A Study Evaluating the Efficacy and Safety of Risvutatug Rezetecan in Participants With Advanced Sarcomas (EMBOLD Sarcoma-202)

• Ris-Rez (Biological): Ris-Rez will be administered
• G-CSF (Biological): G-CSF will be administered

Primary outcomes

• Cohort 1: Progression free survival rate at Week18 (PFS18) [At Week 18]: PFS is defined as the time from the date of randomization until the date of documented disease progression or death due to any cause, whichever occurs first, as assessed by the investigator according to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1)
• Cohort 1 & 2: Confirmed Objective Response Rate (ORR) [Up to approximately 98 weeks]: Confirmed ORR is defined as the proportion of participants who have achieved a confirmed Complete Response (CR) or Partial Response PR as assessed by investigator, according to RECIST 1.1

Secondary outcomes

• Cohort 1 & 2: Number of participants with Adverse events (AEs) and serious AEs (SAEs) by severity [Up to approximately 179 weeks]
• Cohort 1 & 2: Number of participants with AEs/SAEs leading to dose modifications or study intervention discontinuation or death [Up to approximately 179 weeks]
• Cohort 1 & 2: Number of participants with a change from baseline in vital signs [Baseline (Day-1) and up to approximately 179 weeks]: Number of participants will be assessed
• Cohort 1 & 2: Number of participants with a change from baseline in body weight [Baseline (Day-1) and up to approximately 179 weeks]: Number of participants will be assessed
• Cohort 1 & 2: Number of participants with a change from baseline in laboratory parameters (haematology and clinical chemistry) [Baseline (Day-1) and up to approximately 179 weeks]: Number of participants will be assessed
• Number of participants with a change from baseline in cardiac function [Electrocardiogram (ECG)] [Baseline (Day-1) and up to approximately 179 weeks]: Number of participants will be assessed
• Number of participants with a change from baseline in Eastern Cooperative Oncology Group (ECOG) performance status [Baseline (Day-1) and up to approximately 179 weeks]: Number of participants will be assessed
• Cohort 2: PFS rate at Week 18 (PFS18) [At Week 18]: PFS is defined as the time from the date of randomization until the date of documented disease progression or death due to any cause, whichever occurs first, as assessed by the investigator according to RECIST 1.1
• Cohort 1 & 2: Duration of response (DoR) [Up to approximately 179 weeks]: DoR is defined as the time from the date of the first documented objective response (CR/PR) that is subsequently confirmed, until the date of the first documented PD or death, whichever is earlier, as assessed by investigator according to RECIST 1.1
• Cohort 1 & 2: PFS rate at Week 30 (PFS30) [At Week 30]: PFS is defined as the time from the date of randomization until the date of documented disease progression or death due to any cause, whichever occurs first, as assessed by the investigator according to RECIST 1.1
• Cohort 1 & 2: PFS [Up to approximately 179 weeks]: PFS is defined as the time from the date of randomization until the date of documented disease progression or death due to any cause, whichever occurs first, as assessed by the investigator according to RECIST 1.1
• Cohort 1 & 2: Unconfirmed ORR [Up to approximately 179 weeks]: Unconfirmed ORR is defined as the proportion of participants who have achieved a response of CR or PR (without confirmation) as assessed by the investigator according to RECIST 1.1.
• Cohort 1 & 2: Observed pharmacokinetic (PK) concentration of Ris-Rez (conjugated antibody) and payload [Up to approximately 179 weeks]
• Cohort 1 & 2: Proportion of participants with positive and total Antidrug antibody (ADA) and Neutralizing Antibody (NAb) against Ris-Rez [Up to approximately 179 weeks]
• Cohort 1 & 2: Titers of ADA against Ris-Rez [Up to approximately 179 weeks]
• Cohort 1 & 2: Participant-reported experience on study treatment [Up to approximately 179 weeks]: Number of participants who reported their experience with study treatment using validated questionnaires will be measured

Sex: All

Inclusion Criteria:

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

* Participants must be ≥ 12 years of age.
* Has histologically confirmed unresectable advanced or metastatic R/R OSA (Cohort 1) or unresectable advanced or metastatic STS (Cohort 2) that has progressed to at least one prior line of systemic therapy.
* Has documented disease progression on the last line of systemic treatment as confirmed by radiological imaging
* Has an ECOG performance status of 0 or 1, or Lansky PS/Karnofsky PS ≥ 70% for adolescent participants, with no deterioration in the 2 weeks prior to first dose/randomization.
* Has adequate organ function.
* All participants, or their legal guardians, must provide signed informed consent and agree to follow the study protocol before starting any study activities

Exclusion Criteria:

\- Participants are excluded from the study if any of the following key exclusion criteria apply:

* Has received any prior therapy with an Antibody-drug-conjugates (ADC) with a TOPO1-inhibitor payload.
* 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.
* 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 received treatment with an investigational agent within 4 weeks of the first dose of study intervention.
* Is pregnant or breastfeeding.

NIH grants: 2025