Described are crystalline forms of the pharmaceutical compound &ldquo[9S-(9&alpha,10&bgr,12&alpha)]-5,16-Bis[(ethylthio)methyl]-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9, 12-epoxy-1H-diindolo[1,2,3-fg:3&prime,2&prime,1&prime-kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester&rdquo, as well as methods for their use and preparation.
