Galunisertib is a potent inhibitor of TGF beta type 1 receptor. The drug is under clinical development for the treatment of different cancers: pancreatic, hepatocellular, breast, rectal, prostate etc. and reached phase 2/3 in patients with myelodysplastic syndromes.

Maytansine is an ansamycin antibiotic originally isolated from the Ethiopian shrub Maytenus serrata. Maytansine inhibits the assembly of microtubules by binding to tubulin at or near the vinblastine-binding site, decreases microtubule dynamic instability and cause mitotic arrest in cells. It exerts cytotoxicity against a number of tumor cell lines and inhibits tumor growth in vivo. However, in human clinical trials, maytansine showed a small therapeutic window due to its neurotoxicity and harmful effects on the gastrointestinal tract. The potent cell killing ability of maytansine can be used in a targeted delivery approach, such as an antibody-drug conjugate, for the selective delivery of the drug and destruction of cancer cells.

PPI-2458 is a synthetic derivative of fumagillin with antineoplastic and cytotoxic properties. PPI-2458 irreversibly inhibits the enzyme methionine aminopeptidase type 2 (MetAP2), thereby preventing abnormal cell growth and angiogenesis. PPI-2458 is reported to have a better toxicity profile compared to other agents of its class. In a phase 1 clinical study, PPI-2458 was administered to patients with non-Hodgkin lymphoma. The data confirm the participation of active metabolites in the in vivo efficacy of PPI-2458. In in vitro studies, osteoclast formation and activity were inhibited by PPI-2458, a mechanism not previously attributed to MetAP-2 inhibition. PPI-2458 treatment reduced synovial and osteochondral angiogenesis, synovial inflammation, joint damage, and pain behavior. PPI-2458 exerts disease-modifying activity in experimental arthritis through its direct inhibition of several pathophysiologic processes of this disease. These results provide a rationale for assessing the potential of PPI-2458 as a novel rheumatoid arthritis therapy.

LADIRUBICIN is an idarubicin derivative with potential antineoplastic activity. Its primary effect is a DNA alkylation with sequence specificity similar to that of conventional nitrogen mustards. It possesses a wide spectrum antitumor activity against rapidly proliferating murine leukemias and on slowly growing transplantable human tumor xenografts.

Torcitabine is the beta-L-enantiomer of the natural nucleoside D-cytidine. The drug was under development as an antiviral agent for the treatment of chronic hepatitis B virus infection. Torcitabine has poor oral bioavailability, but its 3’,5’-derivative ester (val-L-dC) and the 3’-monovaline ester, valtorcitabine dihydrochloride, have excellent oral bioavailability and consequently the torcitabine prodrug, valtorcitabine, has replaced torcitabine in clinical development. Torcitabine is active against hepadnaviruses, specifically human hepatitis B virus (HBV), duck hepatitis virus (DHBV) and woodchuck hepatitis virus (WHV). Torcitabine triphosphate is a selective inhibitor of the polymerase enzyme of HBV.

Thiodiglycol is the organosulfur structurally similar to diethylene glycol used as a solvent in a variety of applications ranging from dyeing textiles to inks in some ballpoint pens. In chemical synthesis, it is used as a building block for protection products, dispersants, fibers, plasticizers, rubber accelerators, pesticides, dyes, and various other organic chemicals. In the manufacture of polymers, it is used as a chain transfer agent. Thiodiglycol is a precursor in the production of Sulfur mustard and it is also considered as a “Schedule 2” compound (dual-use chemicals with low to moderate commercial use and high-risk precursors) within the terms of the Chemical Weapons Convention treaty.

Fotretamine was developed as an immunosuppressant and antineoplastic agent. However, information about the further development of this drug is not available.

Prinomastat is a synthetic hydroxamic acid derivative with potential antineoplastic activity. Prinomastat inhibits matrix metalloproteinases (MMPs) (specifically, MMP-2, 9, 13, and 14), thereby inducing extracellular matrix degradation, and inhibiting angiogenesis, tumor growth and invasion, and metastasis. As a lipophilic agent, prinomastat crosses the blood-brain barrier. Pfizer conducted multicenter, randomized, double-bind, placebo-controlled trials to evaluate the safety and efficacy of prinomastat in combination with standard chemotherapy in patients with advanced hormone refractory prostate cancer and non-small cell lung cancer. However, this study has been terminated for the reason that Prinomastat did not improve the outcome of chemotherapy in non-small cell Lung cancer patients.

KETOTREXATE is an antifolate developed to overcome methotrexate (MTX) resistance. However, it demonstrated such potential only in MTX-resistant sensitive L1210/FR8 leukemia cells and its clinical development was discontinued. Unlike MTX, KETOTREXATE exhibited minimal inhibition of purified dihydrofolate reductase, which implies that it does not act as a classical antifolate.

Rebeccamycin analog (RA, Becatecarin/ BMS 181176, rebeccamycin derivative, NSC 655649) is an antitumor antibiotic with inhibitory activity against both topoisomerase I and II, and DNA-intercalating properties. The mechanism of action of becatecarin is not exactly known, but it is thought that by inhibiting (blocking) the function of topoisomerase enzymes, it will destroy cancer cells and slow down the growth of the tumour. On 25 July 2006, orphan designation (EU/3/06/388) was granted by the European Commission to Helsinn Birex Pharmaceuticals Ltd, Ireland, for becatecarin for the treatment of cancers of the biliary tree.