The study for each participant consists of a Screening period, a Treatment period that includes an Induction treatment period and a Maintenance treatment period, and a Follow-up period.~During the screening period of up to 28 days before starting SCLC treatment, each participant will be assessed for somatostatin receptor (SSTR) expression by [68Ga]Ga-DOTA-TATE imaging PET/scan.~Eligible participants will be enrolled in cohorts of 3 to 6 participants to receive:~Four cycles of carboplatin area under the curve (AUC) 5 on Day 1 and etoposide 100 mg/m2 on Day 1-3, every 3 weeks at Weeks 1, 4, 7 and 10 in induction period~Tislelizumab 200 mg on Day 1 every 3 weeks in induction and maintenance period~Two administrations of [177Lu]Lu-DOTA-TATE during the induction period: on either Day 3, 4 or 5 of Week 1 and on Week 7 Day 3 period followed by 1 to 4 administrations during the maintenance period on Week 13 Day 1, Week 16 Day 1, Week 19 Day 1 and Week 22 Day 1, depending on the dose assessed.~Up to six different dose level combinations of [177Lu]Lu-DOTA-TATE will be assessed in the study as follows:~Dose Level 1 (DL1): 100 mCi of [177Lu]Lu-DOTA-TATE in the induction period and 100 mCi of [177Lu]Lu-DOTA-TATE in the maintenance period.~Dose Level 2a (DL2a): 150 mCi of [177Lu]Lu-DOTA-TATE in both the induction and the maintenance periods.~Dose Level 2b (DL2b): 150 mCi of [177Lu]Lu-DOTA-TATE in the induction period and 200 mCi of [177Lu]Lu-DOTA-TATE in the maintenance period.~Dose Level 3a (DL3a): 200 mCi of [177Lu]Lu-DOTA-TATE in both the induction and maintenance periods.~Dose Level 3b (DL3b): 200 mCi of [177Lu]Lu-DOTA-TATE in the induction period and 250 mCi of [177Lu]Lu-DOTA-TATE in the maintenance period.~Dose Level 4 (DL4): 250 mCi of [177Lu]Lu-DOTA-TATE in both the induction and maintenance periods.~An infusion of sterile 2.5% Lysine - Arginine amino acid (AA) solution will be co-administered with each [177Lu]Lu-DOTA-TATE dose for renal protection.~The dose escalation part in this study will be guided by the dose limiting toxicity (DLT) rate observed within the first 6 weeks (42 days) of treatment. In addition to DLTs the totality of safety data available at the time will be assessed for each dose escalation decision. Dose escalation/de escalation will be conducted using the Bayesian Optimal Interval Approach (BOIN).
This study aims to establish a safe and well tolerated dose of [177Lu]Lu-DOTA-TATE in combination with carboplatin, etoposide, and tislelizumab in induction treatment and with tislelizumab in maintenance treatment in newly diagnosed patients with Extensive Stage Small Cell Lung Cancer (ES-SCLC).