A Phase 1 First-in Human, Multi-Center, Open Label Dose-Escalation Study to Determine the Safety, Tolerability, Pharmacokinetics and RP2D of ABBV-151 as a Single Agent and in Combination With ABBV-181 in Subjects With Locally Advanced or Metastatic Solid Tumors

Primary Outcome Measures  :

1. Dose Escalation: Recommended Phase 2 Dose (RP2D) ABBV-151 Monotherapy [ Time Frame: Up to 28 days after the first dose of ABBV-151 monotherapy ]The RP2D is defined as the dose level chosen by the sponsor (in consultation with the investigators) for the dose expansion arms, based on safety, tolerability, efficacy, PK, and PD data collected during the dose escalation portion of the study.
   
2. Dose Escalation: RP2D ABBV-151 + ABBV-181 Combination Therapy [ Time Frame: Up to 28 days after the first dose of ABBV-151 and ABBV-181 combination therapy ]The RP2D is defined as the dose level chosen by the sponsor (in consultation with the investigators) for the dose expansion arms, based on safety, tolerability, efficacy, pharmacokinetics (PK), and pharmacodynamic (PD) data collected during the dose escalation portion of the study.
   
3. Dose Expansion: Objective Response Rate (ORR) [ Time Frame: Up to approximately 6 months after the first dose date of last participant in Dose Expansion ]ORR defined as the percentage of participants with a confirmed complete response (CR) or partial response (PR) based on Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.
   

Secondary Outcome Measures  :

1. Dose Expansion: Duration of Response (DOR) [ Time Frame: Up to approximately 6 months after the first dose date of last participant in Dose Expansion ]The DOR for a responder is defined as the time from the participant's initial objective response to the first date of either disease progression or death, whichever occurs first.
   
2. Dose Expansion: Progression-free Survival (PFS) [ Time Frame: Up to approximately 6 months after the first dose date of last participant in Dose Expansion ]Progression-free survival is defined as the time from the participant's first dose of study treatment (ABBV-151 or ABBV-181) to the first date of either disease progression or death, whichever occurs first.
   
3. Maximum Observed Serum Concentration (Cmax) [ Time Frame: Up to approximately 70 days after initial dose of study drug ]Maximum Serum Concentration (Cmax) of study drug.
   
4. Time to Maximum Observed Serum Concentration (Tmax) [ Time Frame: Up to approximately 70 days after initial dose of study drug ]Time to maximum serum concentration (Tmax) of study drug.
   
5. Area Under the Plasma Concentration-time Curve over time from 0 to last measurable concentration (AUCτ) [ Time Frame: Up to approximately 70 days after initial dose of study drug ]Area under the serum concentration-time curve from time 0 to the time of the last measurable concentration (AUCτ).
   
6. Terminal-phase Elimination Rate Constant (β) [ Time Frame: Up to approximately 70 days after initial dose of study drug ]Apparent terminal phase elimination rate constant (β or Beta).
   
7. Terminal Phase Elimination Half-life (t1/2) [ Time Frame: Up to approximately 70 days after initial dose of study drug ]Terminal phase elimination half-life (t1/2) of study drug.

Inclusion Criteria:

• For Dose Escalation only: Subjects with an advanced solid tumor who are considered refractory to or intolerant of all existing therapy(ies) known to provide a clinical benefit for their condition. Additionally, subjects who have been offered standard therapies and refused, or who are considered ineligible for standard therapies, may be eligible for this study on a case-by-case basis, after discussion with and agreement from the sponsor. Subjects with triple-negative breast cancer (TNBC), pancreatic adenocarcinoma, urothelial cancer, Hepatocellular carcinoma (HCC), or Head and neck squamous cell carcinoma (HNSCC) who are being considered for the dose escalation cohorts must also meet the histology specific eligibility criteria described below for dose expansion
• For Dose Expansion only subjects must meet criteria specific to the type of cancer:
• TNBC - Female or male subjects with confirmed breast adenocarcinoma that is ER-negative, PR-negative, and HER2-negative, (as defined per American Society of Clinical Oncology [ASCO]/College of American Pathology [CAP] guidelines), who must have disease progression during or after at least 1 systemic therapy that included a taxane in the metastatic or recurrent setting.
• Pancreatic adenocarcinoma and have disease progression during or after 1 systemic 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 in the adjuvant, locally advanced, or metastatic setting. If the therapy was used in an adjuvant setting, disease progression must have occurred within 6 months of completing adjuvant therapy.
• Urothelial cancer of the bladder and urinary tract and must have progressed following treatment with a platinum-based regimen (administered in any line of therapy) and a programmed death 1/programmed death ligand 1 (PD1/PDL1) antagonist administered in the recurrent or metastatic setting (progression following a PD1/PDL1 antagonist is defined as unequivocal progression on or within 3 months of the last dose of anti-PD1 or anti-PDL1 therapy).
• HCC and must have disease progression during or after 1 prior line of systemic therapy.
• HNSCC (arising from the oral cavity, oropharynx, hypopharynx, or larynx) and must have progressed following treatment with platinum-based regimen (administered in any line of therapy) and a PD1/PDL1 antagonist administered in the recurrent or metastatic setting (progression following a PD1/PDL1 antagonist is defined as unequivocal progression on or within 3 months of the last dose of anti-PD1 or anti-PDL1 therapy).
• Subject has an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 1.
• Subject has adequate bone marrow, renal, hepatic, and coagulation function. Must have a viral status consistent with the requirements described in the protocol specific to type of cancer and stage of study (Dose Escalation or Dose Expansion).

Exclusion Criteria:

• For Dose Expansion only: All subjects, except for subjects with urothelial cancer or HNSCC, must not have had prior exposure to immunotherapies as listed in the protocol.
• Has received anticancer therapy including chemotherapy, immunotherapy, radiation therapy, 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 study drug.
• Subject has no unresolved AEs > Grade 1 from prior anticancer therapy except for alopecia.
• Has a history of primary immunodeficiency, bone marrow transplantation, solid organ transplantation, or previous clinical diagnosis of tuberculosis.
• Has a known uncontrolled metastases to the central nervous system (with certain exceptions).
• Current or prior use of immunosuppressive medication within 14 days prior to the first dose of the study drug.