A randomized phase II study of weekly paclitaxel with or without pelareorep in patients with metastatic breast cancer: final analysis of Canadian Cancer Trials Group IND.213.

BACKGROUND: Pelareorep, a serotype 3 reovirus, has demonstrated preclinical and early clinical activity in breast cancer and synergistic cytotoxic activity with microtubule targeting agents. This multicentre, randomized, phase II trial was undertaken to evaluate the efficacy and safety of adding pelareorep to paclitaxel for patients with metastatic breast cancer (mBC). METHODS: Following a safety run-in of 7 patients, 74 women with previously treated mBC were randomized either to paclitaxel 80 mg/m2 intravenously on days 1, 8, and 15 every 4 weeks plus pelareorep 3 × 1010 TCID50 intravenously on days 1, 2, 8, 9, 15, and 16 every 4 weeks (Arm A) or to paclitaxel alone (Arm B). Primary endpoint was progression-free survival (PFS). Secondary endpoints were objective response rate, overall survival (OS), circulating tumour cell counts, safety, and exploratory correlative analyses. All comparisons used a two-sided test at an alpha level of 20%. Survival analyses were adjusted for prior paclitaxel. RESULTS: Final analysis was performed after a median follow-up of 29.5 months. Pelareorep was well tolerated. Patients in Arm A had more favourable baseline prognostic variables. Median adjusted PFS (Arm A vs B) was 3.78 mo vs 3.38 mo (HR 1.04, 80% CI 0.76-1.43, P = 0.87). There was no difference in response rate between arms (P = 0.87). Median OS (Arm A vs B) was 17.4 mo vs 10.4 mo (HR 0.65, 80% CI 0.46-0.91, P = 0.1). CONCLUSIONS: This first, phase II, randomized study of pelareorep and paclitaxel in previously treated mBC did not show a difference in PFS (the primary endpoint) or RR. However, there was a significantly longer OS for the combination. Further exploration of this regimen in mBC may be of interest.

Clinical activity of abiraterone acetate in patients with metastatic castration-resistant prostate cancer progressing after enzalutamide.

BACKGROUND: Abiraterone acetate and enzalutamide both improve outcomes in patients with metastatic castration-resistant prostate cancer (mCRPC). Optimal sequencing for these agents and whether cross-resistance occurs is unknown. METHODS: Multicentre review of patients with mCRPC treated with abiraterone acetate and prednisone after progressing on enzalutamide. Primary objective was to determine abiraterone acetate response. RESULTS: Thirty patients identified from four North American centres. At abiraterone initiation, median age was 70 years (56-84 years); 70% had ECOG performance status of 0-1; all had prior docetaxel. Median prior enzalutamide treatment duration was 41 weeks (6-95 weeks), with 70% (21 of 30) having a ≥30% prostate-specific antigen (PSA) decline. Median abiraterone acetate treatment duration was 13 weeks (1-52). No objective radiographic responses were observed. Median abiraterone time to progression (PSA, objective or symptomatic) was 15.4 weeks [95% confidence interval (CI) 10.7-20.2]. Median overall survival was 50.1 weeks (95% CI 28.3-72.0). Three patients had a ≥30% PSA decline with abiraterone. Two of these patients had PSA progression as best response with prior enzalutamide. CONCLUSIONS: In this study of patients progressing after enzalutamide, treatment with abiraterone was associated with a modest response rate and brief duration of effect. Primary progression on enzalutamide may not preclude a response to abiraterone.

A prospective clinical utility and pharmacoeconomic study of the impact of the 21-gene Recurrence Score® assay in oestrogen receptor positive node negative breast cancer.

