Proof of Principle Study for an Efficacy Trial of Linaclotide for Cystic Fibrosis
MODEL
A Randomised, Placebo-controlled Crossover Study Defining the Mode of Action of Linaclotide in Healthy Volunteers Using MRI
1 other identifier
interventional
26
1 country
1
Brief Summary
Linaclotide is a medicine used to treat constipation and irritable bowel syndrome with constipation (IBS-C). It works by acting on the surface of the gut lining, where it increases the movement of salt and water into the bowel. This softens stools, makes them easier to pass, and can also reduce gut pain One advantage of linaclotide is that, unlike some natural substances in the gut, it is stable and can act throughout the intestine. Studies in animals show that it has the strongest effect in the upper small intestine, but it may act in other parts of the bowel as well. In people, however, it is not yet clear whether linaclotide mainly works in the small intestine or in the large intestine (colon). Knowing this is important, because it could help the investigators understand whether linaclotide might also be useful in other conditions, such as cystic fibrosis, where the gut does not handle fluid properly. Linaclotide is taken as a capsule, but less than 1% is absorbed into the bloodstream. Instead, it stays in the gut, where it is broken down into smaller active parts. This means both the small intestine and colon may be exposed to its effects. Until now, it has been hard to study this because traditional methods only measure one part of the gut at a time. A team at the University of Nottingham has developed MRI scanning methods that can safely and non-invasively measure water content in the small intestine and colon. The aim of this pilot study is to use MRI in healthy volunteers to see exactly where linaclotide acts. This knowledge will help optimise future studies in conditions such as cystic fibrosis.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P25-P50 for early_phase_1
Started Mar 2026
Shorter than P25 for early_phase_1
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
December 15, 2025
CompletedStudy Start
First participant enrolled
March 9, 2026
CompletedFirst Posted
Study publicly available on registry
May 6, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
August 1, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
October 1, 2026
May 6, 2026
April 1, 2026
5 months
December 15, 2025
April 28, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Small bowel water content
Area under curve (AUC) 0-360 minutes Water content in small bowel as assessed by MRI (mL)
Baseline, and 0, 60, 120, 180, 240, 300, 360 minutes post-dose
Secondary Outcomes (7)
Colon water content
Baseline, and 0, 60, 120, 180, 240, 300, 360 minutes post-dose
Colonic regional segmental volumes
Baseline, and 0, 60, 120, 180, 240, 300, 360 minutes post-dose
Changes in stool consistency
2 days before intervention, 5 days post-intervention
Changes in whole gut transit time (WGTT)
1 day post-intervention
Gastrointestinal symptom rating
2 days pre-intervention and 5 days post-intervention
- +2 more secondary outcomes
Study Arms (2)
Linaclotide
EXPERIMENTAL290 mcg linaclotide across 2 days
Placebo
PLACEBO COMPARATORLactose placebo
Interventions
Eligibility Criteria
You may qualify if:
- Participant is willing and able to give informed consent for participation in the study
- Not currently taking any medications (except for selective serotonin reuptake inhibitors, low dose tricyclic antidepressants, antihistamines, and oral contraceptive pill).
- Aged between 18-60 years.
- Ability to conform to the study protocol, including overnight fasting, dietary and lifestyle restriction, administering linaclotide and placebo intervention, MRI scanning, consuming the rice pudding/blue dye meal, and rating stool frequency and appearance.
You may not qualify if:
- Contraindication to MRI scanning (i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury, unable to lie flat and relatively still for less than 5 minutes.)
- Pregnancy, lactating, or planning pregnancy during the investigation declared by candidate.
- History declared by the candidate of pre-existing gastrointestinal disorder that may affect bowel function.
- Reported history of previous resection of the oesophagus, stomach, or intestine (excluding appendix).
- Intestinal stoma.
- Any medical condition that may potentially compromise participation in the study e.g., known food intolerance to rice pudding, known contraindication to the oral administration of linaclotide or placebo.
- Has a body mass index (BMI) value less than 18.5 or greater than 35.
- Will not agree to follow dietary and lifestyle restrictions required.
- Unable to stop drugs known to alter GI motility including mebeverine, opiates, monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channel antagonists for the duration of the study.
- Participants who are currently (or in the past 3 months) taking antibiotics or probiotics as these may impact GI function.
- Participation in night shift work the week prior to the study day. Night work is defined as working between midnight and 6.00 AM.
