The RESOLVE Phase 1b/2a data for EP-104GI presents a clinically differentiated hypothesis, not a confirmed efficacy claim. Sixty-four percent of patients across cohorts 5–9 maintained clinical remission at 52 weeks after a single administration, with 66% in the highest dose cohort (Cohort 9) and a histologic reduction in inflammation and fibrosis at 36 weeks in Cohort 8b — all from a single-arm, uncontrolled early-phase study. The absence of a placebo comparator is the defining limitation: without a concurrent control arm, these remission rates cannot be attributed to EP-104GI's pharmacological effect rather than natural disease fluctuation, regression to the mean, or patient selection within a dose-escalation cohort structure. No closely comparable regulatory precedent exists for a single-administration depot corticosteroid in EoE. The closest mechanistic reference — budesonide orodispersible tablets (Jorveza), a topical corticosteroid delivering budesonide to the esophageal mucosa via twice-daily oral dosing in PPI-refractory adults — achieved conditional reimbursement and positive HTA outcomes (NICE TA708, CADTH, Danish Medicines Council, HAS) only on the basis of two placebo-controlled Phase 3 RCTs. [1] That precedent passes the mechanistic-fit check on drug class and indication but fails on delivery architecture and dosing paradigm, meaning it confirms the regulatory pathway is navigable for a corticosteroid in EoE without providing a template for the single-administration model. [2] The safety signal — no treatment-related SAEs and no corticosteroid-exposure adverse events — is directionally favorable against budesonide ODT's 13–24% candidiasis rates across its Phase 3 program, but Phase 1b/2a sample sizes cannot characterize a safety profile with the confidence regulators require. The fibrosis reduction signal in Cohort 8b is the most novel finding and has no direct comparator in the budesonide ODT pivotal program. The sharpest risk is that a Phase 3 randomized controlled trial — the only instrument that can convert this hypothesis into evidence — has not yet been initiated, and the competitive landscape now includes an approved topical corticosteroid (budesonide ODT) and an approved biologic (dupilumab, mechanistically distinct via IL-4/IL-13 pathway blockade) against which EP-104GI will need to demonstrate added clinical value. [3]
All efficacy figures derive from the RESOLVE Phase 1b/2a single-arm study with no placebo comparator; the 64–66% clinical remission rates at 52 weeks cannot be interpreted as net treatment effect, and endpoint definitions are not confirmed against the clinico-histological composite standard accepted by regulators and HTA bodies.
| Indication | Eosinophilic Esophagitis |
| Drug | EP-104GI |
| Mechanism of Action | Local corticosteroid delivery |
| Company | Eupraxia Pharmaceuticals Inc. |
| Trial Phase | Phase 1b/2a |
| Trial Acronym | RESOLVE |
| Category | Clinical Trial Event |
| Sub Category | Topline Results Positive |
| Therapeutic Area | Gastroenterology & Hepatology |
| Follow-up Duration | 52 weeks, 36 weeks |
| Clinical Remission Rate (52 Weeks) | 64% (9 of 14 patients across cohorts 5-9) |
| Highest Dose Cohort Remission (52 Weeks) | 66% (2 of 3 patients in Cohort 9) |
| Histologic Reduction (Cohort 8b, 36 Weeks) | EoEHSS Stage -0.26, EoEHSS Grade -0.27 |
| Primary Efficacy Measure | Straumann Dysphagia Index (SDI) |
| Secondary Efficacy Measure | Eosinophilic Esophagitis Histology Scoring System (EoEHSS) |
| Safety Profile | No treatment-emergent or procedure related SAEs, No oropharyngeal candidiasis, No adrenal insufficiency or glucose derangement |
| Dosing Regimen Potential | Annual dosing |
| Technology Platform | Diffusphere™ technology |
| Next Data Expected | December 2026 (Phase 2b interim data) |
Eupraxia Reports Durable 52-Week EP-104GI Data in EoE RESOLVE Trial
Eupraxia Pharmaceuticals Inc. announced updated clinical data from the Phase 1b/2a RESOLVE study for EP-104GI in Eosinophilic Esophagitis (EoE). The data highlights a long duration of response, high remission rates, and favorable tolerability. Across cohorts 5-9, 64% of patients maintained clinical remission 52 weeks after a single administration. Specifically, the highest dose cohort (Cohort 9) showed 66% of patients maintaining clinical remission at 52 weeks. The second highest dose group (Cohort 8b) demonstrated meaningful histologic reduction in inflammation and fibrosis at 36 weeks. No treatment-related Serious Adverse Events (SAEs) or adverse events related to corticosteroid exposure were observed.
