Gastric CancerPhase 2Conerstone3NCT05771584
Therapeutic Cancer Vaccine (AST-301, pNGVL3-hICD) in Gastric Cancer
A Phase 2 study testing AST-301 and rhuGM-CSF in people with Gastric Cancer, run by Aston Sci. Inc. at 6 sites in Taiwan.
Trial summary
The purpose of this early proof-of-concept study to evaluate the safety and immunologic efficacy of AST-301 in gastric cancer patients with HER2 expression (including both HER2 low expression and overexpression) who have completed the standard adjuvant treatment (including those who discontinued the standard adjuvant… Read more about this study
- Who is it for?
- Ages 18 to 85 years
- Conditions the study is for
- Gastric Cancer
- What is being tested?
- AST-301 and rhuGM-CSF
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 6 sitesTaiwan
- Study dates
- 4 Jul 2023to 31 May 2027
- 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 85 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Underwent a curative surgery with standard lymph node dissection (confirmed with no residual tumor, R0 resection) and have completed standard adjuvant treatment
- Has stages II or III according to the 8th edition of the American Joint Committee on Cancer (AJCC)
- HER2 low expression and HER2 overexpression diagnosed according to the 2016 College of American Pathologists (CAP)/American Society for Clinical Pathology (ASCP)/American Society of Clinical Oncology (ASCO) guidelines
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1
- Demonstrates adequate organ function.
Who cannot join
- Has a history of hypersensitivity or other contraindications to rhuGM-CSF
- Has a history of other malignancies ≤5 years prior to first administration of Investigational Product (IP) except for adequately treated non-melanoma skin cancer or epithelial carcinoma without evidence of disease.
- Has received systemic immunosuppressants or were treated with systemic immunosuppressants ≤4 weeks prior to the first administration of Investigational Product (IP).
- Has a history of autoimmune disease or inflammatory disease
- Has active infection including tuberculosis, hepatitis B, hepatitis C or human immunodeficiency virus (HIV) infection
- Is pregnant or breastfeeding or expecting to conceive children
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
Taiwan6 sites
Kaohsiung Medical University Chung-Ho Memorial Hospital
Kaohsiung City, 80756
China Medical University Hospital
Taichung, 404
Taichung Veterans General Hospital
Taichung, 40705
Chi Mei Medical Center
Tainan, 710
Taipei Veterans General Hospital
Taipei, 112
Chang Gung Memorial Hospital Linkou
Taoyuan, 333
About this study
Official title: A Phase 2 Study to Evaluate the Safety and Immunological Efficacy of Therapeutic Cancer Vaccine (AST-301, pNGVL3-hICD) in Patients With HER2 Expressing Gastric Cancer (CORNERSTONE-003)
The purpose of this early proof-of-concept study to evaluate the safety and immunologic efficacy of AST-301 in gastric cancer patients with HER2 expression (including both HER2 low expression and overexpression) who have completed the standard adjuvant treatment (including those who discontinued the standard adjuvant treatment due to intolerance).
Participants will be randomized 1:1 to either Arm 1 (Q3W, 3 cycles), or Arm 2 (Q3W, 6 cycles) of the study.
Safety Monitoring Committee (SMC) will oversee safety of study at 25% (6 participants), 50% (12 participants), and 75% (18 participants) of participants receive at least 1 dose of AST-301 and survival follow up will be performed to determine disease-free survival (DFS).
Read the detailed description
Participants will provide informed consent and will undergo Pre-Screening/Screening procedures before taking part in the study. Participants will be in Arm 1 and Arm 2 will be conducted in parallel. AST-301 will be administrated every 3 weeks for a total of 3 immunizations in Arm 1 and a total of 6 immunizations in Arm 2.
- Arm 1: 3 immunizations of AST-301 admixed with immunoadjuvant recombinant human granulocyte-macrophage colony stimulating factor (rhuGM-CSF) administered at 3-week intervals. (Total 300 μg of AST-301)
- Arm 2: 6 immunizations of AST-301 admixed with immunoadjuvant recombinant human granulocyte-macrophage colony stimulating factor (rhuGM-CSF) administered at 3-week intervals. (Total 600 μg of AST-301) Randomization will be stratified according to HER2 expression (HER2 low expression or HER2 overexpression).
