will focus in these recent developments and the intense continuing clinical research in this field.

A phase I dose-finding study of sunitinib (SU) in combination with gemcitabine (G) in patients (pts) with advanced solid tumors

14522 Background: Sunitinib malate is an oral multitargeted tyrosine kinase inhibitor that shows significant antitumor activity in renal cell carcinoma (RCC) and other cancers. This study assessed the maximum tolerated dose (MTD), safety and pharmacokinetic (PK) profile of SU in combination with G in advanced solid tumor pts. Methods: Pts received escalating oral doses of SU (25–50 mg/day) on a 6-week (wk) cycle (4 wks on, 2 wks off treatment; 4/2 schedule) with G (750–1250 mg/m2) IV over 30 min on Days 1, 8, 22, and 29. Subsequently, patients received SU on a 3-wk cycle (2 wks on, 1 wk off; 2/1 schedule) with G on Days 1 and 8. Safety was evaluated using adverse event (AE) reports and laboratory analyses. Objective responses were assessed by RECIST; PK data were analyzed at each dose level. Results: 34 pts (most common tumor types: RCC, n=19; pancreatic, n=11) received SU+G, including 8 pts on Schedule 4/2 and 26 pts on Schedule 2/1. Schedule 4/2 was not pursued beyond the initial dose level. On schedule 2/1, MTD has not yet been reached, and enrollment continues at the highest dose level (SU 50 mg/day + G 1250 mg/m2). On Schedule 2/1, grade (Gr) 4 non-hematologic AEs included myocardial infarction (n=1) and pulmonary embolism (n=1), neither considered related to study treatment. Gr 4 laboratory abnormalities included thrombocytopenia (n=1) and neutropenia (n=6), with no instances of febrile neutropenia. Evidence of antitumor efficacy has been observed on both schedules, in pts with pancreatic or renal cancer. Among 9 pts with poor-risk or sarcomatoid RCC, 5 pts exhibited partial responses and 3 had stable disease, across different dose levels. At all dose levels analyzed to date, the Cmax and AUC of the drugs and their metabolites following combination therapy were similar to those following single-agent SU or G dosing; these data indicate that there are no clinically significant drug-drug interactions during co-administration. Conclusions: Combination therapy with SU and G in pts with advanced solid tumors is well tolerated, does not result in significant drug-drug interactions, and is associated with notable antitumor activity. The efficacy and safety of this combination will be studied further in disease-specific clinical trials. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Pfizer Bayer, Genentech, Pfizer, Wyeth Pfizer Pfizer, Wyeth Pfizer

Prognostic significance of serum hepatocyte growth factor in clear cell renal cell carcinoma: comparison with serum vascular endothelial growth factor

No adequate serum predictive biomarker currently exists, which can identify the activity of renal cell carcinoma (RCC). We investigate the association of serum hepatocyte growth factor (HGF) and serum vascular endothelial growth factor (VEGF) levels with clinicopathologic parameters in untreated clear cell RCC patients. We measured serum levels of HGF and VEGF in 45 patients with untreated clear cell RCC and 45 healthy controls using an enzyme-linked immunosorbent assay (ELISA). Patients with clear cell RCC had significantly higher serum HGF and VEGF concentrations than healthy subjects: median, 1070.7 versus 728.3 pg/ml (p<0.0001) for HGF; and median, 397.5 versus 245.6 pg/ml (p=0.0003) for VEGF. We found a significant correlation between serum level of HGF and clinical stage and tumor grade. Survival of patients with high serum HGF (>1150 pg/ml) was significantly reduced compared to patients with low serum HGF concentrations (p=0.0044). In patients with nuclear grade 2 or high stage RCC, the higher serum HGF group exhibited significantly lower cause-specific survival (p=0.0087 and p< 0.05, respectively). No significant difference was observed between serum VEGF levels and cause-specific survival rate. Serum HGF might be a diagnostic and prognostic indicator in clear cell RCC, especially for patients with grade 2 or high stage RCC.

