A Study of Dostarlimab in Participants With Untreated Locally Advanced Rectal Cancer in China (China AZUR-1)

A Phase 2, Single-Arm, Open-Label Study With Dostarlimab Monotherapy in Participants With Untreated Stage II/III dMMR/MSI-H Locally Advanced Rectal Cancer in China

The main goal of this study is to evaluate the effect of dostarlimab monotherapy in Chinese participants with locally advanced Mismatch-repair deficient (dMMR)/ Microsatellite instability-high (MSI-H) rectal cancer who have received no prior treatment.

Study Overview

• Status: Active, not recruiting
• Conditions: Neoplasms, Rectal
• Intervention / Treatment: Biological: Dostarlimab

• Study Type: Interventional
• Enrollment (Actual): 23
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Chengdu, China, 610041
    • GSK Investigational Site
  • Chongqing, China, 400010
    • GSK Investigational Site
  • Guangzhou, China, 510060
    • GSK Investigational Site
  • Guangzhou, China, 510655
    • GSK Investigational Site
  • Hangzhou, China, 310016
    • GSK Investigational Site
  • Hangzhou, China
    • GSK Investigational Site
  • Jinan, China, 250117
    • GSK Investigational Site
  • Kunming, China, 650106
    • GSK Investigational Site
  • Shanghai, China, 200032
    • GSK Investigational Site

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Participant has histologically confirmed Stage II to III (T3-T4, N0, or T any, N+), locally advanced rectal adenocarcinoma
• Participant has radiologically and endoscopically evaluable disease
• Participant has a tumor which can be categorized as dMMR or MSI-H by central assessment

Exclusion Criteria:

• Participant has distant metastatic disease
• Participant has received prior radiation therapy, systemic therapy, or surgery for management of rectal cancer
• Has a known additional malignancy that progressed or required active treatment within the past 2 years
• Has an active autoimmune disease that has required systemic treatment in the past 2 years
• Has experienced any of the following with prior immunotherapy: any irAE ≥ Grade 3, immune-related severe neurologic events of any-grade (e.g., myasthenic syndrome/myasthenia gravis, encephalitis, Guillain Barré Syndrome, or transverse myelitis), exfoliative dermatitis of any grade [SJS (Stevens-Johnson Syndrome, TEN (Toxic Epidermal Necrolysis), DRESS (Drug rash with eosinophilia and systemic symptoms)], or myocarditis of any grade. Non-clinically significant laboratory abnormalities are not exclusionary
• Has any history of interstitial lung disease or pneumonitis
• Has received or plans to receive an organ or stem cell transplant that uses donor stem cells (allogeneic stem cell transplant)
• Has a history of severe allergic and/or anaphylactic reactions to chimeric, human, or humanized antibodies, fusion proteins, or known allergies to dostarlimab, or its excipients

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: Dostarlimab monotherapy; Participants will receive dostarlimab as monotherapy.	Biological: Dostarlimab; Dostarlimab will be administered.; Other Names: TSR-042; GSK4057190A

