Last updated: 11/12/2026 17:00:13
A Study of Risvutatug Rezetecan in Combination with Atezolizumab in Participants with Extensive Stage Small Cell Lung Cancer (EMBOLD-SCLC-303)
GSK study ID
300599
Clinicaltrials.gov ID
Not applicable
EudraCT ID
Not applicable
EU CT Number
Trial status
Not yet recruiting
Not yet recruiting
Trial overview
Official title: A Phase 3 Randomized Open-Label Study to Evaluate the Safety and Efficacy of Risvutatug Rezetecan in Combination with Atezolizumab in Participants with Newly Diagnosed Extensive Stage Small Cell Lung Cancer
Trial description: Extensive-stage small cell lung cancer (ES-SCLC) is an aggressive type of lung cancer. Current treatment options are limited, and response to treatment may not last long. Outcomes are especially poor when the cancer has spread to the brain. This study tests whether a new treatment: risvutatug rezetecan (Ris‑Rez) with atezolizumab works better than standard of care treatment. Ris‑Rez is designed to deliver cancer-killing medicine directly to cancer cells. Atezolizumab helps the immune system attack cancer cells. Researchers will see if this combination helps people live longer and keeps the cancer from getting worse.
Primary purpose:
Treatment
Trial design:
Parallel
Masking:
None (Open Label)
Allocation:
Randomized
Primary outcomes:
Overall survival (OS)
Timeframe: Up to 50 months
Progression-free survival (PFS) by Blinded independent central review (BICR) assessment
Timeframe: Up to 50 months
Secondary outcomes:
Time to confirmed deterioration of disease-related symptoms and physical functioning
Timeframe: Up to 63 months
Brain PFS
Timeframe: Up to 63 months
PFS by Investigator Assessment
Timeframe: Up to 63 months
Objective response rate (ORR)
Timeframe: Up to 63 months
Duration of response (DOR)
Timeframe: Up to 63 months
ORR for participants not receiving bridging cycle
Timeframe: Up to 63 months
DOR for participants not receiving bridging cycle
Timeframe: Up to 63 months
Participant reported experience on study treatment
Timeframe: Up to 63 months
Time to worsening of participants overall quality of life
Timeframe: Up to 63 months
Number of participants with adverse events (AEs), serious adverse events (SAEs), adverse events of special interest (AESIs) by severity
Timeframe: Up to 63 months
Number of participants with AEs leading to dose modifications or study intervention discontinuation
Timeframe: Up to 63 months
Number of participants with changes in hematology parameters
Timeframe: Up to 63 months
Observed pharmacokinetic concentration of Ris-Rez
Timeframe: Up to 63 months
Number of participants with Antidrug antibody (ADA) and Neutralizing Antibody (NAb) against Ris-Rez
Timeframe: Up to 63 months
Titres of ADA against Ris-Rez
Timeframe: Up to 63 months
Interventions:
Biological/vaccine: Ris-Rez
Biological/vaccine: Atezolizumab
Drug: Etoposide
Drug: Carboplatin
Drug: Lurbinectedin
Enrollment:
700
Primary completion date:
2031-24-02
Observational study model:
Not applicable
Time perspective:
Not applicable
Clinical publications:
Not applicable
Medical condition
Lung Neoplasm
Product
GSK5764227
Collaborators
Not applicable
Study date(s)
December 2026 to March 2032
Type
Interventional
Phase
3
Participation criteria
Sex
Female & Male
Age
18+ years
Accepts healthy volunteers
No
- Is at least 18 years of age or the legal age of consent in the jurisdiction in which the study is taking place at the time of signing the informed consent form (ICF).
- Has histologically or cytologically confirmed extensive-stage small cell lung cancer (ES-SCLC) at initial diagnosis and at trial entry and has received no prior systemic therapies for SCLC, with 1 exception where participants who have received one cycle of etoposide and carboplatin with or without atezolizumab are eligible
- Has symptomatic central nervous system (CNS) metastases, CNS metastases with hemorrhagic features, or leptomeningeal disease.
- Has known allergy or hypersensitivity to study intervention components or excipients.
Inclusion and exclusion criteria
Inclusion criteria:
- Has histologically or cytologically confirmed extensive-stage small cell lung cancer (ES-SCLC) at initial diagnosis and at trial entry and has received no prior systemic therapies for SCLC, with 1 exception where participants who have received one cycle of etoposide and carboplatin with or without atezolizumab are eligible
- Is capable of giving signed informed consent including compliance with the requirements and restrictions listed in the ICF and protocol.
- Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
- Has adequate organ function.
Is at least 18 years of age or the legal age of consent in the jurisdiction in which the study is taking place at the time of signing the informed consent form (ICF).
Exclusion criteria:
- Has known allergy or hypersensitivity to study intervention components or excipients.
- Has any evidence of current interstitial lung disease or non-infectious pneumonitis or a prior history of interstitial lung disease (ILD) or non-infectious pneumonitis requiring high dose steroids or suspected ILD/non-infectious pneumonitis that cannot be ruled out by imaging.
- Has moderate to severe pulmonary disease or current clinically significant pulmonary compromise that, in the investigator’s judgment, could jeopardize safety or study conduct.
- Has clinically significant bleeding symptoms, bleeding tumors, or significant bleeding tendency within 1 month prior to first dose.
- Known active infectious diseases requiring systemic treatment or known human immunodeficiency virus (HIV).
- Has received any prior systemic anticancer treatment for the disease under study.
- Has received any prior therapy with a Topoisomerase-1 (TOP1i), including antibody-drug conjugates that are effectively loaded as TOP1i, or treatment targeting B7-H3.
- Has severe, uncontrolled, or active cardiovascular disorders.
Has symptomatic central nervous system (CNS) metastases, CNS metastases with hemorrhagic features, or leptomeningeal disease.
Trial location(s)
No location data available.
Study documents
No study documents available.
Results overview
Study Results yet to be posted
Recruitment status
Not yet recruiting
Actual primary completion date
Not applicable
Actual study completion date
Not applicable
Plain language summaries
Plain language summaries of clinical trial results for Phase 2-4 clinical trials that were initiated on or after January 2022 will be posted by GSK within one year following study completion.
Additional information about the trial
Additional information
Not applicable
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