The hydrobromide salt of halofuginone, a semisynthetic quinazolinone alkaloid anticoccidial derived from the plant Dichroa febrifuga, with antifibrotic and potential antineoplastic activities. Halofuginone specifically inhibits collagen type I gene expression and matrix metalloproteinase 2 (MMP-2) gene expression, which may result in the suppression of angiogenesis, tumor stromal cell development, and tumor cell growth. These effects appear to be due to halofuginone-mediated inhibition of the collagen type I and MMP-2 promoters. Collagen type I and MMP-2 play important roles in fibro-proliferative diseases.