Ovarian CancerPhase 1NeoOVSVNCT07724106
A Single-Arm, Open-Label, Prospective Study Evaluating the Safety, Tolerability, and Immunogenicity of the NeoOVSV Vaccine in Patients With Ovarian Cancer After Surgery
A Phase 1 study testing Low Dose, middle dose and high dose in people with Ovarian Cancer and mRNA Vaccine, run by West China Hospital at 1 site in China.
Trial summary
This is a Phase I, single-arm, open-label, prospective, non-randomized, single-center dose-escalation study. The study will evaluate the safety, tolerability, and preliminary activity of the NeoOVSV mRNA-lipid nanoparticle vaccine in patients with stage II/III ovarian cancer after surgery, in combination with standard… Read more about this study
- Who is it for?
- Ages 18 to 75 years, women only
- Conditions the study is for
- Ovarian Cancer, mRNA Vaccine
- What is being tested?
- Low Dose, middle dose and high dose
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 9 participants
- Where
- 1 siteChina
- Study dates
- 10 Sep 2026to 1 May 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 to 75 years
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Female, aged between 18 and 75 years (inclusive) at the time of signing the written informed consent form (ICF)
- Patients with histopathologically confirmed epithelial ovarian cancer (EOC), including: a) Patients with Stage II (Stage IIA/IIB, tumor confined to the pelvis with no extra-abdominal metastasis) or Stage III (Stage IIIA/IIIB/IIIC, tumor involving the serosal surface of intra-abdominal viscera or regional lymph node metastasis) disease, in accordance with the International Federation of Gynecology and Obstetrics (FIGO) 2014 Staging System; b) Have undergone cytoreductive surgery (CRS), with postoperative pathological confirmation of RO/R1 resection (R1 defined as microscopic residual tumor at the surgical margin ≤ 1 mm); c) Qualified tumor tissue obtained during surgery is available for neoantigen screening: ① Fresh tumor tissue ≥ 100 mg (collected on the day of surgery and immediately immersed in RNA stabilization reagent); or ② ≥ 5 unstained sections of formalin-fixed paraffin-embedded (FFPE) tissue (each with a thickness of 5 μm, tumor cellularity ≥ 30%, and no significant necrosis)
- In accordance with the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1, postoperative contrast-enhanced pelvic MRI/CT shows no macroscopic residual disease (R2 resection), and lung metastasis, liver metastasis, and bone metastasis are excluded;
- Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score of 0 to 1 (0: Fully ambulatory, no restriction in daily activities; 1: Ambulatory and able to perform light physical activity, no significant fatigue or dyspnea), with an expected overall survival of ≥ 1 year;
- Adequate function of major organs, with relevant laboratory test results within 14 days prior to enrollment meeting the following requirements (no blood transfusion or blood product administration, no use of hematopoietic growth factors, albumin, or other blood products during this period): Hematology tests: Hemoglobin (Hb) ≥ 90 g/L; Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L; Platelet count (PLT) ≥ 100 × 10⁹/L; Serum biochemistry tests: Total bilirubin (TBIL) ≤ 1.5 × upper limit of normal (ULN); Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤ 2.5 × ULN; Serum creatinine (SCr) ≤ 1.5 × ULN, or creatinine clearance rate (CrCl) ≥ 50 mL/min calculated by the Cockcroft-Gault formula; Endocrine tests: Thyroid-stimulating hormone (TSH), free triiodothyronine (free T3), and free thyroxine (free T4) are within the normal reference range; Coagulation function tests: Prothrombin time (PT) and activated partial thromboplastin time (APTT) ≤ 1.2 × ULN;
- Women of childbearing potential (WOCBP) must have a negative serum β-human chorionic gonadotropin (β-HCG) test prior to enrollment, and agree to use effective contraceptive measures (e.g., condoms, intrauterine device [IUD]) during the study period (from the first dose administration to 6 months after the last dose administration);
- Good treatment compliance, and the patient and their family members agree to cooperate with and complete the scheduled survival follow-up.
