Lamivudine in Combination With Chemoimmunotherapy for the Treatment of Extensive Stage Small Cell Lung Cancer

This phase II trial studies the effect of lamivudine in combination with standard of care chemoimmunotherapy in treating patients with extensive stage small cell lung cancer. Even though small cell lung cancer is initially highly responsive to first-line chemotherapy treatment, treatment resistance inevitably emerges; treatment resistance is when tumor cells stop responding to a drug treatment that they had previously responded to. Lamivudine is an oral antiviral a drug that may be able to reduce the ability of tumors to develop drug resistance. Chemotherapy drugs, such as carboplatin and etoposide, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving lamivudine together with the usual standard of care chemoimmunotherapy may help prevent the growth and spread of the tumor cells to other parts of the body.