A Study of Experimental ABBV-011 Alone and Combined With ABBV-181 for Relapsed or Refractory Small Cell Lung Cancer

Open to people ages 18 years and up

• Must have histologically or cytologically confirmed small cell lung cancer (SCLC) that is relapsed or refractory following at least 1 prior platinum-based systemic chemotherapy, but no more than 3 total prior lines of therapy, and with no curative therapy available.
• Measurable disease, defined as at least 1 tumor lesion greater than or equal to 10 mm in the longest diameter or a lymph node greater than or equal to 15 mm in short axis measurement assessed by computed tomography (CT) scan, according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1.
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• Adequate hematologic, hepatic, neurologic, and renal function.
• All participants in Part B and Part C will be required to have tumor tissue that tests positive for target expression.

• History of confirmed or suspected liver cirrhosis, hepatic veno-occlusive disease (VOD), sinusoidal obstruction syndrome (SOS), alcohol dependence, or ongoing excessive alcohol use.
• Prior history of allogeneic or autologous stem cell transplantation.
• Documented history of stroke or clinically significant cardiac disease as described in the protocol within 6 months prior to the first dose of study drug.
• History of cardiac conduction abnormalities as described in the protocol.
• Recent or ongoing serious infection, as described in the protocol.
• Prior or concomitant malignancies with some exceptions, as described in the protocol.

Additional Exclusion Criteria for Part C:

• History of inflammatory bowel disease.
• Peripheral neuropathy Grade 2 with pain, or Grade 3 or higher.
• Body weight less than 35 kilograms.
• Active pneumonitis or interstitial lung disease (ILD) or a history of pneumonitis/ILD requiring treatment with steroids.
• Participants previously treated with an anti PD-1/PD-L1 targeting agent must meet additional criteria described in the protocol.
• Participant is judged by the Investigator to have evidence of ongoing hemolysis.
• Active autoimmune disease with exceptions as indicated in the protocol.
• History of primary immunodeficiency, solid organ transplantation, or previous clinical diagnosis of tuberculosis.