ARTIA-Bladder: Daily Online Adaptive Short-Course Radiation Therapy (RT) and Concurrent Chemotherapy for Muscle-Invasive Bladder Cancer (MIBC): A Prospective Trial of an Individualized Approach for Reducing Bowel and Bladder Toxicity

PURPOSE/OBJECTIVE(S)

Concurrent chemo-radiotherapy is commonly prescribed for muscle-invasive bladder cancer (MIBC). Post hoc analysis of two large, randomized trials found that hypofractionation improves loco-regional control (LRC) vs. standard fractionation in this population. A challenge in traditional image-guided radiotherapy of the bladder is that daily changes in bladder position and size requires large margins to ensure target coverage. This makes it difficult to spare uninvolved bladder from high-dose treatment, increases the risk of bowel toxicity, and results in historical rates of acute G3+ toxicity exceeding 20-30%. Daily online adaptive RT (ART) may enable reduced, personalized margins that maintain target coverage while reducing dose to OARs. This prospective clinical trial will test whether: 1) participants undergoing ART for MIBC have a lower rate of acute G3+ GI/GU toxicity compared with the 31% historical control rate (Stage III BC2001 trial), and 2) 2-year LRC with ART will be non-inferior to historical controls (75%).

MATERIALS/METHODS

This multi-national trial will enroll 165 adult subjects with stage cT2-T4aN0M0 urothelial MIBC. Subjects will have undergone an attempt at maximal transurethral resection of bladder tumor. Patients with clinically involved nodes or G2+ GI or G3+ GU symptoms/conditions at baseline are ineligible. Concurrent with chemotherapy, participants will receive (at the discretion of the investigator) either 55 Gy in 20 fx to whole-bladder or 46 Gy in 20 fx to whole-bladder plus simultaneous in-field boost of 55 Gy in 20 fx to tumor bed. A personalized ITV will be derived for each subject based on bladder expansion, as assessed on two CT simulations separated by 30 min. Daily ART will be attempted for all subjects. The primary endpoint is acute G3+ GI/GU toxicity. Secondary endpoints are LRC; quality of life (EORTC QLQ-BLM30, EPIC 26 bowel and urinary); global function (EQ-5D-5L ); 2-year disease-free, bladder intact event-free, and overall survival; 2-year bladder cancer-specific mortality; NTCP model of acute GI toxicity for hypofractionated bladder RT; workflow feasibility of ART; improved target coverage ± reduced dose to critical OARs vs. non-ART dosimetry; acute G3+ GI/GU toxicity rate in subjects with ≥75% of their treatments as ART; and acute G3+ GI/GU toxicity in the cohort treated with partial bladder boost. Exploratory translational and correlative endpoints will also be examined.

RESULTS

This trial opened to enrollment on Feb 2, 2023; the study duration is expected to be 4-5 years.

CONCLUSION

This prospective clinical trial will provide robust clinical data to inform healthcare providers' decisions on the use of daily online ART and hypofractionation as a bladder preservation strategy for this population.

Relationship among circulating tumor cells, CEA and overall survival in patients with metastatic colorectal cancer

BACKGROUND

We previously reported results of a prospective trial evaluating the significance of circulating tumor cells (CTCs) in patients with metastatic colorectal cancer (mCRC). This secondary analysis assessed the relationship of the CTC number with carcinoembryonic antigen (CEA) and overall survival.

PATIENTS AND METHODS

Patients with mCRC had CTCs measured at baseline and specific time points after the initiation of new therapy. Patients with a baseline CEA value ≥ 10 ng/ml and CEA measurements within ± 30 days of the CTC collection were included.

RESULTS

We included 217 patients with mCRC who had a CEA value of ≥ 10 ng/ml. Increased baseline CEA was associated with shorter survival (15.8 versus 20.7 months, P = 0.012). Among all patients with a baseline CEA value of ≥ 25 ng/ml, patients with low baseline CTCs (<3, n = 99) had longer survival than those with high CTCs (≥ 3, n = 58; 20.8 versus 11.7 months, P = 0.001). CTCs added prognostic information at the 3-5- and 6-12-week time points regardless of CEA. In a multivariate analysis, CTCs at baseline but not CEA independently predicted survival and both CTCs and CEA independently predicted survival at 6-12 weeks.

CONCLUSIONS

This study demonstrates that both CEA and CTCs contribute prognostic information for patients with mCRC.

A USA registry of gastrointestinal stromal tumor patients: changes in practice over time and differences between community and academic practices

BACKGROUND

The objective of the study was to describe patterns of care of patients with gastrointestinal stromal tumors (GISTs) in the United States in the tyrosine kinase inhibitor (TKI) era.

PATIENTS AND METHODS

From November 2004 through March 2009, data were collected regarding demographics, diagnostic history, treatment, relapse, and survival of 882 patients with GIST from 122 community and academic medical practices.

