(M1130-02-11) Toxicokinetics of cNP8, a Fibronectin-Derived Peptides, in Rats and Dogs Following a Single Intravenous Injection in an Expanded Acute Toxicity Study

Purpose: The toxicokinetics (TK) of cNP8 following a single intravenous (IV) injection to rats and dogs was assessed as part of expanded single-dose toxicity studies. cNP8 is a second-generation fibronectin-derived, cyclic 15-mer peptide, containing eleven natural amino acids. It is being developed as an injection treatment to improve wound healing of acute, deep second degree burns in hospitalized patients. Fibronectin has been shown to play a vital role in wound healing and is deficient in burn patients’ wounds and blood (Deno, et., al., 1984; Herrick, et., al., 1992; and Lin, et., al., 2018).

Methods: The TK portion of the rat study included 4 satellite groups of Sprague-Dawley male and female rats (n = 9/sex/group for the test article groups, and 3/sex for the control group). Animals were dosed via a single IV injection of either vehicle, or cNP8 at 0.2, 1.1/0.5 (males/females), or 2 mg/kg as a slow bolus over a 1-minute duration.  The dog study included 4 groups of male and female Beagle dogs (n = 6/sex/group) dosed with cNP8 via single IV injection of either vehicle, or cNP8 at 0.5, 1, or 2 mg/kg mg/kg as a slow bolus over a 1-minute duration.  Blood samples for TK analysis were collected at predetermined times and plasma was analyzed for cNP8 using validated HPLC-MS/MS assays with calibration ranges of 1.00 to 1,000 ng/mL for both species.  The TK parameters were determined by model independent methods.

Results: In rats, cNP8 reached the maximum plasma concentrations at the first postdose collected sample timepoint (Table 1 and Figure 1).  cNP8 C₀ values were 370, 384, and 918 ng/mL in males and 506, 801, and 4160 ng/mL in females for cNP8 doses of 0.2, 1.1/0.5 ( males/females), and 2 mg/kg, respectively (Table 1).  Corresponding AUC_(0-inf) values were 31.3, 37.9, and 79.5 ng∙h/mL in males and 41.1, 60.8, and 291 ng∙h/mL in females.  The TK exposure (C₀ and AUC_(0-inf)) of cNP8 increased with increasing the dose of cNP8 from 0.2 to 2 mg/kg in females, but not in males (Table 1 and Figure 1).  The TK exposure in males was lower than that in females with cNP8 male/female C₀ ratios of 0.732 and 0.221 and AUC_(0-inf) ratios of 0.762 and 0.273 for cNP8 doses of 0.2 and 2 mg/kg, respectively (Table 1 and Figure 2).  cNP8 exhibited rapid elimination, high clearance, and a large volume of distribution (See Table 1). In dogs, cNP8 reached the maximum plasma concentrations at the first postdose collected sample timepoint (Table 1 and Figure 1). cNP8 mean C₀ values were 1,320, 2,590, and 2,560 ng/mL in males and 1,610, 3,760, and 1,660 ng/mL in females for doses of 0.5, 1 and 2 mg/kg, respectively (Table 1). The corresponding mean AUC_(0-inf) values were 174, 320, and 366 ng∙h/mL in males and 240, 467, and 408 ng∙h/mL in females. In general, the TK exposure (C₀ and AUC_(0-inf)) of cNP8 increased with increasing the dose of cNP8 from 0.5 to 2 mg/kg in males and from 0.5 to 1 mg/kg in females (Table 1 and Figure 1). The female TK exposure at 2 mg/kg dose was lower than that at 1 mg/kg, which may be attributed to the large data variability at the 2 mg/kg dose.  The TK exposure in males appeared to be lower than that in females at the lower doses and was similar to that in females for the highest dose.  The cNP8 male/female ratios for the mean C₀ were 0.820, 0.689, and 1.54 and the ratios for the mean AUC_(0-inf) were 0.725, 0.685, and 0.897 for cNP8 doses of 0.5, 1 and 2 mg/kg, respectively (Table 1 and Figure 2).   cNP8 exhibited rapid elimination, high clearance, and a large volume of distribution (See Table 1).

Conclusion: The pattern of cNP8 systemic exposure appeared to be similar in both species. The overall TK exposure of cNP8 increased with increasing cNP8 dose and was lower in males than females. cNP8 exhibited rapid elimination, high clearance, and a large volume of distribution.

References: Deno DC, McCafferty MH, Saba TM, and Blumenstock FA. Mechanism of acute depletion of plasma fibronectin following thermal injury in rats. Appearance of a gelatinlike ligand in plasma. J Clin Invest. 1984;73(1):20-34.
Herrick SE, Sloan P, McGurk M, Freak L, McCollum CN, and Ferguson MW. Sequential changes in histologic pattern and extracellular matrix deposition during the healing of chronic venous ulcers. Am J Pathol.1992;141(5):1085-95.
Lin K, Lin F, and Clark RA. Elastase Digestion of Fibronectin Releases an Epiviosamine Peptide with Fibroblast Growth and Survival Activity. J Invest Dermatol. 2018;138(11):2480-3.

TK Table

TK Profiles

C0 and AUC vs Dose