Gastric AdenocarcinomaPhase 2PLATANUSNCT07699939
Perioperative HLX10 (Serplulimab) With S-1+Oxaliplatin (SOX) in Locally Advanced and PD-L1-Positive Gastric or Esophagogastric Junction Adenocarcinoma
A Phase 2 study testing serplulimab in people with Gastric Adenocarcinoma and Gastroesophageal Junction (GEJ) Adenocarcinoma, run by National Cancer Center, Japan at 18 sites in 2 countries.
Trial summary
To evaluate the clinical efficacy of perioperative treatment with S-1 + oxaliplatin (SOX)+ HLX10 compared with SOX as the control in patients with cT3-4N1-3M0 PD-L1-positive (CPS ≥ 5) locally advanced gastric adenocarcinoma or gastroesophageal junction adenocarcinoma, in a placebo-controlled, double-blind, randomized… Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Gastric Adenocarcinoma, Gastroesophageal Junction (GEJ) Adenocarcinoma
- What is being tested?
- serplulimab
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 136 participants
- Where
- 18 sitesin 2 countries
- Study dates
- 15 Jul 2026to 30 Jun 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 1) Histologically confirmed gastric adenocarcinoma or gastroesophageal junction adenocarcinoma at the study site. (For gastroesophageal junction adenocarcinoma, only patients classified as Siewert type II or type III who do not require surgery involving simultaneous thoracoabdominal incision are eligible.)
- 2) Tumor tissue determined to be PD-L1 positive (CPS >= 5) based on pre-screening evaluation by the central laboratory.
- 3) Diagnosis of cT3-4N1-3M0 disease according to the AJCC/UICC-TNM 8th edition based on assessments performed within 28 days prior to randomization (the same day of the week 4 weeks before the randomization date is acceptable; the same applies hereafter), with no prior systemic treatment. Pre-randomization laparoscopy is not mandatory, but if performed, no non-curative factors (including liver metastasis, peritoneal metastasis, other distant metastases, or positive peritoneal cytology (CY1)) should be observed.
- 4) Judged by the investigator as capable of undergoing R0 resection.
- 5) Age between 18 years and 80 years on the day of enrollment.
- 6) ECOG performance status (PS) of 0 or 1.
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- 7) The most recent laboratory values obtained within 14 days prior to randomization meet all of the following (however, transfusion, recombinant human thrombopoietin, and administration of granulocyte colony-stimulating factor (G-CSF) within 14 days prior to blood collection are not permitted): (1) Neutrophil count >= 1500/mm^3 (2) Hemoglobin >= 9.0 g/dL (3) Platelet count >= 10 x 10^4/mm^3 (4) Total bilirubin <= 1.5 mg/dL (5) AST <= 100 U/L (6) ALT <= 100 U/L (7) Serum albumin >= 3.0 g/dL (8) Serum creatinine <= 1.5 mg/dL (9) APTT <= 60 s (10) PT-INR <= 1.5
- 8) Females of childbearing potential should test negative for pregnancy test (serum or urine) within 7 days prior to randomization (the same day of the week is acceptable).
- 9) Male patients and females of childbearing potential agree to use contraception from the time of provision of informed consent through a specified period after the last administration of study treatment (until at least 120 days after the last dose of HLX10 and at least 180 days after the last dose of study drug other than HLX10 (S-1 or oxaliplatin)).
- 10) Written informed consent for study participation has been obtained from the patient.
Who cannot join
- 1) Presence of another active malignancy within 5 years prior to enrollment or concurrently. Patients with cured, localized tumors such as basal cell carcinoma of the skin, squamous cell carcinoma of the skin, superficial bladder cancer, non-invasive prostate cancer, non-invasive cervical cancer, and non-invasive breast cancer are permitted.
- 2) Patients scheduled to undergo organ transplantation or bone marrow transplantation.
- 3) Myocardial infarction and/or uncontrolled arrhythmia (including QTc interval >= 450 ms in males or >= 470 ms in females) occurring within 6 months prior to randomization (QTc interval calculated using Fridericia's formula).
- 4) Cardiac dysfunction classified as NYHA Class III-IV, or left ventricular ejection fraction (LVEF) < 50 percent on echocardiography.
