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neoBREASTIM: Atezolizumab Plus RP1 Oncolytic Immunotherapy in the NeoAdjuvant Setting of Triple-Negative Breast Cancer

neoBREASTIM: A Phase 2 Study of Atezolizumab Plus RP1 Oncolytic Immunotherapy in the NeoAdjuvant Setting of Triple-Negative Breast Cancer (TNBC)

Status
Terminated
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06067061
Acronym
neoBREASTIM
Enrollment
2
Registered
2023-10-04
Start date
2024-04-05
Completion date
2025-05-07
Last updated
2025-06-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Triple Negative Breast Neoplasms

Keywords

Triple Negative Breast Cancer, Early-stage, Immunotherapy, Oncolytic virus

Brief summary

Neoadjuvant treatment is an important part of the treatment strategy for locally advanced TNBC having established a positive and significant correlation of pathologic Complete Response (pCR) with long-term clinical benefit such as Event-Free Survival (EFS) and Overall Survival (OS) as shown via large meta-analysis. Much effort has been made to identify novel agents and new drug combinations that can improve pCR rates in this specific clinical setting, which is the leading rationale to evaluate RP1 oncolytic immunotherapy in combination with Atezolizumab.

Detailed description

The combination of RP1 plus Atezolizumab, while being expected to result in increased efficacy, is not expected to result in significant additional toxicity, as compared to either agent alone. Capitalizing on the strong prognostic and predictive value of the TIL infiltrate in early-stage TNBC and the capacity of circulating tumor DeoxyriboNucleic Acid (ctDNA) detection to predict response to immunotherapy and NeoAdjuvant Chemotherapy (NAC), neoBREASTIM - a single-arm phase 2 study - will evaluate a novel, biomarker-driven combination of Atezolizumab plus RP1 oncolytic immunotherapy in the neo-adjuvant setting of patients diagnosed with early-stage, TIL-high TNBC.

Interventions

COMBINATION_PRODUCTAtezolizumab + RP1

Patients will be treated in a window period (ie 3 treatment cycles). After evaluation, patients that had no increase in ctDNA after 3 cycles (see Definition of ctDNA status) will continue on the same treatment (intratumoral injections of RP1 in combination with Atezolizumab) for a total of 10 treatment cycles prior to surgery.

Sponsors

Replimune Inc.
CollaboratorINDUSTRY
Roche Pharma AG
CollaboratorINDUSTRY
Institut Curie
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

An open-label, monocentric, single arm, phase II study with a safety run-in.

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Female subject 2. Age ≥ 18 years old. 3. Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) ≤ 1. 4. Newly diagnosed Triple-Negative Breast Cancer (TNBC), defined as the absence of estrogen expression and progesterone expression, and of Human Epidermal growth factor Receptor 2 (HER2) overexpression, must be determined by local testing of a screening tumor sample as defined by American Society of Clinical Oncology/College of American Pathologists guidelines. 5. TNBC defined as the following combined primary tumor (T), regional lymph node (N), and metastatic (M) American Joint Committee on Cancer staging criteria: cT ≥15 - ≤30 mm, N0, M0 according to Mammogram, breast Ultrasound and MRI, and PET-CT. In case of a difference in the measurement of the primary tumor among different imaging methods, the breast MRI measurement is the reference. 6. Unicentric, unifocal and unilateral disease. 7. Tumor-infiltrating lymphocytes (TILs) ≥ 30%, as defined by the International TILs Working Group 2014. 8. ctDNA dosing at baseline. 9. Agreement to provide tissue samples (tumor biopsy at screening and on-treatment), and at surgery for immune monitoring and translational research activities. 10. Agreement to perform blood samples at screening, on-treatment, and at surgery for immune monitoring and translational research activities.

Exclusion criteria

1. Inflammatory breast cancer. 2. Prior treatment with an oncolytic virus-based therapy. 3. Patients with active significant herpetic infections or prior complications of Herpes Simplex Virus-1 (HSV-1) infection. 4. Patients who require intermittent or chronic use of systemic (oral or IV) antivirals with known antiherpetic activity (e.g., acyclovir). 5. Diagnosis of immunodeficiency. 6. Has active autoimmune disease (e.g. inflammatory bowel disease, systemic lupus erythematosus, ankylosing spondylitis, scleroderma, and multiple sclerosis, celiac disease, Wegener's granulomatosis) that has required systemic treatment in the past 3 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs). 7. Prior systemic immunosuppressive medication (except physiologic corticosteroid replacement therapy) within 30 days of planned start of study therapy. 8. Any live (attenuated) vaccine within 14 days of planned start of study therapy. 9. Prior immunotherapy, including tumor vaccine, cytokine, anti-CTLA4, PD-1/PD-L1 blockade or similar agents, T cell receptor-based (TCR-based) or Chimeric Antigen Receptor-T (CAR-T) cell based adoptive cell therapy. 10. Known history of, or any evidence of active, non-infectious pneumonitis.

Design outcomes

Primary

MeasureTime frameDescription
Safety of the combination Atezolizumab plus RP1 oncolytic during the safety run-in phase9 monthsIncidence of combination Atezolizumab plus RP1 adverse events (AEs) graded according to NCI CTCAE v5.0 and nature and severity
Toxicity of the combination Atezolizumab plus RP1 oncolytic immunotherapy during the safety run-in phase.9 monthsDose Limiting Toxicity (DLT) during the first cycle of treatment of the combination Atezolizumab plus RP1 oncolytic immunotherapy
Residual Cancer Burden (RCB) 0-1 during the phase II part30 monthsRate of RCB 0-1 at time of surgery (in patients with no increase in ctDNA after cycle 3)

Secondary

MeasureTime frameDescription
Percentage of TILs30 monthsThe percentage of TILs will be estimated and compared between RCB rates 0-1 versus 2-3
Pre-treatment expression of Programmed Death-Ligand 1 (PD-L1)30 monthsExpression of PD-L1 will be estimated and compared between RCB rates 0-1 versus 2-3
Correlation between RCB rates and response by Positron Emission Tomography-Scan (PET-CT) or breast MRI60 monthsTo correlate the response by RCB rates with response by PET-CT or breast MRI will be studied
Response rate of RCB Score <= 1 at three cycles26 monthsRate of RCB 0-1 after cycle 3 (in patients with no increase in ctDNA after cycle 3)
Breast Conservation Surgery (BCS)30 monthsThe rate of Breast Conservation Surgery (BCS) will be presented
Correlation between RCB rates and radiomics analyses30 monthsTo correlate the RCB rates with response by radiomics analyses.
RCB rates and response60 monthsTo correlate the response by breast MRI with RCB 0-1 rates,
Safety and toxicity of the combination Atezolizumab plus RP1 oncolytic immunotherapy60 monthsIncidence, nature and severity of adverse events (AEs) graded according to NCI CTCAE v5.0 from the treatment start to the surgery
Invasive disease-free survival (iDFS)60 monthsiDFS will be measured using regular follow-up visits

Countries

France

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026