📚 Part of the GLPI-103 Regulatory Dossier — Reader's Guide. This article shows the live document; edits to the source appear here automatically.

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Summary of Human Pharmacokinetic Study Reports — GLPI-103

Field	Value
Document ID	CLINPHARM-002
Version	1.0
Status	Final
Compound	GLPI-103 (GLP-1 / Apelin [APJ] receptor dual agonist)
Sponsor	Virtual Biopharma Inc.
CTD location	Module 5.3.3 — Reports of Human Pharmacokinetic (PK) Studies
Standard(s)	ICH M3(R2), E7 (special populations), M12 (drug interactions), FDA/EMA population-PK guidance
Confidentiality	Confidential — portfolio use

[MOCK — deep-knowledge assumption] No dedicated clinical-pharmacology dataset is simulated in this portfolio. The PK parameters below are illustrative and internally consistent with the Investigator's Brochure (IB-001 §5.1), the nonclinical PK package (M4-2.2), and the canonical program parameters (REF-002). They stand in for the individual study reports (5.3.3.x) that a real submission would file in full. Phase-3 clinical outcomes remain sourced from CSR-301 (outputs/).

Change History

Version	Date	Author	Summary of Change
1.0	2026-07-05	Clinical Pharmacology	Initial submission-grade summary of the human PK study reports (SAD/MAD PK, popPK, hepatic/renal impairment, DDI)

Abbreviations

ADA anti-drug antibody · AUC area under the curve · CL clearance · CL/F apparent oral clearance · Cmax maximum concentration · CrCl creatinine clearance · DDI drug–drug interaction · eGFR estimated glomerular filtration rate · F absolute bioavailability · popPK population pharmacokinetics · QD once daily · QW once weekly · t½ terminal elimination half-life · Vd volume of distribution.

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1. Background and Scope

GLPI-103 is a fatty-acid-acylated synthetic peptide dual agonist administered as a once-weekly intravenous (IV) solution and a once-daily oral immediate-release tablet co-formulated with a permeation enhancer. Acylation confers reversible albumin binding, which underlies the long terminal half-life and supports the intended dosing intervals. This document summarizes the human pharmacokinetic evidence across the clinical program:

5.3.3.x	Study / analysis	Source	Key objective
5.3.3.1	GLPI103-101 (SAD) intensive PK	CSR-101	Single-dose PK, dose-proportionality, t½
5.3.3.1	GLPI103-102 (MAD) steady-state PK	CSR-102	Accumulation, steady-state, PK/PD
5.3.3.3	Population PK & exposure–response	this document	Covariate model; E–R for efficacy and nausea
5.3.3.3	Hepatic-impairment PK	this document	Effect of hepatic function on exposure
5.3.3.3	Renal-impairment PK	this document	Effect of renal function on exposure
5.3.3.4	Drug–drug interaction studies	this document	CYP probe cocktail; oral-contraceptive; metformin

2. Single- and Multiple-Dose Pharmacokinetics [MOCK]

In the first-in-human single-ascending-dose study (GLPI103-101, N=40) and the multiple-ascending-dose study (GLPI103-102, N=40), GLPI-103 exposure increased in an approximately dose-proportional manner across the studied range for both routes.

Parameter (typical value)	GLPI-103 IV	GLPI-103 Oral
Route / interval	IV, once weekly	Oral, once daily
Absolute bioavailability, F	1.0 (reference)	≈ 1–2% (permeation-enhancer dependent)
Tmax	end of infusion	≈ 0.5–1.5 h (fasted)
Terminal t½	≈ 130 h (5–6 days)	≈ 130 h (elimination-rate-limited by albumin binding)
Accumulation ratio at steady state	≈ 1.4 (QW)	≈ 2.0 (QD)
Time to steady state	≈ 4–5 weeks	≈ 4–5 weeks
Primary elimination	proteolytic catabolism to peptide fragments/amino acids	same
Renal / hepatic clearance of intact peptide	minor	minor

Steady-state exposure was consistent with the once-weekly (IV) and once-daily (oral) regimens and the conservative 8-week titration used in Phase 3 (PROT-301 §6). Inter-subject variability in oral exposure was moderate-to-high, driven by the permeation-enhancer–dependent absorption step, and is accounted for in the population model (§3).

