6-O-BENZYLGUANINE is a guanine analogue with antineoplastic activity. O(6)-benzylguanine binds the DNA repair enzyme O(6)-alkylguanine DNA alkyltransferase (AGT), transferring the benzyl moiety to the active-site cysteine and resulting in inhibition of AGT-mediated DNA repair. Co-administration of this agent potentiates the effects of other chemotherapeutic agents that damage DNA. 6-O-benzylguanine has been used in trials studying the treatment of HIV Infection, Adult Gliosarcoma, Adult Glioblastoma, Stage I Adult Hodgkin Lymphoma, and Stage II Adult Hodgkin Lymphoma, among others.

Celgosivir is a butanoyl ester derivative of castanospermine, a compound derived from the Australian chestnut with activity against hepatitis C virus. Celgosivir rapidly converts to castanospermine in the body, where it is a potent inhibitor of alpha-glucosidase I, a host enzyme required for viral assembly, release, and infectivity.

Seocalcitol (EB 1089) is a vitamin D analog, and agonist of the vitamin D receptor. Antineoplastic activity of seocalcitol was tested in clinical trials against hepatocellular carcinoma, pancreatic, breast and colorectal cancer. Due to inconsistent results of clinical trials, development of seocalcitol was discontinued by Leo Pharma.

Muraglitazar previously known as BMS-298585 has been identified as a non-thiazolidinedione dual agonist of peroxisome proliferator-activated receptor alpha/gamma. Muraglitazar is currently in clinical trial phase III development for the treatment of type 2 diabetes and dyslipidemia.

Trazolopride is an antiemetic, stomachic drug.

Preladenant (SCH-420814) is an adenosine A(2A) receptor antagonist with a high affinity and very high selectivity for adenosine A(2A) receptors, which is being developed by Merck & Co Inc (following its acquisition of Schering-Plough Corp) for the potential treatment of Parkinson's disease. Preladenant is a potent competitive antagonist of the human A2Areceptor (Ki = 1.1 nM) and has >1000-fold selectivity over all other adenosine receptors, making this compound the most selective A2A receptor antagonist reported to date. Preladenant was being researched as a potential treatment for Parkinson's disease. Positive results were reported in Phase II clinical trials in humans, but it did not prove itself to be more effective than a placebo during Phase III trials, and so was discontinued in May 2013.

Marimastat is a broad spectrum matrix metalloprotease (MMP) inhibitor. It is an angiogenesis and metastasis inhibitor. It mimics the peptide structure of natural MMP substrates and binds to matrix metalloproteases, thereby preventing the degradation of the basement membrane by these proteases. This antiprotease action prevents the migration of endothelial cells needed to form new blood vessels. Inhibition of MMPs also prevents the entry and exit of tumor cells into existing blood cells, thereby preventing metastasis. Marimastat has been in pivotal phase III trials in glioblastoma, breast, ovarian and small and non-small cell lung cancer, but these trials have all been discontinued because marimastat failed to show superior efficacy over either standard chemotherapy or placebo.

The novel compounds clamikalant (HMR 1883) or its sodium salt HMR 1098) have been shown to block selectively Kir6.2/SUR1-composed K(ATP) channels. Clamikalant is under development by Aventis Pharma (formerly Hoechst Marion Roussel) for the potential treatment of heart arrest and ventricular arrhythmias. Nevertheless, clamikalant and its sodium salt did not pass the clinical trials