Fiber-Boost Randomized Controlled Trial

NCT07483112 | Recruiting DMC

• 5 other identifiers: BASEC2025-00650KFS-6039-02-2024Lungenliga OstSwiss Cancer FoundationNestlé Health Science
• Study Type: interventional
• Target: 42
• Locations: 1 country
• Sites: 4

Brief Summary

In the present study 'Fiber-Boost', we investigate how a high-fiber diet affects the immunotherapy of advanced lung cancer and what effects it has on the gut microbiome (i.e., the bacteria in the gut) as well as the immune system. Study participants will be assigned to either a test group or a control group. Only patients in the test group will undergo a high-fiber diet. The study lasts 6 weeks per patient and will be conducted at 4 centers within Switzerland. A total of 42 patients are planned to be included in the study.

Conditions

Non-Small Cell Carcinoma of Lung

Keywords

non-small cell lung cancer; immunotherapy; high-fiber diet; microbiome

Outcome Measures

Primary Outcomes (1)

• ctDNA clearance

  Fraction of patients achieving complete ctDNA clearance at 6 weeks

  6 weeks

Secondary Outcomes (5)

• ctDNA dynamics

  3 and 6 weeks

• Radiological treatment response

  6 weeks and 6 months

• Disease control rate

  6 months

• Microbiota dynamics

  6 weeks

• Systemic immune response

  6 months

Study Arms (2)

High-fiber diet

EXPERIMENTAL

Patients in this arm will receive a high-fiber diet over the period of 6 weeks.

Dietary Supplement: High-fiber diet

No high-fiber diet

NO INTERVENTION

Patients in this arm will not receive an intervention and serve as control.

Interventions

High-fiber diet DIETARY_SUPPLEMENT

Patients in the intervention arm will receive a high-fiber diet through daily consumption of a defined amount of plant-based fibers from a commercial product.

High-fiber diet

Eligibility Criteria

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

You may qualify if:

• Age ≥18 years
• Histologically or cytologically confirmed NSCLC
• Advanced or recurrent NSCLC not amenable to curative treatment
• PD-L1 expression ≥50% (TPS) determined by an approved IHC test
• No actionable genetic alterations in genes such as EGFR, ALK, ROS1, HER2, BRAF, RET, MET, NTRK
• First-line palliative PD-1/PD-L1-targeted monotherapy at a 3-weekly schedule indicated per local investigator
• Willingness and ability to undergo study interventions
• ECOG performance status 0-2
• Adequate organ function:
• Hemoglobin ≥70 g/L, platelet count ≥50 G/L, granulocytes ≥1 G/L
• Bilirubin, ALT, AST ≤3 x ULN
• Glomerular filtration rate (Cockroft-Gault) ≥30 mL/min/1.73m²
• Measurable or evaluable disease per RECIST 1.1
• Patients with CNS metastases are eligible, provided there is no requirement for corticosteroids as therapy for CNS disease and no evidence of clinical progression
• Men who are not sterile agree to use contraceptive methods (condoms) or abstain from sexual intercourse during the trial treatment and 3 months thereafter.

You may not qualify if:

• Systemic treatment with an antibiotic within 10 days of ICB treatment/HFD intervention start
• Concomitant immunosuppressive drugs including corticosteroids at a daily dose of ≥10mg prednisone equivalents, methotrexate, azathioprine, TNF-α inhibitors
• Concurrent treatment with other experimental drugs or other anticancer therapy
• Active autoimmune disease requiring systemic immunosuppressive treatment that is seen as contraindication for the use of PD-1/PD-L1-targeted monoclonal antibodies
• Uncontrolled diabetes mellitus
• Severe or uncontrolled cardiovascular disease
• Any other serious underlying medical, psychiatric, psychological, familial or geographical condition, which in the judgment of the investigator may interfere with the planned staging, treatment and follow-up, affect patient compliance or place the patient at high risk from treatment-related complications
• Had an allogeneic tissue/solid organ transplant
• Ongoing supplementation with OptiFibre® or another fiber supplement

Sponsors & Collaborators

• Cantonal Hospital of St. Gallen: lead

Study Sites (4)

Universitätsspital Basel

Basel, 4031, Switzerland

NOT YET RECRUITING

Kantonsspital Graubünden

Chur, 7000, Switzerland

NOT YET RECRUITING

HOCH Health Ostschweiz, Cantonal Hospital St.Gallen

Sankt Gallen, 9007, Switzerland

RECRUITING

Kantonsspital Winterthur

Winterthur, 8401, Switzerland

NOT YET RECRUITING

Related Links

• Related Info

MeSH Terms

Conditions

Carcinoma, Non-Small-Cell Lung

Condition Hierarchy (Ancestors)

Carcinoma, Bronchogenic; Bronchial Neoplasms; Lung Neoplasms; Respiratory Tract Neoplasms; Thoracic Neoplasms; Neoplasms by Site; Neoplasms; Lung Diseases; Respiratory Tract Diseases

Central Study Contacts

Maximilian Boesch, Ph.D.

CONTACT

0041714947143; maximilian.boesch@h-och.ch

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: March 16, 2026
• First Posted: March 19, 2026
• Study Start: October 7, 2025
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: March 19, 2026

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

CH (4)