Cinperene is an investigational compound proposed for clinical use as a strong and long-acting peripheral central anticholinergic. In animal models, cinperene inhibited mydriasis, pilocarpine-induced salivation, and lacrimation, scratching, hunching and other symptoms.

Pibrozelesin (KW-2189) is a semisynthetic water-soluble derivative of the antineoplastic antibiotic duocarmycin B2. Activated by carboxyl esterase, pibrozelesin alkylates DNA by binding to adenine-thymine (A-T)-rich sequences in the minor groove of DNA, thereby inhibiting DNA replication and inducing apoptosis. KW-2189 induced DNA strand breaks in H69 cells in a concentration-dependent manner. DNA cleavage is one of the major mechanisms of KW-2189-mediated cytotoxicity. KW-2189 showed evidence of anti-tumor activity in hepatocellular carcinoma (HCC). However, because of significant and prolonged hematologic toxicity, when given as a single dose every 6 weeks, further development of this drug in HCC is not possible. Pibrozelesin had been in phase II clinical trial for the treatment of advanced malignant melanoma and advanced renal cell carcinoma. No activity in metastatic renal cell carcinoma was demonstrated and the lack of significant antitumor activity in advanced malignant melanoma treatment was shown.

Hydroxyflutamide is the major active metabolite of flutamide. Flutamide undergoes extensive first-pass metabolism by CYP1A2 to its metabolite hydroxyflutamide and its hydrolysis product, 3-trifluoromethyl-4-nitroaniline. Hydroxyflutamide is a more powerful antiandrogen in vivo, with higher affinity for the receptor than that of flutamide. Hydroxyflutamide is in phase II clinical trials for the treatment of prostate cancer. However, a drug resistance problem appears after about one year's treatment. Per-residue free energy decomposition analyses indicate that N705, T877, and M895 androgen receptor mutations are vital residues in the agonist/antagonist mechanism of hydroxyflutamide.

Spirotriazine is a dihydrotriazine derivative patented by Burroughs Wellcome & Co. (U.S.A.) Inc. as the anthelmintic agent. In preclinical models, Spirotriazine shows potent activity against intestinal parasites and negligible microbiological activity.

Evobrutinib is a highly selective, irreversible inhibitor of Bruton's tyrosine kinase (BTK). It potently inhibits BCR- and Fc receptor-mediated signaling and, thus, subsequent activation and function of B cells and innate immune cells such as monocytes and basophils. Evobrutinib demonstrated effectivity in autoimmune disease preclinical models. Evobrutinib is being developed by Merck Serono for the treatment of various autoimmune disorders.

Namitecan (ST1968) is a camptothecin analogue being developed by sigma-tau (a subsidiary of Alfasigma) in Switzerland for the treatment of cancer. Namitecan, a novel hydrophilic camptothecin analog of the 7-oxyiminomethyl series, was selected for clinical development on the basis of its promising preclinical efficacy. Namitecan is a topoisomerase I inhibitor. Namitecan exhibited an acceptable toxicity profile, with neutropenia being the dose-limiting toxic effect, and clinical benefit was appreciable in patients with different tumor types, particularly bladder and endometrium carcinomas.

Zaurategrast (CDP323) is an ethyl ester prodrug of CT7758, a potent carboxylic acid antagonist of integrin alpha4-beta1 (α4β1) or very late antigen 4 (VLA4). CDP323 was under development with UCB and Biogen Idec for the treatment of multiple sclerosis. Its development was discontinued in 2009 based on inadequate interim efficacy data in a phase II clinical trial.

Fluorescein Lisicol (NRL972) is a fluorescent-labelled bile acid analog that is used as an investigational marker for liver function, specifically hepatic biliary transporter function. Fluorescein Lisicol has been used in trials investigating the pharmacokinetics of hepatic cirrhosis, viral hepatitis, non-alcoholic steatohepatitis and non-alcoholic fatty liver disease.

Metesind (AG-331) is a lipophilic thymidylate synthase inhibitor. It inhibits the cofactor binding site of the enzyme. It exerts cytotoxic properties. Metesind was being developed as an anticancer and antimetabolite agent.