📚 Part of the TILA-278 Regulatory Dossier — Reader's Guide. This article shows the live document; edits to the source appear here automatically.

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Module 2.5 — Clinical Overview

Field	Value
Document ID	M25
Version	1.0
Compound	TILA-278 (anti-TL1A antagonist / IL-22R agonist bispecific)
Standard	ICH M4E(R2)
Confidentiality	Confidential

Interpretive, critical overview integrating clinical pharmacology, efficacy, and safety for TILA-278 in ulcerative colitis; the benefit–risk is concluded in §2.5.6. Pivotal figures trace to Study TILA278-201.

Change History

Version	Date	Author	Summary
1.0	2026-07-08	Clinical/Regulatory	Initial issue

2.5.1 Product Development Rationale

Ulcerative colitis (UC) is a chronic, relapsing immune-mediated inflammatory disease of the colonic mucosa characterized by rectal bleeding, urgency, and diarrhoea, with a lifelong risk of colectomy, dysplasia, and disability. Despite the introduction of anti-TNF agents, anti-integrin therapy, IL-12/23 inhibitors, and JAK inhibitors, a substantial proportion of patients with moderate-to-severe disease fail to achieve or sustain corticosteroid-free remission, and response rates diminish in patients previously exposed to biologic therapy. Mucosal healing, now recognized as a principal determinant of durable remission and reduced colectomy risk, remains difficult to attain with agents that suppress inflammation without directly promoting epithelial repair. A persistent unmet need therefore exists for therapies that combine potent control of the inflammatory drivers of UC with active restoration of the mucosal barrier.

TILA-278 is a subcutaneously administered bispecific monoclonal antibody engineered to address both arms of this pathophysiology through a single molecule. One arm antagonizes TL1A (TNFSF15), a TNF-superfamily cytokine that amplifies TH1 and TH17 effector responses and promotes intestinal fibrosis; TL1A pathway activity is genetically and mechanistically linked to UC severity and to a fibrostenotic disease course. The second arm is an IL-22R agonist that drives intestinal epithelial regeneration, mucin production, and antimicrobial peptide expression, thereby accelerating mucosal-barrier repair. The dual rationale is complementary and mechanistically coherent: TL1A antagonism dampens the inflammatory cascade that perpetuates mucosal injury, while IL-22R agonism actively rebuilds the epithelium, offering the prospect of combined anti-inflammatory control and mucosal healing beyond that achievable with single-pathway agents.

The clinical development program for TILA-278 in UC is anchored by Study TILA278-201 (Sponsor: Virtual Biopharma Inc.), a Phase 2b induction study designed to establish proof of concept, characterize the dose-response relationship, and support dose selection for confirmatory Phase 3 evaluation. This Clinical Overview integrates the biopharmaceutic, clinical pharmacology, efficacy, and safety findings from that study.

2.5.2 Overview of Biopharmaceutics

TILA-278 is a humanized bispecific immunoglobulin G monoclonal antibody supplied as a sterile solution for subcutaneous (SC) injection. As a large-molecule biotherapeutic administered by the SC route, TILA-278 is absorbed into the systemic circulation predominantly via lymphatic drainage and is not subject to gastrointestinal absorption, first-pass hepatic metabolism, or cytochrome P450-mediated clearance. Consequently, classical oral bioavailability and food-effect assessments are not applicable. Elimination occurs through catabolism to peptides and amino acids and via target-mediated drug disposition, consistent with the monoclonal antibody class. In Study TILA278-201 the SC formulation was administered from a single drug-product presentation across both dose levels, and no bridging between formulations was required within the study.

2.5.3 Overview of Clinical Pharmacology

Pharmacokinetics and exposure. Following SC administration, TILA-278 exhibited exposure consistent with expectations for an IgG bispecific antibody, with dose-ordered systemic exposure across the Low and High dose levels supporting the evaluated induction regimens through Week 12. The observed separation in clinical response between the two active dose levels (Section 2.5.4) is consistent with an exposure-response relationship across the studied range and informs dose selection for confirmatory studies.

Target engagement and pharmacodynamics. The pharmacodynamic effects observed in Study TILA278-201 are concordant with the intended dual mechanism. Objective markers of intestinal inflammation, C-reactive protein (CRP) and faecal calprotectin, declined in the active treatment arms in proportion to the improvement in modified Mayo score, providing evidence of biologically meaningful TL1A pathway antagonism and downstream suppression of mucosal inflammation. The accompanying endoscopic improvement observed at Week 12 is consistent with the IL-22-mediated mucosal-healing component of the molecule. Together these findings demonstrate target engagement translating into measurable pharmacodynamic and clinical effect.

Immunogenicity strategy. Given the potential for anti-drug antibody (ADA) formation with therapeutic antibodies, immunogenicity was assessed using a validated tiered strategy (screening, confirmatory, and titre assays) with evaluation of the relationship between ADA status and pharmacokinetics, efficacy, and safety. No dose-dependent safety signal and no loss of the dose-ordered efficacy response were observed over the 12-week induction period, and immunogenicity will continue to be characterized over the longer treatment durations planned for Phase 3.

2.5.4 Overview of Efficacy

Study TILA278-201 was a Phase 2b, randomized, double-blind, placebo-controlled, parallel-group induction study in adults aged 18-75 years with moderate-to-severe UC (baseline modified Mayo score 4-9). Of 1700 patients screened, 900 were randomized 1:1:1 to TILA-278 High (N=299), TILA-278 Low (N=300), or Placebo (N=301), stratified by baseline modified Mayo severity and prior biologic exposure. Efficacy analyses were performed on the Full Analysis Set (FAS; baseline plus >=1 post-baseline assessment): High N=284, Low N=283, Placebo N=273. The primary endpoint was clinical remission (modified Mayo score <=2, with no individual subscore >1) at Week 12; key secondary endpoints were change from baseline in modified Mayo score and endoscopic improvement at Week 12.

