A Study to Evaluate the Safety of Dostarlimab in Adult Participants in India With Primary Advanced or Recurrent Endometrial Cancer

Phase 4, Open Label, Single-arm, Interventional, Multicenter Study to Evaluate the Safety of Dostarlimab in Adult Patients in India With Primary Advanced or Recurrent Endometrial Cancer

This study will evaluate the safety of dostarlimab in combination with carboplatin and paclitaxel followed by monotherapy when administered as a first-line treatment in advanced or recurrent endometrial cancer (EC).

Study Overview

• Status: Not yet recruiting
• Conditions: Neoplasms, Endometrial
• Intervention / Treatment: Drug: Dostarlimab; Drug: Carboplatin; Drug: Paclitaxel

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: US GSK Clinical Trials Call Center; Phone Number: 877-379-3718; Email: GSKClinicalSupportHD@gsk.com
• Study Contact Backup: Name: EU GSK Clinical Trials Call Center; Phone Number: +44 (0) 20 89904466; Email: GSKClinicalSupportHD@gsk.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Participant with greater than or equals to (>=) 18 years of age, at the time of signing the informed consent.
• Participant has histologically or cytologically proven EC with recurrent or advanced disease.
• Participant must have primary Stage III or Stage IV disease or first recurrent EC with a low potential for cure by radiation therapy or surgery alone or in combination based on investigator's assessment.
• Eligible for dostarlimab treatment according to the approved prescribing information and the investigator's clinical judgement.
• Woman of childbearing potential (WOCBP) agrees to use contraceptive from screening through at least 180 days after the last dose.
• Negative urine pregnancy test at most 24 hours prior to the first dose of study intervention.
• Capable of giving signed informed consent.
• Participant has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion Criteria:

• Participant has had greater than (>) 1 recurrence of endometrial cancer.
• Participant has a concomitant malignancy, or participant has a prior non endometrial invasive malignancy who has been disease-free for less than (<) 3 years or who received any active treatment in the last 3 years for that malignancy.
• Participant has known uncontrolled central nervous system metastases, carcinomatosis meningitis, or both.
• Participant is considered a poor medical risk due to a serious, uncontrolled medical disorder, nonmalignant systemic disease, or active infection requiring systemic therapy.
• Participant has not recovered adequately from AEs or complications from any major surgery prior to starting therapy.
• Participant has not recovered (i.e., to Grade less than or equal to [<=] 1 or to Baseline) from cytotoxic therapy induced AEs or has received transfusion of blood products (including platelets or red blood cells) or administration of colony-stimulating factors (including Granulocyte colony-stimulating factor [G-CSF], Granulocyte macrophage colony-stimulating factor [GM-CSF], or recombinant erythropoietin) within 21 days prior to the first dose of study drug.
• Either the history of hypersensitivity to excipients of the study intervention or to drugs with a similar chemical structure or class of the study intervention.
• Participant has known active hepatitis B (e.g., hepatitis B surface antigen reactive) or hepatitis C (e.g., hepatitis C virus ribonucleic acid [qualitative] is detected).

• Participant has received neo-adjuvant/adjuvant systemic anticancer therapy for primary Stage III or IV disease and:

  • has not had a recurrence or Progressive disease (PD) prior to first dose on the study, or
  • has had a recurrence or PD within 6 months of completing systemic anticancer therapy treatment prior to first dose on the study.
• Participant has received prior therapy with an anti- Programmed death protein 1 (anti-PD-1), anti- Programmed death ligand 1 (anti-PD-L1), or Programmed death ligand 2 (anti PD L2) agent.
• Participant has received prior anticancer therapy (chemotherapy, targeted therapies, radiotherapy, or immunotherapy) within 21 days or <5 times the half life of the most recent therapy prior to study Day 1, whichever is shorter.
• Systemic glucocorticoids for any purpose other than to manage symptoms of suspected irAEs. If medically deemed necessary (e.g., acute asthma or chronic obstructive pulmonary disease exacerbation, prophylaxis for intravenous (IV) contrast if indicated), Investigators are allowed to use their judgment to treat participants with systemic steroids. In such cases, systemic steroids should be stopped at least 24 hours prior to the next dose of study treatment.
• Participant has received, or is scheduled to receive, a live vaccine within 30 days before first dose of study intervention, during study treatment, and for up to 180 days after receiving the last dose of study intervention.
• Participant has a diagnosis of immunodeficiency and is receiving systemic steroid therapy (>10 milligrams [mg] daily prednisone or equivalent) within 7 days prior to the first dose of the study treatment or is receiving any other form of immunosuppressive medication.
• Participant is currently receiving study intervention, or is enrolled or has participated in any other clinical study involving an investigational intervention and received investigational treatment or used an investigational device within 4 weeks of the first dose of dostarlimab.
• Participant is pregnant or breastfeeding or is expecting to conceive children within the projected duration of the study, starting with the screening visit through 180 days after the last dose of study intervention.
• Judgment by the investigator that the participant should not participate in the study if the participant is unlikely to comply with study procedures, restrictions, and requirements.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Participants receiving Dostarlimab with Carboplatin + Paclitaxel followed by Dostarlimab Monotherapy; Participants will receive dose level 1 of dostarlimab in combination with carboplatin and paclitaxel followed by dose level 2 of dostarlimab monotherapy. Dose level 1 is the lowest dose level.	Drug: Dostarlimab; Dostarlimab will be administered.; Drug: Carboplatin; Carboplatin will be administered.; Drug: Paclitaxel; Paclitaxel will be administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of participants with Grade 3 or greater treatment-emergent adverse events (TEAEs) up to Week 49	Up to Week 49

