A phase I study of sunitinib plus bevacizumab in advanced solid tumors

PURPOSE

Bevacizumab is an antibody against vascular endothelial growth factor; sunitinib is an inhibitor of vascular endothelial growth factor and related receptors. The safety and maximum tolerated dose of sunitinib plus bevacizumab was assessed in this phase I trial.

EXPERIMENTAL DESIGN

Patients with advanced solid tumors were treated on a 3+3 trial design. Patients received sunitinib daily (starting dose level, 25 mg) for 4 weeks on followed by 2 weeks off and bevacizumab (starting dose level, 5 mg/kg) on days 1, 15, and 29 of a 42-day cycle. Dose-limiting toxicities during the first 6-week cycle were used to determine the maximum tolerated dose.

RESULTS

Thirty-eight patients were enrolled. Patients received a median of 3 cycles of treatment (range, 1-17(+)). There was one dose-limiting toxicity (grade 4 hypertension) at 37.5 mg sunitinib and 5 mg/kg bevacizumab. Grade 3 or greater toxicity was observed in 87% of patients including hypertension (47%), fatigue (24%), thrombocytopenia (18%), proteinuria (13%), and hand-foot syndrome (13%). Dose modifications and delays were common at higher dose levels. No clinical or laboratory evidence of microangiopathic hemolytic anemia was observed. Seven patients had a confirmed Response Evaluation Criteria in Solid Tumors-defined partial response (18%; 95% confidence interval, 8-34%). Nineteen of the 32 patients with a postbaseline scan (59%) had at least some reduction in overall tumor burden (median, 32%; range, 3-73%).

CONCLUSIONS

The combination of sunitinib and bevacizumab in patients with advanced solid tumors is feasible, albeit with toxicity at higher dose levels and requiring dose modification with continued therapy. Antitumor activity was observed across multiple solid tumors.

Target identification by phosphoproteomics: RIN1 modulation of sorafenib-induced cytotoxicity in renal cell carcinoma

e14543

Background: Sorafenib (SFB) is a multi-tyrosine kinase inhibitor clinically useful in treatment of metastatic renal cancer. While the inhibition of angiogenesis is considered a major mechanism of action, identification of targets regulating growth inhibitory effects of SFB is necessary to further improve its efficacy and reduce toxicity. Methods: In this study we used targeted phosphoproteomics to identify tyrosine phosphorylated proteins that are differentially affected in control and SFB-treated human CAKI-1 renal cell carcinoma cells. The strategy involved immunoaffinity isolation of phosphotyrosine containing proteins and liquid chromatography - tandem mass spectrometry (MS) for identification of candidate proteins. Results: Among identified proteins, signal transducer and activator of transcription 1 (STAT1) and Ras and Rab interactor 1 (RIN1) were found to be hypophosphorylated in SFB-treated compared to untreated CAKI-1 cells based on quantitative MS analysis, by peptide counts and native peptide reference method. A ∼4-fold decrease in expression and phosphorylation of STAT1 was observed in cells treated with 10 μM SFB for 48h. Up to 8-fold SFB dose-dependent (5–15 μM) decrease in phosphorylation of RIN1 at tyrosine 36, but not in total RIN1 expression, was observed. Similar effects on decreased phosphorylation of STAT1 and RIN1 were also observed in 786-O renal cell carcinoma treated with SFB. Hypophosphorylation of RIN1 at tyrosine 36 was observed in CAKI-1 cells treated with 5 μM sunitinib but not with imatinib (≤ 10 μM). Treatment of CAKI-1 cells with RIN1 targeted, but not control si-RNA led to down-regulation of RIN1 expression and attenuation of antiproliferative effects of SFB. Notably, ∼2-fold higher expression of RIN1 protein (total and phosphorylated) was observed in CAKI-1 cells selected for resistance following continuous exposure to 7.5 μM SFB. However, unlike parent CAKI-1 cells, prolonged exposure of these SFB-resistant CAKI-1 cells to 7.5 μM SFB did not completely abrogate phosphorylation of RIN1 at tyrosine 36. Conclusions: These results demonstrate that RIN1, a Ras effector protein with multiple biochemical functions, is a target for the anti-tumor effects of SFB in kidney cancer cells.

[Table: see text]

Long-term safety of sorafenib (SOR) for the treatment (tx) of advanced clear-cell renal-cell carcinoma (RCC): Data analysis from patients (pts) treated for over 1 year in the phase III TARGET study

e16057

Background: Results of the phase III multicenter TARGET study, a randomized, double-blind, placebo (PBO)- controlled study of tx with SOR in pts with clear-cell RCC in whom 1 prior systemic therapy had failed, indicated that SOR is effective (PFS 5.5 vs 2.8 mo, HR=0.44, P<0.000001, and 39% increase in survival for SOR vs PBO, HR=0.71, P=0.015) and safe in pts with advanced RCC (Escudier et al. N Engl J Med. 2007). With a database cut-off of Sept 8, 2006, we analyzed the safety of long-term use of SOR in pts in TARGET (study start Nov 2003). Methods: Pts (N=903) with advanced metastatic clear-cell RCC that had progressed after 1 systemic tx, ECOG PS 0–2, and low- or intermediate-risk MSKCC score were randomized 1:1 to SOR 400 mg BID or PBO. End points included OS, PFS, and safety. A single planned analysis of PFS showed a significant benefit of SOR over PBO; consequently, pts assigned to PBO were offered SOR. Descriptive analysis of safety and efficacy of pts treated >1 year (y) was conducted. Results: 169/903 pts were randomized to SOR and treated >1 y and 27 pts treated >2 y. Due to crossover of PBO to SOR, only 6 pts randomized to PBO were treated with SOR >1 y. Pts treated with SOR >1 y had median PFS of 10.9 months and a response rate of 22.5%. Median tx duration was 20 months. Drug-related adverse events (AEs) were mainly grades 1 and 2 and occurred early during tx (see Table ); 31% and 22% of pts required dose interruption and reduction, respectively, because of AEs. Conclusions: Long-term tx with SOR did not result in new toxicities or an increase in overall incidence of tx-related AEs. Toxicity was not cumulative and no increase in grades 3/4 AEs was observed. Pts with preexisting cardiac disease or hypertension tolerated long-term tx with SOR; no dose reduction was required. No increase in cardiovascular toxicity was observed in this pt population. Long-term tx of pts with advanced RCC with SOR is medically manageable, with a predictable AE profile. [Table: see text]

[Table: see text]

Efficacy and safety of sorafenib in patients with advanced clear-cell renal cell carcinoma (RCC) with diabetes: Results from the phase III TARGET study

e16099

Background: Results of the phase III TARGET trial, a randomized, double-blind, placebo-controlled study of sorafenib (SOR) treatment in pts with clear-cell RCC in whom 1 prior systemic therapy had failed, indicated that SOR is effective and safe for pts with advanced RCC, leading to the approval of SOR for the treatment of advanced RCC. Diabetes can be associated with increased morbidity during treatment in a variety of malignancies. Therefore, an exploratory subset analysis was performed to evaluate the efficacy and safety of SOR in pts enrolled in TARGET with or without diabetes at baseline. Methods: Pts (N=903) with advanced clear-cell RCC, ECOG PS 0–2, and low- or intermediate-risk MSKCC score were randomized 1:1 to SOR 400 mg BID or placebo (PBO). End points included OS, PFS, and safety. A planned independently-assessed formal analysis of PFS showed significant benefit for SOR over PBO; consequently, pts assigned to PBO were able to cross over to SOR. Results: Pt demographics were similar for all subsets. Pre- crossover data by subset are shown in the table . The incidence of drug-related adverse events (AEs) across subgroups was consistent with that for the overall population. In pts with vs without diabetes, treatment with SOR was not associated with increased hyperglycemia (1 pt/arm in the without diabetes subgroups only) or hypertension. Conclusions: The safety profile of SOR in pts with diabetes was comparable with that for the overall study population. SOR was well tolerated and AEs were manageable. Trends in improved PFS were observed for SOR regardless of baseline diabetes status; however, the small diabetic subset limits interpretation of a SOR OS benefit in this subpopulation. *Final PFS of overall study population based on independent review from Jan 2005; all other data from May 2005 database [Table: see text]

[Table: see text]

Sunitinib in metastatic renal cell carcinoma (mRCC): Preliminary assessment of toxicity in an expanded access trial with subpopulation analysis

