Solid TumorPhase 1NCT06809114
FIH Study to Evaluate Safety, Tolerability, PK, PD & Preliminary Efficacy of AT03-65 With Advanced Solid Tumors
A Phase 1 study testing AT03-65 in people with Solid Tumor, run by Axcynsis Therapeutics Pte Ltd at 4 sites in United States.
Trial summary
A Phase I, First-in-Human Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of AT03-65 in Adults with Advanced Solid Tumors Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Solid Tumor
- What is being tested?
- AT03-65
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 83 participants
- Where
- 4 sitesUnited States
- Study dates
- 14 Jan 2026to Aug 2028
- Phase
- Phase 1
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- At least 18 years old at the time of signing written informed consent form (ICF).
- Eastern cooperative oncology group (ECOG) Performance Status score of 0 or 1 at screening and on C1D1.
- Pathologically documented, definitively diagnosed, advanced/metastatic solid tumor that is resistant or refractory to standard treatment, for which no further standard treatment is available, or the subject refuses or cannot tolerate standard therapy. Subjects must have measurable lesion according to response evaluation criteria in solid tumors (RECIST) v1.1.
- 3a) Monotherapy dose escalation study (Phase 1a):
- Subjects (with documented CLDN6 expression after the lower three dose levels) will be enrolled, including but not limited to the following histological subtypes: serous or endometrioid ovarian cancer, primary peritoneal cancer or fallopian tube cancer, endometrial cancer, NSCLC, breast cancer, esophageal cancer, and gastric/GEJ cancer. There is no upper limit on the number of prior treatment regimens the subject may have received.
- 3b) Monotherapy cohort expansion study (Phase 1b)
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- Subjects must meet the minimum requirement of CLDN6-expressing by IHC (cutoff value to be determined based on Phase Ia data and/or clinical studies of other CLDN6-targeting drugs), to be confirmed prior to enrollment.
- Three cohorts will be involved:
- Cohort 1: 24-30 subjects with advanced/metastatic CLDN6-expressing ovarian cancer, platinum resistant, refractory, or non-tolerant. Patients must have had one (or more) prior platinum-based chemotherapeutic regimen for management of primary disease containing carboplatin, cisplatin, or another organoplatinum compound, which may have included intraperitoneal therapy, high-dose therapy, consolidation, or extended therapy administered after completion of initial chemotherapy; patients must be considered platinum resistant or refractory according to standard Gynecologic Oncology Group (GOG) criteria, i.e., have had a treatment-free interval following platinum of 6 months or less, have persistent disease at the completion of primary platinum-based therapy or have progressed during platinum-based therapy, or be determined to be nontolerant after a recognized desensitization regimen.
- Cohort 2: 24-30 subjects with advanced/metastatic CLDN6-expressing NSCLC. Subjects must have received at least one checkpoint inhibitor combination regimen (or platinum doublet where contraindicated). Patients with established driver mutations (epidermal growth factor receptor [EGFR], anaplastic lymphoma kinase [ALK], ROS proto-oncogene [ROS], mesenchymal epithelial transition factor [MET], rearranged during transfection [RET], B-Raf proto-oncogene, serine/threonine kinase [BRAF], and/or rat sarcoma [RAS]) must have progressed on standard of care for said mutation.
- Cohort 3: 12 subjects with other advanced/metastatic CLDN6-expressing solid tumors who have exhausted options for standard of care therapies. There is no upper limit on the number of prior treatment regimens the subject may have received.
- 4) Subjects have fresh tumor sample or available archival block for CLDN6 IHC (except for the lower three dose levels of Phase Ia). If archival block samples from multiple timepoints are available, the most recent one is preferred.
- 5) Subjects with good organ function
- 6) Has a left ventricular ejection fraction (LVEF) ≥50% as determined by either an echocardiogram (ECHO) or multi-gated acquisition scan (MUGA) within 28 days before the start of study treatment.
- 7) Life expectancy ≥3 months.
- 8) Male subjects with female partners of childbearing potential and female subjects of childbearing potential must agree to use a highly effective form of contraception or avoid intercourse throughout the study period and for at least 6 months after the final administration of IMP. Males must agree not to freeze or donate sperm throughout the study period and for at least 6 months after final administration of IMP. Investigators will advise male subjects on the conservation of sperm prior to study treatment. Females must agree not to donate or retrieve ova for own use throughout the study period and for at least 6 months after final administration of IMP.