Protein Kinase C-Mediated Modulation of FIH-1 Expression by the Homeodomain Protein CDP/Cut/Cux

Under normoxia, FIH-1 (factor inhibiting HIF-1) inhibits the transcriptional activity of hypoxia-inducible factor (HIF); however, under such conditions, we observed a significant level of HIF activity in renal cell carcinoma (RCC). This phenomenon could be attributed to a decrease in the level of functional FIH that has been identified in our previous work. Nonetheless, the molecular mechanism of FIH regulation in cancer, in particular RCC, was unclear until now. In this communication, we have demonstrated that in RCC, the Cut-like homeodomain protein (CDP/Cut) is involved in FIH transcriptional regulation and is controlled by a specific signaling event involving protein kinase C (PKC) zeta. Furthermore, we have defined a unique CDP/Cut binding site on the FIH promoter. With chromatin immunoprecipitation assays, we show that CDP binds to the FIH-1 promoter in vivo and that this binding is PKC zeta dependent. Moreover, we have also defined a potential phosphorylation site in CDP (serine 987) that modulates FIH expression. CDP/Cut is a transcriptional repressor that decreases FIH-1 expression and subsequently leads to a decrease in the repressor activity of FIH-1. Without this repression, HIF activity increases, allowing for the increased transcription of the genes it regulates, such as the vascular endothelial growth factor and GLUT-1 genes. Both CDP and HIF levels are increased in several cancers and are responsible for the metastatic progression of the tumors. Taken together, our results suggest for the first time a potential connection between CDP and FIH that could lead to the development of future therapeutic interventions.

Gemcitabine and pemetrexed in genito-urinary tumors treatment

Among genito-urinary tumors, gemcitabine is indicated only for the treatment of locally advanced and metastatic urothelial cancer. The combination of gemcitabine and cisplatin is a new standard in this disease. Gemcitabine shows activity in refractory germ cell tumors. In salvage treatment its role is ongoing evaluation. The combination of gemcitabine and 5-fuoruracile has modest activity in renal cell carcinoma. Pemetrexed is not indicating in genitor-urinary tumors, further evaluation in urothelial cancer is warranted.

A phase II study of ixabepilone (BMS-247550) in metastatic renal-cell carcinoma

Introduction Ixabepilone (BMS-247550) is a semi-synthetic analog of epothilone B that has been characterized as a microtubule stabilizing agent with a mechanism of action distinct from taxanes. Suggestion of activity in renal cell carcinoma (RCC) has been seen in early clinical studies.Methods Eligible patients had metastatic RCC as well as ECOG performance status 0-2 and normal organ function. Patients received ixabepilone at a dose of 40 mg/m2 intravenously over 3 hours every 21 days. There was no restriction on RCC histology or prior treatment type, but prior treatment with tubule inhibitors was not allowed. The primary endpoint was RECIST defined response and radiographic evaluations were performed every 3 cycles. Toxicity evaluations utilized CTCAE v3.0 and were performed every cycle. Using a Simon two-stage optimal design with α=0.1, β=0.1, a null hypothesized response rate of 0.05 and an alternative response rate of 0.2, an initial 12 patients were to be accrued with full accrual of 37 patients if at least one response were observed.Results A median of 5 cycles were administered. No objective responses were observed in the first 12 evaluable patients, and six patients showed stable disease for more than 18 weeks on therapy. Median time to progression among those with objective progression was 9 weeks. One patient experienced grade 4 anemia and lymphopenia. Grade 3 adverse events included lymphopenia, neutropenia, leukopenia, diarrhea, and infection. Common grade 2 toxicities included alopecia, fatigue, and anemia.Conclusion Ixabepilone administered at a dose of 40 mg/m2 every 21 days should not be advanced for further study in metastatic RCC. Given previous results, however, other dosing schedules may be worthy of further investigation.

