Disclosed is a glassy solid form of CDDO-methyl ester (also known as methyl 2-cyano-3,12-dioxoleana-1,9(11)-dien-28-oate as depicted in the drawing of figure 1), having an x-ray powder diffraction pattern with a halo peak at approximately 13.5 degrees 2 theta, as shown in Figure 2C in the specification, and a Tg. Also disclosed is a pharmaceutical composition comprising (i) a therapeutically effective amount of CDDO-methyl ester and (ii) an excipient that is a glass former, such that said composition has a Tg. Further disclosed is a pharmaceutical composition comprising the glassy solid form of CDDO methyl ester and the use of the pharmaceutical composition in the manufacture of a medicament for the treatment of cancer.
