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

---

Pre-NDA/BLA Briefing Book (TILA-278)

Document ID: MTG-PreNDA
Version: 1.0
Change History: 1.0 — Initial issue.
Standard(s): FDA meetings

Pre-NDA/BLA Meeting Briefing Book — TILA-278

Pre-submission briefing for TILA-278: the completed pivotal evidence, the proposed application content and format, the integrated summaries and datasets plan, and agreement on filing expectations.

1. Purpose of the Meeting and Regulatory Context

Virtual Biopharma Inc. (the Sponsor) requests a Type B pre-submission meeting to align with the Agency on the content, format, and adequacy of the planned marketing application for TILA-278 in adults with moderately to severely active ulcerative colitis (UC). Because TILA-278 is a therapeutic monoclonal antibody, the application will be submitted as a Biologics License Application (BLA) under section 351(a) of the Public Health Service Act and reviewed under 21 CFR Part 601; the "Pre-NDA/BLA" designation reflects the meeting-type nomenclature for pre-submission interactions on PDUFA products. This briefing book is provided in advance of the meeting to focus the discussion on the specific questions in Section 15 and to give the review division the pivotal evidence, the proposed eCTD content, the integrated-summary and dataset strategy, and the filing timeline needed to reach agreement.

The Sponsor's objectives for the meeting are to: (1) confirm that Study TILA278-201, together with the supporting clinical pharmacology and mechanistic evidence, constitutes an acceptable evidentiary basis for the proposed induction indication under the "one adequate and well-controlled investigation plus confirmatory evidence" framework; (2) confirm the proposed organization of Modules 1 through 5 and the scope of the integrated summaries of safety and efficacy; (3) confirm the clinical data-standards and study-datasets deliverables; (4) confirm the nonclinical and Chemistry, Manufacturing, and Controls (CMC) content appropriate to a Chinese hamster ovary (CHO)-derived bispecific antibody; and (5) agree on filing expectations, including the planned submission timing, requested review designation, and any pre-agreed content deferrals.

2. Product Description and Mechanism of Action

TILA-278 is a humanized bispecific IgG1 monoclonal antibody that simultaneously antagonizes TL1A (TNFSF15) and agonizes signaling through the IL-22 receptor. It is produced by recombinant expression in a CHO cell line and is presented as a 150 mg/mL solution for subcutaneous injection (300 mg per 2 mL single-use prefilled syringe). The two binding specificities are engineered into a single antibody with controlled heavy-chain heterodimerization and cognate light-chain pairing, so that one arm neutralizes soluble and membrane TL1A while the second arm engages and activates the IL-22 receptor complex on intestinal epithelium.

The dual mechanism is biologically complementary and directly matched to the pathophysiology of UC. TL1A antagonism attenuates TH1/TH17-driven mucosal inflammation and the pro-fibrotic signaling that contributes to intestinal tissue remodeling, addressing the inflammatory drivers of active colitis. IL-22 receptor agonism promotes intestinal epithelial regeneration, mucin production, antimicrobial peptide expression, and mucosal-barrier repair, actively restoring the epithelial compartment that is disrupted in active disease. Coupling suppression of inflammation with active promotion of mucosal healing provides a coherent rationale for an induction effect that unites symptomatic improvement with objective endoscopic healing, and it distinguishes TILA-278 from single-pathway agents. Because the mechanism does not rely on the cytokine or integrin pathways targeted by conventional biologics, activity is expected across both biologic-naïve and biologic-experienced patients, a hypothesis supported by the subgroup findings of Study TILA278-201.