5010

Background: Sunitinib is an oral, multitargeted tyrosine kinase inhibitor of VEGFRs and PDGFRs, approved multinationally for advanced RCC. The primary aim of this international, open-label trial was to provide sunitinib to mRCC pts who failed =1 prior systemic therapy and were ineligible for other sunitinib trials or had no access to sunitinib before regulatory approval in their country. Methods: Eligibility criteria were minimized to broaden the enrolment population. Pts who were 18 yrs of age or older with histologically-confirmed mRCC received oral sunitinib 50 mg/day in 6-wk cycles (4 wks on Tx, 2 wks off). Physical exam, safety and concomitant meds were assessed every 4 wks. Results: As of Sept 1, 2006, 4,000 pts were enrolled from 181 sites in 36 countries; 2,158 pts (median age, 59 [19- 85]; male/female, 74%/26%) were included in this analysis. Baseline demographics included 106 pts (5%) with non-clear cell histology; 173 pts (8%) with brain mets; 158 pts (7%) with prior antiangiogenic Tx; and 288 pts (13%) with ECOG PS =2. Median Tx duration was 128 days (range 1- 2444) with interruptions in 17% of pts and dose reductions in 30%; 672 pts (31%) discontinued, of which 80 pts (12%) discontinued due to AEs. The median Tx duration was similar to the overall population regardless of age or site of metastatic disease at baseline (brain, bone, lung, liver, lymph nodes or other), but was longer in pts with ECOG PS 0/1 (154 days, range 1–2,444) than with ECOG PS =2 (83 days, range 1–449). The most common treatment-related AEs were diarrhea (39% any grade, 3% grade 3/4), fatigue (35%, 7%) and nausea (33%, 2%), the incidences of which were similar in pts regardless of age or site of baseline metastatic disease; overall, they occurred more frequently in pts with ECOG PS 0/1 vs. ECOG PS =2 (42% vs. 21%, 38% vs. 23%; and 34% vs. 25%, respectively), but differences in grade 3/4 severity were not observed. Median overall survival has not been reached; 19% of pts have died, the lowest incidence among pts with ECOG PS 0/1 (15%) and highest in pts with ECOG PS =2 (43%) and brain mets (34%). Conclusions: Preliminary observations suggest that sunitinib is associated with acceptable tolerability in an expanded access trial regardless of age or site of baseline metastatic disease.

[Table: see text]

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial: Long-term outcomes in first-line patients (pts)

5096

Background: Sorafenib (SOR) doubled median progression-free survival (PFS) versus placebo in a phase III study (TARGETs) for previously treated pts with clear cell renal cell carcinoma (RCC). We report on pts who had not received any prior systemic anti- cancer therapy (1st line) for advanced RCC from the ARCCS program in the US and Canada, which enrolled a broad range of pts. Methods: Pts received SOR 400 mg bid in the ARCCS open-label, nonrandomized treatment protocol if they were =15 years old with advanced (unresectable, recurrent or metastatic) RCC and had ECOG PS 0–2. In the US, ARCCS enrollment ended with SOR approval in 12/05, and pts were transitioned to commercial drug with 1st line pts being eligible for an additional 6-mo follow-up in an extension protocol (EP); Canadian enrollment completed in 8/06. Response evaluation (baseline and =1 post-baseline radiologic assessment) was conducted every 4 wks in the main study and every 8 wks during the EP. Pts without a confirmatory scan were classified as unconfirmed PR. The primary efficacy analysis on PFS was pre-specified to be performed only on the EP-enrolled pts. Results: Of the 2,488 pts valid for safety in ARCCS, nearly 50% were 1st line (n=1239) of which 69% were male with median age 65 yrs; 77% had prior nephrectomy and 29% had prior radiotherapy. Time from diagnoses to treatment was <1 yr for 52% and =1 yr 36% in these 1st line pts. Grade 3 and 4 adverse events with >2% incidence included hand-foot skin reaction 7.7%, fatigue 4.7%, hypertension 3.8%, rash/desquamation 5.2%, dehydration 2.9, diarrhea and dyspnea 2.6%. Confirmed responses are reported in the table ; 15% had unconfirmed PRs. For the 224 1st line pts enrolled in the EP, median PFS was 35.1 wks (95% CI; 32.7, 41.9). Conclusions: SOR toxicity in 1st line pts appeared similar to that in both overall and 2nd line populations previously reported in the phase III study. The PFS among patients enrolled in the EP is encouraging, but may be biased by low enrollment and selection for non-progressors.

[Table: see text]

[Table: see text]

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial in North America: Safety and efficacy

5011

Background: A prior phase III trial (TARGETs) demonstrated that sorafenib (SOR) doubled median progression-free survival versus placebo in previously treated clear cell renal cell cancer (RCC) patients (pts). The ARCCS trial made SOR available to a broader range of RCC pts through an expanded access program. Methods: This open-label, nonrandomized trial enrolled pts with advanced RCC not eligible for, or without access to, other SOR clinical trials; ECOG PS 0–2 with waivers granted for pts with ECOG PS 3–4; age =15 yrs; and adequate prior treatment of brain metastases. Major exclusion criteria included treatment <4 wks prior, life expectancy <2 mos, uncontrolled hypertension, and severe renal impairment requiring dialysis. Objectives were to analyze the safety and efficacy (response by RECIST) of 400 mg bid SOR in a community-based setting. Enrollment ceased on 12/20/05 when SOR became commercially available in the US, and those with no prior therapy or non-clear cell RCC continued in an extension protocol. Enrollment completed in Canada in 8/06. Results: A total of 2488 pts were valid for safety: 69% male with median age 63 yrs and most (83%) had prior nephrectomy; histologies included 78% clear-cell, 7% papillary, 1% chromophobe, and <1% collecting duct and oncocytoma. Median time from diagnosis for all pts was 1.4 yrs (range <1–34). Of those pts receiving prior therapy (n=1249), treatments included interferon alfa (54%), interleukin 2 (43%), bevacizumab (23%), thalidomide (12%), and sunitinib (2%). Grade 3 and 4 adverse events occurring in > 2% pts were hand- foot skin reaction 7.2%, fatigue 5.3%, hypertension 4.4%, rash/desquamation 4%, dehydration and dyspnea 2.7%, and diarrhea 2.5%. Efficacy assessment, mainly PFS, was limited by the short median time (14 wks) on study due to many pts enrolling during the last 2 months of the study. Of 1,850 pts evaluable for response, 17.5% had unconfirmed PR. One (0.1%), 67 (3.6%), 1479 (79.9%) and 303 (16.4%) had CR, PR, SD, and PD, respectively. Conclusions: ARCCS pts were representative of the broader range of RCC pts in the community including those excluded from previous SOR trials. Toxicity and response rates were similar to those reported previously, supporting the generalizability of the phase III trial data.

[Table: see text]

WBC changes as a pharmacodynamic marker of outcome in metastatic renal cell carcinoma (mRCC) patients (Pts) receiving sunitinib

5043

Background: Sunitinib is a VEGF, PDGF, c-Kit and FLT-3 inhibitor with significant anti-tumor activity in mRCC. Myelosuppression is a common side effect observed in mRCC pts treated with sunitinib. Thus, the association of myelosuppression with clinical outcome was investigated. Methods: All mRCC pts receiving sunitinib at The Cleveland Clinic Taussig Cancer Center with available data were investigated. White blood cell (WBC) and differential counts at baseline and day 28 of cycle 1 were collected. Peripheral blood mononuclear cell (PBMC) T helper 1 (Th1), T helper 2 (Th2) and T regulatory cell (Treg) numbers at baseline and day 28 of C1 were determined using flow cytometry. Hematologic parameters were analyzed as continuous variables and also dichotomized using a recursive partitioning algorithm. Fisher’s exact test was used to analyze categorical data, the log rank test was used to assess time to progression (TTP) and Spearman’s rank correlation was used to summarize associations between hematologic and immune parameters. Results: Sixty-seven pts were studied (75% male, median age 59 yrs). Objective responses (OR) included 2 complete and 35 partial responses (overall response rate 55%), with a median (m) TTP of 12.4 months. There was a significant reduction (end of C1 vs. baseline) in the absolute neutrophil count (ANC) (m decrease of 46.4%; p <0.001) and absolute monocyte count (m decrease of 41.3%; p<0.001), but not absolute lymphocyte count (m 6.6% decrease; p=0.5). A decrease in the ANC of =2.5K/uL compared to <2.5 K/uL was associated with improved OR (64% vs. 36%; p= .07) and TTP (m 20.6 months vs. 8 months; p=.003). Patients demonstrating a maximum lymphocyte count =1.2 K/uL at anytime during treatment compared to patients with a maximum lymphocyte count <1.2 K/uL also had a greater OR (64% vs. 25%, p=.02) and TTP (m 17.6 months vs. 4.2 months, p=.03). Changes in Treg number and Th1 and Th2 response bias of PBMC did not correlate with ANC/ lymphocyte changes or clinical outcome. Conclusions: Treatment with sunitinib produces significant neutropenia with minimal effects on total lymphocyte numbers. Changes in ANC and maximum lymphocyte count could represent a pharmacodynamic marker of clinical outcome for mRCC patients treated with sunitinib.

No significant financial relationships to disclose.