636: Prognostic Significance of Orotate Phosphoribosyltransferase Activity in Renal Cell Carcinoma

636: Prognostic Significance of Orotate Phosphoribosyltransferase Activity in Renal Cell Carcinoma

Phase II study of Triapine® in patients with metastatic renal cell carcinoma: a trial of the National Cancer Institute of Canada Clinical Trials Group (NCIC IND.161)

Triapine is a novel small molecule ribonucleotide reductase inhibitor that showed activity in renal cell carcinoma (RCC) cell lines. Evaluating new agents with novel mechanisms remains of interest for patients with incurable RCC. This was a single-arm, multicentre phase II trial where Triapine was given at a schedule of 96 mg/m2 2-h infusion daily x 4 repeated every 2 weeks in patients with recurrent RCC. A median of four cycles of Triapine was administered to 19 eligible patients. One response was seen (7%.) Median time to progression was 3.6 months. Common adverse events (AEs) were grade 1-2, with fatigue in 74%, nausea in 68% and vomiting in 58%. However grade 3/4 neutropenia was seen in 79% and acute reactions of hypoxia, hypotension, methemoglobinemia were seen. Dose reductions/delays due to AEs were common with only 47% of patients receiving > 90% of planned dose intensity. The study closed, at the end of stage 1 as it did not meet the minimal efficacy criteria to proceed. Further evaluation of Triapine at this dose and schedule in patients with advanced kidney cancer is not recommended.

Antitumor Necrosis Factor (TNF-a) Antibodies in the Treatment of Renal Cell Cancer

The kinase inhibitors sorafinib and sunitinib have demonstrated significant activity in renal cell carcinoma (RCC), and are now approved by the FDA for use in advanced disease. There still remains a need for novel therapies. Our group were the first to demonstrate activity of thalidomide in RCC, believed to be in part related to the modulation of tumor necrosis factor (TNF-a), a cytokine secreted by RCC with a number of tumor promoting properties. We subsequently conducted a phase II trial of the TNF-a monoclonal antibody infliximab in patients with previously treated advanced RCC. The drug was well tolerated. The response rate was 16% and stability was achieved in a further 16% of patients. Anti-TNF-a therapy may represent an important approach in the treatment of this disease.

A Phase II Trial of Gefitinib (Iressa, ZD1839) in Stage IV and Recurrent Renal Cell Carcinoma

The epidermal growth factor receptor (EGFR) is overexpressed in 75 to 90% of renal cell carcinomas and may play a role in tumor initiation and progression. Gefitinib (Iressa, ZD1839) is a potent, selective EGFR-tyrosine kinase inhibitor. This trial was undertaken to assess the efficacy and toxicity of gefitinib in advanced renal cell carcinoma. Oral gefitinib, 500 mg once daily, was given continuously. A single-dose reduction to 250 mg daily was allowed for toxicity. The primary end point was response rate (defined as complete remission + partial remission + stable disease). Secondary end points were progression-free survival, overall survival, toxicity, and correlation of response with EGFR status. Twenty-one patients were enrolled on this study, and all are evaluable for response and toxicity. Patient characteristics were median age 61 (range, 35-78 years); 17 males, 4 females; median performance status 0 (range 0-2); median number of prior systemic therapies 1 (range, 0-3). The median and mean number of cycles of therapy received was 3 and 4.7 (range, 1-14+). The best response was stable disease in eight patients (38%). Median progression-free survival was 2.7 months. Median overall survival was 8.3 months. The difference in overall survival was significantly different between patients with progressive disease versus stable disease (6.1 months versus 16+ months; Log-Rank test P value < 0.0001). Three patients required a dose reduction, all for grade 3 diarrhea. There was no apparent correlation between EGFR status and stability of disease or progression of disease. Gefitinib is without significant conventional activity in renal cell carcinoma. The relation of "stable disease" to treatment or to disease-related prognostic heterogeneity remains to be defined.

