3015 Background: BIBF 1120 is a potent inhibitor of VEGFR, PDGFR, FGFR kinases, and of members of the Src family of tyrosine kinases (Src, Lck, Lyn). Methods: Patients (Pts) with advanced solid tumours were enrolled. BIBF 1120 was administered orally once daily (q.d.) continuously, starting at 100 mg/day. Dosing was later amended to twice daily (b.i.d.) in view of transaminitis seen with q.d. dosing. DCE-MRI studies were performed at baseline, days 2 and 28. All pts underwent pharmacokinetic (PK) sampling. Results: 51 pts (26M/25F; median age 57 y, range 22–78 y; ECOG PS 0/1 = 22/27) were treated at: 100 mg q.d. (n = 6), 200 mg q.d. (n = 6), 300 mg q.d. (n = 7), 400 mg q.d. (n = 16), 450 mg q.d. (n = 5); 250 mg b.i.d. (n = 11). Median treatment duration was 57 days (range: 1 day– 22 m). The most common toxicities were nausea, vomiting, diarrhoea, abdominal pain and fatigue, all ≤ grade (G)2. Asymptomatic, reversible elevation of liver enzymes which was dose limiting in 2/5 pts at 450 mg q.d. defined the MTD at 400 mg q.d. At 250 mg b.i.d., 2/11 pts had DLT (G3 elevation in liver enzymes: n = 1; G3 abdominal pain: n = 1). 44 pts treated for ≥2 m were assessable for response: 13 pts had SD for ≥3 m (median 7m, range 3–22 m; renal, prostate, colorectal, chondrosarcoma, leiomyomatosis, fibromatosis). 3 pts with renal cancer had SD for 8, 14+ and 22 m respectively. PK evaluations generally showed increasing gMean Cmax and AUC values with increasing doses, with high inter-patient variability. Tmax was ∼2h post-dosing. gMean t1/2 values ranged from 6.8–26.4h. DCE-MRI of target lesions in 35 pts showed significant antivascular/antiangiogenic effects in some patients and dose cohorts, particularly at 200 mg q.d. and ≥400 mg q.d. DCE-MRI effects were most pronounced at 28 days, especially in metastatic liver lesions. Conclusions: BIBF 1120 is well-tolerated in patients with advanced solid malignancies and induces in vivo antiangiogenic effects detectable by DCE-MRI. Some patients experienced clinically meaningful disease stabilisation. The recommended dose for future Phase II studies was determined to be 250 mg b.i.d. [Table: see text]