Sunitinib therapy for patients (pts) with metastatic renal cell carcinoma (mRCC): Updated results of two phase II trials and prognostic factor analysis for survival

5095

Background: Two single-arm phase 2 trials reported a 42% objective response rate (ORR) with sunitinib as second-line therapy in mRCC pts (JAMA 2006;295:2516–24). Efficacy results were updated and an analysis of prognostic factors for survival was performed on pooled data. Methods: Eligibility criteria and treatment plan were nearly identical for both trials. Pts with mRCC who failed =1 prior cytokine-based therapy received sunitinib in repeated 6-week cycles of 50 mg/day orally for 4 weeks, followed by 2 weeks off treatment. Response was assessed by investigators according to RECIST. Pretreatment clinical and biochemical features were examined for prognostic factors by univariate and multivariate analysis (p<0.05 significance level was used in the backward stepwise selection procedure). Results: Updated efficacy data for 168 evaluable pts showed an ORR of 45% (95% CI: 39%, 54%), median progression-free survival (PFS) of 8.4 months (95% CI: 7.9, 10.7), and median overall survival (OS) of 22.3 months (95% CI: 14.8, 36.0). Twenty pts remain on treatment with sunitinib with the longest pt on the drug for >3.5 years with partial response for >3 years. The median duration of response was 11.6 months (95% CI: 9.9, 15.2), and included 1 pt with a complete response for >2 years. The proportion of pts alive at 2 years is 48%. Final prognostic factors for survival in the multivariate model were ECOG PS 0 vs. =1 (p=0.0034); time interval from diagnosis to sunitinib treatment =1 yr vs. <1 yr (p=0.0002); hemoglobin =13 vs. <13 g/dL for males and =11.5 vs. <11.5 g/dL for females (p=0.0002). Conclusions: Median survival is nearly 2 years, which compares favorably to the historical experience (12.7 months) in second-line therapy with other agents (JCO 2004;22:454–63). The influence of sunitinib therapy on patient survival is being investigated in a randomized phase 3 trial compared to interferon-a in first-line therapy for mRCC. Further study of prognostic factors to sunitinib therapy is warranted in the first-line setting.

No significant financial relationships to disclose.

Sorafenib treatment of clear-cell renal cell carcinoma (CCRCC) and colorectal carcinoma (CRC) cells: Differential effects on gene expression and cell death pathways

15612

Background: The von Hippel Lindau gene (VHL) is often mutated in CCRCC and leads to loss of VHL protein (pVHL) expression. Sorafenib is a TKI with clinical activity in metastatic CCRCC. Studies to define mechanisms governing anti-tumor activity of this agent in CCRCC or CRC cell lines that express wild-type pVHL were conducted. Methods: We evaluated CAKI-1 (CCRCC) and HCT- 116/p53 +/+ (CRC) cell lines as model systems expressing wild-type pVHL. Cells were treated at 37°C in an atmosphere of normoxia (21% O2) or hypoxia (1% O2), 5% CO2 and the remainder N2 in the absence (control) or presence of sorafenib (2.5–20 μM) for 24–96 hours. Expression of target angiogenesis, apoptotic and anti-apoptotic genes was determined by real-time RT- PCR. Fluorescence microscopy following staining with Hoechst 33342 plus propidium iodide was used to analyze cell death by apoptosis and/or necrosis. Caspase-3 activity was measured using the target substrate DEVD-AFC. Results: In CAKI-1 and HCT-116 cells, exposure to 1% O2 relative to 21% O2, led to increased expression (2 to 6-fold) of angiogenesis (VEGF) and anti-apoptosis (TNFAIP3 & MCF2) genes. However, in an atmosphere of 1% O2 relative to 21% O2, a decreased (>2-fold) and increased (>3-fold) expression of the apoptotic (TNFRSF25) gene was observed in CAKI-1 cells and HCT-116 cells. Sorafenib treatment (7.5 μM) of CAKI-1 cells in 1% O2 led to a >3–4-fold decrease in expression of the VEGF and TNFAIP3 and a 3-fold increase TNFRSF25 genes. Following treatment with 10 μM sorafenib for 48h, cell death was >80% by necrosis in CAKI-1 cells and >95% by apoptosis in HCT-116 cells. Apoptotic cell death in the HCT-116 was also confirmed by increased caspase-3 activity in cell extracts following sorafenib treatment. Apoptotic cell death or necrotic cell death induced by sorafenib was unaffected by normoxia or hypoxia. Conclusions: In contrast to CCRCC cells, hypoxia led to upregulation of the apoptotic gene TNFRSF25 in the CRC cells. Anti- proliferative effects of sorafenib were primarily by necrosis in CCRCC cells and by apoptosis in CRC cells.

No significant financial relationships to disclose.

Exposure-response of sunitinib in metastatic renal cell carcinoma (mRCC): A population pharmacokinetic/pharmacodynamic (PKPD) approach

5027

Background: Sunitinib malate (SU) is an oral, multitargeted tyrosine kinase inhibitor of VEGFRs and PDGFRs, and has shown substantial antitumor activity in mRCC (Motzer et al, JAMA 2006 and ASCO 2006). This analysis describes SU, and total drug (TD; SU+SU12662 [active metabolite]) exposure-response relationships in mRCC using a population PKPD approach. Methods: PK and efficacy data from 3 studies (phase II and III) of SU (25–62.5 mg/day; 4 wks dosing followed by 2 wks off) in treatment-naïve (N=44) and cytokine-refractory mRCC pts (N=148) were analyzed. SU and SU12662 concentrations were fitted to a population PK model (a 2- compartment model for both parent and metabolite). Estimates of pt PK were used to calculate steady-state Area Under the Curve (AUCss) for SU, SU12662 and TD, which were used as the exposure measure in a PKPD analysis of partial response (PR) rates, time to tumor progression (TTP), overall survival (OS), and tumor volume changes. Results: The probability of a PR for cytokine-refractory pts increased with increasing AUCss for SU and TD. The odds-ratio suggested a 2.6-fold increase in PR frequency for each unit increase in AUCss. Longer TTP and OS were also noted in pts with high SU and TD AUCss. In treatment-naïve pts on SU, there was very little observed tumor progression or death (only 5 pts progressed and only 1 death) limiting the ability to analyze exposure-response. A tumor growth dynamics model (developed to describe changes in tumor volume [by CT or MRI] in response to treatment, as a function of AUCss) provided a good description of tumor volume changes with SU for both treatment-naïve and cytokine-refractory pts. Efficacy was not related to baseline tumor volume, gender, or race. Based on this model, clinical trial simulations assuming perfect pt compliance predict that 62% of pts would achieve a PR with SU 50 mg/day. Conclusions: SU and TD AUCss correlated significantly with the probability of a PR in cytokine- refractory pts, and longer TTP and OS. Limited data were available for treatment-naïve pts. The tumor growth dynamics model provided a good description of tumor volume changes with SU for both populations. This exposure-response analysis indicates that increased exposure to SU is associated with clinical benefit.

[Table: see text]

Sunitinib versus interferon-alfa (IFN-α) as first-line treatment of metastatic renal cell carcinoma (mRCC): Updated results and analysis of prognostic factors

5024

Background: In a randomized phase III trial of patients (pts) with mRCC, sunitinib demonstrated a significant improvement in progression-free survival (PFS) and objective response rate (ORR) compared to IFN-a as first-line therapy (Proc ASCO 2006;24:2s [Abstract LBA3]). We present the most recent data from this trial and an analysis of prognostic factors. Methods: Untreated pts with clear-cell mRCC were randomized 1:1 to receive either sunitinib (repeated 6-week cycles of 50 mg/day orally for 4 weeks, followed by 2 weeks off treatment) or IFN-a (9 MU given subcutaneously three times weekly). The primary endpoint was PFS. Results: A total of 750 pts were randomized: 375 to sunitinib, 375 to IFN-a. The median duration of treatment is 11 months (range: <1–25) for sunitinib vs. 4 months (range: <1–22) for IFN-a. The updated ORR by investigator assessment is 44% (95% CI: 39, 49) for sunitinib vs. 11% (95% CI: 8, 15) for IFN-a (p <0.000001), including 4 complete responses for sunitinib and 2 for IFN-a. The median duration of response in the sunitinib group (n=165) is 12 months (95% CI: 10, 14) vs. 10 months (95% CI: 8, 17) in the IFN-a group (n=43). The median PFS is 11 months (95% CI: 10, 11) for sunitinib vs. 4 months (95% CI: 4, 5) for IFN-a. The median PFS for pts with 0 risk factors is 14 months (95% CI: 11, 16) for sunitinib vs. 8 months (95% CI: 7, 10) for IFN-a; 9 months (95% CI: 8, 11) vs. 4 months (95% CI: 4, 4), respectively, for pts with 1- 2 risk factors; 4 months (95% CI: 2, 10) vs. 1 month (95% CI: 1, 2), respectively, for pts with =3 risk factors. The sunitinib benefit in PFS extends across all MSKCC prognostic risk factor groups (HR=0.488; 95% CI: 0.406, 0.586). The baseline features that predict longer PFS (by investigator assessment) for the sunitinib group are hemoglobin =LLN (p=0.0043), corrected calcium =10 mg/dL (p=0.001), ECOG score of 0 (p=0.0005), number of metastatic sites 0 or 1 (p=0.0064), and time from diagnosis to treatment =1 yr (p=0.0002). Conclusions: Sunitinib is a reference standard for first-line treatment of mRCC, with significant improvement in PFS and ORR compared to IFN-a. The benefit of sunitinib extends across all subgroups of pts with mRCC. Previously defined MSKCC risk factors for mRCC predict longer PFS with sunitinib.

