Fibrostenotic Crohn's Disease
Conditions
Keywords
Phosphodiesterase 4 Inhibitor, PDE4 Inhibition, Intestinal Fibrosis, Inflammatory Bowel Disease (IBD), Ileal Stricture, Crohn's Disease, PALI-2108, Oral PDE4 Inhibitor
Brief summary
This is a Phase 1b, open-label, exploratory study designed to evaluate the pharmacodynamic effects of PALI-2108, a phosphodiesterase-4 (PDE4) inhibitor, in patients with fibrostenotic Crohn's disease (FSCD). The study will assess molecular, cellular, and histologic changes in intestinal tissue and peripheral blood following short-term oral administration of PALI-2108. Eligible participants with FSCD will undergo paired ileal pinch biopsies and peripheral blood collection at baseline and after 14 days of PALI-2108 treatment. The primary objective is to elucidate the mechanism of action of PALI-2108 in modulating inflammatory and fibrotic pathways relevant to FSCD pathobiology. Analyses will include single-nucleus RNA sequencing (snRNA-seq) of intestinal biopsies and single-cell RNA sequencing (scRNA-seq) of PBMCs to profile treatment-induced transcriptomic changes across immune and stromal cell populations. The FSCD cohort is part of a larger, multi-part study that also includes a completed Phase 1a first-in-human portion in healthy volunteers and an ulcerative colitis (UC) cohort evaluating clinical and biomarker responses to PALI-2108 treatment.
Detailed description
This Phase 1b exploratory study will investigate the pharmacodynamic and mechanistic effects of short-term oral administration of PALI-2108, a selective phosphodiesterase-4 (PDE4) inhibitor, in patients with fibrostenotic Crohn's disease (FSCD). The FSCD cohort builds upon the safety, tolerability, and pharmacokinetic findings from the completed Phase 1a first-in-human study and complements the ongoing ulcerative colitis (UC) cohort that assesses clinical and biomarker responses to PALI-2108 in active disease. Fibrostenotic Crohn's disease is characterized by chronic inflammation and progressive fibrosis of the intestinal wall leading to luminal narrowing, strictures, and obstructive symptoms. Current medical therapies inadequately address the fibrotic component of disease, underscoring the need for interventions targeting both immune and stromal pathways. PDE4 inhibition represents a validated anti-inflammatory approach with emerging evidence for modulation of profibrotic signaling. In this study, patients with ileal or ileocolonic FSCD will receive PALI-2108 orally once daily for 14 days. Paired ileal pinch biopsies and peripheral blood samples will be collected at baseline (Day 1) and at the end of treatment (Day 14). The primary objective is to characterize molecular and cellular changes induced by PDE4 inhibition in intestinal and immune compartments. Transcriptomic profiling will be performed using single-nucleus RNA sequencing (snRNA-seq) on intestinal biopsies and single-cell RNA sequencing (scRNA-seq) on peripheral blood mononuclear cells (PBMCs). Analyses will evaluate treatment-associated changes in gene expression, cell-type composition, and pathway activation, with a focus on immune, epithelial, fibroblast, and myofibroblast populations implicated in FSCD pathology. Secondary and exploratory endpoints will include assessment of safety, tolerability, pharmacokinetics, and biomarker correlations across tissue and blood compartments. Data from this FSCD cohort are expected to provide mechanistic insights into the biological effects of PDE4 inhibition in fibrostenotic disease and to inform dose selection, biomarker strategies, and patient segmentation for subsequent clinical development programs of PALI-2108.
Interventions
Oral PALI-2108 administered once daily for 14 days. Sentinel subjects titrate from 5 mg to 20 mg. Subsequent patients receive a target dose between 10-30 mg based on SRC review, following protocol-specified titration schedules. Dose reductions are permitted for safety. All doses are taken in the fed state. PALI-2108 is an oral, gut-activated PDE4 inhibitor prodrug designed to release its active metabolite (PALI-0008) locally via bacterial β-glucuronidase. This targeted delivery limits systemic exposure and reduces CNS-related effects associated with systemic PDE4 inhibitors, providing localized anti-inflammatory and anti-fibrotic activity in intestinal tissue.
