['small cell lung cancer']
['trilaciclib', 'placebos', 'topotecan']

        Inclusion Criteria:

          -  Male or female subjects aged ≥18 years

          -  Unequivocally confirmed diagnosis of SCLC by histology or cytology, preferably
             including the presence of neuroendocrine features by immunohistochemistry

          -  Progression during or after prior first- or second-line chemotherapy and eligible to
             receive topotecan therapy

          -  At least 1 target lesion that is measurable by RECIST, Version 1.1

          -  Eastern Cooperative Oncology Group (ECOG) performance status of 0 - 2

          -  Adequate organ function

        Exclusion Criteria:

          -  Presence of symptomatic brain metastases requiring immediate treatment with radiation
             therapy or steroids.

          -  Uncontrolled ischemic heart disease or uncontrolled symptomatic congestive heart
             failure

          -  Known history of stroke or cerebrovascular accident within 6 months prior to
             enrollment

          -  Other uncontrolled serious chronic disease or conditions that in the investigator's
             opinion could affect compliance or follow-up in the protocol

          -  Concurrent radiotherapy to any site or radiotherapy within 2 weeks prior to enrollment
             or previous radiotherapy to the target lesion sites (the sites that are to be followed
             for determination of a response)

          -  Receipt of any investigational medication within 2 weeks prior to enrollment

          -  History of topotecan treatment for SCLC
      