No significant financial relationships to disclose.

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial: Subset analysis of patients (pts) with brain metastases (BM)

15506

Background: Sorafenib (SOR) was demonstrated to be safe and effective in a phase III trial of previously treated RCC pts; however, pts with BM were excluded. BM occur in 5–10% of RCC pts, and generally portend a poor prognosis. Safety and efficacy of SOR in this pt population was therefore explored in a subset analysis of ARCCS, a community-based expanded access program. Methods: Pts received SOR 400 mg bid in this open-label, nonrandomized trial if they were =15 years old with advanced RCC and had ECOG PS of 0–2. Pts with BM were included but required to have some prior local therapy for their brain lesions. Prior treatment did not have to be successful, and pts whose BM had been surgically removed were also eligible for this protocol. BM were excluded as target lesions for RECIST unless they were the only lesions being followed. Major exclusion criteria included treatment with other investigational drugs within 4 wks of enrollment; life expectancy <2 mos; active coronary artery disease, ischemia, or hypertension; and severe renal impairment requiring dialysis. The primary endpoints were safety and efficacy (per investigator assessed RECIST criteria). Results: Of 2,488 ARCCS pts valid for safety, 65 (2.6%) had been previously treated for BM: 72.3% male with median age 59.5 yrs. 99% had =1 prior therapy for non-brain disease including 81.5 % radiotherapy, 78.5% nephrectomy and 47.7% prior systemic therapy. Grade 3 adverse events (AE) occurring >2% in this subset were fatigue and seizure (6.2% each) and hand-foot skin reaction, diarrhea, hemoglobin, mucositis, dehydration, vomiting, hyperglycemia, and thrombosis (3.1% each). In the total ARCCS population vs the BM subset, Grade 3 AEs were 35.2% vs 26.2% and Grade 4 AEs were 6.1% vs 9%. There were no CNS-related bleeding events in pts with BM. Of the 47 pts evaluable for response, partial response was reported in 2 (4%), stable disease in 33 (70%), and progressive disease in 12 (26%). Conclusions: The toxicity and efficacy of SOR in pts with brain mets in ARCCS were comparable to those observed in the whole study population. Of note, SOR was well tolerated in this study with no reports of cerebral hemorrhagic events.

[Table: see text]

Use of Von-Hippel Lindau (VHL) mutation status to predict objective response to vascular endothelial growth factor (VEGF) -targeted therapy in metastatic renal cell carcinoma (RCC)

5012

Background: The clinical response to VEGF-targeted therapy in metastatic RCC is robust, yet variability in outcome exists. VHL is often mutated in RCC, but the relation to therapeutic outcome is unclear. Identification of tumor molecular characteristics associated with outcome would aid in patient selection and interpretation of clinical trials. Materials and Methods: Patients with metastatic, clear-cell RCC with available baseline frozen or paraffin-embedded tumor samples who received VEGF-targeted monotherapy with sunitinb, sorafenib, axitinib or bevacizumab at Cleveland Clinic or University of California San Francisco, were included. Patient characteristics, VHL gene status (mutated or not mutated) and objective response rate (ORR) were documented. ORR was investigator-assessed per RECIST criteria. Fisher’s exact test and logistic regression models were used to assess ORR in univariate and multivariate analyses, respectively. Results: One-hundred twenty-three patients were evaluable. The ORR was 36.5% for the entire cohort. VHL mutation was found in 48% of patients and was seen across all three exons. Patients with VHL mutation had an ORR of 46% versus 28% for pts without a mutated VHL gene (p=0.06). In multivariate analysis, presence of a VHL mutation remained an independent prognostic factor associated with improved ORR (p=.02) when multiple clinical prognostic factors (ECOG PS, hemoglobin, corrected calcium, LDH, prior radiation, prior therapy and number of metastatic sites) were also considered. Conclusion: This is the first large study testing the impact of VHL mutation on response to VEGF-targeted agents in metastatic RCC. Although objective responses were more likely among patients with mutated VHL gene, lack of VHL mutation did not preclude a response. Additional tissue analysis and identification of biomarkers relevant to response to VEGF-targeted agents in metastatic RCC are warranted.

[Table: see text]

A phase II trial of low-dose interleukin-2 (IL-2) and bevacizumab in patients with metastatic renal cell carcinoma (mRCC)

5103

Background: Interleukin-2 and bevacizumab, a VEGF ligand-binding antibody, have each demonstrated antitumor activity in mRCC. Increased VEGF levels can lead to immunosuppression and resistance to immunotherapy through inhibition of dendritic cell (DC) differentiation and increase in immunosuppressive regulatory T cells (Tregs). To further evaluate the clinical and immunomodulatory effect of low-dose IL-2 and bevacizumab in mRCC, a phase II trial was conducted. Methods: Previously untreated good and intermediate risk mRCC pts received 8-week cycles of IL-2 (250,000 U/kg/d SC D1–5 during week 1 and 125,000 U/kg/d SC D1–5 during weeks 2–6, followed by a 2 week break). Bevacizumab 10mg/kg was administered IV every 2 weeks starting on day -14. Eligibility included RECIST-defined measurable disease, clear cell histology, normal organ function, and prior nephrectomy. A Simon 2 stage phase II design was employed to test the hypothesis of a 40% improvement in the 3-month PFS vs. historical IL-2-treated controls. Overall response rate (ORR) and toxicity were recorded. Exploratory endpoints included activation of circulating DC’s, Tregs and VEGF levels. Results: To date 16 of a planned 35 pts are enrolled. Median age is 59 years (range, 44–67); Eight patients have >1 site of metastasis; median treatment duration is 8 weeks (8–32+). Among 11 pts evaluable for response, 1 PR and 3 SD lasting >3 months have been observed. All pts with SD have demonstrated some degree of tumor shrinkage. Seven pts have discontinued therapy (5 PD, 2 withdrew consent). Most common treatment-related toxicity included fatigue, nausea, diarrhea, and fever. When comparing immune correlates at day 56 of therapy vs. baseline, all pts had an increase in the number of Tregs (median increase 1.65, range; 0.76–10.4; p= 0.008). Similarly, all pts had a decline in VEGF levels (median decline 164.38 pg/ml, range; 2.20–393.04 pg/ml; p= 0.008). No differences in DC activation have been observed. Conclusions: The combination of LD IL-2 and bevacizumab produces antitumor activity and moderate toxicity. Preliminary correlative data demonstrates inhibition of VEGF and increase in Tregs without effect on DC activation.

No significant financial relationships to disclose.

Randomized phase II trial of first-line treatment with sorafenib versus interferon in patients with advanced renal cell carcinoma: Final results

5025

Background: This trial investigated the efficacy and safety of sorafenib (SOR) vs interferon (IFN) in treatment-naïve patients with clear-cell renal cell carcinoma (RCC). Methods: Previously untreated patients with advanced RCC were randomized to continuous oral SOR 400 mg bid or IFN 9 million units tiw (part 1), with an option of dose escalation to SOR 600 mg bid or crossover from IFN to SOR 400 mg bid upon disease progression (part 2). The primary endpoint was progression-free survival (PFS). Results: Baseline characteristics (ITT, n=189) were similar in SOR (n=97) and IFN (n=92) groups. In the IFN arm, 90/92 patients received treatment; 56 had disease progression, of which 50 crossed to SOR. All 97 patients in the SOR arm received SOR 400 mg bid; 65 had disease progression, of which 44 were dose escalated to 600 mg bid. In part 1, 5% vs 9% patients had complete/partial response, disease control rate (complete/partial response + stable disease) was 79% vs 64%, and median PFS was 5.7 months (CI: 5.0–7.4 months) vs 5.6 months (CI: 3.7–7.4 months) for SOR vs IFN, respectively. Progression-free rates for SOR vs IFN were 90.0% vs 70.4%, 45.9% vs 46.5%, and 11.5% vs 30.4% at 3, 6, and 12 months, respectively. A total of 11% vs 15% of patients receiving SOR or IFN, respectively, discontinued due to adverse events. Overall, the incidence of adverse events was similar between both treatment arms, although skin toxicity (rash and hand-foot skin reaction) and diarrhea occurred more frequently in the SOR group, and flu-like syndrome occurred more frequently in the IFN group. In part 2, median PFS was 5.3 months (CI: 3.6–6.1 months) in patients (n=50) who crossed from IFN to SOR. The median PFS for patients (n=44) with dose escalation to 600 mg bid was 3.6 months (CI: 1.9–5.3 months). The 600 mg bid dose was well tolerated. Conclusions: Although the primary endpoint (PFS) was not reached, SOR showed activity in first-line treatment of RCC based on disease control rate. PFS benefit was observed in patients who crossed to SOR 400 mg bid after progression on IFN. Patients who were dose escalated to 600 mg bid after progression had disease stabilization for a further 3.6 months. Further analyses of possible benefit from SOR dose escalation are required in a larger number of patients.