RESULTS

The most common first-line treatment for the 719 patients presenting with localized GIST was surgery (87%). Use of adjuvant imatinib increased after June 2007; 47% of patients enrolled in the registry considered by the investigator to be at high risk for recurrence received adjuvant imatinib after June 2007 versus 18% before. Overall, 56% of patients received imatinib and 11% received sunitinib. The utilization of targeted therapy increased over time (45% and 0.4% of patients received imatinib and sunitinib, respectively, in 2006 versus 56% and 11%, respectively, in 2009).

CONCLUSIONS

These are the first GIST registry data from the TKI era. The use of targeted therapy for GIST has increased in accordance with updated treatment guidelines. Diagnosis of GIST has evolved with increased use of KIT testing. The duration of targeted therapy in the adjuvant therapy setting is similar in community and academic practices.

MC0553: A phase II safety and efficacy study with the VEGF receptor tyrosine kinase inhibitor pazopanib in patients with metastatic urothelial cancer

259

Background: Vascular endothelial growth factor (VEGF) and platelet derived growth factor (PDGF) are produced by bladder cancer cell lines in vitro and expressed in human tumor tissues. Preclinical studies have also shown that bladder cancer cell lines express VEGF receptor 1 and 2 on their surface membrane. Pazopanib is a vascular endothelial receptor tyrosine kinase inhibitor with anti-angiogenesis and antitumor activity in several preclinical models. A two-stage phase II study was conducted to assess the activity and toxicity profile of pazopanib administered to patients with metastatic, urothelial carcinoma.

Methods: Patients with one prior systemic therapy for recurrent, metastatic urothelial carcinoma were eligible. Patients received pazopanib at a dose of 800 mg orally daily for 4 week cycle.

Results: Nineteen patients were enrolled. Median age was 66 years, with > 89% of patients presenting poorly differentiated bladder cancer. Adverse event data is available on 18 patients. No grade 4 or 5 events have been experienced. Nine patients have experienced 11 grade 3 adverse events of which 7 were deemed at least possibly related to treatment. Most common toxicities were anemia, thrombocytopenia, leucopenia and fatigue. For stage 1, none of the first 16 evaluable patients were deemed success (CR or PR) by the RECIST criteria during the first four 4-week cycles of treatment. Median progression- free survival was 1.9 months. This met the futility stopping rule of interim analysis, and therefore, the trial was recommended to be permanently closed. Correlative studies including measurement of VEGF levels in archived tissues and blood are pending.

Conclusions: Pazopanib did not show activity in urothelial carcinoma patients. The role of anti-VEGF therapies in urothelial carcinoma may need further evaluation in rational combination strategies.

[Table: see text]

Phase I study of everolimus (RAD001) with irinotecan (Iri) and cetuximab (C) in second-line metastatic colorectal cancer: Hoosier Oncology Group GI05-102

523

Background: Preclinically, mTOR and EGFR inhibitors are synergistic. We hypothesize that the mTOR inhibitor RAD001 would enhance efficacy and prevent resistance when added to an anti-EGFR agent. The purpose of the phase I portion of this study was to determine the safety and maximum tolerated dose (MTD) of daily RAD001 combined with weekly Iri and C in mCRC.

Methods: Pts who failed first-line therapy, including an Iri-regimen, were treated with Iri 125 mg/m2 weekly x 2 every 3 weeks, C 400 mg/m2 loading dose, then 250 mg/m2 weekly, and escalating doses of RAD001 orally: 5 mg qod, 5 mg qd and 10 mg qd during 21-day cycles, with a “3+3” design. The study was amended after the first 9 pts enrolled, to include stopping rules for excessive toxicity beyond what was expected for diarrhea, nausea/vomiting and febrile neutropenia due to Iri, and skin rash due to C. Enrollment excluded pts with UGT1A1*28, but allowed KRAS mutated mCRC. RAD001 PK was done on C2D1, and archival tumors were analyzed for pharmacodynamic markers.

Results: 28 pts were enrolled, median age 61 y (25-77), 15 male, ECOG PS 0/1 (19/9). Reasons for treatment discontinuation were: PD (7), adverse events (AEs) (6), pt withdrawal, symptomatic deterioration and non-compliance (1 each). Prior to study's amendment* (n=9), 3 pts were not evaluable for DLT due to: Iri intolerance after one dose (1), non-compliance (1) and gr 3 C infusion reaction (1). DLTs and number of cycles are listed in Table. Following protocol amendment, 2 pts had DLT in cohort 3 (gr 3 mucositis), thus the MTD was 5 mg RAD001. The most common grade 3/4 AEs were: diarrhea (10), neutropenia (5), fatigue (4), acne-rash (4), mucositis (2), nausea (2), vomiting (1). Among 19 pts evaluable for response, there were 1 CR, 2 PR, (RR 16%), 9 SD (47%), 7 PD (37%). PK and pharmacodynamic data is ongoing.

