Walter M. Stadler

Phase II Placebo-Controlled Randomized Discontinuation Trial of Sorafenib in Patients With Metastatic Renal Cell Carcinoma

PURPOSE This phase II randomized discontinuation trial evaluated the effects of sorafenib (BAY 43-9006), an oral multikinase inhibitor targeting the tumor and vasculature, on tumor growth in patients with metastatic renal cell carcinoma. PATIENTS AND METHODS Patients initially received oral sorafenib 400 mg twice daily during the initial run-in period. After 12 weeks, patients with changes in bidimensional tumor measurements that were less than 25% from baseline were randomly assigned to sorafenib or placebo for an additional 12 weeks; patients with > or = 25% tumor shrinkage continued open-label sorafenib; patients with > or = 25% tumor growth discontinued treatment. The primary end point was the percentage of randomly assigned patients remaining progression free at 24 weeks after the initiation of sorafenib. RESULTS Of 202 patients treated during the run-in period, 73 patients had tumor shrinkage of > or = 25%. Sixty-five patients with stable disease at 12 weeks were randomly assigned to sorafenib (n = 32) or placebo (n = 33). At 24 weeks, 50% of the sorafenib-treated patients were progression free versus 18% of the placebo-treated patients (P = .0077). Median progression-free survival (PFS) from randomization was significantly longer with sorafenib (24 weeks) than placebo (6 weeks; P = .0087). Median overall PFS was 29 weeks for the entire renal cell carcinoma population (n = 202). Sorafenib was readministered in 28 patients whose disease progressed on placebo; these patients continued on sorafenib until further progression, for a median of 24 weeks. Common adverse events were skin rash/desquamation, hand-foot skin reaction, and fatigue; 9% of patients discontinued therapy, and no patients died from toxicity. CONCLUSION Sorafenib has significant disease-stabilizing activity in metastatic renal cell carcinoma and is tolerable with chronic daily therapy.

Randomized Phase II Study of Multiple Dose Levels of CCI-779, a Novel Mammalian Target of Rapamycin Kinase Inhibitor, in Patients With Advanced Refractory Renal Cell Carcinoma

PURPOSE To evaluate the efficacy, safety, and pharmacokinetics of multiple doses of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma (RCC). PATIENTS AND METHODS Patients (n = 111) were randomly assigned to receive 25, 75, or 250 mg CCI-779 weekly as a 30-minute intravenous infusion. Patients were evaluated for tumor response, time to tumor progression, survival, and adverse events. Blood samples were collected to determine CCI-779 pharmacokinetics. RESULTS CCI-779 produced an objective response rate of 7% (one complete response and seven partial responses) and minor responses in 26% of these advanced RCC patients. Median time to tumor progression was 5.8 months and median survival was 15.0 months. The most frequently occurring CCI-779-related adverse events of all grades were maculopapular rash (76%), mucositis (70%), asthenia (50%), and nausea (43%). The most frequently occurring grade 3 or 4 adverse events were hyperglycemia (17%), hypophosphatemia (13%), anemia (9%), and hypertriglyceridemia (6%). Neither toxicity nor efficacy was significantly influenced by CCI-779 dose level. Patients were retrospectively classified into good-, intermediate-, or poor-risk groups on the basis of criteria used by Motzer et al for a first-line metastatic RCC population treated with interferon alfa. Within each risk group, the median survivals of patients at each dose level were similar. CONCLUSION In patients with advanced RCC, CCI-779 showed antitumor activity and encouraging survival and was generally well tolerated over the three dose levels tested.

Sorafenib for Treatment of Renal Cell Carcinoma: Final Efficacy and Safety Results of the Phase III Treatment Approaches in Renal Cancer Global Evaluation Trial

