This first-in-human, phase I study evaluated the safety, tolerability, pharmacokinetic and pharmacodynamic profile of ASKP1240 in healthy subjects. Twelve sequential groups (each 6 active and 3 placebo) were randomly assigned to placebo or single ascending doses of intravenous ASKP1240 (0.00003-10 mg/kg). ASKP1240 exhibited nonlinear pharmacokinetics, with mean maximal serum concentrations and area under the serum concentration-time curves ranging from 0.7 to 251.6 lg/mL and 6.5 to 55409.6 h·lg/mL following doses 0.1 mg/kg-10 mg/kg, respectively. CD40 receptor occupancy by ASKP1240, which was dose-dependent, reached a maximum at doses above 0.01 mg/kg. ASKP1240 was well tolerated, with no evidence of cytokine release syndrome or thromboembolic events. Treatment emergent antibodies to ASKP1240 were detected in 5/70 (7.1%) ASKP1240 recipients. In conclusion, antagonism of the CD40/CD154 interaction with ASKP1240 was safe and well tolerated at the doses tested.
Key words: ASKP1240, anti-CD40, pharmacodynamics, pharmacokinetics, randomizedAbbreviations: AEs, adverse events; AUC inf , area under the concentration-time curve from time zero extrapolated to the infinite time; C max , maximal antibody serum concentration; INR, international normalized ratio; LLOQ, lower limit of quantification; MABEL, minimal anticipated biological effect level; MedDRA, Medical Dictionary for Regulatory Activities; MFI, mean fluorescent intensity; PD, pharmacodynamic; PDAS, pharmacodynamic analysis set; PK, pharmacokinetic; PKAS, pharmacokinetic analysis set; SAF, safety analysis set; SD, standard deviation; t 1/2 , terminal half-life; t max , time to C max ; ULN, upper limit of normal.