The present disclosure provides a method of treating a patient with refractory or resistant cancer by administering a therapeutically effective amount of a compound of formula (I), such as Varlitinib, or an enantiomer thereof or a pharmaceutically acceptable salt of any one of the same. Also provided is a compound of formula (I) for use in the treatment of resistant or refractory cancer and use of a compound of formula (I) for the manufacture of a medicament for the treatment of resistant or refractory cancer.
