Ph I/IIa Escalation/Expansion FIH, Open, Multi Center, Single Arm Study Evaluating Safety, Dosimetry and Early Efficacy of 177Lu-SN201 in Progressive/Treatment-refractory, Locally Advanced, Unresectable Metastatic or Recurrent Solid Tumors

Phase I: Dose escalation to identify RP2D and/or MTD dose

时间窗: 24 months

RP2D and/or MTD will be based on the DLT rate. Dose escalation will follow BOIN design, directed by the DLT rate (the current number of participants with DLT divided by the current number of participants in the cohort). The study will evaluate up to 5 dose levels of \[177Lu\]Lu-SN201, however additional dose levels may be explored until MTD/RP2D is identified. If the starting dose is not tolerated, a lower dose may be evaluated based on toxicity, safety, pharmacokinetics, and dosimetry data as determined by the DMC.

Phase IIa: Clinical benefit in solid tumor subgroups at RP2D and/or MTD

时间窗: 24 months

Clinical benefit according to RECIST v1.1 of \[177Lu\]Lu-SN201, as defined by post-treatment tumor response and serum levels of applicable tumor markers, compared to baseline (last collected value/measurement before the start of treatment)

Phase I/IIa: Frequency and severity of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs)

时间窗: 48 months

Clinically significant safety laboratory results will be graded by NCI CTCAE v5.0. AEs (including physical examination, vital signs, ECG, and safety lab findings), related AEs, DLTs, SAEs, and related SAEs, AEs with NCI CTCAE Grades ≥ 3, AEs leading to premature discontinuation, interruptions, duration of interruptions and discontinuation of IRP will be analyzed descriptively utilizing corresponding Medical Dictionary for Regulatory Activities System Organ Classes and Preferred Terms. NCI CTCAE v5.0 toxicity grades will be utilized for classifying severity. Continual assessment of adverse events (AEs) and concomitant medication usage will be conducted.

Phase I/IIa: Incidence of Dose-Limiting Toxicity (DLT) during the first cycle of treatment.

时间窗: 48 months

DLTs are defined as: * Any Grade ≥ 3 AEs of any etiology that are clinically significant and last \> 7 days except: * Nausea, vomiting, or diarrhea will be considered a DLT only if it persists at Grade ≥ 3 for \> 3 days despite adequate supportive care measures. At the Investigator's discretion, participants who experience nausea, vomiting, or diarrhea after receiving IMP may receive antiemetic or anti-diarrheal medication before subsequent doses of IMP. * Isolated laboratory abnormalities Grade ≥ 3 (not present at Baseline) that are not considered to be significant by the Investigator and are resolved to at least Grade 1 within 7 days without clinical sequelae or need for therapeutic intervention. * Any other toxicity occurring at any time during the study that in the view of the participating Investigators and the Medical Monitor represents a clinically significant hazard to the participant. DLTs will be confirmed by the DMC.