For both Arm 1 and Arm 2 of the study there will be a Pre-screen period, followed by study periods: a Screening Period (Day -28 to Day -1), a Treatment Period (3 cycles/Arm 1 and 6 cycles/Arm 2), an end of treatment (EOT) visit and follow-up visits.
- Conditions
- Gastric Cancer
- Being tested
- AST-301, rhuGM-CSF
- Medical subject headings
- Stomach Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AST-301Drug
Also called pNGVL3-hICD
100 μg
rhuGM-CSFDrug
Also called Leukine, Sargramostim
100 μg
| Study group | Role | What they receive |
|---|---|---|
| Total 300 μg of AST-301 | Experimental | AST-301/rhuGM-CSF (3-week interval, 3 cycles in total) Receives: Drug: AST-301; Drug: rhuGM-CSF |
| Total 600 μg of AST-301 | Experimental | AST-301/rhuGM-CSF (3-week interval, 6 cycles in total) Receives: Drug: AST-301; Drug: rhuGM-CSF |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with treatment-related adverse events as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events [NCI CTCAE] version 5.0.
To assess the safety of AST-301 administered in gastric cancer patients.
Measured: up to 20 weeks
Immunologic efficacy of AST-301 immunization
AST-301 specific interferon (IFN)-gamma enzyme-linked immune absorbent spot (ELISpot) assay
Measured: 52 weeks
Secondary outcomes (4)
1year Disease-Free Survival rate (DFS rate)
disease free survival rate at 1 year
Measured: 12 months
Disease-Free Survival rate (DFS rate) at end of study (EOS)
disease free survival at end of study
Measured: Overall study period approximately 31 months
Compare immunogenicity of AST-301 between Arm 1 and Arm 2
AST-301-specific IFN γ response by ELISpot assay
Measured: 52 weeks
Change in central memory T-cell populations between Arm 1 and Arm 2
Central memory T-cell (cluster of differentiation 4 (CD4) + and cluster of differentiation 8 (CD8) +) by a flow cytometry analysis
Measured: 52 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Mar 2023
- Study start4 Jul 2023
- Primary completion9 Feb 2027 (estimated)
- Study completion31 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gastric CancerStudies 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
- Model description
- Phase 2, open label, randomized, early proof-of-concept study
- Masking
- None (open label)
- Enrolment
- 24 participants (actual)
Sponsor and investigators
- Lead sponsor
- Aston Sci. Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Hun Jung, MD, Study director, jhun@astonsci.com
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05771584
- Sponsor's protocol ID
- PN-301-22
- Acronym
- Conerstone3
- Status last verified
- Jul 2026
- First submitted
- 6 Sep 2022
- Last updated
- 22 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 22 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2 Study to Evaluate the Safety and Immunological Efficacy of Therapeutic Cancer Vaccine (AST-301, pNGVL3-hICD) in Patients With HER2 Expressing Gastric Cancer (CORNERSTONE-003)
- ClinicalTrials.gov ID
- NCT05771584
- Acronym / sponsor ID
- Conerstone3 / PN-301-22
- Conditions
- Gastric Cancer
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 24 participants (actual)
- Lead sponsor
- Aston Sci. Inc.Industry (pharma, biotech, devices)
- Study start
- 4 Jul 2023 (actual)
- Primary completion
- 9 Feb 2027 (estimated)
- Study completion
- 31 May 2027 (estimated)
- First posted
- 16 Mar 2023 (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.
The purpose of this early proof-of-concept study to evaluate the safety and immunologic efficacy of AST-301 in gastric cancer patients with HER2 expression (including both HER2 low expression and overexpression) who have completed the standard adjuvant treatment (including those who discontinued the standard adjuvant treatment due to intolerance).
Participants will be randomized 1:1 to either Arm 1 (Q3W, 3 cycles), or Arm 2 (Q3W, 6 cycles) of the study.
Safety Monitoring Committee (SMC) will oversee safety of study at 25% (6 participants), 50% (12 participants), and 75% (18 participants) of participants receive at least 1 dose of AST-301 and survival follow up will be performed to determine disease-free survival (DFS).
Detailed description
Participants will provide informed consent and will undergo Pre-Screening/Screening procedures before taking part in the study. Participants will be in Arm 1 and Arm 2 will be conducted in parallel. AST-301 will be administrated every 3 weeks for a total of 3 immunizations in Arm 1 and a total of 6 immunizations in Arm 2.