Conclusions: The MTD of RAD001 of 5 mg QD with Iri/C weekly is safe and clinically active. A randomized phase II study is near starting accrual.

[Table: see text]

[Table: see text]

Bevacizumab plus interferon-alpha versus interferon-alpha monotherapy in patients with metastatic renal cell carcinoma: Results of overall survival for CALGB 90206

LBA5019

Background: Bevacizumab (BEV) plus interferon alpha (IFN) demonstrated a superior objective response rate and progression-free survival (PFS) versus IFN monotherapy in renal cell carcinoma (RCC) patients in 2 phase III trials. The primary objective of CALGB 90206 was to compare overall survival (OS) for advanced RCC patients receiving BEV plus IFN or IFN alone. Methods: Patients with previously-untreated, metastatic RCC with a clear cell component and Karnofsky performance status of ≥ 70% were eligible. Patients were prospectively randomized to receive BEV (10 mg/kg intravenously every 2 weeks) plus IFN (9 million units subcutaneously three times weekly) or the same dose and schedule of IFN as monotherapy. Randomization was stratified by nephrectomy status and number of MSKCC adverse features. The primary endpoint was OS, defined as the time from randomization to death due to any cause. The trial was designed with 86% power to detect a hazard ratio (HR) of 0.76, assuming a two-sided type I error of 0.05. The primary analysis was an intent-to-treat approach using the stratified log-rank statistic, and the present analysis was based on the target number of 588 deaths. Results: Between October 2003 and July 2005, 732 patients were enrolled; 369 pts to BEV plus IFN and 363 pts to IFN monotherapy. The median duration of follow up among censored patients was 46.2 months (IQR=45.2–48.2). The median OS was 18.3 months (95% CI; 16.5–22.5) for BEV plus IFN and 17.4 months (95% CI; 14.4–20.0, unstratified log rank p = 0.097) for IFN monotherapy. The stratified HR was 0.86 (95% CI; 0.73–1.01) for BEV plus IFN compared to IFN (stratified log-rank p = 0.069). The median OS for BEV plus IFN versus IFN was 32.5 vs. 33.5 months (p = 0.524) for MSKCC good risk, 17.7 vs. 16.1 months (p = 0.174) for intermediate risk and 6.6 vs. 5.7 months (p = 0.245) for poor risk patients. The median PFS was 8.4 months vs. 4.9 months (p<0.0001). Fifty-three percent of patients received subsequent systemic therapy. Conclusions: The addition of BEV to IFN significantly improves the objective response rate and PFS versus IFN monotherapy. Overall survival favored the BEV plus IFN arm, not meeting pre-defined criteria for significance.

[Table: see text]

A multicenter phase II study of cisplatin (C), gemcitabine (G), and bevacizumab (B) as first-line chemotherapy for metastatic urothelial carcinoma (UC): Hoosier Oncology Group GU-0475

5018

Background: Despite CG therapy, most metastatic UC patients die from their disease. Novel approaches are needed. Combining anti-angiogenic therapy with chemotherapy has improved outcomes in other malignancies, offering hope for similar improvements in UC patients. Methods: Metastatic or unresectable chemonaive UC patients (pts) with an ECOG performance status of 0–1 received C 70 mg/m2 iv d1, G 1,000–1,250 mg/m2 iv d1, 8, and B 15 mg/kg iv d1 on a q21d cycle for up to 8 cycles. Gemcitabine was reduced to 1,000 mg/m2 iv d1, 8 for all subsequent pts after 7 thromboembolic events were noted in the first 17 pts. The primary endpoint was progression free survival (PFS). The trial was designed to detect a 33% improvement in PFS from 7.5 months with traditional CG therapy to 11.25 months with CGB. Results: By December 2008, 45 pts were enrolled, with 43 evaluable for toxicity, 36 for response. Demographics include: 33 (77%) male, 10 (23%) female; median age 66 (Range: 41 - 78); 26 (60%) and 17 (40%) ECOG 0/1; 19 (44%) and 24 (56%) lymph node only / visceral metastases. PFS will be evaluated in May 2009 when all pts will have more than 6 month follow-up data. 14 (33%) and 6 (14%) pts experienced grade 3 or 4 hematologic toxicity (4 pts - thrombocytopenia, 2 pts - neutropenic fever). Grade 3 or 4 nonhematologic toxicity was observed in 24 (56%) and 9 (21%) pts (DVT/PE - 9 pts, CNS hemorrhage/proteinuria/hypertension - 1 pt each) Best RECIST response was: complete response 6 pts (17%, 95% CI 6–33%), partial response 18 pts (50%, 95% CI 33–67%); with overall response rate of 67% (95% CI 51–82%). Stable disease lasting at least 12 weeks was observed in 10 pts (28%, 95% CI 14–45%) and progressive disease in 2 pts (5%, 95% CI 1–19%). Conclusions: CGB demonstrates significant clinical activity in the first-line treatment of metastatic UC patients at the expense of considerable toxicity. The durability of disease control will be determined by assessment of PFS. A phase III trial to further define the toxicity risk vs. clinical benefit of bevacizumab addition to platinum-based doublets is planned in this population.

