First-in-human, Phase 1 Study of a Self-amplifying RNA Vaccine (ITI-5000) Alone or in Combination With Pembrolizumab in Stage II-- III Triple Negative Breast Cancer Following Standard Therapy ( VITAL-TNBC )

NCT07652242 | Recruiting Phase 1 DMC FDA Drug

• 1 other identifier: 5000-01-TNBC-P1
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 2

Brief Summary

This study tests an investigational cancer vaccine called ITI-5000 in people who have completed standard treatment for early-stage triple-negative breast cancer (TNBC). ITI-5000 is a self-amplifying RNA (saRNA) vaccine that instructs the immune system to recognize and attack cancer cells expressing two proteins found on TNBC cells-HERV-K and CT83-fused with a molecule called LAMP-1 that helps the immune system respond more strongly. The vaccine is delivered inside lipid nanoparticles (LNPs), similar to other approved mRNA vaccines. The study has two parts:

• Part A: Participants receive ITI-5000 alone at one of two dose levels (1 µg or 10 µg), given as an injection into the upper arm muscle every 28 days for 3 doses total. The goal is to find the safest dose.
• Part B: Participants receive ITI-5000 at the best dose identified in Part A, combined with an approved immunotherapy drug called pembrolizumab (Keytruda®), every 21 days for 3 doses total.

Conditions

Triple Negative Breast Cancer (TNBC)

Keywords

TNBC, saRNA, Pembrolizumab, Phase I Clinical Trial, Immunotherapy, HERV-K Antigen, CT83 Antigen

Outcome Measures

Primary Outcomes (1)

• Part A: To establish the dose-limiting toxicities (DLTs) and maximum tolerated dose (MTD) of ITI-5000 and to characterize the safety and tolerability of ITI-5000 administered as a single agent. Part B: same as Part A but in combination with Pembrolizumab

  From enrollment to end of treatment at 6 months

Secondary Outcomes (1)

• Safety and Tolerability of ITI-5000 when administered in combination with pembrolizumab.

  From enrollment to end of treatment at 12 months

Study Arms (3)

Arm 1 - Part A, Cohort 1 (ITI-5000 1 µg Monotherapy)

EXPERIMENTAL

Participants receive ITI-5000 1 µg as an intramuscular injection every 28 days for 3 doses (Days 1, 29-36, 57-64).

Biological: ITI-5000 TNBC Vaccine

Arm 2 - Part A, Cohort 2 (ITI-5000 10 ug Monotherapy)

EXPERIMENTAL

Participants receive ITI-5000 10 µg as an intramuscular injection every 28 days for 3 doses (Days 1, 29-36, 57-64).

Biological: ITI-5000 TNBC Vaccine

Arm 3 - Part B (ITI-5000 MTD + Pembrolizumab Combination)

EXPERIMENTAL

Participants receive ITI-5000 at the MTD (determined in Part A) as an injection every 21 days for 3 doses, plus pembrolizumab 200 mg IV Q3W or 400 mg IV Q6W per FDA-approved label.

Drug: ITI-5000 TNBC Vaccine + Pembrolizumab

Interventions

ITI-5000 TNBC Vaccine BIOLOGICAL

For Arms 1 and 2, Participants receive ITI-5000 at two different doses for Part A. Cohort 1 will receive 1 ug of the vaccine. Cohort two, will receive 10 ug of the ITI-5000 Vaccine if the 1 ug dose is tolerated.

Arm 1 - Part A, Cohort 1 (ITI-5000 1 µg Monotherapy); Arm 2 - Part A, Cohort 2 (ITI-5000 10 ug Monotherapy)

ITI-5000 TNBC Vaccine + Pembrolizumab DRUG

Participants will receive ITI-5000 TNBC vaccine at the MTD (determined in Part A) as an intramuscular injection every 21 days for 3 doses, plus pembrolizumab 200 mg IV Q3W or 400 mg IV Q6W per FDA-approved label.