- Arm 1: 3 immunizations of AST-301 admixed with immunoadjuvant recombinant human granulocyte-macrophage colony stimulating factor (rhuGM-CSF) administered at 3-week intervals. (Total 300 μg of AST-301)
- Arm 2: 6 immunizations of AST-301 admixed with immunoadjuvant recombinant human granulocyte-macrophage colony stimulating factor (rhuGM-CSF) administered at 3-week intervals. (Total 600 μg of AST-301) Randomization will be stratified according to HER2 expression (HER2 low expression or HER2 overexpression).
For both Arm 1 and Arm 2 of the study there will be a Pre-screen period, followed by study periods: a Screening Period (Day -28 to Day -1), a Treatment Period (3 cycles/Arm 1 and 6 cycles/Arm 2), an end of treatment (EOT) visit and follow-up visits.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Phase 2, open label, randomized, early proof-of-concept study
| Arm | Type | Receives |
|---|---|---|
| Total 300 μg of AST-301 | Experimental | Drug: AST-301, Drug: rhuGM-CSFAST-301/rhuGM-CSF (3-week interval, 3 cycles in total) |
| Total 600 μg of AST-301 | Experimental | Drug: AST-301, Drug: rhuGM-CSFAST-301/rhuGM-CSF (3-week interval, 6 cycles in total) |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Underwent a curative surgery with standard lymph node dissection (confirmed with no residual tumor, R0 resection) and have completed standard adjuvant treatment
- Has stages II or III according to the 8th edition of the American Joint Committee on Cancer (AJCC)
- HER2 low expression and HER2 overexpression diagnosed according to the 2016 College of American Pathologists (CAP)/American Society for Clinical Pathology (ASCP)/American Society of Clinical Oncology (ASCO) guidelines
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1
- Demonstrates adequate organ function.
Key exclusion criteria (6 listed)
- Has a history of hypersensitivity or other contraindications to rhuGM-CSF
- Has a history of other malignancies ≤5 years prior to first administration of Investigational Product (IP) except for adequately treated non-melanoma skin cancer or epithelial carcinoma without evidence of disease.
- Has received systemic immunosuppressants or were treated with systemic immunosuppressants ≤4 weeks prior to the first administration of Investigational Product (IP).
- Has a history of autoimmune disease or inflammatory disease
- Has active infection including tuberculosis, hepatitis B, hepatitis C or human immunodeficiency virus (HIV) infection
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 |
|---|---|---|
| AST-301Also: pNGVL3-hICD100 μg | Drug | Total 300 μg of AST-301, Total 600 μg of AST-301 |
| rhuGM-CSFAlso: Leukine, Sargramostim100 μg | Drug | Total 300 μg of AST-301, Total 600 μg of AST-301 |
Primary outcome
Number of participants with treatment-related adverse events as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events [NCI CTCAE] version 5.0.
Time frame: up to 20 weeks
To assess the safety of AST-301 administered in gastric cancer patients.
Immunologic efficacy of AST-301 immunization
Time frame: 52 weeks
AST-301 specific interferon (IFN)-gamma enzyme-linked immune absorbent spot (ELISpot) assay
4 secondary outcomes
1year Disease-Free Survival rate (DFS rate)
Time frame: 12 months
Disease-Free Survival rate (DFS rate) at end of study (EOS)
Time frame: Overall study period approximately 31 months
Compare immunogenicity of AST-301 between Arm 1 and Arm 2
Time frame: 52 weeks
Change in central memory T-cell populations between Arm 1 and Arm 2
Time frame: 52 weeks
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 22 Jul 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. This study is not recruiting at the moment.
Hun Jung, MD study director
jhun@astonsci.com
6 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing AST-301 and rhuGM-CSF in people with Gastric Cancer, run by Aston Sci. Inc. at 6 sites in Taiwan.
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 5 inclusion and 6 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: under way, not looking for participants, as of the sponsor's last update on 22 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 6 sites in Taiwan. 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. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with treatment-related adverse events as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events [NCI CTCAE] version 5.0. (time frame: up to 20 weeks). The study lists 2 primary outcomes in all. 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 22 Jul 2026.