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Non-Small Cell Carcinoma of LungFiber-BoostNCT07483112

Fiber-Boost Randomized Controlled Trial

A study testing High-fiber diet in people with Non-Small Cell Carcinoma of Lung, run by Cantonal Hospital of St. Gallen at 4 sites in Switzerland.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Non-Small Cell Carcinoma of Lung
What is being tested?
High-fiber diet
Could I receive a placebo?
No, everyone receives an active treatment
How many people
42 participants
Where
4 sitesSwitzerland
Study dates
7 Oct 2025to 31 Dec 2027
Phase
Interventional
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 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age ≥18 years
  • Written informed consent according to Swiss law and ICH/GCP regulations before inclusion and prior to any trial-specific procedures
  • 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
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  • 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
  • Women with child-bearing potential use effective contraception (two independent methods), are not currently pregnant or lactating, and agree to not become pregnant during the trial treatment and during 3 months thereafter. A negative pregnancy test in either urine or blood is required for women with child-bearing potential before trial inclusion.
  • Men who are not sterile agree to use contraceptive methods (condoms) or abstain from sexual intercourse during the trial treatment and 3 months thereafter.

Who cannot join

  • -History of malignancy, unless in remission for at least 3 years before inclusion with the exception of pT1-2 prostate cancer Gleason score <6, adequately treated cervical carcinoma in situ or localized non-melanoma skin cancer
  • Adjuvant or additive systemic ICB treatment within 6 months prior to inclusion
  • 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
  • Major surgical procedures within 14 days prior to inclusion as judged by the investigator
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  • 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

Trial locations and contacts

4 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Maximilian Boesch, Ph.D. contact

0041714947143

maximilian.boesch@h-och.ch

Switzerland4 sites, 4 recruiting

  • Universitätsspital Basel

    Basel, 4031

    Geraldine Borer, 0041613287081, g.borer@usb.ch

    Not yet recruiting

  • Kantonsspital Graubünden

    Chur, 7000

    Gabriela Manetsch-Dalla Torre, 0041812566860, gabriela.manetsch@ksgr.ch

    Not yet recruiting

  • HOCH Health Ostschweiz, Cantonal Hospital St.Gallen

    Sankt Gallen, 9007

    Maximilian Boesch, Ph.D., 0041714947143, maximilian.boesch@h-och.ch

    Recruiting

  • Kantonsspital Winterthur

    Winterthur, 8401

    Beatrice Brinkers, 0041522663655, beatrice.brinkers@ksw.ch

    Not yet recruiting

Other trials in Switzerland

About this study

Official title: Multicenter, Randomized, Controlled Trial to Study the Effects of a High-Fiber Dietary Intervention on ctDNA Clearance and the Microbial and Immunological Landscape in Patients With Advanced Non-Small Cell Lung Cancer Receiving PD-1/PD-L1-Targeted Monotherapy (Fiber-Boost)

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.

Read the detailed description

The activity of immune checkpoint blockade (ICB) mechanistically depends on the host microbiome and is manipulable through diet. In this study termed Fiber-Boost, we propose a multicenter trial of a supplement-based high-fiber diet (HFD) in non-small cell lung cancer (NSCLC) treated with first-line ICB monotherapy. Using a randomized, controlled design, we mechanistically explore the role of dietary fibers in cancer immunotherapy. Circulating tumor DNA (ctDNA) quantification as well as a rich pipeline of companion microbiome and immune profiling technologies will improve the understanding of the diet-microbiome-immune axis in therapeutic anticancer immunity and treatment response. The overarching goal is to elucidate novel therapeutic strategies for ICB sensitization in NSCLC using microbiome-centered, non-pharmaceutical interventions. Sex and gender dimensions are biologically not sufficiently relevant for the current study to merit corresponding stratification or analyses.

Being tested
High-fiber diet
Keywords
non-small cell lung cancer, immunotherapy, high-fiber diet, microbiome
Medical subject headings
Carcinoma, Non-Small-Cell Lung

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • High-fiber dietDietary 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.

Study groups in NCT07483112
Study groupRoleWhat they receive
High-fiber dietExperimentalPatients in this arm will receive a high-fiber diet over the period of 6 weeks.
Receives: Dietary Supplement: High-fiber diet
No high-fiber dietNo interventionPatients in this arm will not receive an intervention and serve as control.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. ctDNA clearance

    Fraction of patients achieving complete ctDNA clearance at 6 weeks

    Measured: 6 weeks

Secondary outcomes (5)

  1. ctDNA dynamics

    ctDNA dynamics over 6 weeks

    Measured: 3 and 6 weeks

  2. Radiological treatment response

    Objective radiological response (RECIST 1.1)

    Measured: 6 weeks and 6 months

  3. Disease control rate

    6-months disease control rate (non-progressive disease at 6 months)

    Measured: 6 months

  4. Microbiota dynamics

    Gut microbiota dynamics by shotgun metagenomics

    Measured: 6 weeks

  5. Systemic immune response

    Systemic immune response dynamics by high-dimensional flow cytometry

    Measured: 6 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted19 Mar 2026
  2. Study start7 Oct 2025
  3. Primary completion31 Dec 2027 (estimated)
  4. Study completion31 Dec 2027 (estimated)

Resources

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 N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
42 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07483112
Sponsor's protocol ID
BASEC2025-00650
Other IDs
KFS-6039-02-2024, Lungenliga Ost, Swiss Cancer Foundation, Nestlé Health Science
Acronym
Fiber-Boost
Status last verified
Oct 2025
First submitted
16 Mar 2026
Last updated
19 Mar 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing High-fiber diet in people with Non-Small Cell Carcinoma of Lung, run by Cantonal Hospital of St. Gallen at 4 sites in Switzerland.

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 17 inclusion and 12 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 19 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in Switzerland. 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.

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 Maximilian Boesch, Ph.D. (0041714947143, maximilian.boesch@h-och.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

ctDNA clearance (time frame: 6 weeks). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07483112.

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 19 Mar 2026.

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