Recombinant Alpha-1 Antitrypsin-Fc Fusion Protein INBRX-101 in Adults With Alpha-1 Antitrypsin Deficiency: A Phase 1 Study.

Background: Alpha-1 antitrypsin deficiency (AATD) is characterized by low alpha-1 antitrypsin (AAT) levels, predisposing individuals to lung disease. The standard of care, plasma-derived AAT (pdAAT), is delivered as weekly infusions to maintain serum AAT concentrations ≥11µM (≈50% of those in healthy individuals). INBRX-101, a recombinant human AAT-Fc fusion protein, was designed to have a longer half-life and achieve higher AAT levels than pdAAT. Methods: In this phase 1 dose-escalation study (N=31), adults with AATD received 1 dose (part 1) or 3 doses (part 2) of 10 (part 1), 40, 80, or 120mg/kg INBRX-101 every 3 weeks (Q3W) via intravenous infusion. The primary endpoint was safety and tolerability. Secondary endpoints were pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of INBRX-101. Results: INBRX-101 was well tolerated. Most treatment-emergent adverse events were grade ≤2. In part 2 (n=18; each dose, n=6), dose-related increases in serum functional AAT (fAAT) were observed; mean fAAT levels remained above the 21 µM target for up to 4 weeks after the final dose in the 120-mg/kg cohort. Antidrug antibodies had no meaningful impact on PK or PD. INBRX-101 was detected in pulmonary epithelial lining fluid (PELF) from all patients assessed (n=11), and PELF fAAT increased after dosing. PK/PD modeling projected steady-state serum fAAT ≥21µM at 120 mg/kg Q3W (average concentration ≈43µM; trough concentration ≈28µM) and Q4W (≈34µM; ≈21µM). Conclusion: The favorable safety profile and ability to maintain serum fAAT levels >21µM with extended-interval dosing, support a phase 2 trial evaluating Q3W and Q4W dosing of INBRX-101.

Pharmacokinetics and antiviral activity of PHX1766, a novel HCV protease inhibitor, using an accelerated Phase I study design.

BACKGROUND: PHX1766 is a novel HCV NS3/4 protease inhibitor with robust potency and high selectivity in replicon studies (50% maximal effective concentration 8 nM). Two clinical trials investigated the safety, tolerability, pharmacokinetics and antiviral activity of PHX1766 in healthy volunteers (HV) and chronic hepatitis C patients, by use of a dose-adaptive overlapping clinical trial design. METHODS: Two randomized, double-blind, placebo-controlled clinical trials were conducted. Single doses of PHX1766 or placebo were administered to 25 HV and six HCV genotype 1-infected patients (50 mg once daily -1,000 mg once daily, 250 mg twice daily and 100 mg of a new formulation of PHX1766 once daily). Multiple doses of PHX1766 or placebo were administered to 32 HV and seven HCV genotype 1-infected patients (50 mg once daily -800 mg twice daily). RESULTS: Oral administration of PHX1766 was safe and well tolerated at all dose levels with rapid absorption (time at which concentration maximum is reached of 1-4 h) and with mean terminal half-lives of 4-23 h. Multiple doses of PHX1766 800 mg twice daily in HCV patients produced an area under the plasma concentration-time curve from time of drug administration to the last time point with a measurable concentration after dosing accumulation ratio of 2.3. The mean maximal observed HCV RNA decline was 0.6 log(10) IU/ml in the first 24 h in the single-dose protocol and 1.5 log(10) IU/ml after 6 days of PHX1766 dosing. CONCLUSIONS: An overlapping, dose-adaptive single-dose and multiple-dose escalating design in HV and HCV-infected patients proved to be highly efficient in identifying a therapeutic dose. Although in vitro replicon studies indicated a robust HCV RNA viral decline of PHX1766, the study in HCV patients demonstrated only modest viral load reduction.

Evaluation of the potential for pharmacokinetic and pharmacodynamic interactions between dutogliptin, a novel DPP4 inhibitor, and metformin, in type 2 diabetic patients.

OBJECTIVE: Dutogliptin is a novel, orally available, potent, and selective DPP4 inhibitor that improves glycemic control in type 2 diabetic patients. The objective of this study was to evaluate the potential pharmacokinetic and pharmacodynamic interactions, as well as the tolerability, of dutogliptin and metformin alone and in combination in type 2 diabetic patients. METHODS: This was a single-center, randomized, open-label, 3-way, crossover study in type 2 diabetic patients. All patients received three treatment regimens, each of 5 days duration in order to reach steady state: 400 mg once daily of dutogliptin (the anticipated clinical dose); 1000 mg metformin twice daily (maximum effective clinical dose); and concomitant administration of 400 mg dutogliptin once daily and 1000 mg metformin twice daily. RESULTS: Co-administration of dutogliptin and metformin did not alter the pharmacokinetics of either agent. The geometric mean ratio, GMR (dutogliptin + metformin/dutogliptin) of the area under the plasma concentration-time curve (AUC(0-24h)) at steady state was 0.91 (90% CI: 0.79-1.06; p = 0.29); the GMR of the maximum plasma concentrations (C(max)) was 0.95 (90% CI: 0.76-1.19; p = 0.70); the time to maximum plasma concentrations (T(max)) was essentially the same for dutogliptin with or without metformin. The GMR (dutogliptin + metformin/metformin) of AUC(0-12h) at steady state was 0.99 (90% CI: 0.84-1.17; p = 0.93); the GMR of C(max) was 0.91 (90% CI: 0.79-1.04; p = 0.18); T(max) was comparable for metformin with or without dutogliptin. Metformin added to dutogliptin had no effect on plasma DPP4 inhibition. All three treatment regimens were well tolerated. CONCLUSIONS: In this small, multiple dose study, the steady state pharmacokinetics of either dutogliptin or metformin were not altered by co-administration of the two agents. Dutogliptin and metformin were well tolerated either alone or in combination and co-administered metformin did not alter the ex vivo DPP4 inhibition by dutogliptin. There is no need to consider pharmacokinetic and pharmacodynamic interactions when determining the dosage of either agent for co-administration. A phase 3 clinical trial is underway to provide more definitive data on the safety and efficacy of dutogliptin administered on a background of metformin treatment.