Rubitecan [Orathecin™] is a topoisomerase I inhibitor extracted from the bark and leaves of the Camptotheca acuminata tree, which is native to China. Rubitecan is an oral compound being developed for the treatment of pancreatic cancer and other solid tumours by SuperGen. Rubitecan binds to and inhibits the enzyme topoisomerase I and induces protein-linked DNA single-strand breaks, thereby blocking DNA and RNA synthesis in dividing cells; this agent also prevents repair of reversible single-strand DNA breaks.

MK 0777 is a selective GABAA α2/3 receptor partial agonist, for potential use in the treatment of Schizophrenia, Anxiety Disorder, and Generalized Anxiety Disorder. MK-0777 is functionally selective for the α2 and α3 subunits, with virtually no activity for the α1 and α5 subunits. Therefore, MK-0777 cause less sedation, interact less with alcohol, and exhibit less abuse potential and physical dependence than benzodiazepines. Unfortunately, in clinical trials, MK-0777 has little benefit for cognitive impairments in people with schizophrenia and anxiety disorder.

Ecopipam (SCH-39166) is a selective D1 dopamine receptor antagonist both in vitro and in vivo. Additionally, it exhibits saturable, high-affinity binding to D5 receptors. Ecopipam was studied clinically for a variety of indications, including schizophrenia, drug abuse, and obesity, but in each case undesirable effects were observed. Currently, ecopipam is in clinical trials for the treatment of Lesch-Nyhan and Gilles de la Tourette's syndromes.

Diflomotecan is an E-ring modified camptothecin analogue, which possesses greater lactone stability in plasma compared with other topoisomerase I inhibitors. Diflomotecan was the first homocamptothecin to enter clinical studies. Phase I data are summarized for both the intravenous and oral schedules. The toxicity is primarily haematological while no severe gastrointestinal toxicity has been observed in contrast to other topoisomerase I inhibitors. Diflomotecan has a high oral bioavailability (72 - 95%) and the oral day 1 - 5 every 3 weeks regimen is recommended for Phase II testing because it is relatively well tolerated. Diflomotecan had been in Phase II clinical trials for the treatment of small cell lung cancer. However, this research has been discontinued.

Epothilone D (KOS-862 or BMS-241027) is an intermediary obtained in the synthesis of members of the epothilone family and is a small-molecule microtubule stabilizer. It was investigated in Phase II trials in colorectal, metastatic breast and non-small-cell lung cancers. However, development was discontinued in 2007 in favor of a second-generation analog with a better safety profile. This drug also was studied for the treatment of Alzheimer's disease. The study ended in October 2013, and evaluation of epothilone D for Alzheimer's disease was subsequently discontinued. The mechanism by which epothilones induce microtubule polymerization appears to be similar to that of paclitaxel, in that epothilones compete with paclitaxel for binding to microtubules and suppress microtubule dynamics in a manner similar to that of paclitaxel.

Datelliptium is a DNA-intercalating agent, an analog of a natural alkaloid ellipticine. The compound was active in vivo against a variety of murine solid tumors. In a phase I clinical trial no objective complete or partial responses were observed in patients with solid tumors or lymphoma treated with datelliptium.

Antafenite is an anthelminthic drug.

Colforsin (NKH477) is a water-soluble forskolin derivative. NKH477, like forskolin, showed adenylate cyclase stimulant activity in guinea pig ventricular membrane but did not inhibit Na+, K(+)-ATPase or phosphodiesterase (PDE) activity. The compound was developed by a Japanese company Nippon Kayaku. Colforsin daropate, a prodrug of colforsin, is marketed in Japan for the treatment of acute heart failure under tradename Adehl.