Treosulfan (l-threitol-1,4-bis-methanesulfonate; dihydroxybusulfan) is a prodrug of a bifunctional alkylating cytotoxic agent that is approved for the treatment of ovarian carcinomas in a number of European countries. The antitumor activity of treosulfan has been shown in a variety of solid tumors. It is used for the treatment of all types of ovarian cancer, either supplementary to surgery or palliatively. Treosulfan is a prodrug that is converted nonenzymatically first to a mono-epoxide – (2S,3S)- 1,2-epoxy-3,4-butanediol-4-methanesulfonate – and then to a diepoxide – l-diepoxybutane, which is also a metabolite of butadiene – under physiological conditions. Such conversions are assumed to account for the alkylating and therapeutic activities of treosulfan.

Taurolidine [bis(1,1-dioxoperhydro-1,2,4-thiadiazinyl-4)-methane (TRD)], a product derived from the aminosulfoacid taurin, was first described as an anti-bacterial substance. Taurolidine is a small dimeric molecule with molecular weight 284. It comprises the semiconditional amino acid taurine. Taurolidine was originally designed as a broad-spectrum antibiotic. Taurolidine has a broad antimicrobial spectrum of activity that is effective against aerobes and anaerobes, Gram-negative and Gram-posi-tive bacteria as well as yeasts and moulds in vitro. Taurolidine is also effective against methicillin-resistant and vancomycin-resistant bacteria (MRSA, VISA and VRE). It was mainly used in the treatment of patients with peritonis as well as antiendoxic agent in patients with systematic inflammatory response syndrome. It has been shown to be an effective bactericidal agent against both aerobic and anaerobic bacteria. It is currently licensed for intraperitoneal use in several European countries for the treatment of peritonitis. The compound appears to be nontoxic and has an excellent safety record since its initial introduction over 30 years ago. Taurolidine also possesses antiadherence properties and has been shown in vivo to reduce the extent and severity of postoperative peritoneal adhesions. It also possesses a strong anti-inflammatory action. This action appears, at least in part, to arise through its ability to inactivate endotoxin. Inflammation-induced tumor development is well described in the literature. Taurolidine’s anti-inflammatory and antiadherence properties prompted an investigation to examine whether it has a role in antitumor therapy. Taurolidine induces cancer cell death through a variety of mechanisms. It appears to act through enhancing apoptosis, inhibiting angiogenesis and tumor adherence, downregulating proinflammatory cytokine and endotoxin levels, and stimulating the immune system in response to surgically induced trauma. Taurolidine is currently in preclinical development for neuroblastoma. In February 23, 2018 the U.S. Food and Drug Administration (FDA) granted orphan drug designation to taurolidine for the treatment of neuroblastoma. Taurolidine is a key component in the Neutrolin®, a novel anti-infective solution for the reduction and prevention of catheter-related infections and thrombosis in patients requiring central venous cathers in end stage renal disease. Neutrolin contains a mix of Taurolidine, Citrate and Heparin. Neutrolin is designed to: 1) Aid in the prevention of Catheter-Related Bloodstream Infections (CRBIs) and 2) Prevent catheter dysfunction (due to blood clotting).

ERIBULIN MESYLATE (HALAVEN®) is a microtubule dynamics inhibitor. It is a synthetic analog of halichondrin B, a product isolated from the marine sponge Halichondria okadai. ERIBULIN MESYLATE (HALAVEN®) inhibits the growth phase of microtubules without affecting the shortening phase and sequesters tubulin into nonproductive aggregates. It exerts its effects via a tubulin-based antimitotic mechanism leading to G2/M cell-cycle block, disruption of mitotic spindles, and, ultimately, apoptotic cell death after the prolonged mitotic blockage. ERIBULIN MESYLATE (HALAVEN®) is indicated for the treatment of patients with metastatic breast cancer who have previously received at least two chemotherapeutic regimens for the treatment of metastatic disease. It is also indicated for the treatment of patients with unresectable or metastatic liposarcoma who have received a prior anthracycline-containing regimen.

SITOGLUSIDE (Daucosterol) inhibits cancer cell proliferation by inducing autophagy through reactive oxygen species-dependent manner. It also perturbs cell cycle and induces apoptotic cell death in A549 cells. Daucosterol has being shown to promote the proliferation of neural stem cells. Daucosterol also protects neurons against oxygen-glucose deprivation/reperfusion-mediated injury by activating IGF1 signaling pathway. Daucosterol could be potentially developed as a medicine for ischemic stroke treatment.

4-Isothioureidobutyronitrile (Kevetrin) is a small molecule that has demonstrated the potential of becoming a breakthrough cancer treatment by inducing activation of p53. It is a water-soluble, small molecule and activator of the tumor suppressor protein p53, with potential antineoplastic activity. Upon intravenous administration, 4-thioureidobutyronitrile activates p53 which in turn induces the expressions of p21 and PUMA (p53 up-regulated modulator of apoptosis), thereby inhibiting cancer cell growth and causing tumor cell apoptosis. 4-Thioureidobutyronitrile may be effective in drug-resistant cancers with mutated p53. p53 tumor suppressor, a transcription factor regulating the expression of many stress response genes and mediating various anti-proliferative processes, is often mutated in cancer cells. Cellceutix continues to build upon the successful Phase 1 trial evaluating Kevetrin in treating advanced solid tumors conducted at Dana-Farber Cancer Institute and Beth Israel Deaconess Medical Center. Kevetrin, in IV form, was shown to safely modulate, in a non-genotoxic manner, the key tumor suppressor protein p53 as measured through increased expression of p21, a key downstream biomarker of p53. Cellceutix is advancing Kevetrin under an Orphan Drug designation from the Food and Drug Administration (FDA) for the treatment of ovarian cancer, pancreatic cancer and childhood retinoblastoma.

