Study Evaluating the Safety, Pharmacokinetics (PK), Pharmacodynamics (PD), and Therapeutic Activity of Selicrelumab (RO7009789) With Vanucizumab or Bevacizumab in Participants With Metastatic Solid Tumors

Inclusion Criteria:

* Part I: Histologically confirmed advanced/metastatic solid tumor (except prostate cancer and squamous non-small cell lung cancer \[NSCLC\])
* Part II: Histologically confirmed advanced/metastatic platinum-resistant ovarian carcinoma (aPROC), head and neck squamous cell carcinoma (HNSCC), or non-squamous NSCLC previously treated with anti-PD-L1/PD-1 inhibitor alone or in combination (e.g. atezolizumab, nivolumab, pembrolizumab, durvalumab, avelumab)
* Checkpoint inhibitor (CPI)- experienced patients must have experienced documented disease progression on or after PD-L1/PD-1 inhibitor therapy
* In CPI-experienced patients, the PD-L1/PD-1 inhibitor must have been part of the most recent systemic anticancer therapy administered prior to study enrollment
* Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2
* Life expectancy \>/= 16 weeks
* Adequate hematologic, renal, hepatic, and cardiovascular function
* Measurable disease per Response Evaluation Criteria in Solid Tumors, v 1.1 (RECIST v1.1)
* Tumors must be acceptable for biopsy. Participants in Part II may be enrolled without a biopsy if the collection is not clinically feasible.
* Agreement to use adequate contraceptive measures among men or among women of childbearing potential

Exclusion Criteria:

* Prostate cancer or squamous NSCLC
* Recent systemic anti-cancer treatment
* Prior treatment with anti-programmed death (PD) 1 or anti-programmed death ligand (PD-L) 1 therapeutic antibody, vanucizumab, or compounds targeting cluster of differentiation (CD) 40 less than 4 weeks or 5xt1/2 (whichever is shorter) prior to enrollment
* Part II: Treatment targeting vascular endothelial growth factor (VEGF) or receptor within 12 months prior to enrollment
* Systemic immunosuppressive medication within 2 weeks prior to day 1 of cycle 1
* Chronic daily treatment with non-steroidal anti-inflammatory drugs
* Unacceptable/unresolved toxicity from prior anti-cancer therapy
* Patients who have had a surgical procedure or significant traumatic injury within 28 days prior to initiation of study treatment, or a core biopsy or other minor surgical procedure within 7 days prior to initiation of study treatment
* Bisphosphonate therapy for symptomatic hypercalcemia
* Significant vascular disease
* History of hypertensive crisis or hypertensive encephalopathy
* Current or recent use of aspirin (\>325 mg/day) or clopidogrel (\>75 mg/day)
* History of vein thrombosis/thromboembolism, or use of anticoagulants within 7 days prior to study drug
* Primary tumor in place in participants with colorectal cancer, or evidence of bowel involvement (metastasis, direct tumor invasion) in participants with other non-gastrointestinal cancer
* Significant cardiovascular or cerebrovascular disease within 6 months prior to D1 of C1
* History of fistula, bowel obstruction, perforation, or abscess
* Prior radiotherapy to pelvis or abdomen, recto-sigmoid involvement, or bowel involvement among participants with aPROC
* Severe non-healing wound, active ulcer or untreated bone fracture
* Pregnant or lactating women
* History of autoimmune disease
* Human immunodeficiency virus (HIV) or hepatitis B or C
* Severe infection or receipt of a live/attenuated vaccine within 4 weeks prior to D1 of C1
* Other significant malignancies within 3 years prior to D1 of C1
* Allergy/hypersensitivity to study drug
* Prior allogeneic bone marrow or solid organ transplant
* Other conditions/findings that may contraindicate use of study drug
* Major surgery within 4 weeks prior to study drug
* Known clinically significant liver disease
* History of hemoptysis or bleeding diathesis, or known coagulopathies
* Known symptomatic or untreated central nervous system (CNS) malignancy