Who cannot join
- Histopathologically confirmed non-epithelial ovarian cancer, including ovarian germ cell tumors (e.g., teratoma, yolk sac tumor), sex cord-stromal tumors (e.g., granulosa cell tumor), and metastatic ovarian tumors (e.g., Krukenberg tumor metastatic to the ovary from the gastrointestinal tract);
- R2 resection (macroscopic residual disease) after cytoreductive surgery, or postoperative imaging (contrast-enhanced pelvic MRI/CT, chest CT) showing distant metastasis (e.g., lung, liver, brain metastasis), or FIGO stage IV disease;
- Prior treatment with any therapeutic cancer vaccine (e.g., peptide vaccine, DNA vaccine, other mRNA vaccines); or prior use of immune checkpoint inhibitors (e.g., anti-PD-1/PD-L1 antibodies, anti-CTLA-4 antibodies) with the last dose administered ≤ 30 days before enrollment;
- Severe surgery-related complications within 4 weeks postoperatively, including but not limited to: intra-abdominal infection requiring intravenous antibiotics for ≥ 7 days, enteric fistula requiring surgical repair, massive hemorrhage requiring transfusion ≥ 400 mL within 24 hours, severe adhesive intestinal obstruction requiring gastrointestinal decompression for ≥ 3 days;
- Active autoimmune disease, or a history of autoimmune disease currently requiring long-term (≥ 2 weeks) immunosuppressive therapy, including but not limited to: rheumatoid arthritis requiring prednisone ≥ 10 mg/day or equivalent immunosuppressants, systemic lupus erythematosus requiring hydroxychloroquine plus glucocorticoids, ulcerative colitis with acute flare within the past 1 year, multiple sclerosis with relapse within the past 2 years, autoimmune thyroiditis requiring high-dose levothyroxine > 150 μg/day;
- Active infection within 1 month before enrollment, including but not limited to: Bacterial infections: pneumonia requiring intravenous antibiotics, pyelonephritis with positive urine culture and fever; Viral infections: HBsAg-positive with HBV DNA ≥ 1×10³ IU/mL (untreated); HCV RNA-positive (untreated with direct-acting antivirals or persistently positive after treatment); HIV-positive; acute varicella-zoster virus (VZV) or cytomegalovirus (CMV) infection with fever or organ involvement; Fungal infections: pulmonary candidiasis, aspergillosis (confirmed by imaging and positive fungal culture);
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- Severe organ dysfunction or history thereof: acute myocardial infarction, unstable angina, heart failure (NYHA class ≥ II), severe arrhythmia (e.g., ventricular tachycardia requiring medication) within the past 6 months; uncontrolled hypertension (systolic BP ≥ 160 mmHg or diastolic BP ≥ 100 mmHg despite antihypertensive treatment); acute exacerbation of chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (CT-proven with FEV1/FVC < 70% on pulmonary function testing), active pulmonary tuberculosis (positive sputum smear or strongly positive tuberculin test without completed standard anti-tuberculosis therapy); liver cirrhosis (Child-Pugh class B or higher), active hepatitis (ALT/AST > 5×ULN), gastrointestinal bleeding within the past 1 year (e.g., esophagogastric variceal bleeding); chronic renal failure requiring dialysis or creatinine clearance < 50 mL/min (calculated by Cockcroft-Gault formula), nephrotic syndrome (24-hour urinary protein > 3.5 g);
- Uncontrolled diabetes mellitus (fasting blood glucose ≥ 11.1 mmol/L despite hypoglycemic agents); hyperthyroidism or hypothyroidism with free T3 and free T4 remaining outside the normal range despite medical treatment;
- Hypersensitivity to any component of the investigational products, including but not limited to: mRNA vaccine components (liposomes, poly-ICLC adjuvant), anti-PD-1 antibodies (e.g., pembrolizumab, nivolumab); or prior severe allergic reactions to similar biological agents (e.g., COVID-19 mRNA vaccines, other monoclonal antibodies) such as anaphylactic shock, laryngeal edema, bronchospasm;
- Use of immunosuppressive agents within 2 weeks before enrollment, including but not limited to: glucocorticoids (prednisone ≥ 10 mg/day or equivalent), cyclosporine, tacrolimus, methotrexate, azathioprine; or planned use of such agents during the trial;
- Diagnosis of another malignancy other than ovarian cancer within the past 5 years, except for cured basal cell carcinoma of the skin, cervical carcinoma in situ, and ductal carcinoma in situ of the breast, all of which must have undergone radical surgery with no recurrence;
- Pregnant (positive serum β-HCG before enrollment) or lactating female; woman of childbearing potential refusing effective contraception during the trial (from first dose to 6 months after last dose);
- Psychiatric disorders (e.g., dementia, major depressive disorder, schizophrenia) or cognitive impairment that prevents understanding of trial procedures or compliance with follow-up;
- Participation in another interventional clinical trial (receipt of investigational drugs, devices, or other study interventions) within 30 days before enrollment; or currently in the follow-up period of another clinical trial without completing the final assessment;
- Unable to provide written informed consent or unwilling to comply with trial-related requirements for personal reasons;
- Any other condition deemed inappropriate by the investigator.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
West China Hospital
Chengdu, Sichuan, 610041
Xuelei Ma, MD, 18708305692, drmaxuelei@gmail.com
About this study
This is a Phase I, single-arm, open-label, prospective, non-randomized, single-center dose-escalation study. The study will evaluate the safety, tolerability, and preliminary activity of the NeoOVSV mRNA-lipid nanoparticle vaccine in patients with stage II/III ovarian cancer after surgery, in combination with standard adjuvant chemotherapy and a PD-1 antibody.
Read the detailed description
Study Overview
This is a Phase I, single-arm, open-label, prospective, non-randomized, single-center dose-escalation study. The study will evaluate the safety, tolerability, and preliminary activity of the NeoOVSV mRNA-lipid nanoparticle vaccine in patients with stage II/III ovarian cancer after surgery, in combination with standard adjuvant chemotherapy and a PD-1 antibody.
Study Population
Eligible participants are patients with FIGO 2014 stage II or III ovarian cancer who have undergone R0 or R1 surgical resection and have not yet started other adjuvant therapy within 4 weeks after surgery.
Dose-Escalation Design
The study uses a traditional "3+3" dose-escalation design. Three dose levels of the NeoOVSV vaccine will be tested:
- Dose Level 1: 25 μg
- Dose Level 2: 50 μg
- Dose Level 3: 100 μg
Each dose level will initially include 3 participants. If no participant develops dose-limiting toxicity (DLT) within 28 days after the first vaccination, the study will proceed to the next dose level. If 1 of 3 participants develops DLT, 3 additional participants will be enrolled at the same dose level. If 2 or more participants at a dose level develop DLT, dose escalation will stop, and the previous dose will be considered the maximum tolerated dose within the planned dose range.
If no maximum tolerated dose is reached after evaluation of the 100 μg dose level, 100 μg will be considered the highest tested dose. The recommended dose for future studies will be selected based on overall safety, tolerability, immune response, feasibility, and clinical findings.
Treatment Plan
Participants will receive standard adjuvant chemotherapy, a PD-1 antibody, and the NeoOVSV vaccine.
Standard chemotherapy will start approximately 4 weeks after surgery, according to current clinical guidelines. Tislelizumab, a PD-1 antibody, will also start approximately 4 weeks after surgery and will be given for 6 doses, usually before chemotherapy.
The NeoOVSV vaccine will be given by intramuscular injection. The preferred injection site is the deltoid muscle of the upper arm. Other suitable intramuscular injection sites may be used when needed.
The vaccine schedule includes:
- Priming phase: 1 injection every 3 weeks during chemotherapy, for a total of 6 doses
- Booster phase: 1 injection every week after chemotherapy, for a total of 3 doses
Each participant will receive only one assigned vaccine dose level.
Study Vaccine
NeoOVSV is a shared-antigen mRNA-lipid nanoparticle vaccine. It contains mRNA sequences encoding seven ovarian cancer-associated antigens:
FOLR1, MUC16, CLDN6, MSLN, WT1, PRAME, and MAGEA4.
The mRNA is formulated in lipid nanoparticles to protect the mRNA and support delivery to immune cells. The vaccine will be manufactured and released according to GMP quality standards before use in the study.
Main Study Assessments
The primary objective is to assess safety and tolerability. Adverse events will be monitored and graded according to CTCAE v5.0. The study will closely monitor injection-site reactions, fever, fatigue, headache, and immune-related adverse events such as rash, thyroid dysfunction, colitis, pneumonitis, or myocarditis.
DLT will be assessed during the first 28 days after vaccination. DLT may include severe treatment-related toxicity, grade 4 adverse events, serious organ toxicity, or adverse events that cause treatment interruption.
Secondary and exploratory assessments include immune response, preliminary clinical activity, and feasibility. Blood samples will be collected at planned time points to evaluate vaccine-induced T-cell and B-cell responses using assays such as IFNγ ELISpot, flow cytometry, single-cell RNA sequencing, TCR sequencing, and BCR sequencing.
Preliminary clinical activity will be assessed by disease-free survival, imaging, tumor markers such as CA125 and HE4, and circulating tumor DNA testing for minimal residual disease.
Feasibility will be evaluated by vaccine production and release time, cold-chain delivery, treatment completion rate, and coordination with chemotherapy and other adjuvant treatments.
Sample Size and Statistical Analysis
The planned sample size is 9 to 18 participants, based on the 3+3 dose-escalation design. This Phase I study is not designed to test treatment superiority or non-inferiority. Safety, tolerability, immune response, disease-free survival, minimal residual disease clearance, and feasibility outcomes will mainly be summarized descriptively.
All participants who receive at least one vaccine dose will be included in the safety analysis. Immune and clinical outcomes will be analyzed in the relevant evaluable populations. Kaplan-Meier methods may be used to describe disease-free survival, and exploratory statistical methods may be used to evaluate associations between immune responses and clinical outcomes.
Participants will be followed after treatment to record survival status and long-term adverse events until death, study closure, or the end of follow-up, whichever occurs first.
- Conditions
- Ovarian Cancer, mRNA Vaccine
- Being tested
- Low Dose, middle dose, high dose
- Keywords
- ovarian cancer, mRNA vaccine
- Medical subject headings
- Ovarian Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low DoseDrug
Participants will receive the NeoOVSV mRNA-lipid nanoparticle vaccine at a dose of 25 μg, corresponding to an approximate injection volume of 0.2 mL, administered by intramuscular injection. Vaccination will start approximately 4 weeks after surgery. The vaccine schedule includes 6 priming doses given once every 3 weeks during adjuvant chemotherapy, followed by 3 booster doses given once weekly after chemotherapy. Standard adjuvant chemotherapy will also start approximately 4 weeks after surgery according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will be administered for 6 doses, generally 1 day before chemotherapy.
middle doseDrug
Participants will receive the NeoOVSV mRNA-lipid nanoparticle vaccine at a dose of 50 μg, corresponding to an approximate injection volume of 0.4 mL, administered by intramuscular injection. Vaccination will start approximately 4 weeks after surgery. The vaccine schedule includes 6 priming doses given once every 3 weeks during adjuvant chemotherapy, followed by 3 booster doses given once weekly after chemotherapy. Standard adjuvant chemotherapy will also start approximately 4 weeks after surgery according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will be administered for 6 doses, generally 1 day before chemotherapy.
high doseDrug
Participants will receive the NeoOVSV mRNA-lipid nanoparticle vaccine at a dose of 100 μg, corresponding to an approximate injection volume of 0.8 mL, administered by intramuscular injection. Vaccination will start approximately 4 weeks after surgery. The vaccine schedule includes 6 priming doses given once every 3 weeks during adjuvant chemotherapy, followed by 3 booster doses given once weekly after chemotherapy. Standard adjuvant chemotherapy will also start approximately 4 weeks after surgery according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will be administered for 6 doses, generally 1 day before chemotherapy.
| Study group | Role | What they receive |
|---|---|---|
| Vaccine group | Experimental | Participants in this single treatment arm will receive standard postoperative adjuvant chemotherapy, tislelizumab as a PD-1 antibody, and the NeoOVSV mRNA-lipid nanoparticle vaccine.
Standard adjuvant chemotherapy will begin approximately 4 weeks after surgery, with the regimen selected according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will also begin approximately 4 weeks after surgery and will be administered for 6 doses, generally 1 day before chemotherapy.
The NeoOVSV vaccine will be administered by intramuscular injection starting approximately 4 weeks after surgery. Three dose levels will be evaluated using a 3+3 dose-escalation design: 25 μg, 50 μg, and 100 μg, corresponding to approximate injection volumes of 0.2 mL, 0.4 mL, and 0.8 mL, respectively. Each dose level will enroll 3 to 6 participants.
The vaccine schedule includes 6 priming doses given once every 3 weeks during chemotherapy, followed by 3 booster doses given once weekl Receives: Drug: Low Dose; Drug: middle dose; Drug: high dose |
What is being measured
The primary outcome is the main question the study is designed to answer.
safety assessment
According to CTCAE Version 5.0, from the first dose administration to the last follow-up (18 months), the time of onset, grade, duration and management of adverse events (AEs) shall be documented, with special attention to:Local reactions: redness, swelling and pain at the injection site (assessed once weekly);Systemic reactions: fever (to be documented if ≥ 38.5°C), fatigue, headache (monitored daily within 72 hours after each dose);Immune-related adverse events (irAEs): thyroid dysfunction (thyroid function tested every 4 weeks), rash, enterocolitis (assessed whenever symptoms occur).
