This study will determine the maximum tolerated dose and the optimal associated 4 weekly dosing schedule of RO5045337, administered as monotherapy in patients with advanced solid tumors. A first cohort of patients will receive the starting dose of 20mg/m2/day, once daily for 10 days in each 28 day cycle. Subsequent cohorts of patients will receive dose escalations, and possible changes in dosing schedule, based on tolerability and pharmacokinetic knowledge gained from prior treatment cohorts. The anticipated time on study treatment is until disease progression or intolerable toxicity.

Inclusion Criteria:

• adult patients, >=18 years of age;
• solid tumor malignancies;
• failed prior therapies, or no standard therapy available;
• ECOG performance status of 0-2.

Exclusion Criteria:

• patients receiving any other agent or therapy to treat their malignancy;
• pre-existing gastrointestinal disorders which may interfere with absorption of drugs;
• clinically significant cardiovascular disease.