Who cannot join
- Subjects previously received or is currently receiving any systemic anti-cancer therapy within 4 weeks or 5xT(1/2) if 5xT(1/2) of the drug/therapy used by the subject is confirmed to be < 4 weeks, 5xT(1/2) shall prevail] - prior to first dose of IMP
- Not yet recovered to Grade 1 or baseline for treatment-related toxicities related to previous treatment with the exception of alopecia. The recovery time after surgery was less than 28 days
- Subjects with clinically significant congenital or acquired cardiovascular diseases.
- Presence of other active invasive cancers other than the one treated in this study within 5 years prior to screening, except appropriately treated BCC of the skin or in situ carcinoma of uterine cervix, or other local tumors considered cured by local treatment
- Subjects with severe or uncontrolled systemic disease, including uncontrolled hypertension, uncontrolled diabetes mellitus, active bleeding diatheses, or active infection requiring intravenous injection (IV) of antibiotics, antivirals or antifungals
- Subjects with medical history of clinically significant lung disease or who are suspected to have these disease by imagining at screening
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- Live vaccine within 4 weeks prior to first dose of IMP
- Presence of active or untreated metastases to central nervous system or meninges or other evidence showing that metastatic lesions in central nervous system or meninges that have not yet been controlled at screening. Note: Subjects with central nervous system or meningeal metastases who are free of neurological symptoms not managed with steroids and stable by imagining 28 days after treatment prior to the first dose may be considered for enrollment
- Presence of leptomeningeal disease.
- Prior treatment with any ADC targeting CLDN6. Note: Prior treatment with immune engagers targeting CLDN6 is permitted.
- Subjects who have received prior allogeneic or autologous bone marrow transplants.
- Subjects who are pregnant (as confirmed by pregnancy tests performed within 7 days before enrollment) or planning to become pregnant.
- Subjects who have received moderate or strong cytochrome P450 (CYP) 2C8 or CYP3A inhibitors or inducers, or P-glycoprotein (P-gp) inhibitors within 14 days prior to the first dose or cannot be discontinued during the study.
- The investigator considers that the patient is not suitable for participating in this study (e.g.,IMP is not in the best interest of patient, patients with mental disorder, patients with poor compliance, etc.).
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States4 sites, 4 recruiting
- Recruiting
Medical University of South Carolina MUSC
Charleston, South Carolina, 29425
Recruitment Coordinator, 843-792-9321, hcc-clinical-trials@musc.edu
- Recruiting
SCRI HealthOne
Denver, Colorado, 80218
SCRI HealthOne Denver, 720-754-2610, cann.ddudenvergeneral@sarahcannon.com
Gerald Falchook
- Recruiting
YALE
New Haven, Connecticut, 06511
Ingrid Palma, ingrid.palma@yale.edu
Adriana Kahn
- Recruiting
Oregon Health & Science University (OHSU)
Portland, Oregon, 97239
Knight Cancer Institute Trial Center, 503-494-1080, trials@ohsu.edu
About this study
Official title: A Phase I, First-in-Human Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of AT03-65 in Adults With Advanced Solid Tumors
A Phase I, First-in-Human Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of AT03-65 in Adults with Advanced Solid Tumors
Read the detailed description
This is a first-in-human (FIH), Phase 1, open-label, dose escalation and dose expansion study to evaluate the safety, tolerability, pharmacokinetics and preliminary efficacy of AT03-65 in adults with advanced solid tumors. AT03-65 is administered via intravenous infusion using an accelerated escalation method for the lower 3 dose level groups and the 3 + 3 escalation method is used in the subsequent dose level groups.
The study design is to identify the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) during 21-day cycle. One or more doses or regimens lower than or at the MTD may be selected for further evaluations under Dose Expansion to further evaluate the IMP and identify the RP2D.
- Conditions
- Solid Tumor
- Being tested
- AT03-65
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AT03-65Drug
Also called AT03-65 Antibody Drug Conjugate
Treatment will continue until disease progression, unacceptable toxicity, subject withdrawal of consent or death.
| Study group | Role | What they receive |
|---|---|---|
| AT03-65 Dose Escalation and Dose Expansion | Experimental | Subjects will receive AT03-65 via intravenous (IV) infusion on Day 1 of a 21-Day treatment cycle. Receives: Drug: AT03-65 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximum tolerated dose (MTD) of AT03-65
The MTD is defined as the highest dose with an observed incidence of DLT in no more than one out of six patients treated at a particular dose level.
Measured: Up to 21 days
Dose-limiting toxicity (DLT)
DLT refers to AEs that occurred during DLT observation period in dose escalation study, excluding toxicities clearly due to the underlying disease or extraneous causes.