Cytochrome P450 CYP1B1 activity in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common malignancy of the kidney and has a poor prognosis due to its late presentation and resistance to current anticancer drugs. One mechanism of drug resistance, which is potentially amenable to therapeutic intervention, is based on studies in our laboratory. CYP1B1 is a cytochrome P450 enzyme overexpressed in a variety of malignant tumours. Our studies are now elucidating a functional role for CYP1B1 in drug resistance. Cytochrome P450 reductase (P450R) is required for optimal metabolic activity of CYP1B1. Both CYP1B1 and P450R can catalyse the biotransformation of anticancer drugs at the site of the tumour. In this investigation, we determined the expression of CYP1B1 and P450R in samples of normal kidney and RCC (11 paired normal and tumour and a further 15 tumour samples). The O-deethylation of ethoxyresorufin to resorufin was used to measure CYP1B1 activity in RCC. Cytochrome P450 reductase activity was determined by following the reduction of cytochrome c at 550 nm. The key finding of this study was the presence of active CYP1B1 in 70% of RCC. Coincubation with the CYP1B1 inhibitor alpha-naphthoflavone (10 nM) inhibited this activity. No corresponding CYP1B1 activity was detected in any of the normal tissue examined (n=11). Measurable levels of active P450R were determined in all normal (n=11) and tumour samples (n=26). The presence of detectable CYP1B1, which is capable of metabolising anticancer drugs in tumour cells, highlights a novel target for therapeutic intervention.

Update of a phase 1 study of intravenous CCI-779 given in combination with interferon-α to patients with advanced renal cell carcinoma

4513 Background: CCI-779 is an mTOR kinase inhibitor with activity in renal cell carcinoma (RCC, Atkins et al. J Clin Oncol, in press). A preliminary report of this phase 1/2 study of CCI-779 and interferon-α (IFN) in patients (pts) with advanced RCC described the safety and antitumor effects of the combination (Dutcher et al. Proc ASCO 22:213, 2003). We update these results. Methods: In an open-label, escalating-dose, single-arm study, CCI-779 was given intravenously once weekly, with IFN given subcutaneously 3 times weekly. The starting dose levels were 6 million units (MU) IFN, 5 mg CCI-779. Dose escalation was based on safety evaluation of pts (≥ 6/cohort) after 4 wks of treatment. Up to 40 pts will be evaluated at the maximum tolerated dose (MTD). Results: As of 01 Dec 2003, 71 pts with advanced RCC were enrolled; 27 continue treatment. Pts (73% men, 27% women) had ECOG performance status of 0: 53% and 1: 46% and median age of 59 yrs (range, 35–80); 45% had prior IL-2 treatment. In dose escalation, pts received 6 MU IFN with CCI-779 at 5 mg (7 pts), 10 mg (6), 15 mg (6), 20 mg (6), or 25 mg (7); 6 pts also received 9 MU IFN with 15 mg CCI-779. Based on dose-limiting toxicities, 15 mg CCI-779, 6 MU IFN was selected as the MTD. To date, 33 additional pts have been accrued at the MTD. Grade 3–4 CCI-779-related adverse events with overall frequency ≥ 5% (n=53) were leukopenia (25%), hyperlipidemia (15%), asthenia (13%), AST increase (8%), mucositis (6%), anemia (6%), thrombocytopenia (6%), and rash (6%). Four pts were removed from study due to CCI-779-related toxicity. Approximately 50% of MTD pts have required CCI-779 dose reductions in subsequent cycles. Median time on treatment for all cohorts was 7 mo, 36 have continued for ≥ 6 mo of whom 9 have continued for > 12 mo. Preliminary tumor responses (RECIST) in 55 pts were confirmed partial response, 7 pts (13%); stable disease, 39 (71%, 19 pts ≥ 6 mo); and progressive disease, 9 (16%). Conclusions: CCI-779 and IFN showed favorable results for safety and efficacy. A phase 3 trial has been initiated that compares this combination of CCI-779 and IFN with each agent alone as first-line therapy in poor-risk pts with metastatic RCC. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Wyeth Research Wyeth Parmaceuticals

Update of a phase 1 study of intravenous CCI-779 given in combination with interferon-α to patients with advanced renal cell carcinoma