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants with Sustained Complete Clinical Response for 12 Months (cCR12) as assessed by Independent Central Review (ICR)	cCR12 is achieved when a participant maintains complete clinical response (cCR) as assessed by Independent central review (ICR) for 12 months from the first disease assessment after last dose of study intervention. Timeframe calculation includes 6 months (9 cycles of dostarlimab, with each cycle lasting 21 days) plus an additional 12 months of assessment time, amounting to a total of 18 months.	18 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Disease-Specific Response at 5 years (DSS5)	DSS5 is defined as the number of participants not dying due to disease under study at 5 years from the first dose of study intervention.	Up to 5 years
Number of Participants with Sustained Complete Clinical Response for 24 Months (cCR24) as assessed by ICR	cCR24 is achieved when a participant maintains cCR as assessed by ICR for 24 months following their first disease assessment after last dose of study intervention. Timeframe calculation includes 6 months (9 cycles of dostarlimab, with each cycle lasting 21 days) plus an additional 24 months of assessment time, amounting to a total of 30 months.	30 months
Number of Participants with Sustained Complete Clinical Response for 36 Months (cCR36) as assessed by ICR	cCR36 is achieved when a participant maintains cCR as assessed by ICR for 36 months following first disease assessment after last dose of study intervention. Timeframe calculation includes 6 months (9 cycles of dostarlimab, with each cycle lasting 21 days) plus an additional 36 months of assessment time, amounting to a total of 42 months.	42 months
Number of Participants with Event Free Survival at 3 years (EFS3) as assessed by Investigator	EFS3 is defined as participants who remained alive and free of disease progression precluding surgery, local recurrence, and distant recurrence at 3 years from the first dose of study intervention as assessed by Investigator.	3 years
Event Free Survival (EFS) as assessed by Investigator	EFS is defined as time from the date of first dose of study intervention to any of the following events including progression of disease that precludes surgery, local recurrence, distant recurrence (all as assessed by the investigator), or death due to any cause.	Up to approximately 77 months
Number of Participants with cCR12 as assessed by Investigator	cCR12 is achieved when a participant maintains cCR as assessed by Investigator for 12 months from the first disease assessment after last dose of study intervention. Timeframe calculation includes 6 months (9 cycles of dostarlimab, with each cycle lasting 21 days) plus an additional 12 months of assessment time, amounting to a total of 18 months.	18 Months
Number of Participants with cCR24 as assessed by Investigator	cCR24 is achieved when a participant maintains cCR as assessed by Investigator for 24 months from the first disease assessment after last dose of study intervention. Timeframe calculation includes includes 6 months (9 cycles of dostarlimab, with each cycle lasting 21 days) plus an additional 24 months of assessment time, amounting to a total of 30 months.	30 Months
Number of Participants with cCR36 as assessed by Investigator	cCR36 is achieved when a participant maintains cCR as assessed by Investigator for 36 months from the first disease assessment after last dose of study intervention. Timeframe calculation includes 6 months (9 cycles of dostarlimab, with each cycle lasting 21 days) plus an additional 36 months of assessment time, amounting to a total of 42 months.	42 Months
Objective Response Rate (ORR) assessed by ICR	ORR is defined as number of participants achieving a partial response (PR), near complete response (nCR) or cCR at post-intervention disease assessment (PIDA) or at least 4 weeks but no longer than 8 weeks after PIDA for participants with nCR or incomplete clinical response (iCR) (PIDA 2) as assessed by ICR.	Up to 37 Weeks
Objective Response Rate (ORR) as assessed by Investigator	ORR by Investigator is defined as number of participants achieving a PR, nCR, or cCR at PIDA.	Up to 37 Weeks
Organ Preservation Rate	Organ Preservation Rate is defined as number of participants who did not undergo any rectal cancer surgery either as primary management or for local recurrence, or who did not have a permanent colostomy created, at any time up to 3 years.	Up to 3 years
Disease-Specific Survival (DSS)	DSS is defined as time from the date of first dose of study intervention to death due to disease under study.	Up to approximately 77 months
Overall Survival (OS)	OS is defined as time from first dose of study intervention to death from any cause.	Up to approximately 77 months
Overall Survival at 5 years (OS5)	OS5 is defined as number of participants being alive at 5 years from first dose of study intervention.	Up to 5 years
Number of Participants with Adverse Events (AEs), Serious Adverse Events (SAEs), Immune related Adverse Events (irAEs) and AEs leading to death or discontinuation of study intervention.		Up to approximately 77 months
Serum concentration of Dostarlimab		Up to approximately 77 months
Concentration at the end of infusion (C-EOI) of Dostarlimab		Up to approximately 77 months
Trough Concentration (C-trough) of Dostarlimab		Up to approximately 77 months
Number of Participants with Anti-Drug Antibodies (ADA) against Dostarlimab		Up to approximately 77 months

Collaborators and Investigators

• Sponsor: GlaxoSmithKline

Study record dates

Study Major Dates

• Study Start (Actual): October 17, 2024
• Primary Completion (Estimated): October 24, 2027
• Study Completion (Estimated): April 15, 2031

Study Registration Dates

• First Submitted: October 10, 2024
• First Submitted That Met QC Criteria: October 10, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Actual): November 17, 2025
• Last Update Submitted That Met QC Criteria: November 14, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Rectal cancer; TSR-042; Dostarlimab; GSK4057190A; dMMR; MSI-H
• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Intestinal Diseases; Gastrointestinal Neoplasms; Digestive System Neoplasms; Digestive System Diseases; Gastrointestinal Diseases; Colorectal Neoplasms; Intestinal Neoplasms; Rectal Diseases; Rectal Neoplasms; Antineoplastic Agents; dostarlimab
• Other Study ID Numbers: 221972

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Qualified researchers may request access to anonymized individual patient-level data (IPD) and related study documents of the eligible studies via the Data Sharing Portal. Details on GSK's data sharing criteria can be found at: https://www.gsk.com/en-gb/innovation/trials/data-transparency/
• 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: No
• Studies a U.S. FDA-regulated device product: No