PURPOSE Mature survival data and evaluation of vascular endothelial growth factor (VEGF) as a prognostic biomarker from the Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGET) study in patients with renal cell carcinoma (RCC) are reported. PATIENTS AND METHODS Nine hundred three previously treated patients were randomly assigned to receive sorafenib versus placebo. On demonstration of progression-free survival (PFS) benefit with sorafenib, patients assigned to placebo were offered sorafenib. Overall survival (OS) was determined at two planned interim analyses and one final analysis, with a secondary OS analysis conducted by censoring placebo patients who crossed over to sorafenib. The relationships between baseline VEGF level and prognosis and efficacy were evaluated. RESULTS The final OS of patients receiving sorafenib was comparable with that of patients receiving placebo (17.8 v 15.2 months, respectively; hazard ratio [HR] = 0.88; P = .146); however, when post-cross-over placebo survival data were censored, the difference became significant (17.8 v 14.3 months, respectively; HR = 0.78; P = .029). Adverse events at 16 months after cross over were similar to those previously reported. Baseline VEGF levels correlated with Eastern Cooperative Oncology Group performance status (P < .0001), Memorial Sloan-Kettering Cancer Center score (P < .0001), and PFS and OS in univariate (PFS, P = .0013; OS, P = .0009) and multivariate (PFS, P = .0231; OS, P = .0416) analyses of placebo patients and with short OS by multivariate analysis of patients receiving sorafenib (P = .0145). Both high-VEGF (P < .01) and low-VEGF (P < .01) groups benefited from sorafenib. CONCLUSION Although an OS benefit was not seen on a primary intent-to-treat analysis, results of a secondary OS analysis censoring placebo patients demonstrated a survival advantage for those receiving sorafenib, suggesting an important cross-over effect. VEGF levels are prognostic for PFS and OS in RCC. The results of TARGET establish the efficacy and safety of sorafenib in advanced RCC.

Bevacizumab Plus Interferon Alfa Compared With Interferon Alfa Monotherapy in Patients With Metastatic Renal Cell Carcinoma: CALGB 90206

PURPOSE Bevacizumab is an antibody that binds to vascular endothelial growth factor (VEGF) and has activity in metastatic renal cell carcinoma (RCC). Interferon alfa (IFN) is a historic standard first-line treatment for RCC. A prospective, randomized phase III trial of bevacizumab plus IFN versus IFN monotherapy was conducted. PATIENTS AND METHODS Patients with previously untreated, metastatic clear-cell RCC were randomly assigned to receive either bevacizumab (10 mg/kg intravenously every 2 weeks) plus IFN (9 million U subcutaneously three times weekly) or the same dose and schedule of IFN monotherapy in a multicenter phase III trial. The primary end point was overall survival (OS). Secondary end points were progression-free survival (PFS), objective response rate (ORR), and safety. RESULTS Between October 2003 and July 2005, 732 patients were enrolled. The prespecified stopping rule for OS has not yet been reached. The median PFS was 8.5 months in patients receiving bevacizumab plus IFN (95% CI, 7.5 to 9.7 months) versus 5.2 months (95% CI, 3.1 to 5.6 months) in patients receiving IFN monotherapy (log-rank P < .0001). The adjusted hazard ratio was 0.71 (95% CI, 0.61 to 0.83; P < .0001). Bevacizumab plus IFN had a higher ORR as compared with IFN (25.5% [95% CI, 20.9% to 30.6%] v 13.1% [95% CI, 9.5% to 17.3%]; P < .0001). Overall toxicity was greater for bevacizumab plus IFN, including significantly more grade 3 hypertension (9% v 0%), anorexia (17% v 8%), fatigue (35% v 28%), and proteinuria (13% v 0%). CONCLUSION Bevacizumab plus IFN produces a superior PFS and ORR in untreated patients with metastatic RCC as compared with IFN monotherapy. Toxicity is greater in the combination therapy arm.

Phase III Trial of Bevacizumab Plus Interferon Alfa Versus Interferon Alfa Monotherapy in Patients With Metastatic Renal Cell Carcinoma: Final Results of CALGB 90206

PURPOSE Bevacizumab is an antibody that binds vascular endothelial growth factor and has activity in metastatic renal cell carcinoma (RCC). Interferon alfa (IFN-alpha) is the historic standard initial treatment for RCC. A prospective, randomized, phase III trial of bevacizumab plus IFN-alpha versus IFN-alpha monotherapy was conducted. PATIENTS AND METHODS Patients with previously untreated, metastatic clear cell RCC were randomly assigned to receive either bevacizumab (10 mg/kg intravenously every 2 weeks) plus IFN-alpha (9 million units subcutaneously three times weekly) or the same dose and schedule of IFN-alpha monotherapy in a multicenter phase III trial. The primary end point was overall survival (OS). Secondary end points were progression-free survival (PFS), objective response rate, and safety. RESULTS Seven hundred thirty-two patients were enrolled. The median OS time was 18.3 months (95% CI, 16.5 to 22.5 months) for bevacizumab plus IFN-alpha and 17.4 months (95% CI, 14.4 to 20.0 months) for IFN-alpha monotherapy (unstratified log-rank P = .097). Adjusting on stratification factors, the hazard ratio was 0.86 (95% CI, 0.73 to 1.01; stratified log-rank P = .069) favoring bevacizumab plus IFN-alpha. There was significantly more grade 3 to 4 hypertension (HTN), anorexia, fatigue, and proteinuria for bevacizumab plus IFN-alpha. Patients who developed HTN on bevacizumab plus IFN-alpha had a significantly improved PFS and OS versus patients without HTN. CONCLUSION OS favored the bevacizumab plus IFN-alpha arm but did not meet the predefined criteria for significance. HTN may be a biomarker of outcome with bevacizumab plus IFN-alpha.