Measured: Up to 21 days
Secondary outcomes (10)
Determine levels of AT03-65 and its constituents over time in plasma
Assess PK concentration of AT03-65 in peripheral blood
Measured: Maximum 2 years
Evaluate changes in circulating tumor DNA in plasma
Assess PD markers related to AT03-65 in peripheral blood
Measured: Maximum 2 years
Determine the presence of antibodies to AT03-65 at different times in plasma
Assess immunogenicity concentration in peripheral blood
Measured: Maximum 2 years
Assessment of Overall Response Rate (ORR) in subjects with advanced / metastatic solid tumors
Percentage of subjects whose best response is observed to be CR or PR throughout the study as assessed by local radiological assessment made by investigator according to RECIST V1.1
Measured: Maximum 2 years
Determine the expression level of CLDN6 in tumor samples
Assess the presence and expression level of CLDN6 in tumor samples
Measured: Maximum 2 years
Progress-Free Survival (PFS) of treatment in subjects with advanced / metastatic solid tumors
PFS as assessed by Local Investigators according to RECIST V1.1
Measured: Maximum 2 years
Assessment of Disease Control Rate (DCR)in subjects with advanced / metastatic solid tumors
Percentage of subjects with best overall response of CR, PR and SD as assessed per RECIST v1.1
Measured: Maximum 2 years
Assessment of Duration of Response (DOR) of treatment in patients with solid tumor
DOR as assessed by Local Investigators according to the RECIST V1.1
Measured: Maximum 2 years
Assessment of Overall Survival (OS) of treatment in subjects with advanced / metastatic solid tumors
OS as assessed as duration from first dose of IMP to death
Measured: Maximum 2 years
Assessment of Clinical Benefit Rate (CBR)in subjects with advanced / metastatic solid tumors
Percentage of subjects whose best response is observed to be CR, PR or SD
Measured: Maximum 2 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Feb 2025
- Study start14 Jan 2026
- Primary completionDec 2027 (estimated)
- Study completionAug 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Solid TumorStudies 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 1
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Model description
- Dose escalation (Phase 1a) followed by Dose Expansion (Phase 1b)
- Masking
- None (open label)
- Enrolment
- 83 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Axcynsis Therapeutics Pte Ltd
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06809114
- Sponsor's protocol ID
- AT0365-P1-01
- Status last verified
- Jan 2026
- First submitted
- 24 Jan 2025
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Data generated by this study will be considered confidential by the Investigator, except to the extent that it is included in a publication. The general strategy regarding publication of the study will be mutually agreed upon by the Investigator and Sponsor. The Sponsor reserves the right to manage the publication of all study results. The Investigator agrees that oral and written communication to third parties of any procedures or results from the study is subject to prior written consent of the Sponsor. Presentation material and/or manuscript(s) for publication will be reviewed by the Sponsor prior to submission for publication. Alterations in the material will only be made in agreement between the Investigator and the Sponsor
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase I, First-in-Human Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of AT03-65 in Adults With Advanced Solid Tumors
- ClinicalTrials.gov ID
- NCT06809114
- Acronym / sponsor ID
- AT0365-P1-01
- Conditions
- Solid Tumor
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 83 participants (estimated)
- Lead sponsor
- Axcynsis Therapeutics Pte LtdIndustry (pharma, biotech, devices)
- Study start
- 14 Jan 2026 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Aug 2028 (estimated)
- First posted
- 5 Feb 2025 (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.
A Phase I, First-in-Human Study to Evaluate the Safety, Tolerability, Pharmacokinetics, Pharmacodynamics, and Preliminary Efficacy of AT03-65 in Adults with Advanced Solid Tumors
Detailed description
This is a first-in-human (FIH), Phase 1, open-label, dose escalation and dose expansion study to evaluate the safety, tolerability, pharmacokinetics and preliminary efficacy of AT03-65 in adults with advanced solid tumors. AT03-65 is administered via intravenous infusion using an accelerated escalation method for the lower 3 dose level groups and the 3 + 3 escalation method is used in the subsequent dose level groups.
The study design is to identify the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) during 21-day cycle. One or more doses or regimens lower than or at the MTD may be selected for further evaluations under Dose Expansion to further evaluate the IMP and identify the RP2D.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Dose escalation (Phase 1a) followed by Dose Expansion (Phase 1b)
| Arm | Type | Receives |
|---|---|---|
| AT03-65 Dose Escalation and Dose Expansion | Experimental | Drug: AT03-65Subjects will receive AT03-65 via intravenous (IV) infusion on Day 1 of a 21-Day treatment cycle. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (16 listed)
- At least 18 years old at the time of signing written informed consent form (ICF).
- Eastern cooperative oncology group (ECOG) Performance Status score of 0 or 1 at screening and on C1D1.
