Siga Technologies Inc., of New York, said it started enrolling the second and final cohort of healthy subjects for the phase III trial of lead antiviral candidate Tpoxx (tecovirimat; ST-246) for the treatment of orthopoxvirus. The study, which is wholly funded by the Biomedical Advanced Research and Development Authority, will enroll about 360 subjects and is designed to generate safety and pharmacokinetic data in support of the prescribing information that will be part of the new drug application filing.