- The Phase 1b/2a RESOLVE trial demonstrated significant durability of symptom responses for EP-104GI in EoE patients. The highest dose cohort (Cohort 9, 20 x 8 mg dose) showed 66% (2 of 3) of patients maintaining clinical remission at 52 weeks. Overall, 64% (9 of 14) of patients across cohorts 5-9 remained in clinical remission 52 weeks after a single administration, supporting the potential for an annual dosing regimen.
- EP-104GI also showed clinically meaningful histologic improvements. In Cohort 8b (20 x 6 mg dose), mean reductions in Eosinophilic Esophagitis Histology Scoring System (EoEHSS) Stage and Grade were -0.26 and -0.27, respectively, at 36 weeks. These reductions indicate a significant decrease in inflammation and fibrosis, consistent with the clinical responses observed across all analyzed cohorts.
- The safety and tolerability profile of EP-104GI was favorable across all dose levels, including the highest dose. No treatment-emergent or procedure-related Serious Adverse Events (SAEs) were reported. Crucially, there were no cases of oropharyngeal candidiasis, adrenal insufficiency, or glucose derangement, which are common adverse events associated with traditional swallowed steroids.
EP-104GI Shows Durable Efficacy and High Remission in EoE
Three recent studies have advanced the evidence base for eosinophilic esophagitis (EoE) pharmacotherapy. The DUPEOETALY study evaluated dupilumab — a monoclonal antibody targeting the IL-4 receptor alpha — in a retrospective observational cohort of 167 Italian patients over 72 weeks. All three primary outcomes improved significantly with treatment duration: DSQ score decreased from 22.14±26.63 to 0.21±2.30, EREFS from 4.95±3.43 to 0.07±0.09, and eosinophil count from 36.80±31.75 to 0.06±0.46 eos/HPF. By week 72, 98.3% of patients achieved remission criteria (DSQ ≤5, Eos ≤15, and EREFS ≤2). Adverse events were minimal, declining from 3.8% at week 12 to 0% by week 60, supporting dupilumab as a viable long-term management option.
A Phase 3 randomized, double-blind, placebo-controlled trial assessed budesonide oral suspension (BOS) 2.0 mg twice daily versus placebo over 12 weeks in 318 patients aged 11–55 years with EoE and dysphagia. BOS demonstrated superiority across co-primary endpoints: 53.1% of BOS-treated patients achieved a stringent histologic response (≤6 eos/hpf) versus 1.0% on placebo (Δ52% [95% CI, 43.3%–59.1%]; P < .001), and 52.6% achieved a dysphagia symptom response versus 39.1% (Δ13% [95% CI, 1.6%–24.3%]; P = .024). BOS-treated patients also showed greater improvements in least-squares mean DSQ scores (−13.0 vs −9.1; Δ−3.9 [95% CI, −7.1 to −0.8]; P = .015) and EREFS (−4.0 vs −2.2; Δ−1.8 [95% CI, −2.6 to −1.1]; P < .001). Most adverse events were mild or moderate in severity.
A pooled post hoc analysis of Phase 2 (NCT01642212) and Phase 3 (NCT02605837) data further examined BOS 2.0 mg twice daily specifically in 76 adolescents aged 11–17 years. Significantly more BOS-treated adolescents achieved histologic responses at week 12 compared with placebo — ≤6 eos/hpf: 46.7% vs 6.5%; ≤1 eos/hpf: 42.2% vs 0.0%; <15 eos/hpf: 53.3% vs 9.7% (all P < .001) — along with a clinicopathologic response (31.1% vs 3.2%; P = .003). BOS-treated patients also demonstrated significantly greater reductions in EoEHSS grade and stage total score ratios (P < .001) and total EREFS (P = .021). The dysphagia symptom response rate was numerically higher with BOS (68.9% vs 58.1%) but did not reach statistical significance (P = .314). BOS was well tolerated, with no clinically meaningful differences in adverse events versus placebo.