3. Population Pharmacokinetics and Exposure–Response [MOCK]

A population PK model was developed from pooled Phase 1–2 concentration data (illustrative). A two-compartment model with first-order absorption (oral) and linear elimination described the data.

• Structural covariates: body weight on clearance and central volume (allometric); formulation/route on bioavailability and absorption rate.
• Statistically identified covariates: baseline body weight (exposure ↓ with higher weight), and mild reductions in apparent clearance with lower renal function; no clinically relevant effect of age, sex, or region on dose-normalized exposure.
• Anti-drug antibodies: low-titre, non-neutralizing ADA (§ IMMUNO-001) had no meaningful effect on GLPI-103 clearance in the covariate analysis.

Exposure–response (E–R):

• Efficacy (HbA1c CFB): a positive, saturating E–R relationship; the higher-exposure IV arm achieved the larger HbA1c reduction (−2.57% vs −2.23% oral; CSR-301 §11.3), consistent with the Emax exposure–response analysis (outputs/stats/, Bayesian/Emax module).
• Tolerability (nausea): a positive E–R relationship for gastrointestinal adverse events; nausea incidence was highest in the higher-exposure IV arm (32.3% vs 21.4% for semaglutide, p=0.003; CSR-301 §12.3), which motivates the titration schedule. The E–R analyses therefore support the selected doses as an appropriate balance of efficacy and tolerability.

4. Intrinsic-Factor (Special-Population) PK [MOCK]

Because intact GLPI-103 is eliminated principally by proteolytic catabolism rather than renal or hepatic clearance, organ impairment was predicted to have limited impact; dedicated studies confirmed this.

Population	Exposure (AUC) vs matched controls	Recommendation
Hepatic impairment (Child–Pugh A/B/C)	≤ 1.2-fold; no clear trend with severity	No dose adjustment
Renal impairment (mild/moderate/severe by eGFR)	≤ 1.3-fold in severe; not dialysis-dependent	No dose adjustment; use with monitoring in severe
Age (≥65 y)	within variability after weight adjustment	No dose adjustment
Sex / Region	no clinically relevant difference	No dose adjustment

The Phase 3 eligibility floor of eGFR ≥ 45 mL/min/1.73 m² (PROT-301 §5) is consistent with these findings; the small renal-function effect is reflected in the population-PK covariate model (§3).

5. Drug–Drug Interaction Studies [MOCK]

As a peptide catabolized to amino acids with negligible cytochrome-P450 (CYP) or transporter involvement, GLPI-103 has low perpetrator potential. The principal theoretical victim/perpetrator consideration is the delayed gastric emptying common to the GLP-1 class, which can alter the rate (not generally the extent) of absorption of co-administered oral drugs.

Study	Design	Result	Labeling implication
CYP probe cocktail	GLPI-103 effect on midazolam/caffeine/omeprazole/dextromethorphan/warfarin exposure	No clinically relevant change	No CYP-based interaction
Oral contraceptive	ethinylestradiol/levonorgestrel ± GLPI-103	Exposure within equivalence bounds	No dose change; contraceptive efficacy maintained
Metformin (background)	steady-state metformin ± GLPI-103	No clinically relevant change	Co-administration acceptable (Phase 3 background therapy)
Gastric-emptying / oral drugs (class effect)	narrow-therapeutic-index orals	Rate of absorption may be affected	Monitoring advised for sensitive oral drugs

6. Conclusions

The human PK of GLPI-103 is characterized by a long, albumin-binding-driven terminal half-life supporting once-weekly IV and once-daily oral dosing; approximately dose-proportional, moderately variable exposure; elimination by proteolytic catabolism with negligible CYP involvement; and no clinically relevant effect of hepatic or renal impairment, age, sex, region, or low-titre ADA on exposure. Exposure–response analyses support the selected doses and explain the efficacy–tolerability gradient across formulations. No dose adjustment is warranted for intrinsic factors; the only interaction consideration is the class-related gastric-emptying effect on sensitive co-administered oral drugs. These findings are integrated in Module 2.7.2 (Summary of Clinical Pharmacology) and reflected in the labeling (USPI/SmPC/KR label).

7. References

IB-001 §5.1; M4-2.2 (nonclinical PK/ADME); M2.7.1 (biopharmaceutics); M2.7.2 (clinical pharmacology); REF-002; CSR-101; CSR-102; CSR-301; IMMUNO-001; BIOANALYTICAL-001; ICH E7, M12.