Anti-PD-L1 immune checkpoint inhibitors in combination with etoposide and platinum for extensive-stage small cell lung cancer: a case report

The conventional etoposide-platinum (EP) regimen and adjuvant radiotherapy remain the gold-standard treatment for small cell lung cancer (SCLC). However, most patients already have multiple metastases when they are first diagnosed with SCLC. The objective response rate (ORR) and 1-year survival rate are low in these patients despite active radiotherapy and chemotherapy. SCLC is oncologically featured by the high tumor mutational burden (TMB) of multiple genes, which makes immunotherapy a possible new treatment strategy for SCLC. New data from the IMpower133 and CASPIAN trials will shed new light on the treatment of SCLC. In 2020, the results from the phase 3 CASPIAN trial have already suggested that programmed cell death-ligand 1 (PD-L1) inhibitors may represent breakthroughs in the management of SCLC. Here, we report a patient with extensive-stage SCLC (ES-SCLC) treated with first-line anti-PD-L1 immune checkpoint inhibitor (PD-L1 inhibitor) (i.e., durvalumab) combined with the EP regimen for 6 cycles. The patient consistently achieved partial response (PR) [nearly complete response (CR)], and no immune-related adverse events were noted during this period. The Karnofsky performance status (PS) score maintained at 1-2 points. We further review the history of SCLC treatment and elucidate the role of combination with immunotherapy in treating SCLC in the coming years.