Carnosol is an ortho-diphenolic diterpene with an abietane carbon skeleton with hydroxyl groups at positions C-11 and C-12 and a lactone moiety across the B ring. Carnosol is the product of oxidative degradation of carnosic acid. Carnosol is a naturally occurring phytopolyphenol found in rosemary that functions as an antioxidant, antimicrobial, and anticarcinogen. Carnosol has been shown to inhibit inductions of COX-2 by blocking PKC signaling. Carnosol is an inhibitor of AR and ER α. Several pre-clinical studies have suggested that carnosol selectively targets tumorigenic cell as opposed to non-tumorigenic cells and is safe and tolerable in animals. Carnosol has been shown to elicit chemopreventive effects by (1) blocking the bioactivation of carcinogens, (2) enhancing antioxidant and/or detoxification enzyme activities, (3) suppressing tumor-promoting inflammation, (4) inhibiting cell proliferation and inducing apoptosis selectively in cancer cells, and (5) blocking tumor angiogenesis and invasion.

RRX-001, also known as ABDNAZ, is a dinitroazetidine derivative with potential radiosensitizing activity. Upon administration, RRx-001 is able to dilate blood vessels, thereby increasing tumor blood flow and thus improving oxygenation to the tumor site. By increasing oxygen levels, these tumor cells may be more susceptible to radiation therapy. Tumor hypoxia is correlated with tumor aggressiveness, metastasis and resistance to radiotherapy. In mouse models, RRx-001 administered intravenously as a single agent was equipotent to cisplatin while better tolerated. RRx-001 also showed activity as a radiosensitizer in both in vitro and in vivo models. The activity of RRx-001 is thought to be associated with a nucleophilic substitution by circulating thiol compounds and covalent binding of RRx-001 to cysteinyl residues in Hb, followed by the generation of nitrogen oxides. During 2014-2015 EpicentRx has launched Phase 2 trials in brain, colorectal, non-small cell lung, small cell lung and cholangiocarcinoma both alone and in combination. The anti-proliferative effects of RRx-001 are not explainable via a single mechanism. RRx-001 exerts its anti-proliferative effect, at least partially, through interference with glucose 6 phosphate dehydrogenase (G6PD), a key enzyme in the pentose phosphate pathway, responsible for maintaining adequate levels of the major cellular reductant, NADPH.

Tetrahydropalmatine is a tetrahydroprotoberberine isoquinoline alkaloid that is a primary active constituent of herbal preparations containing plant species of the genera Stephania and Corydalis. The levo isomer of THP (L-THP) appears to contribute to many of the therapeutic effects of these preparations. The pharmacological profile of L-THP, which includes antagonism of dopamine D1 and D2 receptors and actions at dopamine D3, suggests that it may have utility for treating addiction. Clinical trials where L-THP was used for the treatment of cocaine and heroin addiction have promising results. The clinical trial is planned for the treatment of schizophrenia. L-Tetrahydropalmatine is recorded in the Chinese pharmacopoeia.

Cinobufotalin, the bufadienolide isolated from toad venom, has displayed antitumor activities in many in vitro systems. It has been shown that cinobufotalin induced significant apoptosis in cultured human lymphoma U-937 cells. It induced DNA fragmentation, mitochondrial membrane potential decrease, and reactive oxygen species (ROS) production in U-937 cells. Cinobufotalin induces cytotoxic effect in cultured lung cancer cells. Cinobufotalin (1/5 mg/kg, i.p. twice daily, for 7 days) significantly inhibited A549 xenograft growth in mice. Further, same cinobufotalin administration improved mice survival at week five. Cinobufotalin administration didn’t significantly affect mice body weight, indicating the relative safety of this regimen. Thus, cinobufotalin inhibits A549 xenograft growth in vivo and improves mice survival.

Swainsonine is an indolizidine alkaloid found in Australian Swainsona canescens, North American plants of the genera Astragalus and Oxytropis and also in the fungus Rhizoctonia leguminocola. It is competitive inhibitor of Golgi alpha-mannosidase II and lysosomal alpha-mannosidases. This compound has been reported to be a potent antiproliferative and immunomodulatory agent. However, no evidence of anti-tumor activity of swainsonine was seen in phase II clinical trial, in patients with locally advanced or metastatic renal cell carcinoma. Adverse events such as fatigue, nausea and diarrhea were common but generally mild. Swainsonine is locoweed toxin. Locoweed poisoning is seen throughout the world and annually costs the livestock industry millions of dollars. Swainsonine inhibits lysosomal alpha-mannosidase and Golgi mannosidase II. Poisoned animals are lethargic, anorexic, emaciated, and have neurologic signs that range from subtle apprehension to seizures.