- Pathologically documented, definitively diagnosed, advanced/metastatic solid tumor that is resistant or refractory to standard treatment, for which no further standard treatment is available, or the subject refuses or cannot tolerate standard therapy. Subjects must have measurable lesion according to response evaluation criteria in solid tumors (RECIST) v1.1.
- Subjects (with documented CLDN6 expression after the lower three dose levels) will be enrolled, including but not limited to the following histological subtypes: serous or endometrioid ovarian cancer, primary peritoneal cancer or fallopian tube cancer, endometrial cancer, NSCLC, breast cancer, esophageal cancer, and gastric/GEJ cancer. There is no upper limit on the number of prior treatment regimens the subject may have received.
- 3b) Monotherapy cohort expansion study (Phase 1b)
Key exclusion criteria (14 listed)
- Subjects previously received or is currently receiving any systemic anti-cancer therapy within 4 weeks or 5xT(1/2) if 5xT(1/2) of the drug/therapy used by the subject is confirmed to be < 4 weeks, 5xT(1/2) shall prevail] - prior to first dose of IMP
- Not yet recovered to Grade 1 or baseline for treatment-related toxicities related to previous treatment with the exception of alopecia. The recovery time after surgery was less than 28 days
- Subjects with clinically significant congenital or acquired cardiovascular diseases.
- Presence of other active invasive cancers other than the one treated in this study within 5 years prior to screening, except appropriately treated BCC of the skin or in situ carcinoma of uterine cervix, or other local tumors considered cured by local treatment
- Subjects with severe or uncontrolled systemic disease, including uncontrolled hypertension, uncontrolled diabetes mellitus, active bleeding diatheses, or active infection requiring intravenous injection (IV) of antibiotics, antivirals or antifungals
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 |
|---|---|---|
| AT03-65Also: AT03-65 Antibody Drug ConjugateTreatment will continue until disease progression, unacceptable toxicity, subject withdrawal of consent or death. | Drug | AT03-65 Dose Escalation and Dose Expansion |
Primary outcome
Maximum tolerated dose (MTD) of AT03-65
Time frame: Up to 21 days
The MTD is defined as the highest dose with an observed incidence of DLT in no more than one out of six patients treated at a particular dose level.
Dose-limiting toxicity (DLT)
Time frame: Up to 21 days
DLT refers to AEs that occurred during DLT observation period in dose escalation study, excluding toxicities clearly due to the underlying disease or extraneous causes.
10 secondary outcomes
Determine levels of AT03-65 and its constituents over time in plasma
Time frame: Maximum 2 years
Evaluate changes in circulating tumor DNA in plasma
Time frame: Maximum 2 years
Determine the presence of antibodies to AT03-65 at different times in plasma
Time frame: Maximum 2 years
Assessment of Overall Response Rate (ORR) in subjects with advanced / metastatic solid tumors
Time frame: Maximum 2 years
Determine the expression level of CLDN6 in tumor samples
Time frame: Maximum 2 years
Progress-Free Survival (PFS) of treatment in subjects with advanced / metastatic solid tumors
Time frame: Maximum 2 years
Assessment of Disease Control Rate (DCR)in subjects with advanced / metastatic solid tumors
Time frame: Maximum 2 years
Assessment of Duration of Response (DOR) of treatment in patients with solid tumor
Time frame: Maximum 2 years
Assessment of Overall Survival (OS) of treatment in subjects with advanced / metastatic solid tumors
Time frame: Maximum 2 years
Assessment of Clinical Benefit Rate (CBR)in subjects with advanced / metastatic solid tumors
Time frame: Maximum 2 years
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 13 Oct 2026.
- Individual participant dataSharing planned: No. Data generated by this study will be considered confidential by the Investigator, except to the extent that it is included in a publication. The general strategy regarding publication of the study will be mutually agreed upon by the Investigator and Sponsor. The Sponsor reserves the right to manage the publication of all study results. The Investigator agrees that oral and written communication to third parties of any procedures or results from the study is subject to prior written consent of the Sponsor. Presentation material and/or manuscript(s) for publication will be reviewed by the Sponsor prior to submission for publication. Alterations in the material will only be made in agreement between the Investigator and the Sponsor
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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.
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing AT03-65 in people with Solid Tumor, run by Axcynsis Therapeutics Pte Ltd at 4 sites in United States.
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 16 inclusion and 14 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 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in United States. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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 Chief Medical Advisor (7813756856, h.gardner@axcynsis.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maximum tolerated dose (MTD) of AT03-65 (time frame: Up to 21 days). 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 13 Oct 2026.