Also known as: Pembrolizumab

Arm 3 - Part B (ITI-5000 MTD + Pembrolizumab Combination)

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age: Adults aged 18 years or over.
• Consent: Provided a signed and dated informed consent form (ICF).
• Diagnosis: Histologically confirmed stage 2-3 triple-negative breast cancer (TNBC), defined as HER2-negative, ER-negative, and PgR-negative by immunohistochemistry. BRCA mutations are allowed.
• Prior Treatment: Completed all planned standard therapy (surgery, chemotherapy, radiation, and/or pembrolizumab as applicable) and be within 36 months of definitive surgery.
• Performance Status: ECOG performance status of 0 or 1.
• Organ Function: Adequate organ function at baseline (hematology, biochemistry, etc.).
• Cardiac Function: No significant ischemic heart disease or myocardial infarction within 3 months before vaccination #1; QTc ≤470 msec for females or ≤450 msec for males.
• Pregnancy: Women of childbearing potential must have a negative serum pregnancy test within 3 days before vaccination #1 and agree to use highly effective contraception during the study and for 123 (Part A) or 137 (Part B) days after last study drug.
• Compliance: Able to attend required study visits and follow-up.
• Understanding: Able to understand and provide signed informed consent per IRB/IEC guidelines.
• Vaccinations: Agrees not to receive routine vaccinations until at least 30 days after the last study vaccine.
• Alternative Therapies: Agrees not to use alternative therapies from the time of informed consent through 30 days following vaccination #3.

You may not qualify if:

• Part B only: Discontinued prior treatment with an immune checkpoint inhibitor (ICI) due to immune-related adverse events (irAEs).
• Recent Surgery/Therapy: Major surgery within 4 weeks before vaccination #1 or received cancer-directed therapy or investigational drug/device within 4 weeks or 5 half-lives before vaccination #1.
• Part B only: Received other PD-1/PD-L1 inhibitors (besides pembrolizumab) without proper washout.
• Toxicities: Unresolved toxicities from prior immunotherapy or chemotherapy (must be ≤ Grade 1 or baseline, or deemed irreversible and not worsened by immunotherapy).
• Medical Illness: Significant medical illness, underlying health condition, or abnormal laboratory finding increasing risk.
• Autoimmune Disease: Active autoimmune disease requiring immunosuppressive treatment within the last year.
• Pregnancy/Lactation: Female participants trying to conceive, pregnant, or lactating.
• Positive Pregnancy Test: Positive serum pregnancy test at screening or positive urine test at baseline.
• Other Trials: Concurrent participation in any other interventional clinical trial.
• Allergies: Known allergies to any components of the study vaccine.
• Anaphylaxis: History of anaphylaxis requiring medical intervention (including severe reactions to other mRNA vaccines).
• Cardiac History: History of stroke, transient ischemic attack, unstable angina, or myocardial infarction within 3 months prior to first dose.
• Myocarditis/Pericarditis: History of myocarditis or pericarditis.
• Heart Failure: Symptomatic congestive heart failure (NYHA Class III or IV), significant arrhythmia, or LVEF \<45%.
• QT Risk: History of risk factors for torsade de pointes or use of QT-prolonging medications.

Sponsors & Collaborators

• Immunomic Therapeutics, Inc.: lead

Study Sites (2)

START Midwest

Grand Rapids, Michigan, 49546, United States

RECRUITING

START Midwest

Grand Rapids, Michigan, 49546, United States

RECRUITING

MeSH Terms

Conditions

Triple Negative Breast Neoplasms

Interventions

pembrolizumab

Condition Hierarchy (Ancestors)

Breast Neoplasms; Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Central Study Contacts

Scott L Wehage, M.S.

CONTACT

301-968-3501; clinicaloperations@immunomix.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: This is a Phase 1, multicenter, open-label, parallel assignment clinical trial evaluating the safety, tolerability, and immunogenicity of ITI-5000, a self-amplifying RNA vaccine, administered alone or in combination with pembrolizumab in adults with stage II-III triple-negative breast cancer (TNBC) who have completed standard curative-intent therapy; participants are assigned to either low- or high-dose ITI-5000 monotherapy cohorts (Part A) or to a combination therapy cohort with pembrolizumab at the maximum tolerated dose determined from Part A (Part B), with the primary objectives focused on dose-limiting toxicities and safety, and exploratory endpoints assessing immune response and changes in circulating tumor DNA

Study Record Dates

• First Submitted: June 11, 2026
• First Posted: June 17, 2026
• Study Start: June 1, 2026
• Primary Completion (Estimated): February 1, 2028
• Study Completion (Estimated): August 1, 2028
• Last Updated: June 17, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (2)