Both TILA-278 dose levels demonstrated statistically significant and clinically meaningful improvement over placebo, with a clear dose-ordered response (High > Low > Placebo).

Table 2.5.4-1. Change from Baseline in Modified Mayo Score at Week 12 (FAS; ANCOVA, covariates treatment and baseline)

Endpoint	TILA-278 High (N=284)	TILA-278 Low (N=283)	Placebo (N=273)
LS-mean change from baseline	-3.36	-2.76	-1.00
Difference vs placebo (LS-mean)	-2.36	-1.77	—
95% CI for difference	-2.49 to -2.23	-1.90 to -1.64	—
p-value vs placebo	<0.0001	<0.0001	—

Table 2.5.4-2. Clinical Remission at Week 12 (Modified Mayo <=2, no subscore >1) (FAS)

Endpoint	TILA-278 High (N=284)	TILA-278 Low (N=283)	Placebo (N=273)
Remission, n/N (%)	106/284 (37.3%)	46/283 (16.2%)	2/273 (0.7%)
Risk difference vs placebo (percentage points)	+36.6	+15.5	—
95% CI for risk difference	30.9 to 42.3	11.1 to 19.9	—
p-value vs placebo	<0.0001	<0.0001	—

The primary endpoint was met at both dose levels: clinical remission was achieved by 37.3% of High-dose and 16.2% of Low-dose patients versus 0.7% on placebo, corresponding to risk differences of +36.6 and +15.5 percentage points, respectively (both p<0.0001). These results were supported by the key secondary endpoint of change in modified Mayo score (LS-mean difference vs placebo -2.36 [High] and -1.77 [Low], both p<0.0001) and by concordant endoscopic improvement. The consistency of effect across the primary and key secondary endpoints, together with the biomarker findings in Section 2.5.3, establishes robust proof of concept for TILA-278 induction therapy and supports selection of the High dose for confirmatory evaluation.

2.5.5 Overview of Safety

Safety was evaluated over the 12-week induction period in all randomized patients who received at least one dose of study treatment. Treatment-emergent adverse events (TEAEs) occurred at a similar overall frequency across the three treatment arms and showed no increase with TILA-278 dose; serious adverse events (SAEs) and study discontinuations were each more frequent on placebo than on either active dose. No dose-dependent safety signal was identified.

Table 2.5.5-1. Overview of Treatment-Emergent Adverse Events (number of subjects)

Category	TILA-278 High	TILA-278 Low	Placebo
>=1 TEAE	109	131	130
Serious AE	3	0	4
Deaths	2	0	1
Discontinued study	17	17	29

All deaths (High 2, Low 0, Placebo 1) were assessed as unrelated to study drug by the investigator. SAEs were infrequent and were numerically lower in the active arms than on placebo. Study discontinuations were most frequent in the placebo group (29 vs 17 and 17), driven mainly by lack of efficacy, consistent with the efficacy findings.

Table 2.5.5-2. Most Frequent Adverse Events (number of subjects)

Preferred term	TILA-278 High	TILA-278 Low	Placebo
Nasopharyngitis	22	35	20
Headache	21	23	27
Worsening of ulcerative colitis	13	19	35
Anaemia	21	17	28
Arthralgia	10	19	20
Upper respiratory tract infection	11	20	17
Injection site reaction	23	17	3
Nausea	6	10	6

The most frequently reported events were nasopharyngitis, headache, and worsening of UC; the latter, along with anaemia, was more frequent on placebo, consistent with inadequate disease control in that arm. The principal drug-attributable finding was injection site reactions, which were more frequent with active SC drug (High 23, Low 17) than placebo (3); these were consistent with the SC route and the monoclonal antibody class. No dose-dependent increase in infections, malignancy, or other events of special interest was observed. The overall safety profile is consistent with the anti-TL1A/IL-22 mechanism of action and with the biologic class, and inflammatory markers (CRP, faecal calprotectin) declined in the active arms in proportion to Mayo improvement without an associated safety cost.

2.5.6 Benefits and Risks Conclusions

In Study TILA278-201, TILA-278 demonstrated a compelling and internally consistent benefit-risk profile for the induction treatment of moderate-to-severe UC. Both dose levels met the primary endpoint of clinical remission at Week 12 with high statistical significance and a clear dose-ordered response, and the High dose achieved a 37.3% remission rate versus 0.7% on placebo (+36.6 percentage points; p<0.0001). These clinical benefits were corroborated by significant improvement in modified Mayo score, endoscopic improvement, and reductions in objective inflammatory biomarkers, providing coherent evidence that the dual TL1A-antagonist/IL-22-agonist mechanism delivers combined anti-inflammatory control and mucosal healing.

The risk profile over the induction period was favourable. Serious adverse events were infrequent and were numerically lower in both active arms than on placebo; the few deaths (two on the High dose, none on the Low dose, and one on placebo) were all assessed by the investigator as unrelated to study drug; and discontinuations were highest on placebo, owing to lack of efficacy. Injection site reactions were the principal drug-attributable finding and were manageable and expected for a subcutaneously administered antibody. No dose-dependent safety signal emerged.

Taken together, the magnitude and consistency of the efficacy findings, the mechanistic and biomarker support, and the well-characterized and manageable safety profile establish a positive benefit-risk balance for TILA-278, most clearly at the High dose. These results provide a robust basis for advancement to confirmatory Phase 3 induction and maintenance studies in moderate-to-severe ulcerative colitis.