- Anyone who in the opinion of the investigator is unlikely to be able to comply with the protocol e.g., cognitive dysfunction, chaotic lifestyle related to substance abuse.
- Having taken part in a research study in the last 3 months involving invasive procedures or an inconvenience allowance
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Sir Peter Mansfield Imaging Centre
Nottingham, NG7 2QX, United Kingdom
Related Publications (19)
Wilkinson-Smith, V., Hoad, C., Atkinson, D., Marciani, L., Corsetti, M., Scott, S. M., Taylor, S., Gowland, P., & Spiller, R. (2021). O59 MRI methods to define colonic function in health and constipation. Gut, 70(Suppl 1), A32-A33. https://doi.org/10.1136/GUTJNL-2020-BSGCAMPUS.59
BACKGROUNDStefano, M. A., Sandy, N. S., Zagoya, C., Duckstein, F., Ribeiro, A. F., Mainz, J. G., & Lomazi, E. A. (2022). Diagnosing constipation in patients with cystic fibrosis applying ESPGHAN criteria. Journal of Cystic Fibrosis, 21(3), 497-501. https://doi.org/10.1016/j.jcf.2021.08.021
BACKGROUNDStefano, M. A., Poderoso, R. E., Mainz, J. G., Ribeiro, J. D., Ribeiro, A. F., & Lomazi, E. A. (2020). Prevalence of constipation in cystic fibrosis patients: a systematic review of observational studies. Jornal de Pediatria, 96(6), 686-692. https://doi.org/10.1016/j.jped.2020.03.004
BACKGROUNDRubinstein, S., Moss, R., & Lewiston, N. (1986). Constipation and Meconium Ileus Equivalent in Patients With Cystic Fibrosis. Pediatrics, 78(3), 473-479. https://doi.org/10.1542/PEDS.78.3.473
BACKGROUNDMcHugh, D. R., Cotton, C. U., Moss, F. J., Vitko, M., Valerio, D. M., Kelley, T. J., Hao, S., Jafri, A., Drumm, M. L., Boron, W. F., Stern, R. C., McBennett, K., & Hodges, C. A. (2018). Linaclotide improves gastrointestinal transit in cystic fibrosis mice by inhibiting sodium/hydrogen exchanger 3. American Journal of Physiology - Gastrointestinal and Liver Physiology, 315(5), G868. https://doi.org/10.1152/AJPGI.00261.2017
BACKGROUNDarciani, L., Wright, J., Foley, S., Hoad, C. L., Totman, J. J., Bush, D., Hartley, C., Armstrong, A., Manby, P., Blackshaw, E., Perkins, A. C., Gowland, P. A., & Spiller, R. C. (2010). Effects of a 5-HT(3) antagonist, ondansetron, on fasting and postprandial small bowel water content assessed by magnetic resonance imaging. Alimentary Pharmacology & Therapeutics, 32(5), 655-663. https://doi.org/10.1111/J.1365-2036.2010.04395.X
BACKGROUNDMarciani, L., Garsed, K. C., Hoad, C. L., Fields, A., Fordham, I., Pritchard, S. E., Placidi, E., Murray, K., Chaddock, G., Costigan, C., Lam, C., Jalanka-Tuovinen, J., De Vos, W. M., Gowland, P. A., & Spiller, R. C. (2014). Stimulation of colonic motility by oral PEG electrolyte bowel preparation assessed by MRI: comparison of split vs single dose. Neurogastroenterology and Motility, 26(10), 1426-1436. https://doi.org/10.1111/NMO.12403
BACKGROUNDLuo, M., Liu, Y., Nikolovska, K., Riederer, B., Patrucco, E., Hofmann, F., & Seidler, U. (2024). cGMP-dependent kinase 2, Na+/H+ exchanger NHE3, and PDZ-adaptor NHERF2 co-assemble in apical membrane microdomains. Acta Physiologica, 240(4), e14125. https://doi.org/10.1111/APHA.14125
BACKGROUNDHayee, B., Watson, K. L., Campbell, S., Simpson, A., Farrell, E., Hutchings, P., Macedo, P., Perrin, F., Whelan, K., & Elston, C. (2019). A high prevalence of chronic gastrointestinal symptoms in adults with cystic fibrosis is detected using tools already validated in other GI disorders. United European Gastroenterology Journal, 7(7), 881-888. https://doi.org/10.1177/2050640619841545