- 5) Positive for any of the following: HIV antibody, HBs antigen, or HCV-RNA (HCV-RNA is measured only if HCV antibody is positive).
- 6) HBs antigen negative, HBs antibody and/or HBc antibody positive, and quantitative HBV-DNA detectable (patients are not excluded if HBV-DNA is below the limit of detection).
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- 7) Active tuberculosis.
- 8) Interstitial pneumonia, pneumoconiosis, radiation pneumonitis, drug-related pneumonitis, and/or severe pulmonary dysfunction that may interfere with evaluation and management of suspected drug-related pulmonary toxicity.
- 9) Known active or suspected autoimmune disease, excluding patients whose disease is stable at randomization and who do not require systemic immunosuppressive therapy.
- 10) Patients who received live vaccination within 28 days prior to randomization, except for inactivated virus vaccines used for seasonal influenza prophylaxis.
- 11) Patients who require systemic corticosteroids (a therapeutic dose of > 10 mg/day prednisone or equivalent) or other immunosuppressive medications within 14 days prior to randomization or during the study period. However, in the absence of active autoimmune disease, patients are permitted to use steroids at a dose of <= 10 mg/day prednisone or equivalent, or inhaled steroids, or adrenal hormone replacement therapy.
- 12) Patients who have an active infection requiring systemic anti-infective treatment within 14 days prior to randomization, except for prophylactic antibiotic treatment (e.g., for prevention of urinary tract infection or chronic obstructive pulmonary disease).
- 13) Prior treatment with other antibody or drug therapies for immune checkpoint blockade, such as PD-1, PD-L1, or CTLA-4 therapy.
- 14) Patients currently receiving other clinical study treatment, or for whom the planned start of treatment in this study is < 14 days from completion of the prior clinical study treatment.
- 15) History of severe hypersensitivity to the monoclonal antibody or any component of the study drug.
- 16) History of psychotropic drug abuse or drug dependence.
- 17) Patients with a disease that may increase the risk associated with study participation and use of the study drug, or with other severe acute or chronic diseases that, in the investigator's judgment, render the patient unsuitable for participation in the study.
Trial locations and contacts
18 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
18 sites in 2 countries
Japan14 sites, 14 recruiting
- Recruiting
Chiba Cancer Center
Chiba, Chiba, 260-8717
Keiko Minashi, M.D., +81-43-264-5431
- Recruiting
National Cancer Center Hospital
Chuo Ku, Tokyo, 104-0045
Hidekazu Hirano, M.D., +81-3-3542-2511, NCCH2414_office@ml.res.ncc.go.jp
- Recruiting
Kyushu Cancer Center
Fukuoka, Fukuoka, 811-1395
Yasue Kimura, M.D., +81-92-541-3231
- Not yet recruiting
Gifu University Hospital
Gifu, Gifu
Akitaka Makiyama, M.D., +81-58-230-6000
- Not yet recruiting
Saitama Medical University International Medical Center
Hidaka, Saitama
Shinichi Sakuramoto, M.D., +81-42-984-4111
- Not yet recruiting
Hiroshima University Hospital
Hiroshima, Hiroshima
Kazuteru Tanabe, +81-82-257-5555
- Not yet recruiting
Saitama Prefectural Cancer Center
Ina, Kitaadachi-gun
Hiroki Hara, M.D., +81-48-722-1111
- Recruiting
St. Marianna University Hospital
Kawasaki, Kanagawa
Yohei Kubota, M.D., +81-44-977-8111
- Not yet recruiting
Cancer Institute Hospital of JFCR
Koto-Ku, Tokyo
Akira Oki, M.D., +81-3-3520-0111
- Not yet recruiting
Gunma University Hospital
Maebashi, Gunma
Daisuke Takahari, M.D., +81-27-220-7111
- Not yet recruiting
Shizuoka Cancer Center
Nagaizumi-chō, Sunto-gun
Takeshi Kawakami, +81-55-989-5222
- Not yet recruiting
Osaka International Cancer Institute
Osaka, Osaka
Kazuyoshi Yamamoto, M.D.