[Table: see text]

Bevacizumab plus interferon-alpha versus interferon-alpha monotherapy in patients with metastatic renal cell carcinoma: Results of overall survival for CALGB 90206

LBA5019

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

Phase I/II trial of CCI 779 and bevacizumab in advanced renal cell carcinoma (RCC): Safety and activity in RTKI refractory RCC patients

5039

Background: Combined mTOR and VEGF blockade is a potentially promising and rational strategy for the treatment of advanced RCC. We previously reported the phase I safety and efficacy results of CCI 779 (C) +bevacizumab (B) n RTKI naïve stage IV RCC patients (pts) (J Clin Oncol. 2007;25[18S Suppl]:5034). We now report the interim results of the phase 2 study of C+B in RTKI refractory RCC patients. Methods: Design: Open label, phase I/II study of C+B in advanced RCC pts. Patients with measurable stage IV RCC with a component of clear/conventional cell type, performance status 0–2 and good organ function were eligible. Up to two prior treatment regimens were allowed (at least one prior RTKI). Phase II dose was C = 25 mg IV weekly and B = 10 mg/kg every 2 weeks repeated in 4 week cycles. The primary objective of the phase II portion was to assess the proportion of patients who were progression-free 6 months after study entry. Secondary objectives were assessment of response rates and toxicity. Accrual goal = 40 pts. Results: Thirty-five pts have been enrolled into the phase 2 portion to date with 4 pts ineligible. Twenty-five pts are evaluable for response assessment and 29 pts are evaluable for toxicity. Baseline characteristics (N: 35): M/F: 28/7; Number of met. sites: 1/2/3+: 15/9/11; prior nephrectomy: 31; Number of prior therapies: 1 = 29; 2 = 2. Most common (>5%) Gr 3–4 AEs (N = 29) included fatigue (6), hypercholesterolemia (2), hypertriglyceridemia (2), anorexia (2), rash (2), and anemia (2). Responses were: PR/SD/PD = 4 (16%)/18 (72%)/3 (12%). Median number of cycles administered was 4. Six month progression free rates will mature by may 2009. Conclusions: C+B combination at the recommended phase 2 doses is feasible and well tolerated. Clinical benefit rates (PR/SD) in RTKI refractory RCC patients (88%) are encouraging. Data on 6 month progression-free rates are expected to mature in 4/09. Updated data on safety, response rates, and 6-month progression free rates will be presented on all evaluable patients. Correlative studies on available plasma, serum and tumor samples for angiogenic and molecular biomarkers are underway. Supported by N01-CM62205, R21 CA 119545–02, and Commonwealth Foundation.

[Table: see text]

Initial phase II experience of ipilimumab (IPI) alone and in combination with radiotherapy (XRT) in patients with metastatic castration-resistant prostate cancer (mCRPC)

5138

Background: IPI is a fully human, monoclonal anti-CTLA-4 antibody capable of enhancing anti-tumor immunity. In preclinical models, XRT releases tumor antigens and enhances anti-tumor activity of CTLA-4 blockade. In the dose escalation part of this Phase I/II trial 10 mg/kg dosing of IPI with or without prior priming by single fraction XRT was feasible. We now report initial phase II results. Methods: 45 patients (pts) with mCRPC and ECOG PS of 0–1 received 10 mg/kg q3 weeks (wks) X 4 of IPI in 3 groups: (1) IPI alone n=16, (2) IPI + XRT n=15 chemotherapy naïve (NoCHEMO), and (3) IPI + XRT n=14 chemotherapy experienced (CHEMO) pts. XRT (800 cGy) was given to up to 3 involved bony sites (GI tract sparing) just prior to starting IPI. PSA was monitored monthly, with scans q 3 months. Endpoints were to confirm safety and an initial assessment of activity. Results: 17 pts (38%) experienced 26 immune-related adverse events (irAEs) including diarrhea/colitis (12), rash/pruritus (6), hepatitis (4), endocrinopathy (4). 11 pts (24%) experienced 13 ≥ Grade 3 irAEs: GI (9; 20%) and hepatitis (4; 9%); all resolved with immunosuppression. 10 of 45 pts (22%; 95% CI 10–34%) had confirmed PSA declines ≥ 50% as follows in the table below. Median time to PSA decline was 5.7 wks (r 3 to 21 wks); median duration 23 wks (r 3 to 84+ wks). In one pt dosed with IPI alone, PSA ≤ 0.05 ng/ml, as well as a CR of bone, nodal and prostate lesions continue for 54+ and 84+ wks, respectively. Conclusions: irAEs in the 10 mg/kg cohorts are similar in type and rate to IPI in melanoma. irAEs and PSA declines occurred in chemotherapy naïve and post chemotherapy patients, and with or without XRT. Addition of XRT to 10 mg/kg is well tolerated. Time to response can be delayed, with a durable median response of 23 wks. Further study of IPI in mCRPC is warranted, with or without XRT as a potential immunosupportive maneuver to augment clinical responses to IPI.

