Twenty four subjects will be divided equally among 3 cohorts (20, 30 and 40 μg/cm2/day dose level) of 8 subjects each. Each subject will receive both active (STP705) and control (Placebo) treatment twice a week for a total of 4 weeks. The total length of linear hypertrophic scar will be divided equally for treatment with STP705 and placebo. STP705 and Placebo will be injected intradermal every 1 cm length on the hypertrophic scar.