The study was prematurely terminated because the emerging benefit:risk ratio did not justify continuing dosing patients.

This is a first-in-human, open-label, multi-center, Phase 1 study of RO6927005. The study will establish the safety and tolerability profile of RO6927005 and will be conducted in two parts.

In Part A, the first dose escalations will be carried out using cohorts of 1 patient. Single patient cohorts will be used to investigate increasing doses until a first dose-limiting toxicity (DLT) is reached or until grade-2 related toxicity (except infusion-related reactions), whichever comes first. At least 3 patients will be enrolled in each cohort thereafter, which, if required, can be expanded with additional patients. Part B of the study will consist of a multiple ascending dose phase (multiple patients cohorts - >/= 3 patients) followed by an extension phase of RO6927005 given in combination with gemcitabine/nab-paclitaxel.

Preliminary clinical activity will be explored throughout the study. Patients will be treated until disease progression and/or lack of clinical benefit, unacceptable toxicities, withdrawal from treatment for other reasons, death, pregnancy or termination of the study by the Sponsor, whichever comes first.

Inclusion Criteria:

• Written informed consent
• Age >/= 18 years
• Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-2
• Patients for whom no standard curable therapy exists
• Life expectancy of >/= 12 weeks
• Last dose of systemic anti-neoplastic therapy > 21 days prior to first RO6927005 infusion
• Palliative radiotherapy is allowed up to 2 weeks before the first RO6927005 infusion; palliative 8 Gy radiotherapy is allowed during therapy.
• All acute toxic effects of any prior radiotherapy, chemotherapy, or surgical procedure must have resolved to Grade </= 1, except alopecia (any grade) and Grade 2 peripheral neuropathy
• Adequate hematological, liver, and renal function
• Negative serum or urine pregnancy test within 7 days prior to study treatment in premenopausal women and women </= 2 years after menopause (menopause is defined as amenorrhea for >/= 2 years)
• Agreement to use adequate contraceptive methods per protocol
• Measurable and/or evaluable disease as per the Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1) [Groups 1, 2 of Part A and Group 3 of Part B]

Inclusion Criteria Part A: MAD

• Metastatic and/or locally advanced malignant solid tumors enriched in tumor types known to be mesothelin expressing
• Archival sample or fresh biopsy or tumor effusion must be available for retrospective mesothelin analysis

Inclusion Criteria Part A: MAD and Extension Phase (Group 1 and Group 2)

• Histologically confirmed metastatic and/or advanced malignant mesothelin-positive solid tumors as determined by central pathology lab review
• Patients must be willing to provide a screening and post-dose biopsy for biomarker analysis (extension phase only)
• Mesothelin-positive refractory/recurrent solid tumors, other than malignant pleural mesothelioma (MPM) and pancreatic ductal adenocarcinoma (PDA) (Group 1 only)
• Mesothelin-positive refractory/recurrent MPM (Group 2 only)

Inclusion Criteria Part B

• Histologically confirmed metastatic and/or advanced mesothelin-positive PDA as determined by central pathology lab review
• In the extension phase, patients must be willing to provide a screening and post-dose biopsy for biomarker analysis

Exclusion Criteria:

• Known or clinically suspected central nervous system (CNS) primary tumors or metastases including leptomeningeal metastases; history or clinical evidence of CNS metastases unless they have been previously treated, are asymptomatic, and have had no requirement for steroids or enzyme-inducing anticonvulsants in the last 14 days
• Evidence of significant, uncontrolled concomitant diseases which could affect compliance with the protocol or interpretation of results, including significant pulmonary disease other than primary cancer, uncontrolled diabetes mellitus, and/or significant cardiovascular disease (such as New York Heart Association Class III or IV cardiac disease, myocardial infarction within the last 6 months, unstable arrhythmias, unstable angina, or clinically significant pericardial effusion)
• Active or uncontrolled infections
• Known HIV or known active HBV or HCV infection
• Patients with extrapleural pneumonectomy (EPP)
• Any other diseases, metabolic dysfunction, physical examination finding, or clinical laboratory finding giving reasonable suspicion of a disease or condition that would contraindicate the use of an investigational drug
• Major surgery or significant traumatic injury < 28 days prior to the first RO6927005 infusion (excluding biopsies) or anticipation of the need for major surgery during study treatment
• Dementia or altered mental status that would prohibit informed consent
• Live attenuated vaccinations 14 days prior to treatment
• Pregnant or breast-feeding women
• Known hypersensitivity to any of the components of RO6927005
• High doses of systemic corticosteroids within 7 days prior to first dosing. High dose is considered as > 20 mg of dexamethasone a day (or equivalent) for > 7 consecutive days

Exclusion Criteria (Part B):

• Patients with contra-indication and/or history of severe hypersensitivity reactions to gemcitabine and/or nab-paclitaxel as mentioned in the locally approved label