A prospective randomised phase-II trial with gemcitabine versus gemcitabine plus sunitinib in advanced pancreatic cancer: a study of the CESAR Central European Society for Anticancer Drug Research-EWIV

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most common malignant tumours and is still associated with a poor prognosis in advanced disease. To improve the standard therapy with gemcitabine, we initiated a prospective randomised phase-II trial with gemcitabine (GEM) versus gemcitabine plus sunitinib (SUNGEM) based on data of in vitro trials and phase-I data for the combination treatment. The rational of adding sunitinib was its putative antiangiogenic mechanism of action.

METHODS

A total of 106 eligible patients with locally advanced, unresectable or metastatic PDAC without previous system therapy were randomised to receive GEM at a dosage of 1.000mg/m(2) d1, 8, 15 q28 versus a combination of SUNGEM at a dosage of GEM 1.000mg/m(2) d1+8 and sunitinib 50mg p.o. d1-14, q21d. The primary end-point was progression free survival (PFS), secondary end-points were overall survival (OS), toxicity and overall response rate (ORR).

RESULTS

The confirmatory analysis of PFS was based on the intend-to-treat (ITT) population (N=106). The median PFS was 13.3 weeks (95% confidence interval (95%-CI): 10.4-18.1 weeks) for GEM and 11.6 weeks for SUNGEM (95%-CI: 7.0-18.0 weeks; p=0.78 one-sided log-rank). The ORR was 6.1% (95%-CI: 0.7-20.2%) for GEM and for 7.1% (95%-CI: 0.9-23.5%) for SUNGEM (p=0.87). The median time to progression (TTP) was 14.0 weeks (95%-CI: 12.4-22.3 weeks) for GEM and 18.0 weeks (95%-CI: 11.3-19.3 weeks) for SUNGEM (p=0.60; two-sided log-rank). The median OS was 36.7 weeks (95%-CI: 20.6-49.0 weeks) for the GEM arm and 30.4 weeks (95%-CI: 18.1-37.6 weeks) for the SUNGEM (p=0.78, one-sided log-rank). In regard to toxicities, suspected SAEs were reported in 53.7% in the GEM arm and 71.2% in the SUNGEM arm. Grade 3 and 4 neutropenia was statistically significantly higher in the SUNGEM arm with 48.1% versus 27.8% in the GEM arm (p=0.045, two sided log-rank).

CONCLUSIONS

The combination SUNGEM was not sufficient superior in locally advanced or metastatic PDAC compared to GEM alone in regard to efficacy but was associated with more toxicity.

Gender-specific elimination of continuous-infusional 5-fluorouracil in patients with gastrointestinal malignancies: results from a prospective population pharmacokinetic study

BACKGROUND

This study was initiated to assess the quantitative impact of patient anthropometrics and dihydropyrimidine dehydrogenase (DPYD) mutations on the pharmacokinetics (PK) of 5-fluorouracil (5FU) and to explore limited sampling strategies of 5FU.

PATIENTS AND METHODS

We included 32 patients with gastrointestinal malignancies, receiving 46-h continuous-infusional 5FU and performed PK-sampling at baseline, 15, 30, 45 min, 1 and 2 h after the start of infusion and at the end of infusion, for 2 subsequent cycles. Plasma concentrations of 5FU, 5-fluorodihydrouracil (5FUH2), uracil (U) and 5,6-dihydrouracil (UH2) were determined using LC-MS/MS and submitted to population PK analysis using nonlinear mixed-effects modeling. Broad genotyping of DPYD was performed, and the potential impact of the DPYD genotype on the elimination of 5FU was assessed. Limited sampling strategies were evaluated for their accuracy to predict steady-state concentrations of 5FU (CSS(5FU)), using data simulations based on the final PK-model.

RESULTS

The area-under-the concentration-time curve of 5FU (AUC(5FU)) was found to be <20 mg h/L in 33 occasions (58 %), between 20 and 30 mg h/L in 17 occasions (30 %) and >30 mg h/L in 7 occasions (12 %). Men had a 26 % higher elimination of 5FU and a 18 % higher apparent elimination of 5FUH2. Accordingly, women had a higher AUC(5FU) compared to men (22 vs. 18 mg h/L, p = 0.04). No DPYD risk variants were found, and the DPYD variants detected (c.496A>G, c.1601G>A, c.1627A>G) were not significantly associated with the elimination of 5FU. Individual baseline UH(2)/U ratio was significantly associated with AUC(5FU) (R = -0.49, p < 0.001). Limited sampling strategies with time-points <3 h after the start of infusion were not adequate to predict CSS(5FU). Female gender was the only predictor of nausea/emesis in the multivariate model.

