Elesclomol (also known as STA-4783), originally identified in a cell-based phenotypic screen for pro-apoptotic activity, is a novel small-molecule that potently induces apoptosis of cancer cells through the rapid generation of reactive oxygen species (ROS) and the induction of unmanageable levels of oxidative stress. Elesclomol exhibits antitumor activity against a broad spectrum of types of cancer cell in human tumour xenograft models due to its excessive ROS production and elevated levels of oxidative stress leading to the death of cancer cells. Elesclomol is currently being studied as novel cancer therapeutic, in which it has demonstrated the ability to prolong progression-free survival in study subjects. Elesclomol induces oxidative stress by provoking a buildup of reactive oxygen species within cancer cells. Elesclomol requires a redox-active metal ion to function; the Cu(II) complex is 34 times more potent than the Ni(II) complex and 1040-fold more potent than the Pt(II) complex. Elesclomol is an HSP-90 Inhibitor with pro-apoptotic and potential antineoplastic activities. Elesclomol induces oxidative stress and triggers mitochondrial-induced apoptosis in cancer cells. Elesclomol is being developed by Synta Pharmaceuticals and GlaxoSmithKline as a chemotherapy adjuvant and has received both fast track and orphan drug status from the U.S. Food and Drug Administration for the treatment of metastatic melanoma. Synta Pharmaceuticals announced on February 26, 2009, the suspension of all clinical trials involving Elesclomol due to safety concerns. In March 2010, Synta announced that the FDA had approved resuming clinical development of elesclomol, and that they expected to initiate one or more clinical trials for elesclomol in the second half of the year. In a small, randomized phase II study, elesclomol was shown to significantly increase progression-free survival in people with metastatic melanoma when given in addition to paclitaxel (Taxol).

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.

Deoxyspergualin is a derivative of the antitumor antibiotic spergualin, that used as an immunosuppressive drug. Deoxyspergualin shows immunosuppressive activity both in vitro and in vivo, affecting B-lymphocyte, T-lymphocyte and macrophage/monocyte function. In rodents and human cell systems, Deoxyspergualin shows a dose-dependent inhibition of primary and secondary responses to T-, B- and antigen-presenting cell-dependent reactions. Deoxyspergualin also blocks nuclear translocation of NF-kB in a pre-B-cell line, thereby affecting NF-kB driven transcription of the kappa light chain. Deoxyspergualin inhibits desoxyhypusine synthase, the first enzyme in the formation of active eukaryotic translation initiation factor 5A. This factor is important for the stabilization of certain mRNA transcripts (TNF-a and others). The immunosuppressive properties of Deoxyspergualin have been demonstrated in preclinical animal studies including Systemic lupus erythematosus models. In humans with glucocorticoidresistant kidney transplant rejection, Deoxyspergualin shows the same efficacy rate as the strongly T-cell depleting anti-CD3 monoclonal antibody. Deoxyspergualin has been licensed in Japan for acute renal allograft rejection since 1994. In 2003, an open clinical trial successfully tested Deoxyspergualin in patients with persistent ANCA-associated vasculitis. Adverse events (AE) were common but rarely led to treatment discontinuation. Against this background, Deoxyspergualin was granted an orphan drug status for the treatment of Wegener’s granulomatosis by the European Medicines Agency (EMA).

Palifosfamide or ZIO-201 (isophosphoramide mustard; IPM), a bi-functional DNA alkylator, is the active metabolite of ifosfamide (IFOS). IFOS and the related drug cyclophosphamide (CPA) are widely used anti-cancer drugs. Both are pro-drugs and need to be metabolized to be active. Their clinical use is limited by the toxicity associated with some of their metabolites. Palifosfamide has shown efficacy in diverse cancer models. ZIOPHARM Oncology Inc, under license from Dekk-Tec Inc, was developing palifosfamide, a formulation of isophosphoramide mustard with tris(hydroxymethyl)aminomethane salt-stabilization (palifosfamide-tris) and previously with lysine-stabilization (palifosfamide-lys). Preclinical studies and phase I and I/II clinical trials demonstrated that palifosfamide-tris had an antitumor efficiency comparable or superior to that of ifosfamide. To date ZIO-201 is not present in ZIOPHARM pipeline.

