Varlitinib (Alternative Names: ARRY-334543; ARRY-543; ASLAN-001; Varlitinib tosylate) is a small molecule based reversible pan-HER inhibitor of EGFR, HER2 and HER4. In response to the binding of various ligands, these kinases undergo heterodimerisation and homodimerization, resulting in activation of numerous growth factor signaling pathways, by inhibiting the activation of the HER receptors via drug, effects such as shrinkage of the tumor and longer survival can be anticipated. In a large variety of cancers, the overexpression and/or constitutive activation of EGFR and HER2 are often observed and frequently correlate with poor clinical prognosis. Licensed from Array BioPharma with global rights for all indications, varlitinib is being developed as first-in-class drug for cholangiocarcinoma, gastric and colorectal cancer, and as best-in-class drug for breast cancer.

Nitromiphene (NIT; CI 628) is a triarylethylene antiestrogen shown to be effective in treatment of experimental breast cancer. Nitromiphene is one of the earliest nonsteroidal selective estrogen receptor modulators (SERMs). It is an anti-estrogen capable to translocate the estrogen receptor to the nucleus and to induce the replenishment of the cytosol receptor. Nitromiphene inhibited the uptake of [3H]-estradiol in rat whole homogenates and isolated cell nuclei tissues and the pituitary, and inhibited estradiol-induced female sexual behavior. Nitromiphene has thus been shown to suppress the growth of chemically induced and ransplantedmammary tumors in rodents. Also, Nitromiphene was shown to have potent, prolonged antiuterotropic effects in immature rats. Nitromiphene has been shown to undergo conversion to demethyl Nitromiphene (CI628M), a phenolic metabolite which had greater affinity for estrogen receptors and greater biological potency in vitro than did Nitromiphene. However, the in vivo antiestrogenic effects of Nitromiphene and demethyl Nitromiphene were similar, possibly due to facile O-demethylation of the former compound after administration.

Bristol-Myers Squibb developed BMS-275183 for cancer indications. BMS 275183 is an inhibitor of tubulin polymerization. The drug participated in phase II clinical trials for patients with non-small cell lung cancer and in phase I for patients with advanced cancer. However, further development has been discontinued.

TNP-470 (AGM-1470, (3R,4S,5S,6R)-5-methoxy-4- [(2R,3R)-2-methyl-3-(3-methyl-2-butenyl) -oxiranyl]-1-oxaspiro[2,5]oct-6-yl(chloroacetyl) carbamate) is an anti-angiogenic, semisynthetic analogue of fumagillin, a known antibiotic secreted by the fungus Aspergillus fumigatus fresenius, which is under clinical development for the treatment of cancer by Takeda Chemical Industries Ltd. in Japan and TAP Pharmaceuticals, Inc. in the United States. TNP-470 binds to and irreversibly inactivates methionine aminopeptidase-2 (MetAP2), resulting in endothelial cell cycle arrest late in the G1 phase and inhibition of tumor angiogenesis. This agent may also induce the p53 pathway, thereby stimulating the production of cyclin-dependent kinase inhibitor p21 and inhibiting angiogenesis. In early clinical reports, TNP-470 is tolerated up to 177 mg/m(2) with neurotoxic effects (fatigue, vertigo, ataxia, and loss of concentration) being the principal dose-limiting toxicity (DLT). TNP-470 is being evaluated in Phase I-II trials in the US in patients with Kaposi’s sarcoma, cervical cancer, breast cancer, brain cancer, prostate cancer and renal cell carcinoma.

Simotaxel (MST-997) is a semi-synthetic, orally bioavailable, third-generation taxane derivative and microtubule-stabilizing agent, with potential antineoplastic activity. Simotaxel was being developed through a collaboration between Wyeth (later Pfizer) and Taxolog as a potential treatment for cancer. Upon administration, simotaxel binds to tubulin, promotes microtubule assembly and stabilization, and prevents microtubule depolymerization. This results in G2/M arrest, apoptosis and the inhibition of cell proliferation in susceptible tumor cells. This agent is a poor substrate for P-glycoprotein-related drug resistance mechanisms; therefore, it may be useful for treating multi-drug resistant tumors. MST-997 is more potent than paclitaxel and docetaxel and overcomes paclitaxel and docetaxel resistance in certain tumor cell types. Simotaxel is under investigation in clinical trial NCT00088647 (study evaluating MST-997 in advanced malignant solid tumors).

Acolbifene, the active metabolite of EM-800, was identified as a pure antagonist that acts on both activation domains of the ERs. It is in Phase III clinical trials for the prevention of breast cancer and vasomotor symptoms (Hot flush) in postmenopausal women. Most commonly reported adverse events included irregular menses, leg/muscle cramps, diarrhea, and hot flashes. No serious adverse events were reported.

Mitotenamine is benzo[b]thiophene derivative with nucleotoxic activity patented by Shandong Lanjin Biotech Co. for cancer chemotherapy.

Retelleptine (SR-95325 B) is an antitumoral agent. This ellipticine derivative exhibits high toxicity against several rodent tumor models. Retelliptine is thought to intercalate with DNA and inhibit topoisomerase II during DNA replication. A phase I study reported possible drug-related toxicity sporadically such as somnolence, bronchospasm, dry mouth, and vomiting.

THIOINOSINE (Methylmercaptopurine riboside, NSC- 40774) is a purine derivative with antineoplastic and anti-angiogenic properties. THIOINOSINE is readily converted in cells to its active form, 6-methylmercaptopurine ribonucleoside 5'- monophosphate (MMPR-P), by the enzyme adenosine kinase. THIOINOSINE inhibits amidophosphoribosyltransferase, the first committed step in de novo purine synthesis, and inhibits fibroblast growth factor-2 (FGF2)-induced cell proliferation. It has been used similarly to Mercaptopurine in the treatment of Leukemia. It has being tested in clinical trials for advanced pancreatic cancer.

Asulacrine, also known as CI-921, an inhibitor of topoisomerase II, participated in clinical trials phase II for the treatment of cancer. In spite of the positive and promising results, this drug showed the toxicity, phlebitis that blocks its implementation in the future.