CONCLUSIONS

Gender-specific elimination of 5FU is supported by the present data and may partly explain the gender-specific association between DPYD risk variants and 5FU-specific toxicity.

Clinical benefit of fulvestrant in postmenopausal women with advanced breast cancer and primary or acquired resistance to aromatase inhibitors: final results of phase II Swiss Group for Clinical Cancer Research Trial (SAKK 21/00)

BACKGROUND

The aim of this study was to evaluate the efficacy and tolerability of fulvestrant, an estrogen receptor antagonist, in postmenopausal women with hormone-responsive tumors progressing after aromatase inhibitor (AI) treatment.

PATIENTS AND METHODS

This is a phase II, open, multicenter, noncomparative study. Two patient groups were prospectively considered: group A (n=70) with AI-responsive disease and group B (n=20) with AI-resistant disease. Fulvestrant 250 mg was administered as intramuscular injection every 28 (+/-3) days.

RESULTS

All patients were pretreated with AI and 84% also with tamoxifen or toremifene; 67% had bone metastases and 45% liver metastases. Fulvestrant administration was well tolerated and yielded a clinical benefit (CB; defined as objective response or stable disease [SD] for >or=24 weeks) in 28% (90% confidence interval [CI] 19% to 39%) of patients in group A and 37% (90% CI 19% to 58%) of patients in group B. Median time to progression (TTP) was 3.6 (95% CI 3.0 to 4.8) months in group A and 3.4 (95% CI 2.5 to 6.7) months in group B.

CONCLUSIONS

Overall, 30% of patients who had progressed following prior AI treatment gained CB with fulvestrant, thereby delaying indication to start chemotherapy. Prior response to an AI did not appear to be predictive for benefit with fulvestrant.

Phase II study of Sorafenib (BAY 43–9006) in hormone-refractory patients with prostate cancer: A study of the Central European Society for Anticancer Drug Research—EWIV (CESAR)

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Background: Sorafenib (BAY 43–9006) is a novel, orally active multi-kinase inhibitor with anti-angiogenic and anti-proliferative activity, blocking both Raf/MEK/ERK pathway and receptor tyrosine kinases VEGFR-2 and PDGFR. Activity of sorafenib in hormone-refractory progressive patients (pts) with prostate cancer (PC) was investigated in a Phase II clinical study. Methods: Pts received sorafenib 400 mg bid by continuous oral dosing. Pts with progressive disease during hormonal treatment and no prior chemotherapy therapy for advanced prostate cancer, and either one uni-dimensional measurable lesion according to RECIST-criteria or increasing PSA values reflecting a hormone-refractory situation, were eligible for study entry. Tumor PSA-based response was defined as: increase of PSA from baseline or lowest measured value by 100% = progressive disease (PD); decrease of PSA by >50% in two consecutive measurements = responder; PSA levels in between the two definitions above = stable disease (SD). Primary study objective was the proportion of patients with time to progression of ≥12 weeks (PP-TTP-12) using target lesions and PSA based response evaluation. At least 45 evaluable pts were required to detect an increase in PP-TTP-12 from 20 to 40% in a one stage design. Secondary endpoints were overall response and survival, and toxicity according to Common Toxicity Criteria (CTC v3.0). Results: A total of 55 pts with PC were enrolled between October 2004 and June 2005. The majority of pts (40/55, 72.7%) were treated for at least 6 weeks. Among the 42 pts evaluable for PP-TTP-12, 2 pts (4.8%) had a response and 15 pts (35.7 %) showed SD ≥12 weeks and 25 pts (59.5 %) showed PD. The one-sided binomial test of the null-hypthesis of PP-TTP-12 = 20% can be rejected at a significance level of 5% (p= 0.0019). All 55 pts were included in the evaluation of adverse events. Drug-related serious adverse events (diarrhea (1), constipation (1), fatigue (1), skin (1) cardiac (2) were seen in six patients. Conclusions: These results of a PSA-based evaluation indicate that sorafenib has some clinically useful activity in PC. Further investigations are necessary to evaluate the clinical benefit. Final results will be presented.

No significant financial relationships to disclose.

Anastrozole: pharmacological and clinical profile in postmenopausal women with breast cancer

A significant proportion of breast cancers are estrogen-dependent and are therefore amenable to endocrine therapy. Although tamoxifen has been the mainstream of endocrine treatment for over 20 years, new agents have entered the clinic, which have potentially superior activity and an improved safety profile. The development of orally-active, potent and selective third-line aromatase inhibitors represents a major advantage in the management of hormone-sensitive breast cancer. Anastrozole (Arimidex) was the first of these agents to become available and is currently widely indicated for both first- and second-line treatment for postmenopausal women with breast cancer. This review focuses on the biochemical properties and clinical efficacy of anastrozole, providing an overview of the current clinical status and possible future applications.