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of participants with Grade 3 or greater TEAEs up to Week 170	Up to Week 170
Number of participants with TEAEs up to Week 49	Up to Week 49
Number of participants with TEAEs up to Week 170	Up to Week 170
Number of participants with Immune-related adverse events (irAEs) up to Week 49	Up to Week 49
Number of participants with Immune-related adverse events (irAEs) up to Week 170	Up to Week 170
Number of Participants with Serious Adverse Events (SAEs), treatment related Adverse Events (AEs), treatment related SAEs, fatal AEs, non-fatal SAEs up to Week 49	Up to Week 49
Number of Participants with Serious Adverse Events (SAEs), treatment related Adverse Events (AEs), treatment related SAEs, fatal AEs, non-fatal SAEs up to Week 170	Up to Week 170
Number of Participants with AEs leading to discontinuation of treatment, AEs leading to study withdrawal and AEs leading to dose modification up to Week 49	Up to Week 49
Number of Participants with AEs leading to discontinuation of treatment, AEs leading to study withdrawal and AEs leading to dose modification up to Week 170	Up to Week 170
Change from Baseline in hematology parameters: neutrophils, lymphocytes, monocytes, eosinophils, basophils and platelet count (Giga cells per Liter) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in hematology parameters: neutrophils, lymphocytes, monocytes, eosinophils, basophils and platelet count (Giga cells per Liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in hematology parameter: Red Blood Cell (RBC) count (Trillion cells per Liter) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in hematology parameter: Red Blood Cell (RBC) count (Trillion cells per Liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in hematology parameter: Hemoglobin (Hb) (Grams per Liter) up to Week 49	Baseline (Day 1) and up to 49
Change from Baseline in hematology parameter: Hemoglobin (Hb) (Grams per Liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in hematology parameter: Reticulocytes (Percentage of reticulocytes) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in hematology parameter: Reticulocytes (Percentage of reticulocytes) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in hematology parameter: Mean Corpuscular Volume (MCV) (Femtoliters) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in hematology parameter: Mean Corpuscular Volume (MCV) (Femtoliters) to up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in hematology parameter: Mean Corpuscular Hemoglobin (MCH) (Picograms) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in hematology parameter: Mean Corpuscular Hemoglobin (MCH) (Picograms) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in clinical chemistry parameters: Blood urea nitrogen (BUN), glucose, calcium, sodium, and potassium levels (Millimoles per Liter) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in clinical chemistry parameters: Blood urea nitrogen (BUN), glucose, calcium, sodium, and potassium levels (Millimoles per Liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in clinical chemistry parameters: Total bilirubin, direct bilirubin and creatinine levels (Micromoles per Liter) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in clinical chemistry parameters: Total bilirubin, direct bilirubin and creatinine levels (Micromoles per Liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in clinical chemistry parameters: Total protein levels (Gram per liter) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in clinical chemistry parameters: Total protein levels (Gram per liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in clinical chemistry parameters: Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels (International units per liter) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in clinical chemistry parameters: Aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels (International units per liter) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in Vital signs: systolic blood pressure (SBP) and diastolic blood pressure (DBP) (Millimeters of mercury [mmHg]) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in Vital signs: systolic blood pressure (SBP) and diastolic blood pressure (DBP) (Millimeters of mercury [mmHg]) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in Vital signs: pulse rate (Beats per minute) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in Vital signs: pulse rate (Beats per minute) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in Vital signs: body temperature (Degrees Celsius) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in Vital signs: body temperature (Degrees Celsius) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in Vital signs: respiratory rate (breaths per minute) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in Vital signs: respiratory rate (breaths per minute) up to Week 170	Baseline (Day 1) and up to Week 170
Change from Baseline in electrocardiogram (ECG) values: Heart rate (Beats per minute) up to Week 49	Baseline (Day 1) and up to Week 49
Change from Baseline in electrocardiogram (ECG) values: Heart rate (Beats per minute) up to Week 170	Baseline (Day 1) and up to Week 170

Collaborators and Investigators

• Sponsor: GlaxoSmithKline
• Investigators: Study Director: GSK Clinical Trials, GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start (Estimated): August 17, 2026
• Primary Completion (Estimated): August 30, 2030
• Study Completion (Estimated): August 30, 2030

Study Registration Dates

• First Submitted: June 11, 2026
• First Submitted That Met QC Criteria: June 11, 2026
• First Posted (Actual): June 17, 2026

Study Record Updates

• Last Update Posted (Actual): June 17, 2026
• Last Update Submitted That Met QC Criteria: June 11, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Carboplatin; Paclitaxel; Endometrial cancer; First line treatment; Dostarlimab
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Urogenital Neoplasms; Neoplasms by Site; Neoplasms; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Uterine Diseases; Genital Diseases, Female; Genital Neoplasms, Female; Uterine Neoplasms; Endometrial Neoplasms; Organic Chemicals; Hydrocarbons; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Coordination Complexes; Taxoids; Cyclodecanes; Diterpenes; Carboplatin; Paclitaxel; dostarlimab
• Other Study ID Numbers: 309169

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Study Sponsor will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/gsk-patient-level-data-sharing-july2025.pdf
• IPD Sharing Time Frame: Anonymized IPD will be made available within 6 months of publication of primary, key secondary and safety results for studies in product with approved indication(s) or terminated asset(s) across all indications.
• IPD Sharing Access Criteria: Anonymized IPD is shared with researchers whose proposals are approved by an Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months but an extension may be granted, when justified, for up to 6 months.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes