Obiltoxaximab

Obiltoxaximab (ETI 204) is the second and potent anti-protective antigen (PA) monoclonal antibody with immunogenicity. Obiltoxaximab plays a central role in anthrax toxin assembly and target cell intoxication, promoting survival, and inhibiting bacterial spread to the periphery in animal models. Obiltoxaximab can be used in the research of inhalational anthrax, bacteremia and toxemia^[1][2][3][4]. In Vivo:Obiltoxaximab (16 mg/kg, i.v., a single dose for 70 days) for simulated populations of healthy and infected humans is comparable in overall serum exposures in individual infected macaques following obiltoxaximab, similar results in rabbit experiments^[1].
Obiltoxaximab (16 mg/kg, i.m., 24, 48, 72 h prior to lethal challenge with B. anthracis spores) leads to 100% survival challenged with B. anthracis spores in cynomolgus macaques and prevents systemic bacteremia in the vast majority of animals^[2].
Obiltoxaximab (4 and 8 mg/kg, i.v. and i.m., a single dose for 9 h) postexposure prophylaxis (PEP) leads to 100% survival with the combination of Levofloxacin (HY-B0330) challenged with B. anthracis spores in rabbits^[2].
Obiltoxaximab (8 mg/kg, i.v., a single dose, 29 days) combined with antibiotics or Doxycycline (HY-N0565) lowers bacteremia levels in protective antigen (PA) of anthrax induced rabbits^[5].

Pharmacokinetics of intramuscular Obiltoxaximab^[2]

Study and dose (mg/kg)	Postchallenge dosing schedule	Cmax (μg/mL)	Tmax (days)	AUC0-∞ (μg·day/mL)	T1/2 (days)	CL /F(mL/day/kg)	Vz/F (mL/kg)
PEP 2
8	18 h	80.8	1.0	1030	7.50	7.76	84.0
8	24 h	86.5	1.0	788	5.20	10.2	76.2
16	18 h	165	1.0	2120	8.44	7.54	91.9
16	24 h	119	1.0	1990	9.85	8.03	114
PEP 3
16	24 h	142	1.0	2190	10.4	7.00	110
16	36 h	132	0.50	1540	7.09	10.0	106
16	48 h	104	3.0	2040	12.6	8.00	143