Lifestyle program to boost pre-surgery treatment for early triple-negative breast cancer
The LESLIE Trial: LifEStyle Intervention to Enhance Efficacy of Neoadjuvant Systemic Therapy in Patients With Triple Negative Breast Cancer
This will test whether adding cycles of a fasting-mimicking diet plus supervised exercise to standard pre-surgery chemo-immunotherapy helps people with early triple-negative breast cancer respond better, tolerate treatment, and have a better quality of life.
Quick facts
| Phase | Phase 2 |
|---|---|
| Study type | Interventional |
| Enrollment | 356 (estimated) |
| Ages | 18 Years and up |
| Sex | All |
| Sponsor | Universitaire Ziekenhuizen KU Leuven Academic / other |
| Drugs / interventions | chemotherapy, immunotherapy, pembrolizumab, cyclophosphamide |
| Locations | 10 sites (Antwerp and 9 other locations) |
| Trial ID | NCT06831955 on ClinicalTrials.gov |
What this trial studies
LESLIE is a randomized Phase IIb trial enrolling 356 people with stage II–III triple-negative breast cancer and randomizing them 2:1 to standard neoadjuvant chemo-immunotherapy with or without a cyclic fasting-mimicking diet combined with structured exercise. Neoadjuvant therapy follows a Keynote-522–style regimen over about 21 weeks, and participants in the interventional arm receive regular physiotherapy visits and online dietitian support while undergoing cyclic FMD during treatment cycles. The trial measures treatment response and tolerability as key outcomes, with secondary endpoints including therapy compliance, quality of life, and longer-term survival. The study is multicenter within Belgium and integrates lifestyle support alongside standard oncology care.
Who should consider this trial
Good fit: Adults with biopsy-confirmed stage II–III triple-negative breast cancer (ER/PR ≤10%, HER2 negative), ECOG 0–1, BMI ≥18.5 kg/m², able to perform CPET, with adequate organ and bone marrow function and HbA1c <10% who are planned for neoadjuvant chemo-immunotherapy are ideal candidates.
Not a fit: People with metastatic disease, hormone-receptor or HER2-positive tumors, those who cannot safely fast or exercise (for example low BMI, uncontrolled diabetes, or major comorbidities), pregnant or breastfeeding women, or those who received recent systemic anticancer therapy are unlikely to benefit from this intervention.
Why it matters
Potential benefit: If successful, this approach could increase the effectiveness of pre-surgery therapy, reduce side effects, and improve quality of life for people with early TNBC.
How similar studies have performed: Small early-phase clinical and preclinical studies suggest fasting-mimicking diets and exercise can reduce chemotherapy toxicity and may enhance treatment response, but randomized data in TNBC are limited and the combined approach remains relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * The patient has a biopsy-confirmed diagnosis of stage II-III TNBC 1. Patients with tumor stage T1cN1-2, T2N0-N2, T3N0-N2, T4N0-N2 2. ER and PR negative is defined as an absent or minimal (≤10%) expression of oestrogen and progesterone receptors and absence of HER2 protein over-expression per ASCO/CAP-guidelines 3. All histological subtypes are eligible, including but not limited to invasive breast cancer of no special type (NST) , invasive lobular carcinoma (ILC) etc * WHO/ECOG performance status of grade 0-1 * The participant is able to perform a CPET test (cardiopulmonary exercise testing) * Body mass index ≥ 18.5 kg/m² * Pregnant or breastfeeding women * Presence of adequate bone marrow and organ function * HbA1c \<10% Exclusion Criteria: * had a treatment with any of the following: 1. any other chemotherapy, immunotherapy or anticancer agents within 5 years of the first dose of study treatment 2. injectable hypoglycemics 2. have not have recovered adequately from the toxicity and/or complications from a surgical intervention prior to starting therapy * prior systemic treatment for breast cancer or other malignancies within 5 years of treatment enrollment, except for adequately treated basal cell or squamous skin cancer or in situ cervical cancer. Other malignancies diagnosed more than 5 years before the diagnosis of breast cancer must have been radically treated without evidence of relapse at the moment of patient enrollment in the trial. * has a history of an additional malignancy that is progressing or that has required active treatment in the 5 years prior to breast cancer diagnosis. Exceptions include basal cell carcinoma of the skin or squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer * Prior treatment with anthracyclines * Prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent or with an agent directed to another co-inhibitory T-cell receptor (e.g., CTLA-4, OX-40, CD137) * Has any disorder, which in the Investigator's opinion might jeopardize the participant's safety or compliance with the protocol * Has, as judged by the investigator, any evidence of severe or uncontrolled systemic diseases, including active bleeding diatheses, or active infection including hepatitis B, hepatitis C, and human immunodeficiency virus (HIV). Screening for chronic conditions is not required * Active autoimmune diseases requiring systemic treatments * Patients with type 1 diabetes mellitus * History of alcohol use disorder (DSM-5) * History of eating disorder (DSM-5)
Where this trial is running
Antwerp and 9 other locations
- UZ Antwerpen — Antwerp, Belgium (Recruiting)
- Ziekenhuis aan de Stroom — Antwerp, Belgium (Not_yet_recruiting)
- Cliniques universitaires Saint-Luc (UCLouvain) — Brussels, Belgium (Recruiting)
- UZ Brussel — Brussels, Belgium (Recruiting)
- UZ Gent — Ghent, Belgium (Not_yet_recruiting)
- Jessa Ziekenhuis Hasselt — Hasselt, Belgium (Recruiting)
- AZ Groeninge — Kortrijk, Belgium (Recruiting)
- University Hospital Leuven — Leuven, Belgium (Recruiting)
- Centre Hospitalier Universitaire (CHU) UCL Liège — Liège, Belgium (Recruiting)
- Centre Hospitalier Universitaire (CHU) UCL Namur — Namur, Belgium (Recruiting)
Study contacts
- Principal investigator: Christine Desmedt, PhD — KU Leuven
- Study coordinator: Christine Desmedt, PhD
- Email: christine.desmedt@kuleuven.be
- Phone: +3216321194
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.