RecruitingPhase 1Drug trialA Phase I Clinical Study to Evaluate the Safety, Tolerability, and Pharmacokinetics of HLX3901 in Patients With Advanced SCLC or NECThis study is an open-label first-in-human phase I clinical study to evaluate the safety, tolerability, and pharmacokinetic characteristics of HLX3901 in patients with Advanced Small Cell Lung Cancer or Neuroendocrine Carcinoma.