PURPOSE: The primary purpose of this study was to measure the impact of the 21-gene Recurrence Score® result on systemic treatment recommendations and to perform a prospective health economic analysis in stage I-II, node-negative, oestrogen receptor positive (ER+) breast cancer. METHODS: Consenting patients with ER+ node negative invasive breast cancer and their treating medial oncologists were asked to complete questionnaires about treatment preferences, level of confidence in those preferences and a decisional conflict scale (patients only) after a discussion of their diagnosis and risk without knowledge of the Recurrence Score. At a subsequent visit, the assay result and final treatment recommendations were discussed prior to both parties completing a second set of questionnaires. A Markov health state transition model was constructed, simulating the costs and outcomes experienced by a hypothetical 'assay naïve' population and an 'assay informed' population. RESULTS: One hundred and fifty-six patients across two cancer centres were enrolled. Of the 150 for whom successful assay results were obtained, physicians changed their chemotherapy recommendations in 45 cases (30%; 95% confidence interval (CI) 22.8-38.0%); either to add (10%; 95% CI 5.7-16.0%) or omit (20%; 95% CI 13.9-27.3%) adjuvant chemotherapy. There was an overall significant improvement in physician confidence post-assay (p<0.001). Patient decisional conflict also significantly decreased following the assay (p<0.001). The simulation model found an incremental cost-effectiveness ratio of Canadian Dollars (CAD) $6630/quality-adjusted life years (QALY). CONCLUSION: Within the context of a publicly funded health care system, the Recurrence Score assay significantly affects adjuvant treatment recommendations and is cost effective in ER+ node negative breast cancer.

Outcomes of women with early-stage breast cancer receiving adjuvant trastuzumab.

INTRODUCTION: Large randomized trials assessing the benefit of adjuvant trastuzumab in early-stage breast cancer positive for the human epidermal growth factor receptor 2 (her2) have demonstrated a significant improvement in survival. The objective of the present study was to describe the outcomes of women who received adjuvant trastuzumab for her2-positive breast cancer in British Columbia since publicly funded population-based use was initiated in July 2005. METHODS: Women from British Columbia, newly diagnosed with stage i-iii breast cancer between July 2004 and December 2006, who were positive for her2 overexpression by immunohistochemistry (3+) or amplification by fluorescence in situ hybridization (ratio ≥ 2.0) were included in the study. Data were collected from the prospectively assembled BC Cancer Agency Outcomes Unit, with cases linked to the provincial pharmacy data repository to determine the proportion of women who received adjuvant trastuzumab. RESULTS: Our retrospective study identified 703 her2-positive patients, of whom 480 (68%) received trastuzumab. In patients receiving trastuzumab, the 2-year relapse-free survival was 96.1% [95% confidence interval (CI): 93.6% to 97.7%] and the overall survival was 99.3% (95% CI: 97.9% to 99.8%). Among node-negative and -positive patients, the 2-year relapse-free survival was 97.8% and 94.8% respectively (p = 0.09) for the trastuzumab-treated group and 90.9% and 77.3% (p = 0.01) for the group not receiving trastuzumab (n = 223). Site of first distant metastasis was the central nervous system in 19.5% of the entire cohort and in 37.5% of patients treated with trastuzumab. DISCUSSION: This population-based analysis of adjuvant trastuzumab use among Canadian women demonstrates highly favorable outcomes at the 2-year follow-up.

A phase II study of sunitinib in patients with recurrent epithelial ovarian and primary peritoneal carcinoma: an NCIC Clinical Trials Group Study.

PURPOSE: Sunitinib is a multitargeted receptor tyrosine kinase inhibitor. We conducted a two-stage phase II study to evaluate the objective response rate of oral sunitinib in recurrent epithelial ovarian cancer. PATIENTS AND METHODS: Eligibility required measurable disease and one or two prior chemotherapies, at least one platinum based. Platinum-sensitive or -resistant disease was allowed. Initial dose schedule was sunitinib 50 mg daily, 4 of 6 weeks. Observation of fluid accumulations during off-treatment periods resulted in adoption of continuous 37.5 mg daily dosing in the second stage of accrual. RESULTS: Of 30 eligible patients, most had serous histology (67%), were platinum sensitive (73%) and had two prior chemotherapies (60%). One partial response (3.3%) and three CA125 responses (10%) were observed, all in platinum-sensitive patients using intermittent dosing. Sixteen (53%) had stable disease. Five had >30% decrease in measurable disease. Overall median progression-free survival was 4.1 months. Common adverse events included fatigue, gastrointestinal symptoms, hand-foot syndrome and hypertension. No gastrointestinal perforation occurred. CONCLUSIONS: Single-agent sunitinib has modest activity in recurrent platinum-sensitive ovarian cancer, but only at the 50 mg intermittent dose schedule, suggesting that dose and schedule may be vital considerations in further evaluation of sunitinib in this cancer setting.

A phase II study of erlotinib (OSI-774) given in combination with carboplatin in patients with recurrent epithelial ovarian cancer (NCIC CTG IND.149).