[Table: see text]

[Table: see text]

Analysis of an observational registry of gastrointestinal stromal tumor (GIST) patients (pts) in the United States: reGISTry

10557

Background: This observational reGISTry, initiated 11/04, characterizes the evolving patterns of care for GIST, such as the recent use and approval of Imatinib mesylate (IM) in adjuvant GIST. Methods: Data from consented pts (e.g. demographics, clinical characteristics, therapy, outcomes) are entered onto a web-based database. Updated analyses are performed every 6 months (mo), with data from unique sites being compared to the aggregate. Results: 792 pts enrolled from 121 centers, 55% from community practices. 79% were diagnosed with localized tumor, 87% of which received surgery as primary treatment. 94% had c-kit testing and 4% had mutational analysis performed at any time (1.4% of the pts in the community; 7.8% in Universities). 59% of pts had mutations in KIT Exon 11, 12% in Exon 9, 3% in Exon 17, 9% in PDGFRA Exon 18 and 18% had no detectable mutations. 13% of pts from Universities were enrolled in clinical trials vs 3% in the community. 78% of pts receiving IM at any time started at 400mg qd and 70% of pts receiving Sunitinib malate (SU) started at 50mg (4 wks on, 2 wks off). 6.6% of all pts received neoadjuvant IM, for a median of 4.3 mo for those pts that have completed (81%). 120 pts (15%) received adjuvant IM (13% of the pts in the community; 17% in Universities). Prior to Jun07 (ACOSOG Z9001 adjuvant IM positive results released) 14% of eligible pts received adjuvant IM vs 29% after Jun07. Median duration of adjuvant IM was 361 days for those pts that have completed (43%). Conclusions: reGISTry is a useful tool for measuring evolving pt management patterns in GIST capturing treatment variations from standard guidelines and differentiating management in Universities from that occurring in the community. Mutational analysis and clinical trial participation are still infrequent. The starting dose of IM and SU remains 400mg and 50mg, respectively, for most pts. The use of adjuvant IM has increased after Jun 07, suggesting that prescribing habits may have been influenced by evolving study data in these pts. [Table: see text]

[Table: see text]

Phase II experience with MDX-1106 (Ono-4538), an anti-PD-1 monoclonal antibody, in patients with selected refractory or relapsed malignancies

3018

Background: Programmed death-1 (PD-1), an inhibitory receptor expressed on activated T cells, may suppress antitumor immunity. This expansion cohort in a phase I/II trial of MDX-1106, a fully human IgG4 antibody blocking PD-1, sought to further evaluate the safety and activity of the 10 mg/kg dose. Other objectives included evaluation of pharmacokinetics (PK) and immunological effects. Methods: Patients (pts) with treatment refractory metastatic non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), colon cancer (CC), melanoma (MEL), or prostate cancer (CRPC), and no history of autoimmune disease received a single infusion of MDX-1106 at 10 mg/kg. Disease status was evaluated at week (wk) 8 by RECIST criteria. Pts with stable disease or lesional responses could receive additional MDX-1106 at wks 12 and 16. Those with PR/CR were observed without retreatment. Results: 21 pts (5 CC, 2 NSCLC, 8 MEL, 5 HRPC, 1 RCC) were treated from 10/07 to present, and 6 were retreated. No MDX-1106 related SAEs occurred. One pt developed arthritic symptoms requiring treatment, and 2 pts had asymptomatic TSH elevation. One pt with RCC had a PR after 3 doses, lasting 5+ months (mo). Lesional regressions (“mixed response”) were seen in 2 MEL pts; to date, one has received 7 doses of MDX-1106 over 15 mo without serious toxicity. Biopsy of a regressing MEL lymph node metastasis showed a moderately increased and selective CD8+ T cell infiltrate post treatment. The median serum t 1/2 of MDX-1106 was 20.6 days, which was roughly 50% longer than observed for lower doses. There was no evidence of immunogenicity based on HAHA development. Interestingly, in contrast to PK results, flow cytometric analysis demonstrated sustained occupancy of 60–80% PD-1 molecules on T cells for at least 3 mo following a single dose. Analyses of circulating lymphocyte subsets and tumor B7-H1 expression are in progress. Conclusions: Intermittent dosing of MDX-1106 at 10 mg/kg demonstrated clinical activity against RCC and MEL without serious toxicity. Therapy with MDX-1106 to enhance endogenous antitumor immunity, either alone or combined with other immunological therapies, warrants further study.