RESOLVE Trial Design and Next Steps for EP-104GI in EoE
Several randomized controlled trials have evaluated pharmacologic interventions for eosinophilic esophagitis (EoE), employing histologic, symptomatic, and endoscopic endpoints across pediatric and adult populations. The trials below represent the key evidence base, spanning topical corticosteroids, biologic therapy, and head-to-head comparator designs.
| Trial / Study | Design | Population | Intervention(s) | Primary Endpoints | Key Secondary Endpoints |
|---|---|---|---|---|---|
| Fluticasone vs. Placebo (RCT) | Randomized, placebo-controlled | Children | Topical fluticasone vs. placebo | Symptom reduction (vomiting, dysphagia); histologic remission | Adverse events (oral candidiasis) |
| Fluticasone vs. Oral Prednisone (RCT) | Randomized, active comparator | Children | Topical fluticasone vs. oral prednisone | Symptom resolution; histological improvement at 4 weeks | Symptom relapse at 6-month follow-up; adverse events |
| Mepolizumab vs. Placebo (RCT) | Randomized, placebo-controlled | Not specified | Mepolizumab vs. placebo | Symptom response | Esophageal eosinophil count reduction (67% vs. 25%) |
| BOS Phase 2 Trial (NCT01642212) | Multicenter, randomized, double-blind, placebo-controlled, parallel-group, Phase 2 | Adolescents and adults aged 11–40 years with dysphagia and active esophageal eosinophilia (n = 93) | Budesonide oral suspension (BOS) 2 mg twice daily vs. placebo for 12 weeks | Change in DSQ score from baseline; proportion of patients achieving histologic response (≤6 eos/hpf) | Endoscopic severity score (EREFS); safety parameters |
| OVB vs. Fluticasone MDI (NCT02019758) | Double-blind, double-dummy, randomized controlled trial | Adults with new EoE diagnosis (n = 111; OVB n = 56, MDI n = 55) | Oral viscous budesonide (OVB) 1 mg/4 mL twice daily + placebo inhaler vs. fluticasone MDI 880 μg twice daily + placebo slurry for 8 weeks | Post-treatment maximum eosinophil count (eos/hpf) at week 8; DSQ score at week 8 | Endoscopic severity (EoE endoscopic reference score); histologic response (<15 eos/hpf); safety |
| DUPEOETALY Study | Retrospective observational study | EoE patients unresponsive or intolerant to conventional therapies from 50 Italian centers (n = 167; median age 21.5 years; 77.8% male) | Dupilumab via compassionate use or off-label programs | DSQ score; EREFS; eosinophil count (Eos/HPF) assessed at baseline, 12, 24, 36, 48, 60, and 72 weeks | Remission rate at week 72 (DSQ ≤5, Eos ≤15, EREFS ≤2); adverse events over time |
A New Horizon for Eosinophilic Esophagitis Treatment
Eosinophilic Esophagitis (EoE) is a chronic, immune-mediated inflammatory condition that significantly impacts patients' quality of life, often requiring lifelong management. Current therapeutic strategies, while effective, frequently involve daily medication regimens, restrictive diets, or regular injectable biologics, all of which can contribute to substantial treatment burden and adherence challenges. The recent clinical update for EP-104GI offers a compelling glimpse into a potentially transformative approach for this patient population.
The reported data from the Phase 1b/2a RESOLVE study highlights a remarkable duration of response, with a significant proportion of patients maintaining clinical remission for 52 weeks following a single administration. This 'less is more' paradigm could fundamentally alter the treatment landscape, moving away from the constant vigilance associated with daily swallowed corticosteroids like fluticasone, which, despite their efficacy, carry risks of local side effects such as esophageal candidiasis. Similarly, it presents an alternative to the ongoing commitment required for biologic therapies like dupilumab.
From a strategic perspective, a single-dose therapy with such sustained efficacy and a favorable tolerability profile—notably, the absence of corticosteroid-related adverse events—could carve out a dominant position in the EoE market. It promises to alleviate the significant patient burden, potentially leading to higher adherence rates and improved long-term outcomes. This differentiation could also validate the underlying technology, paving the way for its application in other chronic inflammatory conditions.
However, it is crucial to contextualize these promising early-phase results. The findings, while encouraging, stem from a relatively small patient cohort in a Phase 1b/2a study. The long-term safety and efficacy, particularly in a broader patient population and against established comparators, will need robust confirmation in larger, pivotal Phase 3 trials. The specific mechanism enabling this prolonged effect and the sustained absence of corticosteroid-related side effects, if EP-104GI is indeed a corticosteroid, warrant thorough investigation. If these early signals are confirmed, EP-104GI could represent a significant leap forward, offering a truly patient-centric solution for managing chronic EoE.
Frequently Asked Questions
References
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