4513 Background: CCI-779 is an mTOR kinase inhibitor with activity in renal cell carcinoma (RCC, Atkins et al. J Clin Oncol, in press). A preliminary report of this phase 1/2 study of CCI-779 and interferon-α (IFN) in patients (pts) with advanced RCC described the safety and antitumor effects of the combination (Dutcher et al. Proc ASCO 22:213, 2003). We update these results. Methods: In an open-label, escalating-dose, single-arm study, CCI-779 was given intravenously once weekly, with IFN given subcutaneously 3 times weekly. The starting dose levels were 6 million units (MU) IFN, 5 mg CCI-779. Dose escalation was based on safety evaluation of pts (≥ 6/cohort) after 4 wks of treatment. Up to 40 pts will be evaluated at the maximum tolerated dose (MTD). Results: As of 01 Dec 2003, 71 pts with advanced RCC were enrolled; 27 continue treatment. Pts (73% men, 27% women) had ECOG performance status of 0: 53% and 1: 46% and median age of 59 yrs (range, 35–80); 45% had prior IL-2 treatment. In dose escalation, pts received 6 MU IFN with CCI-779 at 5 mg (7 pts), 10 mg (6), 15 mg (6), 20 mg (6), or 25 mg (7); 6 pts also received 9 MU IFN with 15 mg CCI-779. Based on dose-limiting toxicities, 15 mg CCI-779, 6 MU IFN was selected as the MTD. To date, 33 additional pts have been accrued at the MTD. Grade 3–4 CCI-779-related adverse events with overall frequency ≥ 5% (n=53) were leukopenia (25%), hyperlipidemia (15%), asthenia (13%), AST increase (8%), mucositis (6%), anemia (6%), thrombocytopenia (6%), and rash (6%). Four pts were removed from study due to CCI-779-related toxicity. Approximately 50% of MTD pts have required CCI-779 dose reductions in subsequent cycles. Median time on treatment for all cohorts was 7 mo, 36 have continued for ≥ 6 mo of whom 9 have continued for > 12 mo. Preliminary tumor responses (RECIST) in 55 pts were confirmed partial response, 7 pts (13%); stable disease, 39 (71%, 19 pts ≥ 6 mo); and progressive disease, 9 (16%). Conclusions: CCI-779 and IFN showed favorable results for safety and efficacy. A phase 3 trial has been initiated that compares this combination of CCI-779 and IFN with each agent alone as first-line therapy in poor-risk pts with metastatic RCC. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Wyeth Research Wyeth Parmaceuticals

Thalidomide, interferon-alpha, and capecitabine as second-line therapy for metastatic renal cell cancer(RCC)

4696 Background: Thalidomide and capecitabine have each been reported to have a low level of activity in renal cell carcinoma (RCC). Interferon, an established agent in RCC, has been reported to have anti-angiogenic activity in low daily doses but frequent thrombotic complications when used in usual dosage in combination with thalidomide. We studied the activity of usual dosages for thalidomide and capecitabine with a low daily dosage of interferon. Methods: 16 previously-treated patients with symptomatic RCC were treated with thalidomide 400mg/day, interferon alpha 2b one mIU/day, and capecitabine 600mg/m2 bid. Capecitabine was given days 1–14 Q 21 days. Results: No objective responses were seen in 14 evaluable patients. 8 patients were stable for 3 months and 6 (43%) were stable at 6 months. Few dosage reductions were needed. A low incidence of grade 3 toxicities was seen: constipation 19%, neuropathy 13%, venous thrombosis 13%, neutropenia 6%, thrombocytopenia 6%, skin 6%. Conclusions: This combination, although well tolerated, did not produce objective responses as second-line therapy at these dosages. Higher dosages of interferon may be more effective. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Celgene Celgene Celgene Corporation

Thalidomide, interferon-alpha, and capecitabine as second-line therapy for metastatic renal cell cancer(RCC)

