Sepantronium bromide (YM155) is a selective survivin suppressant that exhibits potent antitumor activities by inducing apoptosis and autophagy in various types of cancer. Sepantronium bromide inhibited the growth of various human cancer cell lines in vitro with GI50 values in the low nM range. Sepantronium bromide blocked the growth of 119 human cancer cell lines, with the greatest inhibition in lines derived from non-Hodgkin's lymphoma, hormone-refractory prostate cancer, ovarian cancer, sarcoma, non-small-cell lung cancer, breast cancer, leukemia, and melanoma, with an average GI50 of 15 nM. Sepantronium bromide inhibited the growth of tumor cell lines regardless of their p53 status and demonstrated significant antitumor activity in 5 mice xenograft models. It also caused tumor regressions in vivo, possibly by its effects in reducing intratumoral survivin expression levels and increasing apoptosis. Sepantronium Bromide had been in phase II clinical trials by Astellas for the treatment of prostate cancer, melanoma, non-Hodgkin's lymphoma, breast cancer, diffuse large B cell lymphoma, non-small cell lung cancer (NSCLC) and other solid tumors. This compound had also been in clinical trials by National Cancer Institute (NCI) for the treatment of solid tumors (phase I) and advanced non-small cell lung cancer (NSCLC) (phase II). However, all these researches about this compound for all indications were discontinued.

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.

Acifran (AY-25,712), an uncommercialized Ayerst compound exerting lipid-lowering activity in vivo, has been shown to also elicit similar effects as niacin in preliminary clinical testing and has been shown to bind to both high affinity (HM74A; GPR109A) and low affinity (HM74; GPR109B) niacin receptors. The EC50 values of the separated acifran enantiomers for the GPR109a and 109b receptors showed that, as with acifran itself, the (+)-enantiomers were essentially twice as active as the racemic mixtures, whereas the activity of the (-)-enantiomers was more variable and highly dependent on purity. S-enantiomer of acifran is the active principle. All of the activity of racemic acifran could be attributed to the (S)-enantiomer, and hence, from this precedent, (+)-enantiomers would be assigned to the S-configuration. However, the absolute configuration was not confirmed experimentally.

PU-H71 is experimental inhibitor of Hsp90. It is being tested in clinical trials against lymphoma and solid tumors.

Apricitabine (ATC) is an investigational drug that was being studied for the treatment of HIV infection. Apricitabine belongs to a class (group) of HIV drugs called nucleoside reverse transcriptase inhibitors (NRTIs). NRTIs block an HIV reverse transcriptase. By blocking reverse transcriptase, NRTIs prevent HIV from multiplying and can reduce the amount of HIV in the body. In vitro studies have shown that apricitabine appears to work on certain HIV strains against which other FDA-approved NRTIs, such as lamivudine (brand name: Epivir), may no longer work. Apricitabine shows antiviral activity in vitro against HIV-1 strains and clinical isolates with mutations in the reverse transcriptase that confer resistance to other NRTIs, including M184V, thymidine analogue mutations (TAMs), nucleoside-associated mutations such as L74V and certain mutations at codon 69. Apricitabine has shown activity in treatment-experienced HIV-1-infected patients with NRTI resistance (with M184V and up to five TAMs) as well as in treatment-naive patients. The study of apricitabine as an HIV medicine was discontinued in 2016. The company developing the drug decided to stop their clinical trials due to a lack of funding and a lack of interest in apricitabine’s early access program.

Ethidium is a DNA intercalating agent first discovered as and used as a veterenary trypanocide. A bromide salt is commonly used as a fluorescent tag in molecular biology. The fluorescene of ethidium bromide increased 21 fold upon binding to double-stranded RNA, 25 fold upon binding double stranded DNA. Because of the binding to DNA, ethidium bromide is a powerful inhibitor of DNA polymerase.

(+)-selfotel ((+)-CGS-19755) is an enantiomer of selfotel, a competitive antagonist at N-methyl-D-aspartate (NMDA)-preferring receptors. The inhibition of NMDA-evoked ACh release from rat striatal slices is stereospecific, with the (+)-enantiomer less potent than the (-)-enantiomer.