The invention described herein pertains to drug delivery conjugates for targeted therapy. The invention described herein relates to methods of treating PSMA expressing cancers with a compound of the formula 1. The invention described herein also relates to methods of treating PSMA-expressing cancers with a compound of the formula 1 in patients where stable disease results after treatment with the compound of the formula 1.本文所述之發明係關於用於靶向療法之藥物遞送結合物。本文所述之發明係關於用式1化合物治療表現PSMA之癌症的方法。本文所述之發明亦係關於用式1化合物治療患者中表現PSMA之癌症的方法,其中以該式1化合物治療後產生穩定疾病。