Study of NMS-03305293 in Adult Patient With Relapsed Small Cell Lung Cancer

This study tests a new investigational drug called NMS-03305293 for people with extensive-stage small cell lung cancer (SCLC) that has relapsed — meaning the cancer came back after previous treatment including platinum-based chemotherapy and immunotherapy. **You may be eligible if...** - You are an adult (18 or older) - You have extensive-stage SCLC confirmed by a tissue sample - Your cancer returned within 6 months after first-line treatment with platinum-based chemotherapy plus immunotherapy - You have received no more than 3 prior lines of treatment - Your cancer is measurable on imaging - You are in adequate health (ECOG performance status of 2 or lower) - You are able to swallow capsules whole **You may NOT be eligible if...** - You are currently enrolled in another clinical trial - You have had brain metastases that are active or untreated - You have significant heart problems or other serious medical conditions - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.