3. Proposed Indication and Basis for Licensure

The proposed indication is the induction of clinical remission in adults with moderately to severely active ulcerative colitis. The evidentiary basis for effectiveness is the single, adequately powered, randomized, double-blind, placebo-controlled pivotal Study TILA278-201, which met its primary endpoint with a large and highly statistically significant treatment effect and a coherent pattern of dose-ordered, mechanism-consistent supportive findings (continuous modified Mayo change, centrally read endoscopic improvement, and inflammatory biomarker reduction). The Sponsor intends to characterize this package under the recognized framework in which substantial evidence of effectiveness is derived from one adequate and well-controlled investigation supported by confirmatory evidence, and seeks the Agency's agreement that this is an acceptable approach for the proposed induction claim. The maintenance of remission beyond the induction period is being addressed in the ongoing development program and is not part of the current proposed labeling claim.

4. Regulatory History and Development Status

The TILA-278 program has proceeded through the standard pre-IND and end-of-Phase-2 interactions with the review division, at which the nonclinical package supporting first-in-human dosing, the Phase 1 clinical pharmacology strategy, and the pivotal Phase 2b design, endpoints, estimands, and statistical approach for Study TILA278-201 were discussed. The clinical program comprises the Phase 1 single-ascending-dose and multiple-ascending-dose studies (Studies TILA278-101 and TILA278-102) characterizing safety, pharmacokinetics, and immunogenicity in healthy participants, and the completed pivotal induction Study TILA278-201. The nonclinical program supporting the BLA is complete, and the commercial CMC control strategy is established. The Sponsor is requesting this pre-submission meeting to confirm the readiness and organization of the application prior to filing; expedited-program status and the associated review designation are addressed in Section 14.

5. Summary of the Clinical Efficacy Evidence (Study TILA278-201)

Study TILA278-201 was a Phase 2b, randomized, double-blind, placebo-controlled, parallel-group induction study in adults aged 18 to 75 years with moderately to severely active UC (baseline modified Mayo score 4 to 9 with a centrally confirmed endoscopic subscore ≥ 2). A total of 1700 subjects were screened and 900 were randomized 1:1:1 to TILA-278 High (600 mg subcutaneously at Weeks 0, 2, 4, and 8), TILA-278 Low (300 mg on the same schedule), or matching placebo, over a 12-week double-blind induction period with visits at Weeks 0, 2, 4, 8, and 12. Randomization was stratified by baseline modified Mayo severity and by prior biologic exposure. The Full Analysis Set (FAS) comprised 284, 283, and 273 subjects in the High, Low, and placebo groups, respectively (840 total). The blind was maintained through identical prefilled syringes, an interactive response technology system, and a matched number of subcutaneous injections at each visit; baseline endoscopy and the Week 12 endoscopy were read centrally by a reader blinded to treatment, visit sequence, and subject identity.

The primary endpoint was clinical remission at Week 12 (modified Mayo score ≤ 2 with no individual subscore > 1). Key secondary endpoints were the change from baseline in the modified Mayo score at Week 12 and endoscopic improvement at Week 12 (centrally read Mayo endoscopic subscore ≤ 1). Type I error was controlled at a two-sided alpha of 0.05 by a pre-specified fixed-sequence hierarchical testing procedure across the primary and key secondary comparisons, and missing Week 12 status was handled by non-responder imputation for binary endpoints, with pre-specified tipping-point and multiple-imputation sensitivity analyses supporting the primary result.

The study met its primary endpoint, with both dose regimens statistically superior to placebo and a clear dose-ordered response across every efficacy domain.

Table 1. Key Week 12 Efficacy Results — Study TILA278-201 (FAS)

Endpoint	TILA-278 High (N=284)	TILA-278 Low (N=283)	Placebo (N=273)
Clinical remission, % (n/N)	37.3 (106/284)	16.2 (46/283)	0.7 (2/273)
Risk difference vs placebo, percentage points	+36.6	+15.5	— (reference)
LS-mean change in modified Mayo score	−3.36	−2.76	−1.00
LS-mean difference vs placebo	−2.36	−1.77	— (reference)
Endoscopic improvement, %	48.9	27.9	6.2