[Table: see text]

Phase II trial of sunitinib in bevacizumab-refractory metastatic renal cell carcinoma (mRCC): Updated results and analysis of circulating biomarkers

5035

Background: Sunitinib malate is an oral, multitargeted tyrosine kinase inhibitor with antiangiogenic and antitumor activity. This study evaluated the safety and activity of sunitinib in mRCC patients (pts) previously treated with the VEGF-neutralizing antibody, bevacizumab. Levels of angiogenic biomarkers, including plasma VEGF and soluble VEGFR-3 (sVEGFR-3), were assessed for predictive significance with clinical response. Methods: Pts were required to have mRCC with disease progression following bevacizumab- based therapy, measurable disease, ECOG performance status 0 or 1, and adequate organ function. Pts were treated with sunitinib 50 mg daily in 6-week cycles (4 weeks on, followed by 2 weeks off). The primary endpoint was objective response according to RECIST. Plasma VEGF and sVEGFR-3 levels were measured in pre-treatment samples and at multiple timepoints on study. Results: A total of 61 pts were enrolled. The objective partial response rate was 23% (95% CI: 13%, 36%); 35 pts (57%) demonstrated stable disease. The median duration of response was 36 weeks (95% CI: 26, NA) and progression-free survival was 30 weeks (95% CI: 18, 34). Plasma VEGF levels increased from baseline (3-fold mean elevation), while plasma sVEGFR-3 levels decreased from baseline (40% mean reduction). Pre-treatment VEGF levels were significantly higher in pts (n=34) with <10 weeks between cessation of bevacizumab and start of sunitinib (p<0.001); ELISA specificity suggests that detected VEGF is not bevacizumab-bound. Pre-treatment sVEGFR-3 levels were significantly lower at baseline in responding pts vs. non-responding pts (p<0.0318). A greater reduction in sVEGFR-3 levels was seen in responding pts vs. non-responding pts (p<0.10). Pretreatment VEGF and VEGF fold-changes did not differ according to clinical response. Conclusions: Sunitinib has significant antitumor activity in bevacizumab-refractory mRCC pts, suggesting absence of cross-resistance between bevacizumab and sunitinib. Biomarkers including plasma VEGF and sVEGFR-3 may have predictive potential in sunitinib-treated patients.

No significant financial relationships to disclose.

Nigro regimen treatment of squamous cell cancer of the anus

14545

Background: To identify prognostic factors for patients with squamous cell cancer (SCC) of the anus treated with Nigro Regimen chemo/radiation therapy. Methods: Survival data of 61 patients with SCC of the anal canal were reviewed who were treated with definitive radiochemotherapy (RCT) between 9/83 and 3/06. All patients received RCT at the Cleveland Clinic Foundation. Results: Patient characteristics were typical of other studies. Median age was 57 years (34–82), women: men (42:19), PS 0–1 (95%), smokers 52%, and clinically lymph node positive tumors 27%. T3–4 tumors were 50%, high for most series. The median follow-up time was 52 mos (7–246 mos). The median disease free survival (DFS) and overall survival (OS) have not been reached. 5-year DFS was 76% (95% C.I. 62–88%) and 5-year OS was 76% (95% C.I. 60–86%). Colostomy free survival at 5-years was 41/61 (67%). Log rank analyses showed that female sex (5-yr DFS 82 vs 55%, p=0.03), and clinical stage (5-yr DFS, stage 1 100%, stage 2 80%, stage 3a 65%, stage 3b 0%) correlated with better disease free survival. Patient age (less than 60 or greater), time of diagnosis (before 1996 or later), and smoking status did not correlate with better disease free survival. There were 14 recurrences, 7 systemic, 7 local with APR salvaging 4 patients with local relapse. There were 2 cases of treatment related hemolytic uremic syndrome, with one death. Conclusions: The Nigro regimen is successful in curing anal cancer in a significant majority of patients. We appear to have reached a therapeutic plateau and have not had any significant improvement in cure rates over the last two decades. Identification of subsets more prone to relapse is crucial, to target with more intense treatment in future trials. In the current series, male sex and advanced clinical stage correlated with poor disease free survival, when anal cancer patients were treated with the Nigro regimen RCT. Future studies should investigate whether more intensive treatment is needed in males, and patients with more advanced disease.

No significant financial relationships to disclose.

Final results of the randomized phase III trial of sorafenib in advanced renal cell carcinoma: Survival and biomarker analysis

5023

Background: Based on the significant PFS benefit of sorafenib (SOR) vs placebo (P) in a Phase III advanced RCC trial, P patients were unblinded and crossed over to SOR in May 2005. Final OS and biomarker data are reported. Methods: Final OS analysis was planned at ∼540 events (a=0.037 after adjusting for previous analyses). To minimize effect of crossover on OS, a secondary analysis was planned censoring P data on June 30, 2005 (a=0.037). Plasma VEGF and sVEGFR2 were measured by ELISA at baseline (BL), cycle (C) 1 day (D) 21, and C3D1. pERK was assayed by IHC. Results: 903 patients were randomized (SOR, 451; P, 452). The only OS analysis before crossover (May 2005) showed an estimated 39% OS improvement for SOR vs P (HR=0.72; p=0.018) (ECCO 2005); 216 P patients had crossed to SOR. OS analysis 6 months after crossover (Nov 2005) showed a 30% improvement in OS for SOR vs P (HR=0.77, p=0.015) (ASCO 2006). These OS differences did not reach prespecified O’Brien-Fleming statistical boundaries. Final OS (Sep 2006) at 561 deaths showed an improvement of 13.5% for SOR vs P and was not significant (median 17.8 vs 15.2 months; HR=0.88; p=0.146; a=0.037). Secondary analysis censoring P data (June 2005) showed a significant OS benefit for SOR vs P (HR=0.78, 95% CI: 0.62, 0.97; p=0.0287; a=0.037), suggesting crossover had confounded OS. Changes in VEGF (n=712) and sVEGFR2 (n=717) were observed after SOR treatment (AACR 2006); VEGF increased 32% (n=279) at C1D21 and 47% (n=203) at C3D1, and sVEGFR2 decreased 18% (n=282) and 24% (n=206). Using a COX proportional hazards model, BL VEGF was an independent prognostic factor (p=0.014); patients with high BL VEGF (>131 pg/ml) had poorer prognosis and a trend towards greater PFS benefit with SOR (SOR vs P, HR=0.48 vs 0.64 for high vs low VEGF, p=0.096). BL sVEGFR2, changes in VEGF or sVEGFR2 at C1D21, and pERK levels in limited diagnostic tumor biopsies were not predictive of SOR response. Conclusion: SOR demonstrated a PFS benefit in advanced RCC, although ITT final OS analysis showed a confounding effect of crossover. Significant OS benefit of SOR was seen in a planned secondary analysis adjusting for crossover. VEGF levels have prognostic importance, and SOR-associated changes in VEGF and sVEGFR2 are consistent with inhibition of VEGF signaling.

No significant financial relationships to disclose.

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial: Safety and efficacy in patients (pts) with non-clear cell (NCC) renal cell carcinoma (RCC)

5036

Background: A phase III trial showed that sorafenib (SOR) doubled progression-free survival (PFS) in previously treated pts with clear cell RCC. Activity of SOR in pts with NCC RCC has not been previously reported. Methods: Pts eligible for this open-label, nonrandomized trial in North America were not eligible for other SOR clinical trials, had recovered from prior treatment-related toxicity, and had advanced RCC; ECOG PS of 0–2; age =15 yrs; no treatment with other investigational drugs within 4 wks; life expectancy >2 mos; no active coronary artery disease, ischemia or hypertension; and no severe renal impairment requiring dialysis. In the US, ARCCS enrollment ended with SOR approval in 12/05, and pts were transitioned to commercial drug with NCC pts being eligible for an additional 6-mo follow-up in an extension protocol (EP), which was designed to better assess PFS in NCC. Tumor assessments and radiological evaluations were conducted every 4 wks in the main protocol and every 8 wks in the EP. Results: Of 2,488 pts valid for safety in ARCCS, 212 (8.5%) had NCC RCC classified as papillary, chromophobe, collecting duct, or oncocytoma, of whom 24 enrolled in the EP. Baseline characteristics and efficacy are shown in the table . Grade 3 and 4 adverse events (AEs) with > 2% incidence across all histologies included fatigue 7.1%, hand-foot skin reaction 6.6%, rash/ desquamation 6.2%, hypertension 4.7%, abdominal pain 3.8% dyspnea 3.8%, pleural effusion 3.3%, nausea 3.8%, vomiting 2.4%, and ascites 2.4%. Grade 3 and 4 serious AEs were reported in 20% of patients. Of those enrolled in the EP with NCC, median PFS was 34.5 wks (65.2% censored). Conclusions: SOR was well tolerated among pts with NCC RCC. Within the limitations of no central pathologic review, SOR toxicity in NCC RCC was similar to that in the broader ARCCS population and SOR may have antitumor activity in papillary and chromophobe subtypes.

