Olvi-Vec Combined With Platinum Plus Etoposide Therapy in Patients With Late Phase SCLC

Inclusion Criteria: * Able to understand and voluntarily sign an informed consent form. * Age ≥ 18 years old, gender not limited. * Small cell lung cancer confirmed by organization or cytology. * After receiving platinum based chemotherapy regimens and/or immunotherapy, platinum based chemotherapy regimens and/or anlotinib, and other recommended treatments according to guidelines, disease progression or recurrence has occurred. * There should be at least one measurable target lesion during the baseline period, according to RECIST 1.1 (if a lesion that has received radiation therapy has obvious evidence of disease progression after radiation therapy, it can be used as a target lesion). * ECOG physical condition score 0 or 1. * Have sufficient bone marrow, liver and kidney organ function- Exclusion Criteria: * Compound small cell lung cancer and transformed small cell lung cancer. * Patients with brain metastases and neurological symptoms; Note: Subjects with previous imaging evidence of brain metastases who have undergone local treatment (such as radiotherapy or surgery) for intracranial metastases and have stable lesions for more than 28 days without symptoms can be enrolled. * Other primary malignant tumors other than small cell lung cancer (excluding non melanoma skin cancer, breast cancer in situ, cervical cancer in situ, and superficial bladder cancer, or other cancers that have been effectively controlled in the past three years and have no evidence of disease recurrence) were previously or currently combined. * Clinically significant cardiovascular diseases At the beginning of the study treatment, the toxicity associated with previous anti-tumor treatments did not recover to ≤ CTCAE grade 1, except for hair loss and peripheral neurotoxicity of CTCAE grade 2. * Known HIV infection (HIV antibody positive), active hepatitis B and C patients. * Receive chemotherapy, targeted therapy, radiotherapy, and biological therapy, with less than 4 weeks since the first administration in this study; Or have received local radiotherapy within 2 weeks. * Having undergone major surgery or significant traumatic injury within 28 days prior to the first administration of the investigational drug -