For the primary endpoint, the risk difference versus placebo was +36.6 percentage points (High) and +15.5 percentage points (Low). The modified Mayo LS-mean change was −3.36 (High), −2.76 (Low), and −1.00 (placebo), corresponding to LS-mean differences versus placebo of −2.36 and −1.77. Endoscopic improvement was achieved by 48.9% (139/284), 27.9% (79/283), and 6.2% (17/273) of subjects, respectively. The near-absent placebo remission rate (0.7%) reflects the stringent composite remission definition and the moderate-to-severe baseline population and underscores the magnitude of the treatment effect. Prespecified subgroup analyses by baseline severity and by prior biologic exposure showed a consistent, clinically meaningful, dose-ordered benefit, including retained efficacy in biologic-experienced and severe-disease subjects. The concordance of the symptomatic, endoscopic, and biomarker findings, together with the early onset and progressive deepening of effect across the induction period, provides internally consistent, multi-domain evidence of a genuine induction effect and supports selection of the High dose as the recommended induction regimen.

6. Summary of Clinical Safety, Pharmacokinetics, and Immunogenicity

TILA-278 was well tolerated at both dose levels over the 12-week induction period, with no dose-dependent safety signal. The overall incidence of treatment-emergent adverse events (TEAEs) was numerically lower in each active group than in placebo (38.4% High, 46.3% Low, versus 47.6% placebo). Serious adverse events were infrequent in all groups (1.1% High, 0% Low, 1.5% placebo). Three deaths occurred during the study (2 High, 0 Low, 1 placebo), all assessed by the investigator as unrelated to study drug. Study discontinuation was more frequent in the placebo group (10.6%) than in the High and Low groups (6.0% each), driven mainly by lack of efficacy; consistent with this, worsening of UC was reported more often on placebo. Injection-site reactions were the principal drug-attributable finding, more frequent with active subcutaneous drug than with placebo, predominantly mild to moderate and transient, and rarely leading to discontinuation. The overall adverse-event profile was consistent with the anti-TL1A/IL-22 mechanism and with the therapeutic-antibody class. The integrated safety database, pooling all TILA-278-exposed subjects across Studies TILA278-101, TILA278-102, and TILA278-201, will support the Module 2.7.4 and integrated safety summary characterizations and the labeling of adverse reactions.

Table 2. Overall Summary of Adverse Events (Safety Analysis Set), n (%)

Category	TILA-278 High (N=284)	TILA-278 Low (N=283)	Placebo (N=273)
≥1 treatment-emergent AE	109 (38.4)	131 (46.3)	130 (47.6)
Serious AE	3 (1.1)	0 (0.0)	4 (1.5)
Deaths	2 (0.7)	0 (0.0)	1 (0.4)
Discontinued study	17 (6.0)	17 (6.0)	29 (10.6)

The pharmacokinetics of TILA-278 are governed by target-mediated drug disposition (TMDD) at both the TL1A and IL-22 receptor targets, producing nonlinear disposition at lower concentrations and more linear behavior at the exposures achieved with the induction regimen. Subcutaneous absorption, bioavailability, and the population-pharmacokinetic model support the dose rationale and the exposure–response relationship linking systemic exposure to the Week 12 remission outcome. Immunogenicity was assessed with a validated tiered anti-drug antibody (ADA) assay (screening, confirmatory, titer, and neutralizing-antibody assessment), with the impact of ADA on pharmacokinetics, efficacy, and safety evaluated across the program; the immunogenicity findings and their clinical relevance will be summarized in Module 2.7.2 and the integrated summaries. Cardiac safety is being addressed through a concentration–QTc analysis of clinical data, consistent with current scientific expectations for a monoclonal antibody; a dedicated thorough-QT study is not planned (see Section 7).

