Mivobulin is a synthetic water-soluble colchicine analog with the broad antitumor activity that competitively binds tubulin at the colchicine-binding site and inhibits tubulin polymerization. Cancer cells exposed to Mivobulin isethionate accumulate in the M phase of the cell cycle and subsequently die. Preclinical studies have demonstrated that Mivobulin isethionate is able to cross the blood-brain barrier. Importantly, Mivobulin isethionate demonstrated significant antitumor activity in a broad spectrum of murine and human tumor models that were cross-resistant to vincristine, cisplatin, vinblastine, navelbine, and doxorubicin and in tumor cell lines exhibiting multidrug resistance owing to P-glycoprotein overexpression. In animal studies, the activity of Mivobulin isethionate was largely independent of the route of drug administration but favored a prolonged treatment schedule. Unfortunately, in clinical trials, Mivobulin fail to demonstrate the significant activity

Denibulin is a novel antineoplastic agent. Denibulin selectively targets and reversibly binds to the colchicine-binding site on tubulin and inhibits microtubule assembly. This results in the disruption of the cytoskeleton of tumor endothelial cells, ultimately leading to cell cycle arrest, blockage of cell division and apoptosis. This causes inadequate blood flow to the tumor and eventually leads to a decrease in tumor cell proliferation. Denibulin hydrochloride had been in phase I clinical trials for the treatment of solid tumours. It was generally well tolerated and showed decrease in tumor vascular parameters. However, no recent development has been reported.

Ibiglustat (GZ/SAR402671 or Genz-682452) is a small molecule inhibitor of glucosylceramide synthase. Ibiglustat has been demonstrated to effectively lower glycosphingolipid synthesis. Genzyme, a Sanofi Company is developing Ibiglustat for the treatment of Parkinson's Disease, Gaucher Disease, and Fabry Disease.

Ibiglustat (GZ/SAR402671 or Genz-682452) is a small molecule inhibitor of glucosylceramide synthase. Ibiglustat has been demonstrated to effectively lower glycosphingolipid synthesis. Genzyme, a Sanofi Company is developing Ibiglustat for the treatment of Parkinson's Disease, Gaucher Disease, and Fabry Disease.

Alvespimycin (17-desmethoxy-17-N,N-dimethylaminoethylamino-geldanamycin) (17-DMAG; NSC 707545) is an inhibitor of the molecular chaperone heat shock protein HSP90. Alvespimycin is a derivative of antineoplastic benzoquinone antibiotic geldanamycin. Alvespimycin binds to HSP90, a chaperone protein that aids in the assembly, maturation and folding of proteins. Subsequently, the function of Hsp90 is inhibited, leading to the degradation and depletion of its client proteins such as kinases and transcription factors involved with cell cycle regulation and signal transduction. Alvespimycin was studied in clinical trials for the treatment of solid tumors and hematologic malignancies however its development was discontinued.

Retaspimycin (IPI-504) was previously under development by manufacturer Infinity Pharmaceuticals in conjunction with MedImmune, a part of AstraZeneca. Retaspimycin is a small-molecule inhibitor of heat shock protein 90 (HSP90) with antiproliferative and antineoplastic activities. Retaspimycin binds to and inhibits the cytosolic chaperone functions of HSP90, which maintains the stability and functional shape of many oncogenic signaling proteins and may be overexpressed or overactive in tumor cells. Retaspimycin-mediated inhibition of HSP90 promotes the proteasomal degradation of oncogenic signaling proteins in susceptible tumor cell populations, which may result in the induction of apoptosis. Orphan drug designation was assigned to the compound by the FDA for the treatment of gastrointestinal stromal cancer (GIST). Infinity Pharmaceuticals has discontinued the development of retaspimycin (IPI-504) an inhibitor of the HSP-90) complex, for the treatment of cancer due to lack of efficacy in 1913.