Tesetaxel is a taxane derivative patented by Daiichi Pharmaceutical Co., Ltd. as antitumor agent. Preclinical research suggests that tesetaxel may overcome P-glycoprotein-mediated multidrug resistance, thereby facilitating extended intracellular retention and possibly clinical effectiveness. Tesetaxel exhibited potent cytotoxicity against various human and murine cancer cell lines and was particularly potent against cell lines expressing P-glycoprotein. Orally administered tesetaxel showed potent in vivo antitumor activity in murine syngeneic and human xenograft models. The cytotoxic effect of tesetaxel, unlike that of other taxanes, was not influenced by the level of P-glycoprotein expression or by the presence of a P-glycoprotein modulator. In patients with metastatic breast cancer, tesetaxel was shown to have significant, single-agent antitumor activity in two multicenter, Phase 2 studies.

Tariquidar, a non-competitive, specific P-glycoprotein (Pgp) inhibitor, is an anthranilamide derivative with multidrug resistance properties. Tariquidar binds to the ATP-binding cassette (ABC) transport protein Pgp, thereby inhibiting transmembrane transport of anticancer drugs resulting in their increased intracellular concentrations augmenting cytotoxicity of an anticancer drug. Tariquidar was discovered by Xenova Group and was developed for the treatment of multidrug resistance in cancer. In October 2002 the US Food and Drug Administration (FDA) has granted fast track review status to tariquidar for the treatment of multi-drug resistance in first-line treatment of non-small cell lung cancer (NSCLC) patients. Tariquidar is still undergoing research as an adjuvant against multidrug resistance in cancer.

Tanespimycin (17-allylamino-17-demethoxygeldanamycin, 17-AAG) is a synthetic analogue of geldanamycin, an antibiotic first purified in 1970 from Streptomyces hygroscopicus. Tanespimycin is an Hsp90 inhibitor that has demonstrated the potential to disrupt the activity of multiple oncogenes and cell signaling pathways implicated in tumor growth, including HER2, a key pathway in breast cancer. Tanespimycin was being under development by Kosan Biosciences. It was in phase 3 clinical development with bortezomib for the treatment of multiple myeloma (MM). However, in 2010 the company halted development of tanespimycin, during late-stage clinical trials as a potential treatment for multiple myeloma. While no definitive explanation was given, it has been suggested that Bristol-Myers Squibb halted development over concerns of the financial feasibility of tanespimycin development given the 2014 expiry of the patent on this compound, and the relative expense of manufacture.

Marizomib is a natural beta-lactone produced by the marine bacterium Salinispora tropica. Marizomib has a broad inhibition profile for the 20S proteasome and has been shown to inhibit the CT-L (beta5) CT-T-laspase-like (C-L, beta1) and trypsin-like (T-L, beta2) activities of the 20S proteasome. The drug is being tested in phase II clinical trials for the treatment of Multiple Myeloma and Malignant Glioma and in phase I in patients with Non-small Cell Lung Cancer, Pancreatic Cancer, Melanoma or Lymphoma

3,5-Diiodothyropropionic acid (DITPA), a carboxylic acid analog with low metabolic activity, was observed to induce alpha-MHC mRNA in heart cell culture with EC50 approximately 5 x 10(-7) M. Zarion Pharmaceuticals was developing DITPA (3,5-diiodothyropropionic acid), a thyroid hormone analogue, for the treatment of Allan-Herndon-Dudley syndrome. In May 2013, the US FDA granted DITPA orphan drug status for the treatment of Allan-Herndon-Dudley syndrome. However, development of DITPA for the treatment of Allan-Herndon-Dudley syndrome was discontinued.

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.

AR-42, also known as (S)-HDAC-42, is a phenylbutyrate-based histone deacetylase (HDAC) inhibitor. HDACs are enzymes that determine acetylation status of histones, thereby affecting chromatin structure and regulating the expression and activity of numerous proteins involved in both cancer initiation and cancer progression. AR-42 possesses antitumor activity at multiple cellular levels. It is currently in Phase I/Ib trials for hematological malignancies and solid tumors.

Picropodophyllin (also known as picropodophyllotoxin (PPP)), an orally active insulin-like growth factor 1 receptor (IGF1R) inhibitor that exhibits no activity at the insulin receptor, FGFR, PDGFR or EGFR. Picropodophyllin possesses antineoplastic activity. PPP is currently tested as an orally administrated single agent treatment in an open-label combined Phase I/II clinical study in advanced cancer patients with solid tumors which progress in spite of several lines of treatment. In addition, it effectively inhibits rhambodmyosarcomas tumor proliferation and metastasis in vitro and in an animal model.

Tempol is used as an industrial catalyst and chemical oxidant. However, its ability to scavenge free oxygen species has generated interest in the biochemical potential of this compound. Biologically Tempol catalyzes the disproportionation of superoxides, facilitates hydrogen peroxide metabolism, and inhibits Fenton chemistry. These properties generated investigational interest for the use of tempol to mediate radiation damage during chemotherapy. Tempol has been used in human clinical trials for mitigation of radiation damage in related to anal cancer, and brain cancer. Tempol has also been investigated in a number of animal and invitro models for conditions, such as oxidative damage, brain hemorrhage, anxiety, malaria, platelet agregation,