7. Nonclinical Program Summary

The nonclinical program was designed in accordance with ICH S6(R1) for biotechnology-derived pharmaceuticals. The cynomolgus monkey was identified as the sole pharmacologically relevant species based on binding to, and functional activity at, both the TL1A and IL-22 receptor targets; rodents were not pharmacologically responsive and were therefore not used for toxicological characterization. The pivotal package comprises repeat-dose toxicology in the cynomolgus monkey by the subcutaneous route (with toxicokinetics, anti-drug-antibody monitoring to support exposure interpretation, and a recovery phase), a tissue cross-reactivity assessment using human and cynomolgus tissue panels, and safety-pharmacology endpoints (cardiovascular, respiratory, and central nervous system observations) incorporated into the repeat-dose design rather than conducted as stand-alone core-battery studies. Reproductive and developmental toxicity considerations appropriate to the intended population, including an enhanced pre- and postnatal development evaluation in the cynomolgus monkey, support the reproductive-risk labeling.

Consistent with ICH S6(R1) and current cardiac-safety expectations for large-molecule biologics, the following study types were not conducted and are not considered warranted for TILA-278: standard genotoxicity testing (a monoclonal antibody is not expected to interact directly with DNA or chromosomes), carcinogenicity bioassays (not warranted for this modality and indication), and dedicated ion-channel (for example, hERG) or thorough-QT studies (a large protein is not expected to distribute to or interact with cardiac ion channels; cardiac safety is addressed through clinical concentration–QTc analysis). The scientific justification for the absence of these studies is documented in the Nonclinical Overview (Module 2.4) and will be presented in the BLA; the Sponsor requests the Agency's agreement that this omission is acceptable.

8. Chemistry, Manufacturing, and Controls Summary

TILA-278 drug substance is a humanized bispecific IgG1 antibody expressed in a CHO cell line and purified by a platform downstream process comprising Protein A affinity capture followed by polishing chromatography and orthogonal viral-clearance steps (low-pH viral inactivation and virus-retentive nanofiltration). Viral safety of the cell substrate and the manufacturing process is evaluated in accordance with ICH Q5A(R2), including the demonstrated viral-clearance capacity of the purification train. The drug product is a 150 mg/mL solution for subcutaneous injection presented in a 300 mg per 2 mL single-use prefilled syringe.

The control strategy reflects both the general expectations for a therapeutic antibody and the specific attributes of a bispecific molecule. Critical quality attributes include the bispecific-specific attributes of correct heavy-chain heterodimerization and cognate light-chain pairing (that is, control of chain-mispairing and homodimer/half-antibody species), in addition to the usual charge and size heterogeneity, glycosylation, aggregation, and post-translational modifications. Because the molecule carries two distinct functional activities, the potency control strategy employs orthogonal bioassays reflecting each mechanism: a TL1A-neutralization (antagonist) assay and an IL-22-receptor-mediated cell-based (agonist) assay. Specifications are established in accordance with ICH Q6B, stability is supported per ICH Q5C, and manufacturing changes and process/analytical comparability are managed in accordance with ICH Q5E. Process and analytical development, control strategy, and lifecycle management follow the ICH Q8/Q11/Q12 principles. The Quality Overall Summary (Module 2.3) and Module 3 will present the full drug-substance and drug-product information, the analytical-method validation, the viral-safety and comparability packages, and the stability data supporting the proposed shelf life.

9. Proposed BLA Content and Format (CTD/eCTD)

The application will be submitted in electronic CTD format in accordance with the Agency's eCTD requirements and the CTD organization defined in ICH M4/M4E(R2). The Sponsor proposes the standard five-module structure summarized below and requests confirmation that the proposed content and granularity are acceptable.