Phase II Trial of ZD1839 in Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck

PURPOSE The epidermal growth factor receptor (EGFR) is a mediator of squamous cell carcinoma of the head and neck (SCCHN) development. ZD1839 is an orally active, selective EGFR tyrosine kinase inhibitor. This phase II study sought to explore the activity, toxicity, and pharmacodynamics of ZD1839 in SCCHN. PATIENTS AND METHODS Patients with recurrent or metastatic SCCHN were enrolled through the University of Chicago Phase II Consortium. Patients were allowed no more than one prior therapy for recurrent or metastatic disease and were treated with single-agent ZD1839 500 mg/d. Patient tumor biopsies were obtained and stained immunohistochemically for EGFR, extracellular signal-regulated kinase 1 (ERK1), and phosphorylated ERK1 (p-ERK). Study end points included response rate, time to progression, median survival, and inhibition of p-ERK. RESULTS Fifty-two patients were enrolled (40 male and 12 female) with a median age of 59 years (range, 34 to 84 years). Fourteen patients received ZD1839 through a feeding tube. Half the cohort received ZD1839 as second-line therapy. Forty-seven patients were assessable for response, with an observed response rate of 10.6% and a disease control rate of 53%. Median time to progression and survival were 3.4 and 8.1 months, respectively. The only grade 3 toxicity encountered was diarrhea in three patients. Performance status and development of skin toxicity were found to be strong predictors of response, progression, and survival. Ten biopsy samples were assessable and revealed no significant change in EGFR or p-ERK expression with ZD1839 therapy. CONCLUSION ZD1839 has single-agent activity and is well tolerated in refractory SCCHN. In contrast to other reports, development of skin toxicity was a statistically significant predictor of response and improved outcome.

Antiandrogen Withdrawal Alone or in Combination With Ketoconazole in Androgen-Independent Prostate Cancer Patients: A Phase III Trial (CALGB 9583)

PURPOSE Antiandrogen withdrawal (AAWD) results in a prostate-specific antigen (PSA) response (decline in PSA level of > or =50%) in 15% to 30% of androgen-independent prostate cancer (AiPCa) patients. Thereafter, adrenal androgen ablation with agents such as ketoconazole (K) is commonly utilized. The therapeutic effect of AAWD alone was compared with simultaneous AAWD and K therapy. PATIENTS AND METHODS AiPCa patients were randomized to undergo AAWD alone (n=132), or together with K (400 mg orally [p.o.] tid) and hydrocortisone (30 mg p.o. each morning, 10 mg p.o. each evening; n=128). Patients who developed progressive disease after AAWD alone were eligible for deferred treatment with K. RESULTS Eleven percent of patients undergoing AAWD alone had a PSA response, compared to 27% of patients who underwent AAWD and simultaneous K (P=.0002). Objective responses were observed in 2% of patients treated with AAWD alone compared to 20% in patients treated with AAWD/K (P=.02). There was no difference in survival. PSA and objective responses were observed in 32% and 7%, respectively, of patients receiving deferred K, and were more common in patients with prior AAWD response. Treatment with K was well tolerated, and resulted in a decline in adrenal androgen levels, which rose at the time of disease progression. CONCLUSION K has modest activity in AiPCa patients, while AAWD alone has minimal activity. Adrenal androgen levels fall with treatment with K and then climb at the time of progression, suggesting that progressive disease while on K may be due to tachyphylaxis to the adrenolytic properties of K.

Antitumor Activity and Biomarker Analysis of Sunitinib in Patients With Bevacizumab-Refractory Metastatic Renal Cell Carcinoma

