Anti-cancer compounds and conjugates thereof

Disclosed are compounds based on dolastatins, drug-conjugates, methods of preparing drug-conjugates, and uses thereof. Also disclosed are pharmaceutical compositions and methods of treatment. The compounds and drug-conjugates disclosed herein can be used to treat diseases such as bladder cancer, breast cancer, colon cancer, rectal cancer, endometrial cancer, kidney cancer, lung cancer, melanoma, non-Hodgkin lymphoma, glioblastoma, pancreatic cancer, prostate cancer, and thyroid cancer.