Table 3. Proposed BLA Module Content

Module	Content
Module 1 (Regional/Administrative)	Form FDA 356h, cover letter and comprehensive table of contents, administrative forms, financial-disclosure and debarment certifications, proposed Prescribing Information and carton/container labeling, pediatric-plan documentation, risk-management materials, and this meeting's agreements.
Module 2 (Summaries)	CTD Introduction (2.2), Quality Overall Summary (2.3), Nonclinical Overview and Written/Tabulated Summaries (2.4/2.6), Clinical Overview (2.5) including benefit–risk assessment, and Clinical Summary (2.7.1–2.7.6).
Module 3 (Quality)	Drug-substance and drug-product information for the CHO-derived bispecific antibody, including control strategy, analytical-method validation, viral safety (ICH Q5A(R2)), comparability (ICH Q5E), specifications (ICH Q6B), and stability (ICH Q5C).
Module 4 (Nonclinical)	Pharmacology, pharmacokinetics, and toxicology study reports (ICH S6(R1)), with the scientific justification for the absence of genotoxicity, carcinogenicity, and dedicated cardiac (hERG/thorough-QT) studies.
Module 5 (Clinical)	Clinical pharmacology (Studies TILA278-101 and TILA278-102), the pivotal Study TILA278-201 clinical study report and datasets, the integrated summaries of efficacy and safety, immunogenicity and bioanalytical reports, literature references, and the tabular listing of studies.

10. Integrated Summaries of Efficacy and Safety (ISE/ISS)

The Sponsor proposes to pool subject-level data across the clinical program to support the integrated summary of safety (ISS) and the integrated summary of efficacy (ISE). The ISS will pool all TILA-278-exposed subjects across the Phase 1 studies (Studies TILA278-101 and TILA278-102) and the pivotal Study TILA278-201, using a pre-specified pooling strategy with harmonized MedDRA coding, adverse-event and laboratory analyses, and characterization of injection-site reactions, immunogenicity, infections, and other events of interest relevant to the mechanism and class. The ISE will present the pivotal efficacy results of Study TILA278-201 as the principal evidence of effectiveness, with the dose-ordered response and the prespecified subgroup analyses (baseline severity and prior biologic exposure) presented to characterize the consistency and generalizability of the effect. The Sponsor requests the Agency's agreement on the proposed pooling strategy, the analysis populations, and the scope of the integrated summaries given the single-pivotal-study evidentiary framework.

11. Clinical Data Standards and Study Datasets

Clinical study data will be submitted in conformance with the CDISC standards required by the Agency and described in the current Study Data Technical Conformance Guide: tabulation datasets in SDTM, analysis datasets in ADaM, and metadata in Define-XML. Each study and the integrated analyses will be accompanied by a Study Data Reviewer's Guide (SDRG) and an Analysis Data Reviewer's Guide (ADRG), together with annotated case report forms, analysis-results metadata, and dataset-validation output. Analyses will follow the pre-specified statistical analysis plan and estimands consistent with ICH E9(R1), and the datasets will reproduce the primary and key secondary results reported for Study TILA278-201. The Sponsor requests confirmation that the proposed data-standards versions, dataset scope (including which pooled datasets will be provided for the ISS/ISE), and reviewer-guide deliverables meet the review division's expectations.

12. Pediatric Study Plan

Ulcerative colitis occurs in the pediatric population, and the Sponsor will address pediatric requirements in accordance with the applicable pediatric legislation. The pediatric study plan documentation, including the proposed pediatric assessments and any request for waiver or deferral of studies in age groups where studies are not appropriate or should follow adult approval, will be provided in Module 1. The Sponsor requests the Agency's confirmation that the proposed pediatric plan and the timing of pediatric studies relative to the BLA are acceptable.

13. Proposed Labeling and Risk-Management Considerations

The proposed Prescribing Information will be prepared in the current content-and-format (labeling rule) structure and will present the induction indication, dosing and administration for the subcutaneous prefilled-syringe presentation, the adverse-reaction profile derived from the integrated safety database (with injection-site reactions as the principal drug-attributable finding), immunogenicity information, and use-in-specific-populations content supported by the nonclinical reproductive assessment and clinical pharmacology. Consistent with the tolerability profile observed to date and the absence of a dose-dependent safety signal, the Sponsor's current position is that routine pharmacovigilance is sufficient and that a risk-evaluation-and-mitigation strategy is not warranted; the Sponsor will present its pharmacovigilance and risk-management approach and requests the division's agreement on the labeling and risk-management framework.