Sponsors
Study design
Intervention model description
Study Type: Interventional (Clinical Trial) Phase: 1b Allocation: Non-Randomized Intervention Model: Single Group Assignment Masking: None (Open Label) Primary Purpose: Basic Science / Mechanistic Exploration
Eligibility
Inclusion criteria
1. Provision of signed and dated informed consent form (ICF) 2. Stated willingness to comply with all study procedures and availability for the duration of the study 3. Aged at least 18 years but not older than 60 years 4. Body mass index (BMI) within 18.5 kg/m2 to 30.0 kg/m2, inclusively 5. Non- or ex-smoker 6. Healthy adult male or female 7. Have no clinically significant (CS) diseases captured in the medical history or evidence of CS findings on the physical examination (including vital signs) and/or ECG, as determined by an Investigator 8. Provision of signed and dated ICF 9. Stated willingness to comply with all study procedures and availability for the duration of the study 10. If male, meets one of the following criteria: 1. Is able to procreate and agrees to use one of the accepted contraceptive regimens and not to donate sperm from the first study drug administration to at least 90 days after the last study drug administration. An acceptable method of contraception includes one of the following: * Abstinence from heterosexual intercourse * Male condom with spermicide or male condom with a vaginal spermicide Or 2. Is unable to procreate; defined as surgically sterile If female, meets one of the following criteria: 1. Is of childbearing potential and agrees to use an acceptable contraceptive method. Acceptable contraceptive methods include: * Abstinence from heterosexual intercourse from 14 days prior to the Screening visit through to at least 30 days after the last dose of the study drug * Use of 1 highly effective method in combination with 1 effective method of contraception. • The following are examples of highly effective contraceptive methods, used from at least 28 days prior to the Screening visit through to at least 30 days after the last dose of the study drug: * Systemic contraceptives (combined birth control pills, injectable/implant/insertable hormonal birth control products, or transdermal patch) * Intrauterine device * Male partner vasectomized at least 6 months prior to the Screening visit • The following are examples of effective contraceptive methods, used from the Screening visit through to at least 30 days after the last dose of the study drug: * Male condom with spermicide * Female condom, or cervical cap, or diaphragm, each used with spermicide * Contraceptive sponge 2. Is of non-childbearing potential, defined as surgically sterile (i.e., has undergone complete hysterectomy, bilateral oophorectomy, or tubal ligation), or is in a postmenopausal state (ie, at least 1 year without messes and without an alternative medical condition prior to the Screening visit) 11. Diagnosis of ileal or ileocolonic CD based on supporting guideline criteria established at least 3 months prior to Screening, i.e.: c) Clinically symptomatic fibrostenosing Crohn's disease, defined by ≥1 obstructive symptom attributable to the index ileal stricture within the prior 12 weeks and corroborated at Screening by the Stricturing Crohn's Disease patient-reported questionnaire (SPRO). d) Symptoms must be accompanied by an ileal stricture within reach of the endoscope. 12. Screening IUS confirms the presence of at least 1 stricture in the terminal ileum or proximal colon, within reach of an endoscope (passable or non-passable). Strictures should be noncritical, naïve or anastomotic stricture(s), caused by CD and confirmed by endoscopy. 13. Stable background therapy for CD and agree to maintain background therapy for the study duration. 14. Patients may or may not experience stricture related symptoms, such as abdominal pain, during Screening 15. Willingness to follow a stable diet during the study
Exclusion criteria
1. Female who is lactating 2. Female who is pregnant according to the pregnancy test at Screening or Day -1 3. History of significant hypersensitivity to PALI-2108 or any other PDE-4 inhibitor (including excipients of the formulations) as well as severe hypersensitivity reactions (like angioedema) to any drugs 4. Presence or history of significant gastrointestinal, liver or kidney disease, or surgery that may affect drug bioavailability or transit 5. Presence of history of renal disease 6. History of significant cardiovascular, pulmonary, hematologic, neurological, psychiatric, endocrine, immunologic, or dermatologic disease 7. An active infection or a recent history of serious infections 30 days prior to first study drug administration 8. Presence of CS vital sign and/or ECG abnormalities (based on the average of triplicate ECG readings) at the Screening visit, as defined by medical judgment 9. Major surgery in the 4 weeks prior to the first study drug administration 10. Vaccination with any live vaccine within 4 weeks prior to study drug administration 11. Maintenance therapy with any drug or significant history of drug dependency or alcohol abuse (\> 3 units of alcohol per day, intake of excessive alcohol, acute or chronic) 