[Table: see text]

Prognostic significance of circulating tumor cells in patients with metastatic colorectal cancer

BACKGROUND

We demonstrated that circulating tumor cell (CTC) number at baseline and follow-up is an independent prognostic factor in metastatic colorectal cancer (mCRC). This analysis was undertaken to explore whether patient and treatment characteristics impact the prognostic value of CTCs.

PATIENTS AND METHODS

CTCs were enumerated with immunomagnetic separation from the blood of 430 patients with mCRC at baseline and on therapy. Patients were stratified into unfavorable and favorable prognostic groups based on CTC levels of > or = 3 or <3 CTCs/7.5 ml, respectively. Subgroups were analyzed by line of treatment, liver involvement, receipt of oxaliplatin, irinotecan, or bevacizumab, age, and Eastern Cooperative Oncology Group performance status (ECOG PS).

RESULTS

Seventy-one percent of deaths have occurred. Median follow-up for living patients is 25.8 months. For all patients, progression-free survival (PFS) and overall survival (OS) for unfavorable compared with favorable baseline CTCs is shorter (4.4 versus 7.8 m, P = 0.004 for PFS; 9.4 versus 20.6 m, P < 0.0001 for OS). In all patient subgroups, unfavorable baseline CTC was associated with inferior OS (P < 0.001). In patients receiving first- or second-line therapy (P = 0.003), irinotecan (P = 0.0001), having liver involvement (P = 0.002), >/=65 years (P = 0.0007), and ECOG PS of zero (P = 0.04), unfavorable baseline CTC was associated with inferior PFS.

CONCLUSION

Baseline CTC count is an important prognostic factor within specific subgroups defined by treatment or patient characteristics.

MC044h, a phase II trial of sorafenib in patients (pts) with metastatic neuroendocrine tumors (NET): A Phase II Consortium (P2C) study

4504

Background: Treatment options for metastatic NET, including islet cell carcinoma (ICC) and carcinoid tumor (CT), are limited. These tumors frequently express vascular endothelial growth factor receptor-2 (VEGFR-2) and platelet derived growth factor receptor receptor-β (PDGFR-β). Sorafenib, a small-molecule inhibitor of the VEGFR-2 and PDGFR-β tyrosine kinase domains, is a rational targeted therapy to evaluate in NET. Methods: Eligibility criteria included: ECOG PS = 2, = 1 prior chemotherapy, good organ function and signed informed consent. Prior interferon and prior or concurrent octreotide at a stable dose were allowed. Pts unable to take oral medications, with uncontrolled hypertension or with symptomatic coronary artery disease were excluded. Pts received sorafenib 400 mg po BID. Primary endpoint was response by RECIST in two cohorts (ie, CT and ICC) using separate 2-stage phase II designs. Results: 93 pts were enrolled: (50 CT, 43 ICC). For pts evaluable for the primary endpoint, 4 of 41 (10%) CT pts and 4 of 41 (10%) ICC pts had a PR. There were 3 minor responses (MR = 20–29% decrease in sum of target lesion diameters) in CT pts and 9 MRs in ICC pts for PR+MR rate of 17% for CT pts and 32% for ICC pts. For pts evaluable, 6-month progression-free survival was observed in 8/20 CT and 14/23 ICC pts. Grade 3–4 toxicity occurred in 43% of pts, with skin (20%), GI (7%) and fatigue (9%) most common. Translational studies from tumor tissue will be presented. Conclusions: Sorafenib at 400 mg po BID has modest activity in metastatic neuroendocrine tumors, with frequent grade = 3 toxicity. Supported by NOI CM6225.

No significant financial relationships to disclose.