14. Filing Expectations and Agreements Sought

The Sponsor plans to submit the BLA following alignment at this meeting and requests agreement on the overall content and format described above, so that the submission is complete and fileable at the time of receipt. Given the magnitude of the induction treatment effect, the serious and chronically debilitating nature of moderate-to-severe UC, and the program's expedited-program status, the Sponsor intends to request the applicable expedited review designation for the application and seeks the division's feedback on that request. The Sponsor also requests agreement on any pre-agreed content approaches (for example, the single-pivotal-study framework, the integrated-summary pooling strategy, the data-standards deliverables, and the justification for the omitted nonclinical study types), and on the mechanism for documenting these agreements so they are reflected in the filing.

15. Questions for the Agency

1. Evidentiary basis. Does the Agency agree that Study TILA278-201, supported by the clinical pharmacology data and the coherent, dose-ordered, mechanism-consistent secondary and biomarker findings, provides an acceptable basis for the proposed induction indication under the "one adequate and well-controlled investigation plus confirmatory evidence" framework?
2. Application content and format. Does the Agency agree that the proposed CTD/eCTD organization and module content described in Section 9 are acceptable for the BLA?
3. Integrated summaries. Does the Agency agree with the proposed ISS/ISE pooling strategy, analysis populations, and scope described in Section 10?
4. Data standards and datasets. Does the Agency agree that the proposed CDISC SDTM/ADaM/Define-XML deliverables, reviewer guides, and pooled datasets described in Section 11 meet review expectations?
5. Nonclinical scope. Does the Agency agree that the ICH S6(R1)-based nonclinical package — with the cynomolgus monkey as the sole pharmacologically relevant species and without genotoxicity, carcinogenicity, or dedicated cardiac (hERG/thorough-QT) studies — is adequate to support the BLA?
6. CMC. Does the Agency agree that the proposed control strategy for the CHO-derived bispecific antibody, including the bispecific-specific chain-pairing attributes and the orthogonal dual-mechanism potency assays, and the viral-safety, comparability, specification, and stability packages, are appropriate for licensure?
7. Immunogenicity. Does the Agency agree with the tiered anti-drug-antibody assay strategy and the planned characterization of the impact of immunogenicity on pharmacokinetics, efficacy, and safety?
8. Pediatric plan. Does the Agency agree with the proposed pediatric study plan and the timing of pediatric studies relative to the BLA?
9. Labeling and risk management. Does the Agency agree that routine pharmacovigilance is sufficient and that a risk-evaluation-and-mitigation strategy is not warranted, and does it have comments on the proposed Prescribing Information?
10. Filing logistics. Does the Agency have comments on the planned submission timing and on the Sponsor's intended request for expedited review designation?

16. Proposed Meeting Logistics and Participants

The Sponsor requests a Type B pre-submission meeting and will provide the proposed date, format (face-to-face, teleconference, or written response only), and the list of Sponsor attendees and their functions (regulatory affairs, clinical development, biostatistics, clinical pharmacology, nonclinical safety, and CMC/quality) in the meeting request. The Sponsor will identify the review-division participants it hopes will attend and will circulate a proposed agenda mapped to the questions in Section 15. Any pre-meeting information requests from the division can be accommodated in advance of the meeting date.

17. Supporting Documents and Appendices

The following materials are available to support the discussion and are cross-referenced from the sections above: the Study TILA278-201 clinical study report and synopsis; the Phase 1 clinical pharmacology study reports (Studies TILA278-101 and TILA278-102); the Clinical Overview and Clinical Summary (Modules 2.5 and 2.7); the Nonclinical Overview and Summaries (Modules 2.4 and 2.6); the Quality Overall Summary (Module 2.3); the immunogenicity and bioanalytical reports; the draft integrated summaries of efficacy and safety; the CDISC dataset specifications and reviewer guides; the draft Prescribing Information; and the pediatric-plan and expedited-program documentation. Full study reports and datasets will be provided in the BLA in accordance with the content and format agreed at this meeting.