This is a randomized, double-blind, placebo-controlled, single ascending dose study to assess the safety and tolerability of PDC-APB by intramuscular (IM) injection compared to placebo. In this First-in-Human study it is anticipated that up to 5 dose levels (2.5 mg, 10 mg, 0.125 mg and 1.0 mg PDC-APB) will be studied in sequential cohorts. Each cohort will enroll 8 subjects, 6 subjects randomized to active treatment and 2 randomized to placebo, in a double-blind manner. A sentinel group of 2 subjects in each cohort will be randomized to active (1 subject) or placebo (1 subject). If the dose is tolerated in the sentinel group, the remaining 6 subjects in the cohort will be treated (5 active and 1 placebo).