[Table: see text]

[Table: see text]

The Advanced Renal Cell Carcinoma Sorafenib (ARCCS) expanded access trial: Safety and efficacy in patients (pts) with prior bevacizumab (BEV) treatment

5041

Background: Sorafenib (SOR) is an oral multi-kinase inhibitor of tumor-cell angiogenesis and proliferation. Phase III (TARGETs) data have demonstrated prolonged progression-free survival in pts with advanced clear cell renal cell carcinoma (RCC) in whom prior therapy failed. Activity of SOR following treatment with BEV, an anti-vascular endothelial growth factor and antiangiogenic monoclonal antibody, has not been evaluated. Methods: A subset analysis was conducted to describe safety and efficacy in the SOR expanded access program in North America for pts receiving prior BEV. Inclusion criteria for this open-label, nonrandomized trial included advanced RCC; ineligibility for, or lack of access to, other SOR clinical trials; age =15 years; ECOG PS of 0–2; recovery from prior treatment; adequate prior treatment of brain metastases. Major exclusion criteria included life expectancy <2 months; active coronary artery disease, ischemia or hypertension; severe renal impairment requiring dialysis. Pts previously treated with BEV required =28 days from last dose, no =Grade 3 hemorrhagic episode during therapy, and no history of =Grade 2 hemorrhagic event 6 mos prior to BEV treatment. Results: Of the 2,488 pts in ARCCS valid for safety analysis, 289 pts had received prior BEV: 65% male with median age 61 yrs. Grade 3 and 4 toxicities occurring in >2% of prior BEV pts included hand-foot skin reaction 9.0%; fatigue 6.9%; hypertension 4.8%; dehydration, dyspnea, anorexia, and abdominal pain 3.1%; back pain, rash/desquamation, and mucositis 2.8%; pleural effusion and diarrhea 2.1%. Of the 195 BEV-pretreated pts evaluable for response, 152 (77.5%) had stable disease and 5 (2.5%) had confirmed partial responses (PR). There were 26 (13.3%) unconfirmed PRs reported according to RECIST, 4 of which missed a second scan due to US ARCCS enrollment ceasing upon FDA approval of SOR in 12/05. Conclusions: We observed activity of SOR following BEV therapy for advanced RCC. AEs in this subset were generally well tolerated and similar to those in the overall ARCCS population. Further investigation is warranted to elucidate mechanisms for response to SOR following prior antiangiogenic treatment.

[Table: see text]

Clinical factors associated with outcome in metastatic renal cell carcinoma patients treated with VEGF-targeted therapy

5046

Background: Therapy targeted against the vascular endothelial growth factor (VEGF) pathway is a standard of care in metastatic renal cell carcinoma (RCC). Identification of clinical features of patients more likely to benefit from these agents would aid in patient selection and interpretation of clinical trial results. Methods: We reviewed 120 metastatic RCC patients receiving bevacizumab, sorafenib, sunitinib or axitinib on one of eight prospective clinical trials at the Cleveland Clinic Taussig Cancer Center. Clinical features associated with outcome were identified by univariate analysis, and then a stepwise modeling approach based on Cox proportional hazards regression was used to identify independent prognostic factors and form a model for progression-free survival (PFS). A bootstrap algorithm was used to provide internal validation. Results: Forty-one patients (34%) achieved an objective response by RECIST criteria (95% C.I. 27–44%). The median PFS for the entire group was 13.8 months (m) (95% C.I. 10.7–19.0 m). Multivariate analysis identified the following independent adverse prognostic factors (PF) for PFS: time from diagnosis to current treatment <2 years, baseline platelet count >300 K/μL, baseline neutrophil count >4.5 K/μL, baseline corrected serum calcium <8.5 or >10.0 mg/dL and initial ECOG performance status >0. Using these factors three prognostic subgroups were formed based on the number of adverse PF present . Median PFS in patients with 0 or 1 adverse PF was 20.1 m (95% C.I. 19.0–22.3 m) compared to 13 m (95% C.I. 8.6–17.6 m) in patients with 2 adverse PF and 3.9 m (95% C.I. 1.8–7.2 m) in patients with >2 adverse PF. Conclusions: Five independent prognostic factors for predicting PFS were identified and used to categorize patients with metastatic RCC receiving VEGF-targeted therapies into three risk groups. These factors can be readily incorporated to clinical patient care, stratification schema for clinical trials utilizing these novel agents and for interpretation of clinical trial results using VEGF-targeted agents therapy.

No significant financial relationships to disclose.

Durable complete responses and near complete responses to sunitinib in metastatic renal cell carcinoma

15514

Introduction: Sunitinib is a tyrosine kinase inhibitor with activity against VEGFR and PDGFR recently approved by the FDA for the treatment of advanced renal cell carcinoma (RCC). There is no existing literature that details complete responses (CRs) in patients taking sunitinib for metastatic RCC. Methods: Seventy-four patients with metastatic RCC receiving sunitinib at the Cleveland Clinic Taussig Cancer Center on clinical trials were reviewed to determine the number of patients with RECIST-defined CRs. Additionally, patients who achieved near-CRs defined as a greater than 90% reduction in composite tumor volume or residual disease of less than or equal to 1 cm were reviewed. Results: Two patients (2.7%) achieved a RECIST-defined CR lasting >15 months. The patients who obtained CRs had non-bulky pulmonary metastases, favorable or intermediate MSKCC risk profiles, were treated with sunitinib in the first-line setting and had a significant reduction in composite tumor measurements within the first two cycles. An additional 2 patients achieved near-CRs, including one patient that previously progressed on bevacizumab. These 2 near-CR patients remain progression-free for more than 19 months. Finally, 1 patient achieved sufficient downstaging and reduction of tumor volume such that the remaining lesion could be excised, resulting in a surgical CR. This patient is currently off sunitinib and remains progression-free 4 months after surgery. Conclusion: Sunitinib is capable of producing durable CRs in cytokine-naïve metastatic RCC patients with non-bulky pulmonary metastases. Additionally, near-CRs can be seen despite non-pulmonary metastatic sites and prior VEGF-targeted therapy.

No significant financial relationships to disclose.

Prognostic factors associated with long-term survival in previously untreated metastatic renal cell carcinoma

PURPOSE

To identify prognostic factors (PF) for long-term survival in metastatic renal cell carcinoma (RCC) patients.

METHODS

We retrospectively reviewed a metastatic RCC database at the Cleveland Clinic Foundation consisting of 358 previously untreated patients who were enrolled in institutional review board-approved clinical trials of immunotherapy and/or chemotherapy at our institution from 1987 to 2002. In order to identify patient characteristics associated with long-term survival, we compared 226 'short-term' survivors [defined as overall survival (OS) <2 years] with 31 'long-term' survivors (OS >or=5 years).

RESULTS

Using logistic regression models, four adverse PF were identified as independent predictors of long-term survival: hemoglobin less than the lower limit of normal, greater than two metastatic sites, involved kidney (left), and Eastern Cooperative Oncology Group (ECOG) performance status (PS). Using the number of poor prognostic features present, three distinct risk groups could be identified. Patients with 0 or 1 adverse prognostic feature present had an observed likelihood of long-term survival of 32% (21/66) compared with 9% (8/91) for patients with two adverse features present and only 1% (1/93) for patients with more than two adverse features.

CONCLUSIONS

Independent predictors of long-term survival in previously untreated metastatic RCC include baseline hemoglobin level, number of involved sites, involved kidney, and ECOG PS. Incorporation of these factors into a simple prognostic scoring system enables three distinct groups of patients to be identified.

Downregulation of topoisomerase IIbeta in myeloid leukemia cell lines leads to activation of apoptosis following all-trans retinoic acid-induced differentiation/growth arrest

Among the topoisomerase (topo) II isozymes (alpha and beta), topo IIbeta has been suggested to regulate differentiation. In this study, we examined the role of topo IIbeta in all-trans retinoic acid (ATRA)-induced differentiation of myeloid leukemia cell lines. Inhibition of topo IIbeta activity or downregulation of protein expression enhanced ATRA-induced differentiation/growth arrest and apoptosis. ATRA-induced apoptosis in topo IIbeta-deficient cells involved activation of the caspase cascade and was rescued by ectopic expression of topo IIbeta. Gene expression profiling led to the identification of peroxiredoxin 2 (PRDX2) as a candidate gene that was downregulated in topo IIbeta-deficient cells. Reduced expression of PRDX2 validated at the mRNA and protein level, in topo IIbeta-deficient cells correlated with increased accumulation of reactive oxygen species (ROS) following ATRA-induced differentiation. Overexpression of PRDX2 in topo IIbeta-deficient cells led to reduced accumulation of ROS and partially reversed ATRA-induced apoptosis. These results support a role for topo IIbeta in survival of ATRA-differentiated myeloid leukemia cells. Reduced expression of topo IIbeta induces apoptosis in part by impairing the anti-oxidant capacity of the cell owing to downregulation of PRDX2. Thus, suppression of topo IIbeta and/or PRDX2 levels in myeloid leukemia cells provides a novel approach for improving ATRA-based differentiation therapy.