Measured: Throughout treatment, followed up to 18 months after treatment
Secondary outcomes (4)
Disease-Free Survival (DFS)
Time from date of surgery to first recurrence (per RECIST 1.1 on contrast-enhanced pelvic MRI/CT) or death from any cause. Tumour evaluation every 3 months; tumour markers (CA125, HE4) measured every 4 weeks.
Measured: From surgery date up to 24 months post-surgery; assessed every 3 months until recurrence, death, or end of follow-up.
Immunogenicity assessment
Neoantigen-specific immune responses will be assessed using peripheral blood samples. T-cell responses will be evaluated by ex vivo IFNγ ELISpot after stimulation with vaccine neoantigen peptide pools, with response rates calculated based on predefined positivity criteria. Flow cytometry will assess CD8+ T-cell function, proliferation, and polyfunctional T-cell subsets. Single-cell RNA sequencing will be performed on purified T cells after vaccine priming.
T-cell clonal expansion and persistence will be assessed by TCR sequencing, including tracking of vaccine-specific clones for up to 12 months.
Neoantigen-specific B-cell responses will be evaluated by BCR sequencing of CD19+ B cells isolated from PBMCs, with analysis of vaccine-specific B-cell clonal expansion and persistence for up to 12 months.
Measured: Baseline preoperatively; 1 week after the third priming dose of the vaccine; 1 week after completion of the priming phase; 1 week after the first booster dose; and 6 months of follow-up.
12-month and 24-month DFS rates
Proportion of patients who remain free of disease at 12 and 24 months after surgery.
Measured: At 12 months and 24 months post-surgery (fixed time points).
Minimal Residual Disease (MRD) Clearance
Clearance status of peripheral blood ctDNA using the MSK-ACCESS assay (high-depth sequencing covering 129 cancer-related genes). Result reported as "Detected" or "Not Detected".
Measured: Pre-operatively (baseline); 1 week after the third priming dose; 1 week after completion of the priming phase; 1 week after the first booster dose; and at 6-month follow-up (5 fixed time points).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jul 2026
- Study start10 Sep 2026 (estimated)
- Primary completion1 May 2028 (estimated)
- Study completion1 May 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ovarian CancerStudies of the same condition, open and under way.
- More trials run by West China HospitalThe sponsor's other registered studies.
- 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
- Single group
- Model description
- Stage II / III ovarian cancer patients.
- Masking
- None (open label)
- Enrolment
- 9 participants (estimated)
Sponsor and investigators
- Lead sponsor
- West China Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Xuelei Ma MD, West China Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07724106
- Sponsor's protocol ID
- 2026(862)
- Acronym
- NeoOVSV
- Status last verified
- Sep 2026
- First submitted
- 15 Jun 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: IPD will not be shared.
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Single-Arm, Open-Label, Prospective Study Evaluating the Safety, Tolerability, and Immunogenicity of the NeoOVSV Vaccine in Patients With Ovarian Cancer After Surgery
- ClinicalTrials.gov ID
- NCT07724106
- Acronym / sponsor ID
- NeoOVSV / 2026(862)
- Conditions
- Ovarian Cancer, mRNA Vaccine
- Keywords
- ovarian cancer, mRNA vaccine
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 9 participants (estimated)
- Lead sponsor
- West China HospitalUniversity, hospital or other
- Study start
- 10 Sep 2026 (estimated)
- Primary completion
- 1 May 2028 (estimated)
- Study completion
- 1 May 2028 (estimated)
- First posted
- 23 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.
This is a Phase I, single-arm, open-label, prospective, non-randomized, single-center dose-escalation study. The study will evaluate the safety, tolerability, and preliminary activity of the NeoOVSV mRNA-lipid nanoparticle vaccine in patients with stage II/III ovarian cancer after surgery, in combination with standard adjuvant chemotherapy and a PD-1 antibody.
Detailed description
Study Overview
This is a Phase I, single-arm, open-label, prospective, non-randomized, single-center dose-escalation study. The study will evaluate the safety, tolerability, and preliminary activity of the NeoOVSV mRNA-lipid nanoparticle vaccine in patients with stage II/III ovarian cancer after surgery, in combination with standard adjuvant chemotherapy and a PD-1 antibody.
Study Population
Eligible participants are patients with FIGO 2014 stage II or III ovarian cancer who have undergone R0 or R1 surgical resection and have not yet started other adjuvant therapy within 4 weeks after surgery.