Alisertib (MLN8237) is an orally available selective aurora A kinase inhibitor developed by Takeda. Alisertib inhibited AAK over ABK with a selectivity of more than 200-fold in cells and produced a dose-dependent decrease in bipolar and aligned chromosomes in the HCT-116 xenograft model, a phenotype consistent with AAK inhibition. Alisertib inhibited proliferation of human tumor cell lines in vitro and produced tumor growth inhibition in solid tumor xenograft models and regressions in in vivo lymphoma models. It is currently in phase II clinical trials for acute myeloid leukaemia; B cell lymphoma; brain cancer; mesothelioma; prostate cancer; small cell lung cancer.

Amonafide L-malate (AS1413, Xanafide) is a DNA intercalator and topoisomerase II inhibitor that induces apoptosis by disrupting chromatin organisation independently of ATP. This is different from classical topoisomerase II inhibitors which induce apoptosis by causing extensive DNA damage. Amonafide L-malate is also able to evade P-glycoprotein and related transporters that contribute to multi-drug resistance. AS1413 had orphan drug status in both the U.S. and the E.U. for the treatment of AML and also received Fast Track status from the U.S. FDA for the treatment of secondary AML. Amonafide L-malate was originated by Xanthus Pharmaceuticals. It was added to Antisoma's pipeline through the acquisition of Xanthus Pharmaceuticals, Inc. in June 2008. Antisoma discontinued development of Amonafide L-malate after data from the open-label, international Phase III ACCEDE trial in over 420 patients showed that 600 mg/m 2 IV amonafide for 5 days plus cytarabine missed the primary endpoint of significantly improving initial remission rate, defined as the proportion of patients who achieve CR or CRi, vs. daunorubicin plus cytarabine.

P276-00 (also known as riviciclib) is a novel, potent, small-molecule, flavone-derived inhibitor of cyclin-dependent kinases (Cdk), Cdk 4 D1, Cdk1 B, and Cdk9 T, with potent cytotoxic effects against chemosensitive and chemoresistant cancer cell lines. P276-00 was in phase II clinical trial for the treatment mantle cell lymphoma, but that study was terminated based on interim results and all subjects were off study at that time. Although, there were not the major safety or tolerability concerns. However, this drug successfully passed phase II clinical trial for the treatment Melanoma, squamous cell carcinoma of head and neck, malignant melanoma and in combination with Gemcitabine in the treatment of advanced pancreatic cancer.

Acetorphine is a synthetic narcotic analgesic. Acetorphine was reported to have uses in veterinary medicine with pronounced advantages in the immobilization of the giraffe in which toxic effects were reduced as compared to the effects of etorphine. In July 1966, the Director-General of the World Health Organization informed the Secretary-General that WHO had arrived at the conclusion that etorphine and acetorphine should be included in Schedule I of the Convention, since they could give rise to similar abuse, and produce similar ill effects as the substances already listed therein. Acetorphine is a Schedule I controlled substance in the United States.

Alisertib (MLN8237) is an orally available selective aurora A kinase inhibitor developed by Takeda. Alisertib inhibited AAK over ABK with a selectivity of more than 200-fold in cells and produced a dose-dependent decrease in bipolar and aligned chromosomes in the HCT-116 xenograft model, a phenotype consistent with AAK inhibition. Alisertib inhibited proliferation of human tumor cell lines in vitro and produced tumor growth inhibition in solid tumor xenograft models and regressions in in vivo lymphoma models. It is currently in phase II clinical trials for acute myeloid leukaemia; B cell lymphoma; brain cancer; mesothelioma; prostate cancer; small cell lung cancer.

Cethexonium is a cyclohexanols derivative with antimicrobial activities.