13554 Background: Bevacizumab (Bev), a monoclonal antibody targeted against VEGF, has shown to improve efficacy in CRC when combined with chemotherapy. Combination schedules of fluoropyrimidines with mitomycin C (MMC) are active in both CRC and GC. This study was to explore the combination of Bev with a previously reported schedule of Capecitabine (Cap) and MMC (BECAM) in heavily pretreated patients (pts) with GC or CRC. METHODS Pts had to be refractory to at least 3 treatment lines, incl. 5-FU, oxaliplatin, irinotecan, and cetuximab in CRC; 2 lines with 5-FU, platinum, irinotecan or taxane in GC. A treatment cycle consisted of a 1-hour-infusion of Bev 7.5 mg/kg d1, bolus MMC 7mg/m2 d1 and Cap 1000mg/m2 bid d1-14, all qd22. Toxicity was assessed every 3 weeks (wk) and tumor evaluation (CT/MRI) was done every 9 wk. RESULTS 19 pts were included: m/f 8/11; GC 4, CRC 15, age 63 yrs [42-76], Karnofsky PS 80% [70-100]. Median no. of preceding regimens was 3 [2-6]. A total of 87 cycles were given. Median no. of cycles per pt. was 3 [2-15]. 18 pts were evaluable for toxicity (WHO scale) and efficacy: Grade 3/4 toxicities were thrombocytopenia (5/0), hypertension (1/0), and hemorrhage (0/1). The latter caused cessation of further administration of Bev. Gastrointestinal and other hematologic toxicities did not exceed grade 2. RESPONSE PR was seen in 3 pts (16%; 1/4 GC, 2/14 CRC), stable disease for > 9 wk in 5 pts (1 GC, 4 CRC), leading to a tumor control rate of 44%. Median progression free and overall survival were 3.0 [2-11] and 5.0 [2.5-13] months. However, duration of objective response was remarkable in lasting 7.4-10.0 months. CONCLUSIONS BECAM shows considerable activity in this group of heavily pretreated pts with CRC or GC. Toxicity was generally mild except for MMC-induced thrombocytopenia and (probably) Bev-induced bleeding (gastric tumor site). Despite previous reports of limited activity with Bev/5-FU in refractory pts (NCI TRC trial), BECAM is able to induce long lasting objective responses and therefore merits further investigation in both tumor types. [Table: see text].