Darinaparsin is a novel mitochondrial-targeted agent being developed for the treatment of various hematologic and solid cancers. In a Phase II study in the US, intravenous darinaparsin demonstrated evidence of clinical activity in malignant lymphoma, and in particular peripheral T-cell lymphoma (PTCL). Darinaparsin was granted Orphan Drug Designation in the US and Europe as a treatment of PTCL. The oral formulation is also being tested in Phase I for the treatment of solid tumors. Darinaparsin induces G2/M cell cycle arrest and apoptosis in tumor cells, primarily through disruption of mitochondrial functions, increased reactive oxygen species (ROS) production and modulation of signal transduction pathways.

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.

Carboxyamidotriazole (L651582) is a carboxyamide-amino-imidazole compound originally developed as a coccidiostat, an antiprotozoal agent that acts upon Coccidia parasites. Carboxyamidotriazole (L651582) is an orally-active agent with potential antineoplastic activity. Carboxyamidotriazole binds to and inhibits non-voltage-operated Ca2 channels, blocking both Ca2 influx into cells and Ca2 release from intracellular stores and resulting in the disruption of calcium channel-mediated signal transduction and inhibition of vascular endothelial growth factor (VEGF) signaling, endothelial proliferation, and angiogenesis. This agent may also inhibit tumor cell growth, invasion, and metastasis.

Safingol, the synthetic L-threo-stereoisomer of endogenous (D-erythro-) sphinganine, is an inhibitor of protein kinase C and sphingosine kinase in vitro, and in some cell types has been implicated in ceramide generation and induction of apoptosis. Safingol inhibits enzymatic activity and 3H-phorbol dibutyrate binding of purified rat brain PKC (IC50 = 37.5 uM and 31uM, respectively). Inhibits human PKCα, the major overexpressed isoenzyme in MCF-7 DOXR cells (IC50 = 40 uM). Safingol enhances the cytotoxic effect of the chemotherapeutic agent Mitomycin C (MMC) in gastric cancer cells by promoting drug-induced apoptosis. Safingol is an inhibitor of SphK (Sphingosine kinase). Safingol has been shown to act synergistically with other chemotherapeutic agents and may potentiate chemotherapy drug-induced apoptosis in vitro and in vivo.

Pidobenzone, an amino acid ester of hydroquinone, is a second-generation worldwide patented depigmenting agent, reliable and free of collateral risks. Pidobenzone 4% lipogel represents a useful, reliable, and safe treatment of the different types of melasma. No data are available regarding the efficacy of pidobenzone as monotherapy for solar lentigines. The combination of cryotherapy and pidobenzone 4% has been found to be the most useful treatment of solar lentigines and the prevention of eventual posttreatment hyperchromia.

Duazomycin (N-acetyl-DON) is one of the few naturally occurring compounds containing an aliphatic alpha diazoketo group, and is produced by Streptomyces ambofaciens. It is a derivative of 6-diazo-5-oxo-L-norleucine (DON) which was initially isolated from an unidentified Streptomyces species and which is produced together with N-acetyl-DON and duazomycin B (azotomycin) by S. ambofaciens. Duazomycin inhibited purine biosynthesis and caused accumulation of phosphoribosyl-N-formylglycineamide (FGAR) at low levels of inhibitor; higher levels blocked the synthesis of FGAR, indicating that the antibiotic behaved essentially like DON. Duazomycin is readily deacetylated by mammalian acylase to DON. As a glutamine antagonist, duazomycin was used in combination with azathioprine for the treatment of patients with advanced Wegener’s granulomatosis with renal involvement. Prolonged survival, remission of systemic signs and symptoms, roentogenologic improvement of pulmonary lesions, reduction in proteinuria and arrest of progression of renal insufficiency were observed.

Taltobulin, also known as HTI-286 and SPA-110, is a fully synthetic analog of the natural tripeptide hemiasterlin, inhibits tubulin polymerization and circumvents transport-based resistance to taxanes. Taltobulin was a potent inhibitor of proliferation (mean IC50 = 4 nm in 18 human tumor cell lines) and had substantially less interaction with multidrug resistance protein (P-glycoprotein) than currently used antimicrotubule agents, including paclitaxel, docetaxel, vinorelbine, or vinblastine. Taltobulin showed strong antitumor activity both in androgen-dependent and androgen- independent tumors and may be a promising agent in second- line treatment strategies for patients suffering from docetaxel- refractory prostate cancer.