PURPOSE To assess the safety and efficacy of sunitinib in patients with bevacizumab-refractory metastatic renal cell carcinoma (mRCC) and explore biomarkers for sunitinib response. PATIENTS AND METHODS Patients with mRCC and disease progression after bevacizumab-based therapy received oral sunitinib 50 mg once daily in 6-week cycles on a 4/2 schedule (4 weeks with treatment followed by 2 weeks without treatment) in a phase II multicenter study. The primary end point was objective response rate (ORR). Secondary end points included progression-free survival (PFS), duration of response (DR), overall survival (OS), and safety. Plasma soluble proteins (vascular endothelial growth factor [VEGF]-A, VEGF-C, soluble VEGF receptor [sVEGFR]-3, and placental growth factor [PlGF]) levels were measured. RESULTS Sixty-one patients were enrolled. The ORR was 23.0% (95% CI, 13.2% to 35.5%), median PFS was 30.4 weeks (95% CI, 18.3 to 36.7 weeks), median DR was 44.1 weeks (95% CI, 25.0 to 102.7 weeks), and median OS was 47.1 weeks (95% CI, 36.9 to 79.4 weeks). Mean plasma VEGF-A and PlGF levels significantly increased whereas VEGF-C and sVEGFR-3 levels decreased with sunitinib treatment. Lower baseline levels of sVEGFR-3 and VEGF-C were associated with longer PFS and ORR. Most treatment-related adverse events were of mild-to-moderate intensity and included fatigue, hypertension, and hand-foot syndrome. CONCLUSION Sunitinib has substantial antitumor activity in patients with bevacizumab-refractory mRCC and modulates circulating VEGF pathway biomarkers. These data support the hypothesis that sunitinib inhibits signaling pathways involved in bevacizumab resistance. Baseline levels of sVEGFR-3 and VEGF-C may have potential utility as biomarkers of clinical efficacy in this setting.

Androgen Receptor Mutations in Androgen-Independent Prostate Cancer: Cancer and Leukemia Group B Study 9663

PURPOSE The mechanisms responsible for prostate cancer androgen independence are diverse. Mutations of the androgen receptor (AR) gene that broaden ligand specificity have been implicated. Bone marrow specimens containing prostate tumor were obtained from men undergoing antiandrogen withdrawal for AR sequence analysis and clinical correlation. MATERIALS AND METHODS Eligible men enrolled on a trial of antiandrogen withdrawal had a minimum prostate-specific antigen (PSA) level of 5 ng/dL that was increasing on castration therapy including an antiandrogen. With informed consent, marrow biopsies were obtained to collect prostate tumor. Additional samples were obtained from men enrolled on chemotherapy trials. AR cDNA or DNA was polymerase chain reaction-amplified, cloned, and sequenced. The AR CAG repeat length was recorded. RESULTS One hundred eighty-four bone marrow biopsies were obtained, and 48 had prostate tumor detected by light microscopy. The ARs from these 48 samples were sequenced. Overall, five (10%) of 48 tumors had mutated ARs. AR point mutations were detected in the hormone-binding domain involved in transcription factor binding. Three mutations were novel in prostate cancer. One tumor sample had a CAG repeat length of 21, compared with germline length of 22 repeats. There was no association between detectability of AR mutations and antiandrogen withdrawal response or survival. CONCLUSION These data suggest that AR mutations are present in approximately 10% of patients with prostate cancer who experience treatment failure with hormone therapy that included an antiandrogen. Mutations in the AR likely confer a growth advantage for a subset of progressive prostate cancers. Correlation of AR mutation with antiandrogen withdrawal response or survival could not be made.

Portable Filter-Based Microdevice for Detection and Characterization of Circulating Tumor Cells

Purpose: Sensitive detection and characterization of circulating tumor cells (CTC) could revolutionize the approach to patients with early-stage and metastatic cancer. The current methodologies have significant limitations, including limited capture efficiency and ability to characterize captured cells. Here, we report the development of a novel parylene membrane filter-based portable microdevice for size-based isolation with high recovery rate and direct on-chip characterization of captured CTC from human peripheral blood. Experimental Design: We evaluated the sensitivity and efficiency of CTC capture in a model system using blood samples from healthy donors spiked with tumor cell lines. Fifty-nine model system samples were tested to determine the recovery rate of the microdevice. Moreover, 10 model system samples and 57 blood samples from cancer patients were subjected to both membrane microfilter device and CellSearch platform enumeration for direct comparison. Results: Using the model system, the microdevice achieved >90% recovery with probability of 95% recovering at least one cell when five are seeded in 7.5 mL of blood. CTCs were identified in 51 of 57 patients using the microdevice, compared with only 26 patients with the CellSearch method. When CTCs were detected by both methods, greater numbers were recovered by the microfilter device in all but five patients. Conclusions: This filter-based microdevice is both a capture and analysis platform, capable of multiplexed imaging and genetic analysis. The microdevice presented here has the potential to enable routine CTC analysis in the clinical setting for the effective management of cancer patients. Clin Cancer Res; 16(20); 5011–8. ©2010 AACR.