This study is a randomized, open-label, multi-center investigator-initiated clinical trial. Patients who meet the inclusion criteria receive the treatment plan stipulated in the protocol. A Bayesian design is used to explore the efficacy and safety of teprotumumab combined with pulse chemotherapy in the treatment of advanced second-line extensive-stage small cell lung cancer.

Inclusion Criteria:

• 1.Age ≥18 years old, both male and female are acceptable.

• 2. Histology and pathology diagnosis of extensive stage small cell lung cancer, and must meet the following standards:

  1. always has not received the immune therapy,
  2. Previously received immunotherapy, with the number of treatment lines ≥2 and the immunotherapy being effective(immunotherapy PFS > 3 months, withdrawal time > 3 months)
  3. never used anlotinib,

• 3. ECOG: 0 ~ 2;

• 4 . The expected lifetime 12 weeks or more;

• 5. Major organs function normal

Exclusion Criteria:

• 1.Those who are allergic to toripalimab or etoposide or have metabolic disorders;
• 2.With known the special ripley sheet resistance, etoposide contraindication;
• 3.Other circumstances that the researcher assessed as unsuitable for participation in this clinical study.