Dose-Escalation Design
The study uses a traditional "3+3" dose-escalation design. Three dose levels of the NeoOVSV vaccine will be tested:
- Dose Level 1: 25 μg
- Dose Level 2: 50 μg
- Dose Level 3: 100 μg
Each dose level will initially include 3 participants. If no participant develops dose-limiting toxicity (DLT) within 28 days after the first vaccination, the study will proceed to the next dose level. If 1 of 3 participants develops DLT, 3 additional participants will be enrolled at the same dose level. If 2 or more participants at a dose level develop DLT, dose escalation will stop, and the previous dose will be considered the maximum tolerated dose within the planned dose range.
If no maximum tolerated dose is reached after evaluation of the 100 μg dose level, 100 μg will be considered the highest tested dose. The recommended dose for future studies will be selected based on overall safety, tolerability, immune response, feasibility, and clinical findings.
Treatment Plan
Participants will receive standard adjuvant chemotherapy, a PD-1 antibody, and the NeoOVSV vaccine.
Standard chemotherapy will start approximately 4 weeks after surgery, according to current clinical guidelines. Tislelizumab, a PD-1 antibody, will also start approximately 4 weeks after surgery and will be given for 6 doses, usually before chemotherapy.
The NeoOVSV vaccine will be given by intramuscular injection. The preferred injection site is the deltoid muscle of the upper arm. Other suitable intramuscular injection sites may be used when needed.
The vaccine schedule includes:
- Priming phase: 1 injection every 3 weeks during chemotherapy, for a total of 6 doses
- Booster phase: 1 injection every week after chemotherapy, for a total of 3 doses
Each participant will receive only one assigned vaccine dose level.
Study Vaccine
NeoOVSV is a shared-antigen mRNA-lipid nanoparticle vaccine. It contains mRNA sequences encoding seven ovarian cancer-associated antigens:
FOLR1, MUC16, CLDN6, MSLN, WT1, PRAME, and MAGEA4.
The mRNA is formulated in lipid nanoparticles to protect the mRNA and support delivery to immune cells. The vaccine will be manufactured and released according to GMP quality standards before use in the study.
Main Study Assessments
The primary objective is to assess safety and tolerability. Adverse events will be monitored and graded according to CTCAE v5.0. The study will closely monitor injection-site reactions, fever, fatigue, headache, and immune-related adverse events such as rash, thyroid dysfunction, colitis, pneumonitis, or myocarditis.
DLT will be assessed during the first 28 days after vaccination. DLT may include severe treatment-related toxicity, grade 4 adverse events, serious organ toxicity, or adverse events that cause treatment interruption.
Secondary and exploratory assessments include immune response, preliminary clinical activity, and feasibility. Blood samples will be collected at planned time points to evaluate vaccine-induced T-cell and B-cell responses using assays such as IFNγ ELISpot, flow cytometry, single-cell RNA sequencing, TCR sequencing, and BCR sequencing.
Preliminary clinical activity will be assessed by disease-free survival, imaging, tumor markers such as CA125 and HE4, and circulating tumor DNA testing for minimal residual disease.
Feasibility will be evaluated by vaccine production and release time, cold-chain delivery, treatment completion rate, and coordination with chemotherapy and other adjuvant treatments.
Sample Size and Statistical Analysis
The planned sample size is 9 to 18 participants, based on the 3+3 dose-escalation design. This Phase I study is not designed to test treatment superiority or non-inferiority. Safety, tolerability, immune response, disease-free survival, minimal residual disease clearance, and feasibility outcomes will mainly be summarized descriptively.
All participants who receive at least one vaccine dose will be included in the safety analysis. Immune and clinical outcomes will be analyzed in the relevant evaluable populations. Kaplan-Meier methods may be used to describe disease-free survival, and exploratory statistical methods may be used to evaluate associations between immune responses and clinical outcomes.
