Yen, Eugene F.

Background/Objectives: This study aimed to establish the clinical utility of a therapeutic drug monitoring (TDM)-supported, model-informed precision dosing (MIPD) approach (precision-guided dosing [PGD]) by assessing the impact of pharmacokinetic (clearance [CL]) and clinical laboratory parameters on adalimumab (ADA) dosage adjustments during maintenance therapy for inflammatory bowel disease (IBD). Methods: In the EMPOWER study, blood was collected at any time post-ADA injection. Pharmacokinetic (PK) testing was conducted in an accredited lab. Inputs for the PGD test included ADA concentrations, antibodies to ADA, albumin levels, and the current dosing regimen. CL was calculated using nonlinear mixed-effect models. Results were reported to health care providers (HCPs) within 3 days. HCPs’ treatment decisions were recorded and classified as treatment reduction, continuation, intensification, or ADA discontinuation. The physician global assessment (PGA) of disease activity was collected. Relationships between drug concentrations, CL, disease activity, and physician decision-making were assessed using logistic regression. Results: A total of 213 cases were assessed by 21 HCPs. ADA treatment was intensified in 24% and discontinued in 13% of cases. An ADA concentration ≤ 10 μg/mL was associated with a 23.7-fold and 3.0-fold higher likelihood of therapy intensification and PGA > 0, respectively, compared to concentrations > 10 μg/mL. An ADA concentration < 5 μg/mL was associated with a 3.3-fold higher likelihood of treatment discontinuation. CL ≥ 0.318 L/day was associated with a 10.4-fold higher likelihood of therapy intensification. Higher CL (>0.8 L/day) was associated with a 3.5-fold and 4.2-fold higher likelihood of treatment discontinuation and PGA > 0, respectively. Conclusions: PGD enables earlier and precise optimization of ADA dosing by predicting trough levels at any time during the therapy cycle. Optimized dosing to achieve target ADA concentrations and low clearance is crucial to mitigate therapy discontinuation and active disease in IBD patients.

SummaryBackgroundMatrix metalloproteinase‐9 is a proteolytic enzyme whose expression is increased in ulcerative colitis.AimTo evaluate the safety and efficacy of GS‐5745, a fully humanised anti‐matrix metalloproteinase‐9 monoclonal antibody, in moderately‐to‐severely active ulcerative colitis.MethodsWe randomised 74 patients with ulcerative colitis to treatment with single or multiple ascending intravenous or subcutaneous doses of GS‐5745 or placebo. Multiple‐dose cohorts received either IV infusions (0.3, 1.0, 2.5 or 5.0 mg/kg GS‐5745 or placebo) every 2 weeks (three total IV infusions) or five weekly SC injections (150 mg GS‐5745 or placebo). The primary outcomes were the safety, tolerability and pharmacokinetics of escalating single and multiple doses of GS‐5745. Exploratory analyses in the multiple‐dose cohorts included clinical response (≥3 points or 30% decrease from baseline in Mayo Clinic score and ≥1 point decrease in the rectal bleeding subscore or a rectal bleeding subscore ≤1) and clinical remission (a complete Mayo Clinic score ≤2 with no subscore >1) at Day 36. Biological effects associated with a clinical response to GS‐5745 were explored using histological and molecular approaches.ResultsTwenty‐three of the 42 patients (55%) receiving multiple doses of GS‐5745 had adverse events, compared with 5/8 patients (63%) receiving placebo. GS‐5745 showed target‐mediated drug disposition, approximately dose‐proportional increases in maximum plasma concentration and more than dose‐proportional increases in the area under the plasma drug concentration‐time curve. Clinical response occurred in 18/42 patients (43%) receiving GS‐5745 compared with 1/8 patients (13%) receiving placebo. Clinical remission occurred in 6/42 patients (14%) receiving GS‐5745 and 0/8 (0%) receiving placebo. Patients with a clinical response to GS‐5745 had reductions in matrix metalloproteinase‐9 tissue levels (mean 48.9% decrease from baseline compared with a mean 18.5% increase in nonresponders, P = 0.008) significant improvements in histopathology scores (confirmed with three separate histological disease activity indices), as well as changes in colonic gene expression that were consistent with reduced inflammation.ConclusionThis phase 1 trial provides preliminary evidence for the safety and therapeutic potential of GS‐5745 in the treatment of ulcerative colitis.