A Study of Prexasertib (LY2606368) in Participants With Extensive Stage Disease Small Cell Lung Cancer

Inclusion Criteria:

Have ED-SCLC and have received a prior platinum-based regimen
Participants in Cohort 1 and in the addendum must have had an objective response to prior platinum-based therapy with subsequent progression ≥90 days after the last dose of platinum
Participants in Cohort 2 must have either not had an objective response to prior platinum based therapy or had progression <90 days after the last dose of platinum
Have a performance status of 0 to 1 on the Eastern Cooperative Oncology Group scale

Exclusion Criteria:

Have received more than 2 prior therapies for ED-SCLC (including immunotherapy, targeted therapies, or chemotherapy)
Have symptomatic central nervous system (CNS) malignancy or metastasis. Asymptomatic participants with treated CNS metastases are eligible for this study if they are not currently receiving corticosteroids to treat CNS metastases
Have previously completed or withdrawn from this study or any other study investigating prexasertib or a checkpoint kinase I (CHK1) inhibitor or have shown hypersensitivity to any of the components of the prexasertib formulation
Have a serious cardiac condition