PK sampling
PK parameters of INM004 levels were determined in all subjects receiving at least one dose of the medication. In stage I the participants were hospitalized for 24 hours after the infusion and PK samples were obtained at the following times: 0, 15, 30, 45, 60, 90, 120, 150, 180, 210, 240, 270, 300, 360, and 480 min, and at 12, 24, 48, and 72 hours after infusion. A baseline and final laboratory tests for immunogenicity were obtained at day 0 and 30, respectively. Ambulatory PK samples, clinical visits, and safety laboratories at days 3, 4, 5, and 30 after infusion were scheduled. During stage II, the participants received three repeated doses of 4 mg.kg-1 every 24 hours during 3 days. The volunteers stayed hospitalized for 24 hours after the last infusion. PK samples were obtained at the following times: 0, 30, 60, 120, 180, 240, 360, and 480 min, and at 12 and 24 hours after first infusion; at 60, 120, 360 min, and 12 and 24 hours after the second infusion; and at 60, 120, 360 min, and 12, 24, 48, 72, 96 and 120 hours, and at day 30 after the third infusion. Ambulatory visits and safety laboratory tests were identical to those scheduled in stage I.
Quantification of the F(ab´)2 equine polyclonal antibody concentrations in plasma was performed by Enzyme-Linked Immunosorbent Assay (ELISA) developed for preclinical studies of INM004 and validated for human plasma samples11. Blood samples (5 ml) for PK analyses were collected by venipuncture, and the results analyzed by non-compartmental (NCA) PK methods. The fixed main effects treatment, period and sequence were analyzed for the PK parameters of interest [Cmax, AUC (0-t) and AUC (0-Inf)]. The AUC was obtained from the graph of the drug plasma levels over time for each subject. The 90% confidence interval limits for PK were calculated. Cmax and Tmax were estimated directly from the curve with interpolation. AUC (0-inf) and AUC (0-t) were calculated using the trapezoidal rule based on the individual concentrations observed. The elimination half-time (t½) was calculated as Ln (2) / λz, where λz was estimated from a log-linear regression of the last 3 to 5 points of the curve, after reaching plateau. Coefficients of variation were calculated for Cmax and AUC(0‑inf).