Overview

"In this study researchers are testing GSK5764227, a new medicine that targets specific proteins (B7-H3) on cancer cells, thereby reducing the cancers ability to grow and spread. This study specifically aims to evaluate how well GSK5764227 works in treating relapsed SCLC compared to standard treatment topotecan, by checking whether GSK5764227 makes cancers smaller or disappear completely and if it helps participants live longer. The study is also assessing whether GSK576227 is safe and tolerated well by participants compared to topotecan and provide a better understanding of the main side effects of both drugs. Participants with relapsed SCLC will be randomly divided into two groups: one group receiving GSK5764227 and the other receiving topotecan."

Eligibility

Inclusion Criteria:

Participants are eligible to be included in the study only if all of the following criteria apply:

• Adults >18 or the minimum legal adult age at the time the informed consent form is signed
• Has histologically or cytologically confirmed extensive-stage small cell lung cancer (ES-SCLC).
• Has received 1 prior platinum-based systemic therapy with a PD- (L)1 inhibitor with at least 2 cycles of therapy and a chemotherapy free-interval of >30 days, with documented progression
• Has at least 1 target lesion per RECIST 1.1, as determined by the investigator.
• Is capable of giving signed informed consent, including compliance with the requirements and restrictions listed in the ICF and in the protocol.
• Has an ECOG performance status of 0 or 1

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

• Pathological diagnosis of complex SCLC or transformed SCLC.
• Has received any prior therapy with an Antibody-drug conjugate (ADC) with a Topoisomerase-1 (TOPO1)-inhibitor payload or treatments targeting B7-H3.
• Has known sensitivity to study intervention components or excipients or other allergy that, in the opinion of the investigator or medical monitor, contraindicates participation in the study.
• Has severe, uncontrolled or active cardiovascular disorders.
• Has clinically significant bleeding symptoms or significant bleeding tendency within 1 month prior to the first dose.
• Known active infectious diseases requiring systemic treatment or known Human immunodeficiency virus (HIV).
• Has symptomatic brain metastases or untreated progression exclusively due to brain metastasis during or after the last treatment prior to screening, evidence of leptomeningeal/meningeal/brainstem metastasis or evidence of spinal cord metastases.
• Has any evidence of current interstitial lung disease or pneumonitis or a prior history of ILD or non-infectious pneumonitis requiring high dose steroids.
• Has documented Hepatitis B or Hepatitis C