A Randomized, Controlled, Double-Blind, Multicenter Phase III Clinical Trial to Evaluate the Efficacy and Safety of Enlonstobart, With or Without SYS6010 as Adjuvant Therapy, in Participants With Pathologically Residual Esophageal Squamous Cell Carcinoma Following Complete Surgical Resection

November 2, 2026 updated by: CSPC Megalith Biopharmaceutical Co.,Ltd.

This is a randomized, controlled, double-blind, multicenter phase iii clinical trial to evaluate the efficacy and safety of enlonstobart, with or without SYS6010 as adjuvant therapy, in participants with pathologically residual esophageal squamous cell carcinoma following complete surgical resection.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This study is a randomized, double-blind, three-arm, placebo-controlled, multicenter Phase III trial designed to evaluate the efficacy and safety of SG001, with or without SYS6010, compared to placebo as adjuvant therapy following radical surgery with R0 resection but with pathological residual disease (ypT1-4aN0M0 or ypT0-4aN+M0) in patients with resectable Stage II -III esophageal squamous cell carcinoma who achieved R0 resection following curative surgery after neoadjuvant therap.

The study plans to enroll 585 participants who have previously undergone curative surgery for esophageal cancer, with R0 resection at surgery, pathologically confirmed failure to achieve pCR, and who have signed an informed consent form. Participants will be randomly assigned in a 2:2:1 ratio to the following groups in a double-blind manner: SG001 + SYS6010 vs. SG001 + placebo-mimicking SYS6010 vs. SG001 placebo-mimicking + placebo-mimicking SYS6010.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
585

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Clinical Trials Information Group officer
  • Phone Number: 031169085587
  • Email: ctr-contact@cspc.cn

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Be able to understand and voluntarily sign the written ICF;

  2. Age over 18 years, male or female;

  3. With histologically/cytologically confirmed esophageal squamous cell carcinoma that is clinically staged as stage II-III , neoadjuvant therapy must be completed prior to randomization, followed by curative surgery for esophageal squamous cell carcinoma, and all of the following criteria must be met:

    Neoadjuvant therapy includes: at least 2 cycles of platinum-based chemotherapy (± immune checkpoint inhibitors) or chemoradiotherapy, with no clinically or radiologically confirmed disease progression during the neoadjuvant therapy phase.

    Participants must have achieved R0 complete resection, with the surgery resulting in a tumor-free state and negative surgical margins.

    Prior to randomization, the Center's Independent Pathology Review Committee (CPIRC) will evaluate the participant's postoperative pathology report (pathology report must be provided). Participants who do not achieve pathological complete response (non-pCR) and have pathological residual disease (ypT1-4aN0M0 or ypT0-4aN+M0) will have their pathology results assessed and confirmed by the Center's Independent Pathology Review Committee in cases of uncertain pathology (e.g., ypNx).

    Postoperative adjuvant therapy must begin 4-16 weeks after curative surgery.;

  4. Eastern Cooperative Oncology Group (ECOG) performance status score: 0-1;

  5. Life expectancy ≥ 3 months;

Exclusion Criteria:

  1. Pathologically diagnosed esophageal carcinoma, including adenocarcinoma, adenosquamous carcinoma, or other histological subtypes;
  2. Previous treatment with irinotecan-based agents or topoisomerase I inhibitor-based toxin-conjugated antibody (ADC) drugs; For patients who have received treatment with immune checkpoint inhibitors (e.g., anti-PD-1/PD-L1 monoclonal antibodies) during the neoadjuvant phase: a history of Grade ≥3 immune-related adverse events (irAEs), or a history of irAEs leading to permanent discontinuation of immunotherapy, or a history of immune-related interstitial pneumonia, myocarditis, encephalitis, or severe neurological toxicity of any grade;
  3. Patients who have received other anticancer therapies following curative surgery for esophageal squamous cell carcinoma, including chemotherapy, targeted therapy, radiation therapy, biologic therapy, immunotherapy, or treatment with traditional Chinese medicine products approved for such indications; Patients with a known allergy to any component of the SYS6010 product or to humanized monoclonal antibody products;
  4. BMI < 16.0 kg/m² or body weight < 40 kg;

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: SG001 + SYS6010
Drug: SYS6010

SYS6010 is an antibody conjugate drug (ADC), composed of one anti-EGFR monoclonal antibody coupled to one JS1 via an enzyme specific linker.