BACKGROUNDHannig, G., Tchernychev, B., Kurtz, C. B., Bryant, A. P., Currie, M. G., & Silos-Santiago, I. (2014). Guanylate cyclase-C/cGMP: an emerging pathway in the regulation of visceral pain. Frontiers in Molecular Neuroscience, 7(1 APR), 31. https://doi.org/10.3389/FNMOL.2014.00031
BACKGROUNDFord, A. C., & Suares, N. C. (2011). Effect of laxatives and pharmacological therapies in chronic idiopathic constipation: systematic review and meta-analysis. Gut, 60(2), 209-218. https://doi.org/10.1136/GUT.2010.227132
BACKGROUNDDellschaft, N., Murray, K., Ren, Y., Marciani, L., Gowland, P., Spiller, R., & Hoad, C. (2025). Assessing Water Content of the Human Colonic Chyme Using the MRI Parameter T1: A Key Biomarker of Colonic Function. Neurogastroenterology and Motility, 37(4). https://doi.org/10.1111/NMO.14999
BACKGROUNDDellschaft, N., Hoad, C., Marciani, L., Gowland, P., & Spiller, R. (2022). Small bowel water content assessed by MRI in health and disease: a collation of single-centre studies. Alimentary Pharmacology & Therapeutics, 55(3), 327-338. https://doi.org/10.1111/APT.16673
BACKGROUNDe Lisle, R. C., & Borowitz, D. (2013). The Cystic Fibrosis Intestine. Cold Spring Harbor Perspectives in Medicine, 3(9), a009753. https://doi.org/10.1101/CSHPERSPECT.A009753
BACKGROUNDCorsetti, M., & Tack, J. (2013). Linaclotide: A new drug for the treatment of chronic constipation and irritable bowel syndrome with constipation. United European Gastroenterology Journal, 1(1), 7-20. https://doi.org/10.1177/2050640612474446
BACKGROUNDBusby, R. W., Kessler, M. M., Bartolini, W. P., Bryant, A. P., Hannig, G., Higgins, C. S., Solinga, R. M., Tobin, J. V., Wakefield, J. D., Kurtz, C. B., & Currie, M. G. (2013). Pharmacologic Properties, Metabolism, and Disposition of Linaclotide, a Novel Therapeutic Peptide Approved for the Treatment of Irritable Bowel Syndrome with Constipation and Chronic Idiopathic Constipation. The Journal of Pharmacology and Experimental Therapeutics, 344(1), 196-206. https://doi.org/10.1124/JPET.112.199430
BACKGROUNDBryant, A. P., Busby, R. W., Bartolini, W. P., Cordero, E. A., Hannig, G., Kessler, M. M., Pierce, C. M., Solinga, R. M., Tobin, J. V., Mahajan-Miklos, S., Cohen, M. B., Kurtz, C. B., & Currie, M. G. (2010). Linaclotide is a potent and selective guanylate cyclase C agonist that elicits pharmacological effects locally in the gastrointestinal tract. Life Sciences, 86(19-20), 760-765. https://doi.org/10.1016/J.LFS.2010.03.015
BACKGROUNDAtluri, D. K., Chandar, A. K., Bharucha, A. E., & Falck-Ytter, Y. (2014). Effect of linaclotide in irritable bowel syndrome with constipation (IBS-C): a systematic review and meta-analysis. Neurogastroenterology and Motility, 26(4), 499-509. https://doi.org/10.1111/NMO.12292
BACKGROUNDAliyu, A., Dellschaft, N., Hoad, C., Williams, H., Gaudoin, E., Sulaiman, S., Crooks, C., Gowland, P., Aran, A., Lange, R., Bois De Fer, B., Corsetti, M., Marciani, L., & Spiller, R. (2025). Magnetic Resonance Imaging Reveals Novel Insights into the Dual Mode of Action of Bisacodyl: A Randomized, Placebo-controlled Trial in Constipation. Clinical Pharmacology and Therapeutics, 117(5), 1284-1291. https://doi.org/10.1002/CPT.3532
BACKGROUND
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- early phase 1
- Allocation
- RANDOMIZED
- Masking
- TRIPLE
- Who Masked
- PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- CROSSOVER
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Professor Robin Spiller
Study Record Dates
First Submitted
December 15, 2025
First Posted
May 6, 2026
Study Start
March 9, 2026
Primary Completion (Estimated)
August 1, 2026
Study Completion (Estimated)
October 1, 2026
Last Updated
May 6, 2026
Record last verified: 2026-04