Related Experiment Video
Updated: Feb 23, 2026

Preliminary Study on Acupuncture Combined with Grain-sized Moxibustion for Treating Rheumatoid Arthritis with Finger Joint Pain
Published on: May 16, 2025
Dose/Exposure-Response Modeling to Support Dosing Recommendation for Phase III Development of Baricitinib in Patients
Xin Zhang1, Laiyi Chua1, Charles Ernest1
1Eli Lilly and Company, Indianapolis, Indiana, USA.
Abstract:
Baricitinib is an oral inhibitor of Janus kinases (JAKs), selective for JAK1 and 2. It demonstrated dose-dependent efficacy in patients with moderate-to-severe rheumatoid arthritis (RA) in a phase IIb study up to 24 weeks. Population pharmacokinetic/pharmacodynamic (PopPK/PD) models were developed to characterize concentration-time profiles and dose/exposure-response (D/E-R) relationships for the key efficacy (proportion of patients achieving American College of Rheumatology 20%, 50%, or 70% response rate) and safety endpoints (incidence of anemia) for the phase IIb study. The modeling suggested that 4 mg q.d. was likely to offer the optimum risk/benefit balance, whereas 2 mg q.d. had the potential for adequate efficacy. In addition, at the same total daily dose, a twice-daily regimen is not expected to provide an advantage over q.d. dosing for the efficacy or safety endpoints. The model-based simulations formed the rationale for key aspects of dosing, such as dose levels and dosing frequency for phase III development.
Related Concept Videos
Drug Dosing in Renal Diseases: Dose Adjustments Based on Drug Clearance and Elimination Rate Constant
Impact of Pharmacokinetic–Pharmacodynamic Models: Regulatory Decisions
Drugs for Treatment of Crohn's Disease in IBD Using Biologic Agents: Anti-TNF
Dose-Response Relationship: Potency and Efficacy
Rational Dosage Regimen: Maintenance Dose and Loading Dose
In most cases, drugs are administered repetitively or infused continuously to maintain a steady-state concentration in the body. At a steady...
Determination of Multiple Dosing Parameters: Loading and Maintenance Doses

