Bruera et al. BMC Cancer 2010, 10:567 http://www.biomedcentral.com/1471-2407/10/567 increase in activity and efficacy: ORR 60%, PFS 9.8 months, OS 22.6 months [17]. Another phase III study failed to demonstrate any increase [18]. As the activity of MCRC treatment progressively increased using triplet combinations, liver-metastasectomies also raised up to 8-11% of MCRC pts [17,18]. A major problem concerning the addition of more drugs in a chemotherapy combination is designing a proper schedule assuring the balance between dose intensity (DI) of each drug and tolerability. We pre- viously showed that 12-hour (10PM to 10AM) timed-flat- infusion (TFI) of 5-FU associated to CPT-11 can be safely administered at high 5-FU/DI without Leucovorin; ORR was 40%, median PFS 10 months, median OS 21 months [19]. The 12-hour (10PM to 10AM) TFI/5-FU infusion traces the 12-hour circadian-timed infusion of 5-FU [3,20,21]. Recently, we designed the triplet sche- dule FIr/FOx by splitting TFI/5-FU weekly with alternat- ing CPT-11 or OHP: ORR was 66.7%, median PFS was 12 months, median OS 20 months [22]. This present phase II study proposes FIr-B/FOx or “Poker” association (so called because it represents the combination of four drugs), adding Bevacizumab to this triplet chemotherapeutic schedule, in order to assess its activity, efficacy and safety. Methods Patient Eligibility Pts were eligible if they had histologically confirmed diagnosis of measurable MCRC; age 18-75 years; World Health Organization (WHO) performance status ≤ 2; adequate hematological, renal and hepatic functions; life expectancy more than 3 months. Ineligibility criteria: pregnancy and breast-feeding; uncontrolled severe diseases; cardiovascular disease (uncontrolled hypertension, uncontrolled arrhythmia, ischemic cardiac diseases in the last year); thromboem- bolic disease, coagulopathy, preexisting bleeding dia- theses; proteinuria > 1 g/24 h urine; surgery within the previuos 28 days before; previous adjuvant chemotherapy or radiotherapy completed less than 6 months before. The study was approved by the Local Ethical Committee (Comitato Etico, Azienda Sanitaria Locale n.4 L’Aquila, Regione Abruzzo, Italia) and conducted in accordance with the Declaration of Helsinki. All patients provided written, informed consent. Methods Schedule This was a single-arm, multicenter phase II study evalu- ating activity of weekly alternating 5-FU, CPT-11, BEV and OHP (FIr-B/FOx) as first-line treatment of MCRC. FIr-B/FOx or “Poker” association consisted of 5-FU associated to alternating CPT-11/BEV or l-OHP according Page 2 of 10 to the following weekly schedule: TFI/5-FU (Fluorouracil Teva®, Teva), 900 mg/m2/die, over 12-hour (from 10:00 p.m to 10:00 a.m.), days 1-2, 8-9, 15-16 and 22-23; CPT- 11 (Campto®, Pfizer), 160 mg/m2, administered over 90 minutes as an intravenous infusion in 250 ml of NaCl 0.9%, days 1 and 15; BEV (Avastin®, Roche), 5 mg/kg, administered over 90 minutes at the first, 60 minutes at the second and 30 minutes from the third time, intrave- nous infusion in 100 ml of NaCl 0.9%, days 1 and 15; l-OHP (Eloxatin®, Sanofi-Aventis) over 2-hours as an intra- venous infusion in 250 ml of dextrose 5%, at the dose of 60-70-80 mg/m2, days 8 and 22. Cycles repeated every 4 weeks. 5-FU was administered by a portable pump (CADD Plus, SEVIT) using a venous access device. Study design Physical examination and routine laboratory studies were performed at baseline and every week on-treatment, including complete blood cell count, electrolytes, liver and renal function tests, urine examination and coagula- tion function; tumor markers every cycle; electrocardio- gram every two weeks and echocardiogram at baseline, and every 3 cycles. Primary end-point was ORR; secondary end-points were PFS, toxicity, OS. ORR was evaluated according to RECIST criteria [23]; PFS and OS using Kaplan and Meier method [24]. PFS was defined as length of time between the beginning of treatment and disease progres- sion or death (resulting from any cause) or to last con- tact; OS as length of time between the beginning of treatment and death or to last contact. Clinical evaluation of response was planned by CT- scan; PET was added based on investigators’ assessment; objective responses were confirmed three months later. Follow-up was scheduled every three months up to dis- ease progression or death. Toxicity was registered every week according to National Cancer Institute Common Toxicity Criteria (NCI-CTC, version 3.0). DLT was defined as grade 3-4 non-haematological toxicity (mainly represented by diarrhea, mucositis, neurotoxicity, hand- foot syndrome, asthenia), grade 4 hematologic toxicity, febrile neutropenia, or any toxicity determining a > 2 weeks treatment delay. The concept of limiting toxicity syndromes (LTS), consisting of at least a dose-limiting toxicity (DLT) asso- ciated or not to other limiting or G2 toxicities, was established. These were classified as: LTS in single site (LTS-ss), if characterized only by the DLT; LTS in mul- tiple sites (LTS-ms), if characterized by ≥ 2 DLTs or a DLT associated to other, at least G2, non-limiting toxicities. Statistical design This phase II study was planned according to two-steps Simon’s design [25]: assuming as minimal interesting activity an ORR 50%, 8 objective responses among the