Gemcitabine and carboplatin in the treatment of metastatic cholangiocarcinoma and gallbladder cancer

15102

Background: There is currently no standard therapy for patients with unresectable or metastatic biliary tract cancers. Gemcitabine has been shown to be active against these tumors with a 20–30% response in various phase II studies. Gemcitabine is also synergistic with platinum compounds. Aim: We conducted a Phase II study of gemcitabine plus carboplatin in patients with unresectable or metastatic choloangiocarcinoma or gallbladder cancer to assess the regimen’s safety and efficacy. Methods: Since 3/2002, 49 (48 evaluable) patients were treated with gemcitabine at 1000 mg/m2 IV over 30 minutes days 1 and 8 with carboplatin at AUC 5 IV on day 1 of a 21 day cycle. There were 34 women and 15 men enrolled. Ages ranged from 34 to 87 with a median age of 65 years. Results: Best radiologic responses - 5CR, 9 PR, 24 stable disease and 10 progression. CR+PR 14/48 (29.2%) and stable disease 24/48 (50%). Toxicity: Hematological toxicities: Grade 3 neutropenia 33%, febrile neutropenia 0.02%, anemia 12.5% and thrombocytopenia 14.6%. Grade 4 hematological toxicites were rare - neutropenia 0.04%, and thrombocytopenia 0.06%. Non-hematologic toxicities were generally mild (fatigue, edema, nausea, vomiting, elevated liver enzymes, electrolyte abnormalities). Except for one patient who had depression there were no grade 4 non-hematological toxicity. Grade 3 non- hematological toxicites were also rare occurring only in 1 to 3 patients. Conclusions: Gemcitabine and carboplatin is active against biliary cancer and is highly tolerable. This study is being supported by Eli Lilly & Co.

No significant financial relationships to disclose.

Phase I study of CNTO 95, a fully human monoclonal antibody to αv integrins, docetaxel, and prednisone in hormone refractory prostate cancer patients (HRPCP)

15595

Background: CNTO 95 has demonstrated preclinical antitumor activity through binding to multiple av integrins, resulting in growth inhibition indirectly through anti-angiogenic effects as well as directly by inhibiting tumor cell proliferation. The target, av integrins, has been demonstrated by immunohistochemistry in a large proportion of human prostate cancer tissues. Docetaxel and prednisone have become a standard of care for HRPCP. The primary objective of this study was to evaluate the safety of combining CNTO 95 with this standard. Methods: Patients received day 1 infusions of 75 mg/m2 docetaxel together with twice daily oral prednisone in every 3 week cycles, with weekly infusions of either 5 or 10 mg/kg of CNTO 95 for 7 weeks beginning with the second docetaxel cycle, then CNTO 95 on the days of docetaxel thereafter. Patients were monitored for safety and PSA. Radiologic tumor assessments were performed at least every 4 cycles. Results: Six patients have received docetaxel and prednisone with CNTO 95 at either 5 mg/kg (n=3) or 10 mg/kg (n=3). In the 5 mg/kg group, 1 received 8 cycles then withdrew consent because of fluctuating PSA levels; 1 received 9 cycles then had soft tissue disease progression; and 1 has completed 9 cycles and remains on study treatment. In the 10 mg/kg group, all patients remain on study and have received 7, 6, and 6 cycles of treatment, respectively. There were no unexpected toxicities and only one Grade 3 toxicity (febrile neutropenia) attributed to docetaxel. A 50% decline in PSA occurred in 1 patient treated in the 10 mg/kg group. Conclusions: The combination of standard dose docetaxel and prednisone with 10 mg/kg of CNTO 95 was well tolerated and 3 new patients are planned to be treated with these doses on this study. Further study is warranted.

[Table: see text]

Biweekly oxaliplatin with gemcitabine and capecitabine in advanced gastrointestinal malignancies: A phase I study

4560

Background: Oxaliplatin (OX), gemcitabine (GEM) and capecitabine (CAP) are all active agents against various gastrointestinal and other malignancies and have different mechanisms of action and toxicity profiles. This Phase I study aims to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) associated with this triplet regimen. Methods: The modified Fibonacchi 3/cohort dose escalation schema was used to determine the MTD and DLT of OX, GEM and CAP. Oxalipaltin [85–100 mg/m2] IV over 2 hours and gemcitabine [800–1,000 mg/m2] were given at a constant rate infusion of 10 mg/m2/min on days 1 & 15, while CAP [600–800 mg/m2] was given PO BID on days 1–7 and 15–21. 1 cycle = 28 days. Pharmacogenomic correlates including ERCC2, GSTP1, TYMS, TS del and TSER G>C were also obtained. A structured neurological toxicity assessment and questionnaire was also performed. Once MTD was established, additional patients were treated at the MTD and pharmacokinetic studies were performed on these additional patients. Results: 30 patients (M:F 2:1; 23% non-caucasian) with median age of 62 (range: 38–78) and PS of 0–1 were enrolled from 3/05 to 8/06. All patients had advanced GI malignancies (19 pancreatic, 6 biliary, 2 duodenal, 1 gastric, 1 esophageal, 1 GI unknown primary). Dose levels, # patients, DLT and best responses are tabulated below. Conclusions: The MTD of this triplet regimen is OX at 100 mg/m2, GEM at 800 mg/m2 days 1 & 15 with CAP at 800 mg/m2 PO BID days 1–7, 15–21. DLTs for this regimen include grade 3 fatigue and dyspnea as well as Grade 4 thrombocytopenia. CR is achieved in 2 patients (cholangiocarcinoma and pancreatic), while a patient with a GI unknown primary achieved PR. Several patients with pancreatic cancer achieved prolonged SD. An exploration of any association of toxicities and response with pharmacogenomic correlates is ongoing. A Phase II study in patients with pancreaticobiliary cancers is planned. This study is supported by Sanofi-Aventis Pharmaceuticals.

