Inclusion Criteria: - Patients with histologically-confirmed, advanced unresectable solid tumors who have progressed within three months before screening/baseline visit. Only patients who have confirmed PIK3CA mutation will be allowed for screening. - Availability of a representative formalin fixed paraffin embedded tumor tissue sample. - At least one measurable or non-measurable lesion - Age ≥ 18 years - World Health Organization (WHO) Performance Status ≤ 2 - Good organ (hepatic, kidney, BM) function at screening/baseline visit. Exclusion Criteria: - Brain metastasis unless treated and free of signs/symptoms attributable to brain metastasis in the absence of corticosteroid therapy (anti-epileptic therapy is allowed). - Prior treatment with PI3K inhibitor. - Patient with peripheral neuropathy NCI-CTC Grade ≥ 3. - Patient with diarrhea NCI-CTC Grade ≥ 2. - Patient with acute or chronic pancreatitis - Impaired cardiac function or clinically significant cardiac disease incl. unstable angina pectoris ≤ 3 months prior to starting study drug and Acute Myocardial Infarction (AMI) ≤ 3 months prior to starting study drug. - Patients with clinically manifest diabetes mellitus, history of gestational diabetes mellitus or documented steroid-induced diabetes mellitus. - Women who are pregnant or breast feeding or adults of reproductive potential not employing an effective method of birth control. Other protocol-defined inclusion/exclusion criteria may apply