Drug: SG001

SG001 is a recombinant, fully human, anti-PD-1 monoclonal antibody.
Experimental: SG001 + placebo-mimicking SYS6010
Drug: SG001

SG001 is a recombinant, fully human, anti-PD-1 monoclonal antibody.

Drug: SYS6010 placebo-mimicking

SYS6010 placebo-mimicking is a placebo mimicking of SYS6010
Placebo Comparator: SG001 placebo-mimicking + placebo-mimicking SYS6010
Drug: SYS6010 placebo-mimicking

SYS6010 placebo-mimicking is a placebo mimicking of SYS6010

Drug: SG001 placebo-mimicking

SG001 placebo-mimicking is a placebo mimicking of SG001

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
DFS
Time Frame: From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 60 months

Disease Free Surviva Arm1 vs Arm3 Arm2 vs Arm3
From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 60 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
OS ：Description: Overall survival
Time Frame: From date of randomization until the date of death from any cause, assessed up to 60 months.

Overall survival
From date of randomization until the date of death from any cause, assessed up to 60 months.
DMFS
Time Frame: From date of randomization until the date of first documented distant recurrence/distant metastasis or date of death from any cause, whichever came first, assessed up to 60 months.

Distant Metastasis-Free Survival
From date of randomization until the date of first documented distant recurrence/distant metastasis or date of death from any cause, whichever came first, assessed up to 60 months.
Serum concentrations of toxin-bound antibodies for SYS6010
Time Frame: From first dose of treatment to 30 days after the last dose of treatment.

Serum concentrations of toxin-bound antibodies following single and multiple doses of SYS6010
From first dose of treatment to 30 days after the last dose of treatment.
Plasma concentration of SG001 following single and multiple doses of SG001
Time Frame: From first dose of treatment to 30 days after the last dose of treatment.

Plasma concentration of SG001 following single and multiple doses of SG001
From first dose of treatment to 30 days after the last dose of treatment.
Quality of life indicators assessed using the EORTC QLQ-C30;
Time Frame: Evaluated during the screening period (Day -28 to Day 1)，during the treatment period (at each tumor assessment), and at the End of Treatment visit.
Evaluated during the screening period (Day -28 to Day 1)，during the treatment period (at each tumor assessment), and at the End of Treatment visit.
mmunogenicity: incidence and titers of ADA for SYS6010 and SG001, incidence of neutralizing antibodies (if applicable).
Time Frame: From first dose of treatment to 30 days after the last dose of treatment.
From first dose of treatment to 30 days after the last dose of treatment.
AE
Time Frame: From first dose of treatment to 90 days after the last dose of treatment.

Incidence and severity of adverse events
From first dose of treatment to 90 days after the last dose of treatment.
Serum concentrations of total antibodies for SYS6010;
Time Frame: From first dose of treatment to 30 days after the last dose of treatment.

Serum concentrations of total antibodies following single and multiple doses of SYS6010.
From first dose of treatment to 30 days after the last dose of treatment.
Plasma concentration of SG001 following single and multiple doses of SG001;
Time Frame: From first dose of treatment to 30 days after the last dose of treatment.

Serum concentrations of JS-1 following single and multiple doses of SYS6010.
From first dose of treatment to 30 days after the last dose of treatment.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
CSPC Megalith Biopharmaceutical Co.,Ltd.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 30, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 30, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 30, 2030

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 26, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 2, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 9, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 9, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SYS6010-027

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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