Cancer, which is the disease of our age, arises because of a very complex set of mechanisms. Especially with the proliferation of cancer disease and the increase in cancer-related deaths, it has a great impact on the development of drug studies by improving existing treatments or researching new treatment methods. Cantharidine and its analogs are natural anhydrides with an inhibitory effect on protein phosphatases. However, they are not included in cancer therapies due to their toxicity. In recent studies, it has been found that derivatives of cantharidin as isoindole-1,3-dione and its derivatives have anticancer effects. The main purpose of this study to investigate the effects of four different drugs, which are newly synthesized isoindole derivatives for use in cancer treatment, on different cancer cells. The cytotoxic effects of drugs on A549 (human lung adenocarcinoma), HeLa (human cervical carcinoma), PC3 (human prostate carcinoma), MCF-7 (human breast carcinoma), and Caco-2 (human colorectal carcinoma) cell lines were investigated by the MTT assay method, and the optimum incubation time was determined, then IC50 values were calculated. Then, the IC50 concentrations of the drugs were applied at 48 hours, which is the optimum incubation period, and apoptotic stages and cell cycle stages were compared using flow cytometry to understand whether the drugs have a suppressive function in cancer development. Scratch assay was performed to investigate the migration effect of drugs on cells. The results showed that the drugs are suppressive to cancer cells and can be used for therapeutic purposes in the future.