[Table: see text]

[Table: see text]

Phase I/II trial of CCI-779 and bevacizumab in stage IV renal cell carcinoma: Phase I safety and activity results

5034

Background: The mammalian target of rapamicin (mTOR) and vascular endothelial growth factor (VEGF) pathways are critically involved in the pathogenesis and progression of clear cell renal cell carcinoma. Methods: The goal of the phase I portion of the trial was to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of the combination of the mTOR inhibitor CCI-779 (C) and the anti-VEGF monoclonal antibody Bevacizumab (B). Patients with measurable stage IV clear cell RCC, performance status 0–2 and good organ function were eligible. Up to two prior treatment regimens were allowed. Treatment consisted of 25 mg IV weekly C and escalating IV doses of B (level 1= 5 mg/kg; level 2= 10 mg/kg) every other week. A cycle was defined as 4 weeks. Results: A total of 10 male and 2 female patients, median age 66 yrs (50–77) were enrolled to the phase I portion of the trial. PS: 0/1= 6/6; prior nephrectomy = 10; prior systemic therapy = 7 (prior cytokine therapy = 6); Number of metastatic sites: 1/2/≥3 = 2/2/8; one patient (out of 6) in dose level 1 experienced DLT which consisted of grade 3 hypertriglyceridemia. 1/6 patient in dose level 2 experienced DLT with grade 3 mucositis. Other grade 3 toxicities that were not DLTs included hypertension, proteinuria, hemorrhage, nausea/vomiting, dehydration, anorexia, pneumonitis, anemia, and hypophosphatemia. The best responses in the 12 evaluable patients included 7 PRs and 3 SDs. One patient had PD due to symptomatic deterioration and in one patient response information is not available at the time of this submission. Conclusions: Combination therapy with CCI-779 and Bevacizumab is safe and shows promising clinical antitumor activity. The recommended phase II dose is CCI-779 25 mg/week with bevacizumab 10 mg/kg every other week. The phase II study in stage IV renal cell cancer patients refractory to FDA approved receptor tyrosine kinase inhibitors is under way. The goals of the phase II portion are to determine the proportion of patients who have not had disease progression at 6 months, safety, response rates and correlative biomarker studies including determination of the tumor’s VHL-HIF-VEGF status, PTEN/AKT expression, plasma angiogenic activity and angiogenic cytokines. Supported by NCI N01-CM-62205

No significant financial relationships to disclose.

Long term efficacy of peripheral androgen blockade on prostate cancer: CALGB 9782

4573

Background: The treatment of patients with a rising PSA after definitive local therapy is controversial. Patients are reluctant to undergo androgen suppression due to side effects and interest focuses on the timing and intensity of additional therapy. The use of peripheral androgen blockade in this setting is appealing. Methods: Patients with a rising PSA after definitive local therapy were enrolled in a multi-institutional trial. Accrual of 101 patients lasted from Sept 30, 1998 to July 16, 2001. All patients had undergone previous definitive local therapy at least 1 year, and no more than 10 years prior to enrollment. All patients had a repeated rising PSA, above 1 ng/ml, with no detectable evidence of recurrent disease. CT and bone scans were negative. Patients received a combination of oral therapy consisting of Finasteride, at a dose of 5 mg/day, and Flutamide, at a dose of 250 mg TID. Results: The median age was 71, with a median baseline testosterone level of 322 ng/dl. A >80% PSA decline was seen in 91/94, (97%) of the patients. Three other patients had PSA declines of 77%, 73% and 38%, all of which were maintained for at least 28 days. The median time to PSA nadir was 3.2 months. The current median follow-up is 59 months. To date, only 22 patients have progressed, with 47 patients still on peripheral androgen blockade. Eight patients have died without progression, and 22 patients went off therapy for other reasons not related to progression. Also noted were patients showing PSA responses to Flutamide withdrawal, and per protocol remaining on Finasteride. Toxicity to date remains very mild. Conclusions: Peripheral androgen blockade showed excellent activity produced durable PSA responses in this select group of patients. While the clinical significance of a decline in PSA alone is not fully understood_the durability of these PSA responses is encouraging. The median duration of progression free survival and overall survival has not been reached, and is likely to be longer than five years. Quality of life data is undergoing further analysis. This report supports further study of less aggressive treatments for patients who have only a rising PSA after definitive local therapy.

No significant financial relationships to disclose.