Safety
The most common (>10%) local (injection-site) adverse reactions observed in clinical studies were tenderness, pain, erythema and arm motion limitation.
Injection site adverse reactions, including warmth, tenderness, itching, erythema, induration, edema, and nodule, consistently occurred at lower frequencies and for shorter duration in participants given BioThrax by the intramuscular route, as compared to the subcutaneous route.
The most common (>5%) systemic adverse reactions were muscle aches, fatigue and headache.
The change in the route of administration from subcutaneous to intramuscular did not statistically significantly influence the occurrence or duration of systemic adverse reactions, with the exception of muscle ache (increase seen in occurrence only).
Serious allergic reactions, including anaphylactic shock, have been observed during post-marketing surveillance in individuals receiving BioThrax.
Study Design: A randomized, double-blind, placebo-controlled, multi-center clinical study in which 1,564 healthy adult volunteers were enrolled to evaluate the impact on safety and immunogenicity of changing the administration route from SQ to IM, and reducing the number of doses (i.e. omitting the week 2 dose).
* Per-dose, statistical assessment performed on Intent-to-Treat population data. Evaluations performed at 15-60 minutes and 1-3 days following each injection and prior to the next scheduled injection.
** N is the highest number per treatment arm; denominator (N) varied with dose number due to attrition over time.
† Subjects received saline (instead of BioThrax) for the Week 2 dose.
‡ The two saline groups (SQ and IM) were combined.
