Study to Evaluate Adverse Events and Change in Disease Activity When Intravenously (IV) Infused Livmoniplimab is Used in Combination With IV Infused Budigalimab in Adult Participants With Urothelial Carcinoma (UC)

Inclusion Criteria:

• Participant has histologically or cytologically confirmed urothelial carcinoma (i.e., cancer of the bladder, renal pelvis, ureter, or urethra). Mixed histologictypes are allowed if urothelial (transitional cell) is the predominant histology.

• Participant has radiologically documented metastatic disease.

• Participant must have experienced radiographic progression or relapse on checkpointinhibitor (anti-programmed cell death protein 1 [PD-1] or anti-programmeddeath-ligand 1 [PD-L1]) in the metastatic, adjuvant, or neo-adjuvant setting.Participant must have received at least 2 cycles of anti-PD-1 or anti-PD-L1.

• Participants eligible for platinum must have received a platinum containing regimen (cisplatin or carboplatin) in the metastatic, locally advanced, neoadjuvant, oradjuvant setting. If platinum was administered in the neoadjuvant or adjuvantsetting, participant must have progressed within 6 months of completion oftreatment. Platinum ineligible participants may enroll in this study withoutreceiving a platinum containing regimen.

• Participant has at least 1 measurable lesion per response evaluation criteria insolid tumors (RECIST) v1.1 as determined by investigator.

• Life expectancy must be at least 3 months.

Exclusion Criteria:

• Participant has received more than 1 prior chemotherapy regimen for urothelialcancer in metastatic setting, including chemotherapy agents planned in comparatorarm.

• Platinum based chemotherapy administered in adjuvant or neoadjuvant settingwill count towards this criterion if participant progressed within 6 months ofcompletion.

• Chemotherapy administered during concurrent chemoradiotherapy for primarycancer will not count towards this criterion.

• The substitution of carboplatin for cisplatin does not constitute a new regimenprovided no new chemotherapeutic agents were added to the regimen and noprogression was noted prior to the change in platinum.

• Antibody-drug conjugate (ADC) will not count towards this criterion.

• Participant who previously received gemcitabine in combination with platinum inmetastatic setting will be eligible to receive docetaxel or paclitaxel incomparator arm.

• Participant has received more than 1 antibody-drug conjugate (ADC) in metastaticsetting.

• Has had prior radiation therapy within 28 days prior to first dose of study drug orwho has not recovered (i.e., <= Grade 1 or at baseline) from adverse events due toradiotherapy.

• History of additional malignancy or history of prior malignancy, except foradequately treated basal or squamous skin cancer, or cervical carcinoma in situwithout evidence of disease, or malignancy treated with curative intent and with noevidence of disease recurrence for 5 years since the initiation of that therapy.

• Prior allogeneic stem cell or solid organ transplantation.