I. To assess the pharmacodynamic (PD) effects of gamma-secretase inhibitor RO4929097 on Notch signaling pathway in tumor and surrogate tissues, as well as soluble markers of angiogenesis in plasma, when administered using 6 different dosing schedules. (Exploratory) II. To evaluate the relationship between PK and PD effects in an attempt to define the optimal biological dosing schedule (OBDS) that can provide a sustained inhibition of Notch signaling pathway over time with a tolerable toxicity profile. (Exploratory) III. To correlate inhibition of Notch signaling pathway measured in tumor and surrogate tissues with preliminary antitumor activity and assess the potential clinical predictive value of OBDS as defined above. (Exploratory) IV. To assess the effect of the various pharmacogenomic polymorphisms of the cytochrome P450 pathway on PK and PD parameters. (Exploratory)