- Recruiting
Osaka Medical and Pharmaceutical University Hospital
Takatsuki, Osaka
Toshifumi Yamaguchi, M.D., +81-72-683-1221
- Not yet recruiting
Kanagawa Prefectural Hospital Organization Kanagawa Cancer Center
Yokohama, Kanagawa
Mitsuhiro Furuta, M.D., +81-45-520-2222
South Korea4 sites, 4 recruiting
- Not yet recruiting
National Cancer Center Korea
Goyang-si, Gyeonggi-do
- Not yet recruiting
Seoul St. Mary's Hospital
Seocho, Seoul
- Not yet recruiting
Asan Medical Center
Songpa-dong
- Not yet recruiting
Ajou University Hospital
Suwon, Gyeonggi-do
About this study
Official title: Perioperative HLX10 (Serplulimab) With S-1+Oxaliplatin (SOX) in Locally Advanced and PD-L1-Positive Gastric or Esophagogastric Junction Adenocarcinoma: A Randomized Phase 2 Investigator-Initiated Trial
To evaluate the clinical efficacy of perioperative treatment with S-1 + oxaliplatin (SOX)+ HLX10 compared with SOX as the control in patients with cT3-4N1-3M0 PD-L1-positive (CPS ≥ 5) locally advanced gastric adenocarcinoma or gastroesophageal junction adenocarcinoma, in a placebo-controlled, double-blind, randomized phase II investigator-initiated clinical study.
- Being tested
- serplulimab, Placebo
- Keywords
- SOX regimen, PD-1 inhibitor, Perioperative chemotherapy, serplulimab, Immuno-chemotherapy
- Medical subject headings
- Adenocarcinoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
serplulimabDrug
Also called S-1 (tegafur/gimeracil/oteracil), oxaliplatin
Patients receive perioperative treatment with S-1 plus oxaliplatin (SOX) in combination with Serplulimab.
PlaceboDrug
Also called S-1 (tegafur/gimeracil/oteracil), oxaliplatin
Patients receive perioperative treatment with S-1 plus oxaliplatin (SOX) in combination with placebo.
| Study group | Role | What they receive |
|---|---|---|
| SOX+HLX10 | Experimental | Neoadjuvant treatment period: SOX+HLX10 Surgery Postoperative adjuvant treatment period: HLX10 Receives: Drug: serplulimab |
| SOX+Placebo | Placebo comparator | Neoadjuvant treatment period: SOX + Placebo Surgery Postoperative adjuvant treatment period: SOX Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pathological complete response (pCR) rate by central pathology review
In the ITT population, this is defined as the proportion of subjects with complete disappearance of the tumor based on central pathology review.
Measured: Approximately 4-5 months after randomization (after surgery)
Secondary outcomes (2)
Investigator-assessed event-free survival
In the ITT population, this is defined as the time from the date of randomization to the first occurrence of any of the following events.
Measured: From randomization up to 28 months
Overall survival
In the ITT population, OS is defined as the time from the date of randomization to the date of death from any cause.
Measured: From randomization up to 28 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Jul 2026
- Study start15 Jul 2026
- Primary completion30 Nov 2028 (estimated)
- Study completion30 Jun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gastric AdenocarcinomaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 136 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Cancer Center, Japan
- Sponsor type
- Other government
- Responsible party
- Sponsor
- Investigators
- Ken Kato, M.D., Ph.D., Principal investigator, National Cancer Center, Japan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07699939
- Sponsor's protocol ID
- NCCH2414/ATLAS2502
- Acronym
- PLATANUS
- Status last verified
- Aug 2026
- First submitted
- 7 Jul 2026
- Last updated
- 5 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Perioperative HLX10 (Serplulimab) With S-1+Oxaliplatin (SOX) in Locally Advanced and PD-L1-Positive Gastric or Esophagogastric Junction Adenocarcinoma: A Randomized Phase 2 Investigator-Initiated Trial
- ClinicalTrials.gov ID
- NCT07699939
- Acronym / sponsor ID
- PLATANUS / NCCH2414/ATLAS2502
- Keywords
- SOX regimen, PD-1 inhibitor, Perioperative chemotherapy, serplulimab, Immuno-chemotherapy
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 136 participants (estimated)
- Lead sponsor
- National Cancer Center, JapanOther government
- Study start
- 15 Jul 2026 (actual)
- Primary completion
- 30 Nov 2028 (estimated)
- Study completion
- 30 Jun 2029 (estimated)
- First posted
- 13 Jul 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
To evaluate the clinical efficacy of perioperative treatment with S-1 + oxaliplatin (SOX)+ HLX10 compared with SOX as the control in patients with cT3-4N1-3M0 PD-L1-positive (CPS ≥ 5) locally advanced gastric adenocarcinoma or gastroesophageal junction adenocarcinoma, in a placebo-controlled, double-blind, randomized phase II investigator-initiated clinical study.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| SOX+HLX10 | Experimental | Drug: serplulimabNeoadjuvant treatment period: SOX+HLX10 Surgery Postoperative adjuvant treatment period: HLX10 |
| SOX+Placebo | Placebo comparator | Drug: PlaceboNeoadjuvant treatment period: SOX + Placebo Surgery Postoperative adjuvant treatment period: SOX |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (10 listed)
- 1) Histologically confirmed gastric adenocarcinoma or gastroesophageal junction adenocarcinoma at the study site. (For gastroesophageal junction adenocarcinoma, only patients classified as Siewert type II or type III who do not require surgery involving simultaneous thoracoabdominal incision are eligible.)
