HALO_SectionHT-100 is a delayed-response form of halofuginone hydrobromide, a derivative of a natural compound found in a species of plant. The drug is being developed for Duchenne by Massachusetts-based Halo Therapeutics, LLC with the aim of blocking the fibrosis, or scarring, that occurs in Duchenne muscle tissue when muscle cells are damaged. It is widely thought that fibrosis in Duchenne is a barrier to normal muscle regeneration.

Halofuginone is also a potent anti-inflammatory agent, and in addition promotes one of the key processes in muscle regeneration. Inflammation and lack of healthy muscle regeneration are critical problems in Duchenne muscle.