Participants will be followed after treatment to record survival status and long-term adverse events until death, study closure, or the end of follow-up, whichever occurs first.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Stage II / III ovarian cancer patients.
| Arm | Type | Receives |
|---|---|---|
| Vaccine group | Experimental | Drug: Low Dose, Drug: middle dose, Drug: high doseParticipants in this single treatment arm will receive standard postoperative adjuvant chemotherapy, tislelizumab as a PD-1 antibody, and the NeoOVSV mRNA-lipid nanoparticle vaccine. Standard adjuvant chemotherapy will begin approximately 4 weeks after surgery, with the regimen selected according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will also begin approximately 4 weeks after surgery and will be administered for 6 doses, generally 1 day before chemotherapy. The NeoOVSV vaccine will be administered by intramuscular injection starting approximately 4 weeks after surgery. Three dose levels will be evaluated using a 3+3 dose-escalation design: 25 μg, 50 μg, and 100 μg, corresponding to approximate injection volumes of 0.2 mL, 0.4 mL, and 0.8 mL, respectively. Each dose level will enroll 3 to 6 participants. The vaccine schedule includes 6 priming doses given once every 3 weeks during chemotherapy, followed by 3 booster doses given once weekl |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Female, aged between 18 and 75 years (inclusive) at the time of signing the written informed consent form (ICF)
- Patients with histopathologically confirmed epithelial ovarian cancer (EOC), including: a) Patients with Stage II (Stage IIA/IIB, tumor confined to the pelvis with no extra-abdominal metastasis) or Stage III (Stage IIIA/IIIB/IIIC, tumor involving the serosal surface of intra-abdominal viscera or regional lymph node metastasis) disease, in accordance with the International Federation of Gynecology and Obstetrics (FIGO) 2014 Staging System; b) Have undergone cytoreductive surgery (CRS), with postoperative pathological confirmation of RO/R1 resection (R1 defined as microscopic residual tumor at the surgical margin ≤ 1 mm); c) Qualified tumor tissue obtained during surgery is available for neoantigen screening: ① Fresh tumor tissue ≥ 100 mg (collected on the day of surgery and immediately immersed in RNA stabilization reagent); or ② ≥ 5 unstained sections of formalin-fixed paraffin-embedded (FFPE) tissue (each with a thickness of 5 μm, tumor cellularity ≥ 30%, and no significant necrosis)
- In accordance with the Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1, postoperative contrast-enhanced pelvic MRI/CT shows no macroscopic residual disease (R2 resection), and lung metastasis, liver metastasis, and bone metastasis are excluded;
- Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) score of 0 to 1 (0: Fully ambulatory, no restriction in daily activities; 1: Ambulatory and able to perform light physical activity, no significant fatigue or dyspnea), with an expected overall survival of ≥ 1 year;
- Adequate function of major organs, with relevant laboratory test results within 14 days prior to enrollment meeting the following requirements (no blood transfusion or blood product administration, no use of hematopoietic growth factors, albumin, or other blood products during this period): Hematology tests: Hemoglobin (Hb) ≥ 90 g/L; Absolute neutrophil count (ANC) ≥ 1.5 × 10⁹/L; Platelet count (PLT) ≥ 100 × 10⁹/L; Serum biochemistry tests: Total bilirubin (TBIL) ≤ 1.5 × upper limit of normal (ULN); Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤ 2.5 × ULN; Serum creatinine (SCr) ≤ 1.5 × ULN, or creatinine clearance rate (CrCl) ≥ 50 mL/min calculated by the Cockcroft-Gault formula; Endocrine tests: Thyroid-stimulating hormone (TSH), free triiodothyronine (free T3), and free thyroxine (free T4) are within the normal reference range; Coagulation function tests: Prothrombin time (PT) and activated partial thromboplastin time (APTT) ≤ 1.2 × ULN;
Key exclusion criteria (16 listed)
- Histopathologically confirmed non-epithelial ovarian cancer, including ovarian germ cell tumors (e.g., teratoma, yolk sac tumor), sex cord-stromal tumors (e.g., granulosa cell tumor), and metastatic ovarian tumors (e.g., Krukenberg tumor metastatic to the ovary from the gastrointestinal tract);
- R2 resection (macroscopic residual disease) after cytoreductive surgery, or postoperative imaging (contrast-enhanced pelvic MRI/CT, chest CT) showing distant metastasis (e.g., lung, liver, brain metastasis), or FIGO stage IV disease;
- Prior treatment with any therapeutic cancer vaccine (e.g., peptide vaccine, DNA vaccine, other mRNA vaccines); or prior use of immune checkpoint inhibitors (e.g., anti-PD-1/PD-L1 antibodies, anti-CTLA-4 antibodies) with the last dose administered ≤ 30 days before enrollment;
- Severe surgery-related complications within 4 weeks postoperatively, including but not limited to: intra-abdominal infection requiring intravenous antibiotics for ≥ 7 days, enteric fistula requiring surgical repair, massive hemorrhage requiring transfusion ≥ 400 mL within 24 hours, severe adhesive intestinal obstruction requiring gastrointestinal decompression for ≥ 3 days;