12. Any CS illness in the 28 days prior to the first study drug administration 13. Use of St. John's wort in the 28 days prior to the first study drug administration 14. Any history of tuberculosis 15. Positive test result for alcohol and/or drugs of abuse at Screening or prior to the first study drug administration 16. Positive Screening results to HIV antigen/antibody (Ag/Ab) combo, hepatitis B surface antigen, or hepatitis C virus tests 17. Any other CS abnormalities in laboratory test results at Screening that would, in the opinion of an Investigator, increase the subject's risk of participation, jeopardize complete participation in the study, or compromise interpretation of study data 18. Inclusion in a previous group for this clinical study 19. Intake of PALI-2108 in the 28 days prior to the first study drug administration 20. Intake of an investigational drug in the 28 days prior to the first study drug administration 21. Donation of 50 mL or more of blood in the 28 days prior to the first study drug administration 22. Donation of 500 mL or more of blood (Canadian Blood Services, Hema-Quebec, clinical studies, etc.) in the 56 days prior to the first study drug administration 23. History or current diagnosis of UC, indeterminate colitis, ischemic colitis, nonsteroidal anti-inflammatory drug-induced colitis, idiopathic colitis (ie, colitis not consistent with CD), radiation colitis, microscopic colitis, colonic mucosal dysplasia, or untreated bile acid malabsorption. 24. CD related complications (previous extensive small bowel resection, ileorectal anastomosis, proctocolectomy, short bowel syndrome, ileostomy \[diverting or end\], colostomy, small bowel stoma, ileoanal pouch, inactive fistulae in or adjacent to an ileal stricture, anal and perianal stricture, active intra-abdominal or perianal abscess that has not been appropriately treated, abscess in relation to the stricture, toxic megacolon, very severe inflammation, or presence of deep ulceration in the colon or terminal ileum). 25. Ileitis not associated with CD (e.g., ileitis associated with infections, spondyloarthropathies, ischemia, etc.). 26. Strictures that cannot be reached by ileocolonoscopy 27. Severe FSCD based on symptoms, or unstable disease 28. Expected to require hospitalization, endoscopic balloon dilation, surgical resection, or additional therapy during the study 29. Receiving cyclosporine, tacrolimus, sirolimus, or mycophenolate mofetil within 8 weeks of screening or Janus kinase inhibitor therapy within 4 weeks of screening. 30. Current or history of vasculitis, valvulopathy or large vessel disorder or major abnormalities documented by cardiac echocardiography with Doppler
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Safety and tolerability of PALI-2108 administered for 14 days. | 14 days | Adverse events in FSCD patients receiving PALI-2108 |
| Safety and tolerability of PALI-2108 | 14 Days | Incidence of clinically significant laboratory abnormalities |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maximum Concentration (Cmax) | Day 1 | Maximum plasma concentrations of PALI-2108 and its metabolites (PALI-0008 and PALI-0708 ) following dosing with PALI-2108 |
| Concentration at 12 hours (C12) | Day 1 | Plasma concentrations of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) at 12 hours following dosing with PALI-2108 |
| Time to Cmax (Tmax) | Day 1 | Time to reach maximum plasma concentrations of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) |
| Area under the plasma concentration-time curve (AUC0-24) | Day 1 | Area under the plasma concentration-time curve of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) during the first 24 hours period after first dosing with PALI-2108 |
| Terminal half-life (t1/2) | Day 1 and Day 13 | Plasma elimination half-life of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) after first dose of PALI-2108 |
| Trough plasma concentration (Ctrough) | Day 2 through Day 14 | Plasma concentration of PALI-2108 and its metabolites (PALI-0008 and PALI-070) measured in the morning, before PALI-2108 dosing |
| Maximal concentration at steady state (Css) | Day 13 | Maximal plasma concentration of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) measured at plasma drug steady state |
| Area under the plasma concentration-time curve (AUC0-12) | Day 13 | Area under the plasma concentration-time curve of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) during the first 12 hours period after dosing with PALI-2108 |
| Area under the plasma concentration-time curve (AUC0-8) | Day 14 | Area under the plasma concentration-time curve of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) during the first 8 hours period after last dosing with PALI-2108 |
| Tissue concentration | Day 14 | Concentrations of of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) in ileal, ascending and descending colonic tissue at plasma steady state. |
| Tissue/plasma concentration ratio | Day 14 | Ratio between tissue and plasma concentrations of PALI-2108 and its metabolites (PALI-0008 and PALI-0708) in ileal, ascending and descending colonic tissue at plasma steady state. |
Countries
Canada