Stadler, Walter M.

364 Background: Flavopiridol + FOLFOX showed activity in refractory GCT pts in a phase I trial (Rathkopf, Clin Cancer Res, 2009). This phase II study assessed the efficacy of this regimen in refractory GCT and the necessity of including 5-FU/LV. Methods: Previously treated pts with progressive GCT were eligible if they had received or were not candidates for high-dose chemotherapy (HDCT). Pts on Arm A received flavopiridol 70mg/m2 plus oxaliplatin 85mg/m2. Arm B (flavopiridol + FOLFOX) tested identical doses of flavopiridol and oxaliplatin plus 5-FU (400mg/m2 bolus, then 1800mg/m2 over 48 hours) and LV 400mg/m2. Treatment was every 2 weeks in 6-week cycles. The primary endpoint was response rate (RR) by RECIST. An identical Simon 2-stage design was used for each arm to differentiate between a RR ≥40% vs. ≤20%, with arm B opening only if arm A was ineffective. With ≥3 responses among the first 12 pts, another 13 pts would be enrolled with responses in ≥8/25 pts needed to show efficacy. Tumor biopsies pre-, during, and post-treatment were assessed by IHC for p53, p21, and cleaved caspase-3. Results: Of 36 pts (7 arm A, 29 arm B), 33 had nonseminoma. Primary site was testis in 27 and mediastinum in 7; 22 pts had received prior HDCT and 13 had LR (>2 years), including 2 on arm A and 11 on arm B. Arm A closed early after 0/7 pts responded (2 SD). Of 25 evaluable pts on arm B, 6 achieved a PR, 9 had SD, and 10 had PD. Notably, 5/10 evaluable LR pts on Arm B had a PR, including 1 pathologic CR, 1 PR-negative markers who received radiation (RT) to a residual bone metastasis, and 1 PR-positive markers who received RT to a residual nodal mass. These 3 pts remain disease-free ≥19 months (m) post-chemotherapy and ≥17m post-RT or surgery. Median PFS and OS were 2.3m and 7.3m for all pts and 3.2m and 11.2m for arm B pts. There was 1 treatment-related death due to sepsis. Conclusions: Although neither arm met the prespecified endpoint, flavopiridol plus FOLFOX (arm B) was particularly active in LR pts, with a 50% overall RR, including several durable responses. Further study of FOLFOX with or without flavopiridol is warranted in LR pts. Correlative data will be presented. Clinical trial information: NCT00957905.

617 Background: Over the past decade, seven agents were approved for metastatic renal cell carcinoma (mRCC) leading to a rapidly evolving clinical landscape. Clinical trials addressing treatment efficacy, sequencing, and other questions may continue to impact management decisions. Furthermore, our prior retrospective experience indicates a significant proportion of pts may not receive systemic therapy in the first year after diagnosis with metastatic disease. This analysis describes contemporary patterns of care in the first 109 real world pts enrolled in a multicenter, prospective, observational registry. Methods: MaRCC Registry will enroll 500 pts from up to 60 US academic (ACAD) and community (COMM) sites with ~2 years of recruitment and ≥ 3 years of follow-up. Key inclusion criteria are age ≥ 18 years and diagnosis of mRCC with no prior systemic therapy (STx) for mRCC at study entry. Pts currently not on STx but who are being observed are permitted. Key endpoints include descriptive characteristics of treatments (e.g. treatment agents, sequence, duration, reasons for therapy choice and discontinuation), treatment effectiveness (e.g. overall response rate, progression free survival, overall survival), quality of life (PROs), medication adherence, and health resource utilization. Results: At data cutoff, 105 pts have been accrued with known STx status; median age 64 (Q1-3 range, 56-70); 66% male; 75% ACAD; 87% clear cell histology; and 31% stage IV at diagnosis. Initial management strategies are shown in the table. The initial management decision after accrual was to defer systemic therapy (Def STx) in 40% (N=44). In ACAD and COMM sites, Def STx percentages were 38% and 48% respectively. Baseline demographics and clinical characteristics were not notably different between Def STx pts and those treated with STx. Conclusions: In our prospective registry, we have identified a large percentage of pts who initially received Def STx. In the context of contemporary pts undergoing investigational and standard of care STx, we will describe the management and outcomes of the Def STx population. [Table: see text]

563 Background: Clinical trials mRCC pts are different from real world pts, resulting in bias in the literature. The MaRCC Registry is designed to survey questions not asked in tri als, such as why physicians make certain management decisions. This analysis describes reasons for physician treatment (tx) selection in the first 109 real world pts enrolled in a multicenter, prospective, observational registry. Methods: MaRCC Registry will enroll 500 pts from up to 60 US academic (ACAD) and community (COMM) sites with ~2 years of recruitment and ≥ 3 years of follow-up. Key inclusion criteria are age ≥ 18 years and diagnosis of mRCC with no prior systemic therapy (STx) for mRCC at study entry. Pts currently not on STx but who are being observed are permitted. Key endpoints include descriptive characteristics of txs, tx and patient outcomes, medication adherence, and health resource utilization. Results: At data cutoff, 105 pts have been accrued with known STx status; median age 64 (Q1-3 range, 56-70); 66% male; 75% ACAD; 87% clear cell histology; and 31% stage IV at diagnosis. Initial management decision was: 40% deferred systemic therapy (DSTx), 22% pazopanib, 18% clinical trial, 10% sunitinib, and 6% other. Among STx pts (N = 61), the most common categories for therapy choice as selected by providers were likelihood of clinical benefit (41%) followed by pt characteristics (30%). Within the clinical benefit category, the most common reason was OS/PFS (31%). Within the pt characteristic category the most common reasons included performance status/frailty (12%) or prognostic factors (12%). Common reasons for DSTx pts (N = 44) were active surveillance (AS) with disease present (39%), AS without disease present following a procedure (11%), or local therapy (7%). ACAD sites had higher percentages of pts with DSTx undergoing AS with disease present and local therapy. Conclusions: This is the first report describing factors driving physician decision making in management of mRCC. Management choices are not captured in other prospective or retrospective studies. Early experience suggests that clinical benefit and pt characteristics were common reasons for initial STx. Side effect profile rarely determined initial STx selection.