- Active autoimmune disease, or a history of autoimmune disease currently requiring long-term (≥ 2 weeks) immunosuppressive therapy, including but not limited to: rheumatoid arthritis requiring prednisone ≥ 10 mg/day or equivalent immunosuppressants, systemic lupus erythematosus requiring hydroxychloroquine plus glucocorticoids, ulcerative colitis with acute flare within the past 1 year, multiple sclerosis with relapse within the past 2 years, autoimmune thyroiditis requiring high-dose levothyroxine > 150 μg/day;
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 |
|---|---|---|
| Low DoseParticipants will receive the NeoOVSV mRNA-lipid nanoparticle vaccine at a dose of 25 μg, corresponding to an approximate injection volume of 0.2 mL, administered by intramuscular injection. Vaccination will start approximately 4 weeks after surgery. The vaccine schedule includes 6 priming doses given once every 3 weeks during adjuvant chemotherapy, followed by 3 booster doses given once weekly after chemotherapy. Standard adjuvant chemotherapy will also start approximately 4 weeks after surgery according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will be administered for 6 doses, generally 1 day before chemotherapy. | Drug | Vaccine group |
| middle doseParticipants will receive the NeoOVSV mRNA-lipid nanoparticle vaccine at a dose of 50 μg, corresponding to an approximate injection volume of 0.4 mL, administered by intramuscular injection. Vaccination will start approximately 4 weeks after surgery. The vaccine schedule includes 6 priming doses given once every 3 weeks during adjuvant chemotherapy, followed by 3 booster doses given once weekly after chemotherapy. Standard adjuvant chemotherapy will also start approximately 4 weeks after surgery according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will be administered for 6 doses, generally 1 day before chemotherapy. | Drug | Vaccine group |
| high doseParticipants will receive the NeoOVSV mRNA-lipid nanoparticle vaccine at a dose of 100 μg, corresponding to an approximate injection volume of 0.8 mL, administered by intramuscular injection. Vaccination will start approximately 4 weeks after surgery. The vaccine schedule includes 6 priming doses given once every 3 weeks during adjuvant chemotherapy, followed by 3 booster doses given once weekly after chemotherapy. Standard adjuvant chemotherapy will also start approximately 4 weeks after surgery according to current clinical guidelines, such as paclitaxel plus carboplatin. Tislelizumab will be administered for 6 doses, generally 1 day before chemotherapy. | Drug | Vaccine group |
Primary outcome
safety assessment
Time frame: Throughout treatment, followed up to 18 months after treatment
According to CTCAE Version 5.0, from the first dose administration to the last follow-up (18 months), the time of onset, grade, duration and management of adverse events (AEs) shall be documented, with special attention to:Local reactions: redness, swelling and pain at the injection site (assessed once weekly);Systemic reactions: fever (to be documented if ≥ 38.5°C), fatigue, headache (monitored daily within 72 hours after each dose);Immune-related adverse events (irAEs): thyroid dysfunction (thyroid function tested every 4 weeks), rash, enterocolitis (assessed whenever symptoms occur).
4 secondary outcomes
Disease-Free Survival (DFS)
Time frame: From surgery date up to 24 months post-surgery; assessed every 3 months until recurrence, death, or end of follow-up.
Immunogenicity assessment
Time frame: Baseline preoperatively; 1 week after the third priming dose of the vaccine; 1 week after completion of the priming phase; 1 week after the first booster dose; and 6 months of follow-up.
12-month and 24-month DFS rates
Time frame: At 12 months and 24 months post-surgery (fixed time points).
Minimal Residual Disease (MRD) Clearance
Time frame: Pre-operatively (baseline); 1 week after the third priming dose; 1 week after completion of the priming phase; 1 week after the first booster dose; and at 6-month follow-up (5 fixed time points).
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 9 Sep 2026.
- Individual participant dataSharing planned: No. IPD will not be shared.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Low Dose, middle dose and high dose in people with Ovarian Cancer and mRNA Vaccine, run by West China Hospital at 1 site in China.
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 7 inclusion and 16 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 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. 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 Nan Lin, MD (18708305692, linnan@stu.scu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
safety assessment (time frame: Throughout treatment, followed up to 18 months after treatment). 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 9 Sep 2026.