A Phase 3 interventional study of Puxitatug Samrotecan and Doxorubicin in Endometrial Cancer and Malignant Solid Tumour, sponsored by AstraZeneca. Recruiting at 320 sites in 28 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-29.
Sponsored by AstraZeneca · Phase 3, Interventional, and Treatment
This is a Phase III, 2-arm, randomized, open label, multicenter, global study assessing the efficacy and safety of puxitatug samrotecan compared to physician's choice of chemotherapy (doxorubicin or paclitaxel) in participants with B7-H4 selected advanced/metastatic EC that progressed following platinum based chemotherapy and anti-PD-1/anti-PD-L1 therapy.
The target population of interest in this study is participants with B7-H4-selected advanced/metastatic EC who have progressed on or after platinum-based chemotherapy and anti-PD-1/anti-PD-L1 therapy, either separately or in combination and should have received no more than 2 prior lines of therapy in advanced/metastatic setting. Participants will be randomized in a 1:1 ratio to Puxi-Sam (arm A) or physician's choice of chemotherapy (arm B; doxorubicin or paclitaxel). The total study size will be approximately 700 eligible participants.
During the treatment period, participants will receive Puxi-Sam IV Day 1 Q3W (Arm A) or either doxorubicin treatment IV Day 1 Q3W or paclitaxel treatment IV on Days 1, 8, and 15 in 28-day cycle (Arm B).
This study aims to see if Puxi-Sam allows participants to live longer without their endometrial cancer getting worse, or simply to live longer, compared to participants receiving standard of care chemotherapy. This study is also looking to see how the treatment and the endometrial cancer affects participants' quality of life.
The main inclusion criteria include but are not limited to the following:
The main exclusion criteria include but are not limited to the following:
Puxi-Sam IV (intravenous) Q3W .
Drug: Puxitatug Samrotecan
Physician's choice of chemotherapy Doxorubicin IV Q3W or Paclitaxel IV on Days 1, 8, and 15 in 28 day cycles.
Drug: Doxorubicin · Drug: Paclitaxel
2.4 mg/kg on Day 1 Q3W Route of administration: IV infusion
Also known as: Puxi-Sam
60 mg/m2 on Day 1 Q3W Route of administration: IV
Also known as: ADRIAMYCIN®
80 mg/m2 on Days 1, 8, and 15 in 28-day cycle Route of Administration: IV
Also known as: TAXOL®
Progression Free Survival (PFS) for Arm A vs Arm B
PFS is defined as the time from randomization until progression per RECIST 1.1 as assessed by BICR or death due to any cause.
Time frame: Approximately 3 years
Overall survival (OS) for Arm A vs Arm B
OS is defined as the time from randomization until the date of death due to any cause.
Time frame: Approximately 3 years
Assessment of Overall Response Rate (ORR) for Arm A vs Arm B
ORR is defined as the proportion of participants who have a response of CR or PR, as determined by BICR assessments, per RECIST 1.1.
Time frame: Approximately 3 years
Assessment of Duration of response (DoR) for Arm A vs Arm B
DoR will be defined as the time from the date of first documented response until the date of documented progression per RECIST 1.1 as assessed by BICR, or death due to any cause.
Time frame: Approximately 3 years
Assessment of progression-free survival 2 (PFS2) for Arm A vs Arm B
PFS2 will be defined as the time from randomization to the earliest of the progression event (following the initial Investigator-assessed progression), after first subsequent therapy, or death.
Time frame: Approximately 3 years
Time until first subsequent anticancer therapy after discontinuation of the randomized treatment, or death (TFST) for Arm A vs Arm B
TFST is defined as the time from randomization until the start date of the first subsequent anticancer therapy after discontinuation of the randomized treatment, or death due to any cause.
Time frame: Approximately 3 years
Time until the second subsequent anticancer therapy after discontinuation of the first subsequent treatment, or death (TSST) for Arm A vs Arm B
TSST is defined as the time from randomization until the start date of the second subsequent anticancer therapy after discontinuation of the first subsequent treatment, or death due to any cause.
Time frame: Approximately 3 years
Time until discontinuation of treatment for any reason, or death (TDT) for Arm A vs Arm B
TDT is defined as the time from randomization until discontinuation of treatment for any reason, including disease progression, toxicity, and death.
Time frame: Approximately 3 years
Worsening in endometrial symptoms for Arm A vs Arm B
Time to worsening is defined as time from date of randomization to the date of worsening while on treatment for endometrial symptoms, physical functioning, and health-related quality of life based on select items from the EORTC IL389.
Time frame: Approximately 3 years
Showing the first 100 of 320 sites across 28 countries.
Plan to share: Yes — Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal Vivli.org. All requests will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. Yes, indicates that AZ are accepting requests for IPD, but this does not mean all requests will be shared.
Supporting information: Study protocol, Sap
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