A Study to Evaluate Adverse Events and Change in Disease Activity of Intravenous ABBV-706 Versus Standard of Care in Adult Participants With Relapsed/Refractory Small Cell Lung Cancer

A Phase 3 Randomized, Open Label, Multicenter Study to Evaluate the Safety and Efficacy of ABBV-706 Versus Standard of Care in Subjects With Relapsed/Refractory Small Cell Lung Cancer (SCLC)

Small cell lung cancer (SCLC) is characterized by aggressive and rapid growth and a tendency to develop early spread to distant sites including mediastinal lymph nodes, liver, bones, adrenal glands, and brain. The purpose of this study is to assess safety, tolerability, and change in disease activity of ABBV-706 compared to standard of care (SOC) treatment (topotecan, lurbinectedin, or amrubicin).

ABBV-706 is an investigational drug being developed for the treatment of SCLC. There are two treatment arms in this study. Participants will either receive ABBV-706 or SOC. Approximately 531 adult participants will be enrolled in the study across 175 sites worldwide.

Participants with SCLC will receive intravenous (IV) ABBV-706 or SOC [topotecan (IV or orally), or lubinectedin (IV), or amrubicin (IV)]. The estimated duration of the study is approximately 53 months.

There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic and may require frequent medical assessments, blood tests, questionnaires, and scans.

Inclusion Criteria:

• Diagnosis of histologically or cytologically confirmed Relapsed/Refractory (R/R) Small Cell Lung Cancer (SCLC).

• Participants must have progressed on prior systemic therapy, with CPI (if eligible) and prior tarlatamab, defined as:

  • In the 1L and 2L setting respectively, platinum-based chemotherapy (i.e., carboplatin or cisplatin and etoposide with CPI, if eligible for CPI) and 2L tarlatamab; or
  • In the 1L and 2L setting, platinum-based chemotherapy (i.e., carboplatin and etoposide with atezolizumab and lurbinectedin in combination with atezolizumab maintenance and 2L tarlatamab; or
  • In the 1L setting, platinum-based chemotherapy (i.e., carboplatin or cisplatin and etoposide with CPI if eligible) in combination with tarlatamab in frontline induction and/or maintenance

• Participants must be considered suitable to receive SOC comparator (topotecan, lurbinectedin, or amrubicin).

• Participants must have an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 1 during the screening period prior to the first dose of study treatment.

• Participants must have measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Target lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.

• Participants with brain metastasis from an extracranial solid tumor are eligible if the brain metastases are:

  • Previously treated and not requiring anticonvulsants and steroids for at least 7 days prior to first dose of study treatment. If required for management, subjects on a steroid equivalent of prednisone dose of ≤ 10 mg/day are eligible or;
  • Untreated and asymptomatic not requiring anticonvulsants and steroids for at least 7 days prior to the first dose of study treatment. If required for management, subjects on a steroid equivalent of prednisone of ≤ 10 mg/day are eligible.

Exclusion Criteria:

• Participants with known active/symptomatic central nervous system metastases.
• Participants with a history of interstitial lung disease (ILD) or pneumonitis that previously required treatment with systemic steroids, or any evidence of active ILD/pneumonitis on screening chest computed tomography (CT) scan.
• Participants with any clinically significant conditions that would adversely affect the participation in the study, and the subject should have a life expectancy of at least 3 months.
• Participants who have received prior treatment with a seizure-related 6 homolog (SEZ6) targeted Antibody drug conjugate (ADC), other targeted ADCs, or any other investigational agent not including tarlatamab in 1L.
• Participants who have received prior treatment with any Top1i such as topotecan, irinotecan, belotecan, camptothecin, rubitecan, exatecan or locally approved topoisomerase I inhibitor (Top1i) payload.