Phase III randomized trial of sunitinib malate (SU11248) versus interferon-alfa (IFN-α) as first-line systemic therapy for patients with metastatic renal cell carcinoma (mRCC)

LBA3

Background: Two multicenter phase II trials of 2nd line monotherapy with sunitinib (SU11248) in patients (pts) with mRCC showed a response rate of approximately 40% (JCO 2006;24:16–24; Proc ASCO 23, 380s). This international, randomized phase III trial compared the efficacy and safety of sunitinib to IFN-α in treatment naïve pts with mRCC. Methods: Untreated pts with clear-cell mRCC were randomized 1:1 to receive sunitinib (6-week cycles: 50 mg orally once daily for 4 weeks, followed by 2 weeks off) or IFN-α (6-week cycles: subcutaneous injection 9 MU given three times weekly). The primary endpoint was progression-free survival (PFS). Secondary endpoints included objective response rate, overall survival, and adverse events. Based on a planned sample size of 690 patients, the trial was designed to have 90% power to detect a 35% improvement in median PFS from 20 weeks to 27 weeks (4.6 months to 6.2 months; 2-sided unstratified log-rank test; significance level 0.05). Results of a planned analysis on the primary endpoint, PFS, are presented in this report. Results: From Aug 2004 to Oct 2005, 750 patients were randomized: 375 to sunitinib, 375 to IFN-α. Baseline characteristics were well balanced, and included pooled median age = 60 and prior nephrectomy = 90%. Median PFS assessed by third-party independent review was 47.3 weeks (95% CI 40.9, not yet reached) for sunitinib vs. 24.9 weeks (95% CI 21.9, 37.1) for IFN-α [hazard ratio 0.394 (95% CI 0.297, 0.521) (p < 0.000001)]. The objective response rate by third-party independent review was 24.8% (95% CI 19.7, 30.5) for sunitinib vs. 4.9% (95% CI 2.7, 8.1) for IFN-α (p < 0.000001). The objective response rate by investigator assessment was 35.7% (95% CI 30.9, 40.8) for sunitinib vs. 8.8% (95% CI 6.1, 12.1) for IFN-α (p < 0.000001). 632 pts (85%) are alive, with 49 deaths on sunitinib arm and 65 deaths on IFN-α arm. 8% withdrew from the study due to adverse event on sunitinib arm vs. 13% on IFN-α arm. Conclusions: These results demonstrate a statistically significant improvement in PFS and objective response rate for sunitinib over IFN-α in first-line treatment of pts with mRCC.

[Table: see text]

Thyroid function tests (TFTs) abnormalities in patients (pts) with metastatic renal cell carcinoma (mRCC) treated with sunitinib

4605

Background: Sunitinib is a multi-targeted receptor tyrosine kinase inhibitor of vascular endothelial growth factor and platelet-derived growth factor receptors. It has anti-tumor activity in mRCC pts with toxicity including fatigue. We investigated TFTs abnormalities and related signs and symptoms in pts with mRCC receiving sunitinib. Methods: The medical records of pts with mRCC enrolled in 4 ongoing clinical trials of sunitinib were reviewed. TFTs assessment (TSH, T3 and T4) was undertaken based on the clinical suspicion of treating physicians. Patient demographics, frequency and values of TFTs and any signs and symptoms of thyroid dysfunction were collected. Abnormal TFTs and treatment outcome were correlated. Results: Between 5/2004 and 12/2005, 62 pts (43 males, 19 females) were treated with sunitinib. The median age was 58 years (range, 23–72). Fifty-five pts had TFTs assessed while on treatment and 40 pts (65% of total) had one or more abnormality. Two pts had well-controlled hypothyroidism prior to initiation of sunitinib. TFTs abnormalities were consistent with hypothyroidism in all pts including one who initially developed transient hyperthyroidism. Signs and symptoms possibly related to hypothyroidism were found in 33 pts (53% of total) with abnormal TFTs and were initially attributed to sunitinib. Signs and symptoms included fatigue in 33 pts, anorexia in 20 pts, fluid retention in 17 pts, and skin/hair changes in 13 pts. Thyroid hormone replacement was undertaken in 12 pts and resulted in improvement of symptoms in 6 pts. Among the 40 pts with abnormal TFTs 29 pts had tumor evaluation; 13 had SD, 8 had PR, 2 had CR. There was no correlation between abnormal TFTs and treatment outcome. Conclusions: TFTs abnormalities are common in pts with mRCC treated with sunitinib. Thyroid hormone replacement is indicated in such pts to improve hypothyroidism-related symptoms and possibly to improve treatment tolerance.

[Table: see text]

Randomized phase III trial of sorafenib in advanced renal cell carcinoma (RCC): Impact of crossover on survival

4524

Background: Sorafenib was approved for advanced RCC in the USA December 2005. A Phase III randomized double-blind, placebo-controlled trial demonstrated an estimated 39% improvement in survival for patients receiving sorafenib versus placebo (HR= 0.72, p = 0.018) (ECCO 2005). These data supported independently reviewed doubling of PFS to 24 weeks in RCC patients receiving sorafenib compared with placebo (12 weeks) (p < 0.000001) (ASCO 2005). Based on the statistical significance and magnitude of PFS benefit, patients were unblinded and placebo patients allowed to crossover to sorafenib in April 2005. A prospectively planned interim OS analysis reflecting impact of crossover of placebo patients is presented. Methods: OS data up to November 30, 2005, were analyzed in this interim analysis using a stratified log-rank test comparing the two treatment groups. In order to examine the effect of crossover on OS, a secondary analysis was performed censoring data from patients randomized to placebo at June 30, 2005. Results: A total of 903 patients were randomized (451 to sorafenib, 452 to placebo) and >200 placebo patients crossed over to sorafenib. Baseline characteristics were similar between treatment arms. There were 367 deaths. The median OS was 19.3 months for sorafenib versus 15.9 months for placebo (HR = 0.77; 95% CI 0.63, 0.95; p = 0.015); although this did not attain the level of significance specified for the interim analysis (α = 0.009), a continued favorable trend in survival benefit was observed. With censoring of crossover data, the median OS was 19.3 months for sorafenib versus 14.3 months for placebo (HR = 0.74, 95% CI 0.58, 0.93; p = 0.010). Conclusion: Sorafenib is the first novel, oral approved treatment for advanced RCC in more than a decade. Previous information on the effect of crossover on OS in randomized oncology studies is limited. The lower HR observed after censoring placebo patients crossed over to sorafenib suggests a continued beneficial effect of sorafenib. Final results await more mature data.

[Table: see text]

Phase II trial of weekly docetaxel and gemcitabine as first line therapy for patients with advanced non-small cell lung cancer

17076

Background: A platinum doublet has been the standard treatment for patients with advanced non-small cell lung cancer (NSCLC) and good performance status. This treatment results in almost a doubling of 1-year survival, along with an improvement in quality of life despite treatment related toxicities. However, platinum based treatment is associated with significant toxicity. Methods: In this trial, we prospectively evaluated a weekly regimen of docetaxel and gemcitabine for advanced NSCLC from December 2001 to January 2005. The endpoints of this study included objective response rate, survival and toxicity. Forty-two patients with previously untreated, advanced NSCLC with PS 0–1 were included. Patients received docetaxel (36 mg/m2) and gemcitabine (600 mg/m2) on days 1,8 and 15 of a 28-day cycle. Responses were assessed every two cycles. Results: The median age was 63 years; with 22 males and 20 females; 67% were >60 years old; and 38 patients had stage IV disease. In the intent-to-treat (ITT) analysis of response, 16 patients had a partial response (38%) and 15 patients had stable disease (36%). The 1-year survival was 48%; median survival for all patients was 11.3 months and the median progression-free survival was 5.1 months. Toxicities (> grade 3) included neutropenia (29%), asthenia (26%), thrombocytopenia (14%), diarrhea (14%), pneumonitis (7%), peripheral neuropathy (5%), peripheral edema (5%), nail changes (2%), and myositis (2%). Conclusions: This study demonstrated that this non-platinum doublet (docetaxel + gemcitabine) given on a weekly schedule for advanced NSCLC was well tolerated with efficacy comparable to platinum based chemotherapy regimens.