OBJECTIVES: Approximately 50% of ovarian cancers have elevated levels of epidermal growth factor receptor (EGFR) which correlates with a poor prognosis. Preclinical evidence suggests that EGFR tyrosine kinase inhibitors (TKIs), such as erlotinib (OSI-774), may potentiate the anti-tumour effects of cytotoxic agents, including carboplatin. Blocking EGFR could thus potentially reverse drug resistance. The primary objective of the study was to assess the response rate to the addition of erlotinib in patients with recurrent ovarian cancer who were receiving carboplatin. METHODS: Patients enrolled on this study had either local or advanced recurrent ovarian cancer with measurable disease. They may have had up to 2 prior chemotherapy regimens, one of which must have contained platinum, and they must have responded to prior platinum therapy. Patients were stratified by platinum sensitivity and were treated with erlotinib 150 mg daily on a continuous dosing schedule, and carboplatin at an AUC of 5 every 21 days. RESULTS: Fifty patients with recurrent ovarian cancer entered the study, 33 in the platinum-sensitive arm and 17 in the platinum-resistant arm. Of patients evaluable for response, there were 14 partial responses (PR) of 30 evaluable for response (57% objective response rate (ORR)) in the platinum-sensitive arm, and 1 PR of 14 evaluable for response (7% ORR) in the platinum-resistant arm. CONCLUSIONS: The combination of erlotinib and carboplatin was active in patients with platinum-sensitive disease, but not in platinum-resistant disease. The toxicities seen were those expected with carboplatin and erlotinib.

A phase IB study of ABT-751 in combination with docetaxel in patients with advanced castration-resistant prostate cancer.

BACKGROUND: This study investigated the safety, pharmacokinetics (PK) and clinical antitumor activity of ABT-751, a novel sulfonamide antimitotic and vascular disrupting agent, in combination with docetaxel (Taxotere) in patients with castration-resistant prostate cancer (CRPC). PATIENTS AND METHODS: Patients received docetaxel (60-75 mg/m(2)) i.v. on day 1 and ABT-751 (100-200 mg) orally daily for 14 days, repeated every 3 weeks for up to 10 times on four escalating dose levels (DLs). RESULTS: Thirty-two patients received a median of 8.5 treatment cycles (range 1-10). One of six patients on DL 3 (D 60 mg/m(2) + A 200 mg) and 4 (D 75 mg/m(2) + A 200 mg) experienced dose-limiting toxicity, and both DLs were expanded. Overall, severe adverse events occurred more commonly on DL 4 than 3 (47% versus 18% of patients). PK data for docetaxel and ABT-751 were similar to reported literature. Best post-treatment prostate-specific antigen decline of > or =50% occurred in 60% and objective responses occurred in 45% of patients. Median overall survival was 24 months (95% confidence interval 8.3-37.7 months). CONCLUSIONS: The combination of ABT-751 and docetaxel is safe and active in CRPC. Based on the cumulative safety analysis, the recommended phase II dose of ABT-751 is 200 mg daily with docetaxel 60 mg/m(2) for this patient population.

A phase II study of sorafenib in patients with chemo-naive castration-resistant prostate cancer.

BACKGROUND: The purpose of this trial was to evaluate the antitumor activity of sorafenib, a multikinase inhibitor of cell proliferation and angiogenesis, in patients with castration-resistant prostate cancer. PATIENTS AND METHODS: This was a multicenter, two-stage, phase II study. Sorafenib 400 mg was administered orally twice daily continuously. Primary end point was prostate-specific antigen (PSA) 'response' defined as a > or =50% decrease for > or =4 weeks. RESULTS: In all, 28 patients were enrolled. Eastern Cooperative Oncology Group performance status was zero or one in 19 and 9 patients. Two patients had no metastases, and 26 had bone and/or lymph node disease. A median of two cycles (range 1-8) was delivered. Adverse events were typical for sorafenib. The PSA response rate was 3.6% [95% confidence interval (CI) 0.1% to 18.3%] with response occurring in one patient (baseline = 10 000 and nadir = 1643 microg/l). No measurable disease responses occurred in eight patients. Time to PSA progression was 2.3 months (95% CI 1.8-6.4). Of 16 patients who discontinued sorafenib and then did not receive any immediate therapy, 10 had postdiscontinuation PSA declines of 7%-52%. CONCLUSIONS: Sorafenib has limited activity using current PSA criteria. The declines in PSA observed on treatment discontinuation indicate an effect on PSA production/secretion. Further study may be warranted but needs to consider the limitations of PSA as an indicator of progression and response.