- 2) Tumor tissue determined to be PD-L1 positive (CPS >= 5) based on pre-screening evaluation by the central laboratory.
- 3) Diagnosis of cT3-4N1-3M0 disease according to the AJCC/UICC-TNM 8th edition based on assessments performed within 28 days prior to randomization (the same day of the week 4 weeks before the randomization date is acceptable; the same applies hereafter), with no prior systemic treatment. Pre-randomization laparoscopy is not mandatory, but if performed, no non-curative factors (including liver metastasis, peritoneal metastasis, other distant metastases, or positive peritoneal cytology (CY1)) should be observed.
- 4) Judged by the investigator as capable of undergoing R0 resection.
- 5) Age between 18 years and 80 years on the day of enrollment.
Key exclusion criteria (17 listed)
- 1) Presence of another active malignancy within 5 years prior to enrollment or concurrently. Patients with cured, localized tumors such as basal cell carcinoma of the skin, squamous cell carcinoma of the skin, superficial bladder cancer, non-invasive prostate cancer, non-invasive cervical cancer, and non-invasive breast cancer are permitted.
- 2) Patients scheduled to undergo organ transplantation or bone marrow transplantation.
- 3) Myocardial infarction and/or uncontrolled arrhythmia (including QTc interval >= 450 ms in males or >= 470 ms in females) occurring within 6 months prior to randomization (QTc interval calculated using Fridericia's formula).
- 4) Cardiac dysfunction classified as NYHA Class III-IV, or left ventricular ejection fraction (LVEF) < 50 percent on echocardiography.
- 5) Positive for any of the following: HIV antibody, HBs antigen, or HCV-RNA (HCV-RNA is measured only if HCV antibody is positive).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| serplulimabAlso: S-1 (tegafur/gimeracil/oteracil), oxaliplatinPatients receive perioperative treatment with S-1 plus oxaliplatin (SOX) in combination with Serplulimab. | Drug | SOX+HLX10 |
| PlaceboAlso: S-1 (tegafur/gimeracil/oteracil), oxaliplatinPatients receive perioperative treatment with S-1 plus oxaliplatin (SOX) in combination with placebo. | Drug | SOX+Placebo |
Primary outcome
Pathological complete response (pCR) rate by central pathology review
Time frame: Approximately 4-5 months after randomization (after surgery)
In the ITT population, this is defined as the proportion of subjects with complete disappearance of the tumor based on central pathology review.
2 secondary outcomes
Investigator-assessed event-free survival
Time frame: From randomization up to 28 months
Overall survival
Time frame: From randomization up to 28 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ken Kato, M.D., Ph.D. principal investigator
National Cancer Center, Japan
18 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing serplulimab in people with Gastric Adenocarcinoma and Gastroesophageal Junction (GEJ) Adenocarcinoma, run by National Cancer Center, Japan at 18 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 10 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 5 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 18 sites in Japan, South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ken Kato, M.D., Ph.D. (+81-3-3542-2511, NCCH2414_office@ml.res.ncc.go.jp), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pathological complete response (pCR) rate by central pathology review (time frame: Approximately 4-5 months after randomization (after surgery)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2026.