Study to Determine the Safety, Tolerability, Pharmacokinetics and Recommended Phase 2 Dose (RP2D) of Livmoniplimab (ABBV-151) as a Single Agent and in Combination With Budigalimab (ABBV-181) in Participants With Locally Advanced or Metastatic Solid Tumors

Inclusion Criteria:

• For Dose Escalation only: Participants with an advanced solid tumor who areconsidered refractory to or intolerant of all existing therapy(ies) known to providea clinical benefit for their condition. Additionally, participants who have beenoffered standard therapies and refused, or who are considered ineligible forstandard therapies, may be eligible for this study on a case-by-case basis, afterdiscussion with and agreement from the sponsor. Participants with pancreaticadenocarcinoma, urothelial cancer (UC), hepatocellular carcinoma (HCC), or head andneck squamous cell carcinoma (HNSCC) who are being considered for the doseescalation cohorts must also meet the histology specific eligibility criteriadescribed below for dose expansion.

• For Dose Expansion only participants must meet criteria specific to the type ofcancer:

• Pancreatic adenocarcinoma and have disease progression during or after 1systemic therapy (gemcitabine monotherapy or in combination with other agents,FOLFIRINOX [or another regimen including both 5-fluorouracil and oxaliplatin],capecitabine monotherapy or in combination with other agents) administered inthe adjuvant, locally advanced, or metastatic setting. If the therapy was usedin an adjuvant setting, disease progression must have occurred within 6 monthsof completing adjuvant therapy.

• UC of the bladder and urinary tract and must have progressed followingtreatment with:

• Cohort 4: A platinum-based regimen (administered in any line of therapy) and aprogrammed death 1/programmed death ligand 1 (PD1/PDL1) antagonist administeredin the recurrent or metastatic setting (progression following a PD1/PDL1antagonist is defined as unequivocal progression on or within 3 months of thelast dose of anti-PD1 or anti-PDL1 therapy).

• Cohort 11: One or more prior line of therapy in the locally advanced ormetastatic setting. Participant must have experienced radiographic progressionor relapse during or after a CPI (anti-PD1 or anti-PD-L1) for locally advancedor metastatic disease.

• HCC and must have disease progression during or after 1 prior line of systemictherapy.

• HNSCC (arising from the oral cavity, oropharynx, hypopharynx, or larynx) andmust have progressed following treatment with platinum-based regimen (administered in any line of therapy) and a PD1/PDL1 antagonist administered inthe recurrent or metastatic setting (progression following a PD1/PDL1antagonist is defined as unequivocal progression on or within 3 months of thelast dose of anti-PD1 or anti-PDL1 therapy).

• Microsatellite stable colorectal cancer (MSS-CRC) [unselected] participantswith microsatellite stable or mismatch repair proficient colorectaladenocarcinoma (as determined by polymerase chain reaction (PCR)/Next-Generation sequencing (NGS) or immunohistochemistry (IHC),respectively) who have received 1-2 prior chemotherapy regimens.

• Non-small cell lung cancer (NSCLC) relapsed/refractory (R/R): Participants withhistologically or cytologically confirmed advanced or metastatic NSCLC who havereceived 1 prior line of chemotherapy and 1 prior anti-PD-(L)1 antibody,administered either concurrently or sequentially in the metastatic setting.

• MSS-CRC (CMS4 enriched): Participants with microsatellite stable or mismatchrepair proficient colorectal adenocarcinoma who have received priorfluorouracil-based combination chemotherapy regimens including oxaliplatin andirinotecan (with or without VEGF and/or EGFR targeted agents) and with a CMS4subtype as determined by NGS of tumor biopsies. Archival tissue must besubmitted for assessment of CMS4 subtype status during prescreening.Participants must have progressed on or refused available standard of caretherapies. Additionally, participant who are considered not appropriate orineligible for available standard of care therapies per investigator assessmentwill be eligible for this study.

• Ovarian granulosa (OG) cell tumor: Participants with histologically confirmedadvanced nonresectable or metastatic adult granulosa cell tumor of the ovarythat is not amenable to curative intent surgery or radiation. Additionally,there is documentation of radiological evidence of relapse after at least 1line of systemic chemotherapy.

• Participant has an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0to 1.

• Participant has adequate bone marrow, renal, hepatic, and coagulation function.

• Must have a viral status consistent with the requirements described in the protocolspecific to type of cancer and stage of study (Dose Escalation or Dose Expansion).

Exclusion Criteria:

• For Dose Expansion only:

• Participants with HCC, pancreatic adenocarcinoma, or MSS-CRC having priorexposure to a prior PD-1/PD-L1 antagonist in any line of therapy.

• Participants (except for participants with urothelial cancer or HNSCC) who havehad prior exposure to immunotherapies as listed in the protocol.

• Has received anticancer therapy including chemotherapy, immunotherapy, radiationtherapy, biologic, herbal therapy, or any investigational therapy within a period of 5 half-lives or 28 days (whichever is shorter), prior to the first dose of the studydrug.

• Participant has unresolved AEs > Grade 1 from prior anticancer therapy except foralopecia.

• Has a history of primary immunodeficiency, bone marrow transplantation, solid organtransplantation, or previous clinical diagnosis of tuberculosis.

• Has a known uncontrolled metastases to the central nervous system (with certainexceptions).

• Current or prior use of immunosuppressive medication within 14 days prior to thefirst dose of the study drug.

• Has clinically significant uncontrolled condition(s).

• History of inflammatory bowel disease, interstitial lung disease or pneumonitis,myocarditis, Stevens-Johnson syndrome, toxic epidermal necrolysis or drug reactionwith eosinophilia and systemic symptoms (DRESS).

• Live vaccine administration <= 28 days prior to the first dose of study drug.