[Table: see text]

Phase I trial of docetaxel, carboplatin and lenalidomide in patients with advanced solid tumors

13027

Lenalidomide (LEN) is an immunomodulatory derivative of thalidomide with significantly greater in vitro activity and different toxicity. It may interfere with the expression of angiogenic factors (TNF-alpha & IL-6), vascular endothelial growth factor (VEGF) and induce apoptosis in resistant cell lines. In preclinical trials it has shown synergy with chemotherapy. Primary objective of this study was to determine the maximum tolerated doses (MTD) of docetaxel (D) and carboplatin (Cb), combined with oral LEN. Secondary objectives were toxicity and activity. Eligibility included pathologically proven solid tumors, ≤ 2 prior chemotherapy regimens, performance status ECOG 0/1, and adequate organ function. Patients (Pts) with active brain metastases, or prior treatment with D, Cb, or LEN, were excluded. Treatment was continued for a maximum of 6 cycles, followed by optional continuation of LEN until disease progression or toxicity. MTD was defined as the dose level (dl) immediately lower than that producing dose limiting toxicity (DLT) during cycle 1 in ≥ 2 of 3–6 pts. DLT were ≥ grade (G) 3 non-hematological, or G 4 hematological toxicity. No growth factors were used during cycle 1. Four pts were treated at dl I, D 60 mg/m2, and Cb AUC 6 on Day 1, and LEN 10 mg orally daily for 14 of a 21d cycle. Dose de-escalation was done following the first cohort due to DLT. 10 pts were treated at lower dl -1, D 60 mg/m2, and Cb AUC 6 on Day 1, and LEN 5 mg orally daily for 14 of a 21d cycle. 3 of 14 pts had prior chemotherapy. Tumors included non small cell lung cancer (NSCLC) (9), and one each with thymic, rectal, apocrine carcinoma, angiosarcoma and unknown primary. The median number of cycles was 4 (range 1–6). DLTs occurred in 3 of 4 pts at dl I (G 3 electrolyte (E) (2), G 4 neutropenia (N) (1) and 1 of 10 pts at dl-1 (G 4 N). Overall G 3/4 toxicities were: N (7), thrombocytopenia (2), and E (2). There were no treatment-related deaths or irreversible toxicities. Of the evaluable pts, 5 had a partial response (5/9 NSCLC), & 5 had stable disease. D 60 mg/m2, and Cb AUC 6 on Day 1, and LEN 5 mg orally daily for 14 days of a 21 d cycle is the MTD without use of prophylactic growth factors. This combination is active and further evaluation in a phase II trial is warranted.

[Table: see text]

HKI-272, an irreversible pan erbB receptor tyrosine kinase inhibitor: Preliminary phase 1 results in patients with solid tumors

3018

Background: HKI-272 is a potent, low molecular weight, orally active, irreversible pan erbB receptor tyrosine kinase inhibitor. It inhibits the growth of tumor cells that express erbB-1 (epidermal growth factor receptor, EGFR) and erbB-2 (HER-2) in culture and xenografts. HKI-272 also inhibits the growth of cultured cells that contain sensitizing and resistance-associated EGFR mutations (Kwak et al, Proc Natl Acad Sci USA 102:7665–70, 2005). We are conducting a phase 1 study in patients (pts) with advanced-stage tumors that express EGFR or HER-2 to assess HKI-272 for tolerability, safety, pharmacokinetics, and preliminary antitumor activity. Methods: Pts (3–6/cohort) received 40, 80, 120, 180, 240, 320, or 400 mg HKI-272 orally once on day 1 and then once daily beginning on day 8. Timed blood samples were collected on days 1 and 21 for pharmacokinetic analysis. Results: Enrollment of 73 pts is complete. Preliminary data for 51 pts as of 28 Nov 2005 are presented. Patients were a median 60 years and 26% men. The most frequently occurring tumor types at primary diagnosis were breast (23 pts), non-small cell lung (9), and colorectal, ovarian, and renal (3 pts each). Dose escalation ended when 2 pts who received 400 mg HKI-272/day had drug-related dose-limiting toxicity of grade 3 diarrhea. Thus, the maximum tolerated dose (MTD) was 320 mg HKI-272/day. HKI-272-related adverse events (AEs), any grade, that occurred in ≥10% of pts were diarrhea (84%), nausea (55%), asthenia (45%), anorexia (31%), vomiting (29%), chills (12%), and rash (10%). Grade 3 related AEs that occurred in >1 pt were diarrhea (11) and asthenia (4). HKI-272 Cmax and AUC increased in a dose-dependent manner. At steady state at the MTD, mean values were Cmax: 112±58 ng/mL, AUC: 1618±930 ng.h/mL, t1/2: 15±2.5 h. Day 1 and 21 AUC values were comparable. Tumor assessments (modified RECIST criteria) were made at baseline and at the end of alternate cycles (28 days/cycle). Two breast cancer pts had confirmed partial responses (PRs) and 2 had unconfirmed PRs. Conclusions: When HKI-272 was administered on a continuous, once-daily, oral treatment schedule, the MTD was 320 mg/day, with diarrhea as the most frequently occurring related AE. HKI-272 has antitumor activity in HER-2-positive breast cancer.

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A comparison of quality of life and symptoms in kidney cancer patients receiving sorafenib versus placebo

4534

Background: Results from the Phase III TARGETs study showed that sorafenib significantly prolonged progression-free survival compared with placebo in patients with advanced renal cell carcinoma. Overall survival was longer with sorafenib than placebo with a hazard ratio of 0.72. The impact of sorafenib treatment on health-related quality of life (HRQL) and symptoms was also evaluated. Methods: HRQL was measured by the Functional Assessment of Cancer Therapy-General (FACT-G). Symptoms were measured by the FACT-Kidney Cancer Symptom Index (FKSI), in which patients used a Likert scale (0–4) to respond to each of 15 items. FACT-G and FKSI were administered at baseline, at Day 1 of each cycle, and at end-of-treatment visit. Statistical analyses used a random coefficient model over five cycles, using MSKCC risk and treatment as factors and baseline score and relative days as covariates, adjusted for multiple comparisons with Bonferroni correction. Results: A total of 903 patients were randomized. The FACT-G completion rates at baseline, and Cycles 2, 3, 4, and 5 were; 96%, 91%, 95%, 99%, and 100%, respectively. The FKSI completion rates were; 94%, 89%, 94%, 97%, and 100%, respectively. The completion rate within each patient reported outcome (PRO) measure, across all visits, was 93%. At baseline, there was no between-treatment difference in score for either FACT-G or FKSI. There was no treatment difference after adjusting for multiple comparisons in mean FACT-G total score (p = 0.96) or its domains (physical well-being [p = 0.92]; emotional well-being [p = 0.46]); social well-being [p = 0.75]; functional well-being [p = 0.94]), and no difference in total score of FKSI over time. FKSI single-item analysis showed that sorafenib-treated patients had significantly less symptoms vs placebo (e.g. cough [p < 0.0001], fevers [p = 0.0015], ‘worry that condition will worsen’ [p = 0.0004], shortness of breath [p ≤ 0.0312], and ‘ability to enjoy life’ [p = 0.0119]). Only ‘concern about treatment side-effects’ favored placebo patients (p < 0.0001). Conclusions: Sorafenib demonstrates clinical benefit without adversely impacting overall HRQL, and has a positive impact on individual symptoms.

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Expression of caveolin-1 in renal neoplasms

14509

Background: Caveolin-1 is the major structural and functional component of caveolae, which are specialized lipid raft microdomains on cell membrane important for signaling pathways related to cell adhesion, growth and survival. Studies have shown that clear cell renal cell carcinoma (CCRCC) expressed caveolin-1 and that the over-expression correlated with adverse pathological findings and poor outcomes. The expression of caveolin-1 in other types of renal tumors has not been studied. Methods: A tissue microarray (TMA) was constructed from 60 normal kidneys, 22 CCRCC, 20 papillary renal cell carcinomas (PRCC), 16 chromophobe renal cell carcinomas (ChRCC), and 19 oncocytomas (ONC). The TMA was immunostained for caveolin-1 protein. Membranous caveolin-1 expression was scored using the internal vascular endothelial cells as positive control. Results: Membranous caveolin-1 expression was detected in 19/22 (86.4%) CCRCC, in 1/20 (5%) PRCC, 0/16 (0%) ChRCC, and 1/19 (5.3%) ONC. Cytoplasmic caveolin-1 was detected in 16/22 (72.7%) CCRCC, 13/20 (65%) PRCC, 8/16 (50%) ChRCC and 13/19 (68.4%) ONC. Membranous caveolin-1 expression correlated with tumor size (Pearson correlation = 0.266, p = 0.043). There was no correlation between membranous or cytoplasmic caveolin-1 expression and other pathological parameters, including Fuhrman nuclear grade, or TNM stage. Conclusion: Caveolin-1 exhibits distinct subcellular localization in different renal tumors. Membranous caveolin-1 is most commonly detected in CCRCC, rarely found in PRCC and ONC, and is absent in ChRCC. This finding suggests that caveolin-1 may play an important role in the pathogenesis of CCRCC.

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