Tesmilifene is a small-molecule antineoplastic drug and chemopotentiator that was under development by YM BioSciences for the treatment of breast cancer. Tesmilifene was developed as a selective ligand of the antiestrogen binding sites without estrogen receptor affinity. Tesmilifene potentiates the cytotoxicity of a variety of chemotherapy drugs in vitro and in vivo. Tesmilifene in combination with doxorubicin provides an unexpected and very large survival advantage over doxorubicin alone in a randomized trial in phase III clinical trial in advanced breast cancer. Unfortunately, Tesmilifene application associated with high rate disease and treatment-related adverse events and poor quality of life. Based on these results further development of Tesmilifene was discontinued

Caracemide is a nonspecific inhibitor of macromolecules affecting the synthesis of DNA, RNA, and proteins. Caracemide is an active inhibitor of ribonucleotide reductase as evidenced in the Novikoff tumor model. These inhibitory effects are concentration-dependent with 70 percent of DNA synthesis inhibited by a drug concentration of 1 mkM with a 4 h incubation. However, RNA and protein synthesis inhibition require a concentration of 50-100 mkM. DNA strand breaks were observed only at high in vivo concentrations of 100 mkM. The antineoplastic activity of caracemide was observed in the P388 murine model and in mammary (MX-I) and colon (CX-1) human tumor xenographs implanted in the subrenal capsules of athymic mice. In the MX-1 mammary tumor, a single daily injection provided greater activity than an intermittent schedule. Caracemide was inactive against murine L1210 leukemia, B16 melanoma, Lewis lung carcinoma, CD8FI mammary carcinoma and Colon 38. The toxicity on phase I studies was frequent but generally mild. Of note, significant central nervous system dysfunction manifested by lethargy, depression, and confusion occurred in some and was not predictable. In phase I studies Caracemide failed to demonstrate efficacy in patients with advanced renal cell cancer and advanced large bowel cancer.

Chlorpyrifos-methyl is a broad-spectrum organophosphorous insecticide and potential toxic pollutant widely used in agriculture and effective against a wide range of insect pests in commercial importance crops. Chlorpyrifos-methyl have endocrine disruption activity, especially anti-androgenic effects and Chlorpyrifos-methyl administration leads to hepatotoxicity and neurotoxicity in mammals. The fish exposed to chlorpyrifos-methyl exhibited behavioral changes in the form of neurotoxin toxicity: less general activity than control group, loss of equilibrium, erratic swimming and staying motionless at a certain location

Tesmilifene is a small-molecule antineoplastic drug and chemopotentiator that was under development by YM BioSciences for the treatment of breast cancer. Tesmilifene was developed as a selective ligand of the antiestrogen binding sites without estrogen receptor affinity. Tesmilifene potentiates the cytotoxicity of a variety of chemotherapy drugs in vitro and in vivo. Tesmilifene in combination with doxorubicin provides an unexpected and very large survival advantage over doxorubicin alone in a randomized trial in phase III clinical trial in advanced breast cancer. Unfortunately, Tesmilifene application associated with high rate disease and treatment-related adverse events and poor quality of life. Based on these results further development of Tesmilifene was discontinued