A Study of RO5509554 as Monotherapy and in Combination With Paclitaxel in Participants With Advanced Solid Tumors

Open-Label, Multicenter, Dose Escalation Phase Ia/Ib Study With Expansion Phase to Evaluate Safety, Pharmacokinetics and Activity of RO5509554, Administered as an Intravenous Infusion as Monotherapy and in Combination With Paclitaxel in Patients With Advanced Solid Tumors

This open-label, multicenter, dose-escalation study will assess the safety, tolerability, pharmacokinetics and pharmacodynamics of RO5509554 in participants with advanced solid tumors which are not amenable to standard treatment. In Part I (Dose Escalation), multiple ascending doses of RO5509554 will be administered as monotherapy in participants with solid tumors. Participants with locally advanced and/or metastatic ovarian (including fallopian tube) and breast carcinoma will receive multiple ascending doses of RO5509554 in combination with paclitaxel. In Part II (Expansion Cohort), RO5509554 will be administered as monotherapy to participants with locally advanced and/or metastatic Pigmented Villonodular Synovitis (PVNS)/Tenosynovial Giant Cell Tumor (TGCT), soft tissue sarcoma or malignant mesothelioma, ovarian (including fallopian tube), endometrial or breast cancer and pancreatic cancer. Participants with Human Epidermal Growth Factor Receptor 2 (HER2)/neu negative breast cancer will receive RO5509554 in combination with paclitaxel. Anticipated time on study treatment is until disease progression, unacceptable toxicity, death or participant refusal, whichever occurs first.

Inclusion Criteria:

• Histologically confirmed advanced and/or metastatic solid tumors which are not amenable to standard therapy, with exceptions as defined in exclusion criteria
• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1
• Measurable disease according to RECIST criteria version 1.1
• Adequate bone marrow, cardiac, liver and renal function

Exclusion Criteria:

• Participants with histologically proven Hepatocellular Carcinoma (HC), Non Small Cell Lung Cancer (NSCLC), Small Cell Lung Cancer (SCLC), gastric cancer, malignant melanoma, nonmetastatic and locally controlled PVNS/TGCT
• Participants with known auto-immune disease
• Known or suspected central nervous system (CNS) metastases including leptomeningeal metastasis; participants with radiologically stable, asymptomatic previously irradiated lesion are eligible provided participant is greater than or equal to (>/=) 4 weeks beyond completing cranial irradiation and >/= 3 weeks of corticosteroid therapy
• Significant, uncontrolled concomitant diseases, including significant cardiovascular or pulmonary disease
• Prior chemotherapy, radiotherapy (other than short cycle of palliative radiotherapy for bone pain), any investigational agent or immunotherapy within 28 days of first receipt of study drug
• Prior corticosteroids as anti-cancer therapy within minimum of 14 days of first receipt of study drug
• Poorly controlled type 1 or type 2 diabetes mellitus
• Prior toxicities from chemotherapy or radiotherapy which have not regressed to Grade less than or equal to (</=) 1 severity National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) version 4.03 or later versions
• Known Human Immunodeficiency Virus (HIV), Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) infection
• Pulmonary embolism or any other thrombo-embolic event within 6 months prior to study entry
• History of hematological malignancy within the last 5 years prior to study entry
• Participant requires high dose corticosteroid treatment ( i.e. greater than (>) 20 mg dexamethasone a day or equivalent for > 7 consecutive days)
• Any surgical procedure, including the required baseline tumor biopsy, within less than 14 days of first receipt of study drug. Major surgery within 28 days of first receipt of study drug
• Pregnant or lactating women