265 Background: UC response to CT is not durable. Angiogenesis may play a role in the progression of UC. We evaluated whether maintenance sunitinib delays progression after response to CT. Methods: Pts with ECOG PS 0-2, adequate organ function, stable disease, partial or complete response (SD, PR, CR) after 4-6 cycles of CT for advanced UC were randomized to oral sunitinib 50 mg/day, 28 days on, 14 days off (6-week cycle) or placebo. Disease was assessed every 12 wks. At progression, placebo pts were offered open label sunitinib. Primary endpoint: progression rate at 6 months (ms); secondary endpoints: safety, objective response rate, survival, VEGF/sVEGFR2 serum level changes. Using a randomized selection design 42 pts/arm has 90% probability of selecting sunitinib if true reduction in 6-ms progression rate is 15% (from 50% to 35%). Results: Study was closed early due to slow accrual. 54 pts with median age 69 years, median ECOG PS 1, 70% with bladder primary, 26 with SD, 23 with PR, 5 with CR to CT were randomized to sunitinib (26) or placebo (28). The median number of cycles was 2/arm (sunitinib 0-15, placebo 0-13). The 6-ms progression rate was 81% (95%CI 61-93%), median time-to-progression (TTP) 5 ms (0.3-22.2, 95%CI 2.4-6.3) for sunitinib and 75% (95%CI 55-89%), 2.7 ms (0.8-19.6, 95%CI 2.5-7.4) for placebo. Response rate in pts with SD at enrollment was 9% for sunitinib and 7% for placebo. Most common G3/4 AEs on sunitinib were diarrhea (15.4%/0%), fatigue (15.4%/3.8%), thrombocytopenia (15.4%/7.7%), hypertension (11.5%/0%). 16 placebo pts received sunitinib with best response 1 PR (6.25%), 6 SD (37.5%), 5 PD (31.25%); 4 not response evaluable. Median TTP was 3.4 ms (0.1-22, 95%CI 1.6-5.5). 11 pts had G3/4 AEs, 5 pts discontinued sunitinib due to AEs (4 related, 1 unrelated). Placebo pts had no change in VEGF/sVEGFR2 over time. Sunitinib pts had no change in VEGF but sVEGFR2 significantly decreased after 1 cycle (p<0.0001) and at progression (p=0.0002). VEGF/sVEGFR2 did not correlate with TTP. Conclusions: Maintenance sunitinib was feasible but did not improve 6-ms progression rate; open label sunitinib had limited activity. sVEGFR-2 decreased on sunitinib.

BACKGROUNDAngiogenesis contributes to the progression of urothelial carcinoma (UC). In the current study, the authors investigated the role of maintenance sunitinib in patients with advanced UC.METHODSPatients with locally recurrent/metastatic UC and adequate organ function who achieved stable disease or a partial or complete response after 4 to 6 chemotherapy cycles were randomized to sunitinib at a dose of 50 mg/day (28 days on and 14 days off) or placebo. The primary endpoint was the 6‐month progression rate. Secondary endpoints were safety, survival, change in serum vascular endothelial growth factor (VEGF)/soluble VEGF receptor‐2 (sVEGFR2), and the activity of sunitinib in patients who developed disease progression while receiving placebo. A total of 38 eligible patients per treatment arm were required to select better therapy with 90% probability (α = .05).RESULTSA total of 54 eligible patients were randomized to either the sunitinib arm (26 patients) or the placebo arm (28 patients). The median number of cycles received was 2 cycles per treatment arm. The most common grade 3 to 4 adverse events (graded according to version 3.0 of the National Cancer Institute Common Terminology Criteria for Adverse Events) among patients receiving sunitinib were thrombocytopenia, diarrhea, mucositis, fatigue, and hypertension. There were no grade 3 or 4 adverse events noted among > 5% of patients receiving placebo. The 6‐month progression rate was 72% versus 64%. The median progression‐free survival (PFS) was 2.9 months (range, 0.5 months‐32.5 months) versus 2.7 months (range, 0.8 months −65 months) for the sunitinib versus placebo arms, respectively. Patients receiving placebo were found to have no changes in their serum VEGF/sVEGFR2 levels over time. Patients treated with sunitinib had no significant change in their VEGF level, but the sVEGFR2 level significantly decreased after cycles 1 and 2 (P < .0001) and at the time of disease progression (P = .0002). A baseline VEGF level that was at or greater than the median was found to be correlated with a longer PFS. Sixteen patients who were receiving placebo received sunitinib at the time of disease progression, with the best responses being 1 partial response (6.3%), 6 cases of stable disease (37.5%), and 5 cases of progressive disease (31.3%); 4 patients were not evaluable for response. The median PFS was 3.7 months (range, 0.1 months‐22 months).CONCLUSIONSThe current multicenter study was limited by premature closure and a small sample size. Maintenance sunitinib did not appear to improve the 6‐month progression rate. Open‐label sunitinib was found to have only modest activity. The sVEGFR2 level decreased among patients receiving sunitinib. Cancer 2014;120:692–701. © 2013 American Cancer Society.