4696 Background: Thalidomide and capecitabine have each been reported to have a low level of activity in renal cell carcinoma (RCC). Interferon, an established agent in RCC, has been reported to have anti-angiogenic activity in low daily doses but frequent thrombotic complications when used in usual dosage in combination with thalidomide. We studied the activity of usual dosages for thalidomide and capecitabine with a low daily dosage of interferon. Methods: 16 previously-treated patients with symptomatic RCC were treated with thalidomide 400mg/day, interferon alpha 2b one mIU/day, and capecitabine 600mg/m2 bid. Capecitabine was given days 1–14 Q 21 days. Results: No objective responses were seen in 14 evaluable patients. 8 patients were stable for 3 months and 6 (43%) were stable at 6 months. Few dosage reductions were needed. A low incidence of grade 3 toxicities was seen: constipation 19%, neuropathy 13%, venous thrombosis 13%, neutropenia 6%, thrombocytopenia 6%, skin 6%. Conclusions: This combination, although well tolerated, did not produce objective responses as second-line therapy at these dosages. Higher dosages of interferon may be more effective. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Celgene Celgene Celgene Corporation

Significance of Orotate Phosphoribosyltransferase Activity in Renal Cell Carcinoma

The anticancer agent 5-fluorouracil (5-FU) is clinically used against various cancers, including renal cell carcinoma (RCC). It is a prodrug and orotate phosphoribosyltransferase (OPRT) is the principal enzyme that directly converts 5-FU to the active anticancer metabolite 5-fluoro-2'-deoxyuridine 5'-monophosphate. In addition, OPRT is the key enzyme in the de novo DNA and RNA synthetic process. Little is known about the significance of OPRT in various cancers, including RCC. We investigated the activity of OPRT in 83 RCCs and evaluated the association between the level of OPRT activity and the stage/grade of RCC. The relationship between OPRT activity in RCC cells and their sensitivity to 5-FU was also examined. OPRT activity in nonfixed, fresh frozen RCC and normal kidney was determined enzymatically by the 5-FU phosphorylation assay. The sensitivity of RCC cells to 5-FU was assessed by the microculture tetrazolium dye assay. The activity of OPRT was approximately 8.5-fold higher in RCC than in normal kidney. OPRT activity in stage III/IV RCC was 3-fold higher than in stage I/II RCC. The level of OPRT activity in grade 3 RCC was 3-fold higher than that in grade 1/2 cancer. Patients with RCC with low OPRT activity had longer postoperative disease specific survival than those with high activity at 5-year followup. OPRT activity in RCC cells positively correlated with their sensitivity to 5-FU. To our knowledge this is the first study to demonstrate that OPRT activity in RCC was higher than that in normal kidney and OPRT activity positively correlated with RCC stage/grade. In addition, higher OPRT activity in RCC predicted worse prognosis and higher sensitivity to 5-FU. These results suggest that the level of OPRT activity may be used as a prognostic parameter and predictive indicator for 5-FU efficacy in RCC and OPRT may be a molecular therapeutic target in RCC.

Chromosomal gains and losses detected by comparative genomic hybridization and proliferation activity in renal cell carcinoma.

The number of DNA losses found using comparative genomic hybridization (CGH) and the proliferation index MIB-1 have been shown to be prognostic factors in renal cell carcinoma (RCC). We evaluated the associations of these two factors with each other and with histopathology and clinical outcome. In this prospective study, specimens from 20 primary RCCs were investigated using CGH and MIB-1 assay. The associations of the commonest chromosomal aberrations with histopathology, stage and the clinical outcome of the disease were evaluated. CGH detected genetic aberrations in all tumours. Losses of genetic material (85%) were more common than gains (65%). Most common was loss in the short arm of chromosome 3, which was found in 70% of the tumours. Other frequent changes (20%) were losses of 4q, 13q, 18 and Xp, as well as gains of 5q, 7p, 7q (25%) and chromosome 12. The number of deleted chromosomal areas varied from none to six. The MIB-1 index varied from 0 to 39 (median 4.0). The total number of chromosomal aberrations or deletions showed no association with MIB-1 index or nuclear grade. Most grade 1 and 2 tumours showed a low MIB-1 index. All nuclear grade 4 tumours progressed and were associated with short survival. CGH gives an overview of DNA changes in RCC and helps to locate targets for more precise genetic evaluation. CGH findings are also helpful for classifying tumours. In this study, genetic aberrations in primary RCCs were not associated with histopathology, proliferation or clinical outcome, which suggests that CGH does not necessarily give any additional information on the prognosis of the disease. MIB-1 index and TNM stage were associated with survival.