Antroquinonol is isolated from Antrodia camphorata, a camphor tree mushroom, and is a valuable traditional Chinese herbal medicine that exhibits pharmacological activities against several diseases, including cancer. Antroquinonol displayed anticancer activity against hepatocellular carcinoma cell lines through activation of 5′ adenosine-monophosphate-activated protein kinase and inhibition of the mammalian target of rapamycin (mTOR) pathway. Antroquinonol also exhibits anticancer activity in human pancreatic cancers through inhibition of the phosphoinositide-3 kinase (PI3K)/Akt/mTOR pathway, which in turn downregulates the expression of cell cycle regulators. The translational inhibition causes a G1 arrest of the cell cycle and ultimately mitochondria-dependent apoptosis. A study on the A549 pulmonary adenocarcinoma cell line demonstrated that antroquinonol-induced apoptosis was associated with disrupted mitochondrial membrane potential and activation of caspase-3 and poly ADP ribose polymerase cleavage. Moreover, antroquinonol treatment downregulated the expression of B-cell lymphoma 2 proteins, which was correlated with decreased PI3K and mTOR protein levels, without altering the levels of pro- or antiapoptotic proteins. Antroquinonol is currently in phase II trials (USA and Taiwan) for the treatment of non-small-cell lung carcinoma (NSCLC), atopic dermatitis; colorectal cancer; hepatitis B; hyperlipidaemia; pancreatic cancer. Antroquinonol was also approved for drug clinical trials by the Russian Ministry of Health (MoH). The MoH gave permission to test the efficacy and safety of Phase II clinical trials in patients with acute myeloid leukemia in Russia. Antroquinonol received the Orphan Drug Designation by the FDA in treatment of pancreatic cancer, liver cancer and acute myeloid leukaemia.

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.

EW-7197 is an orally bioavailable inhibitor of the serine/threonine kinase, transforming growth factor (TGF)-beta receptor type 1 (TGFBR1), also known as activin receptor-like kinase 5 (ALK5), with potential antineoplastic activity. EW-7197 is in phase I clinical trials for the treatment of solid tumors. Also, EW-7197 has a strong potential as an anti-fibrosis therapeutic agent.

ABC-294640 is an orally bioavailable and selective sphingosine kinase-2 (SphK2) inhibitor with IC50 of approximately 60 uM. ABC-294640 inhibits SK2, a lipid kinase that catalyzes formation of the lipid signaling molecule sphingosine 1-phosphate (S1P). S1P promotes cancer growth, and proliferation and pathological inflammation, including TNFα signaling and other inflammatory cytokine production. Specifically, by inhibiting the SK2 enzyme, ABC-294640 blocks the synthesis of S1P which regulates fundamental biological processes such as cell proliferation, migration, immune cell trafficking and angiogenesis, and are also involved in immune-modulation and suppression of innate immune responses from T cells. Preliminary evidence suggests that because of its specificity for targeting SK2, rather than SK1, ABC-294640 may have a better therapeutic ratio than nonspecific sphingosine kinase inhibitors or those targeting only SK1. Oral administration of ABC-294640 to mice bearing mammary adenocarcinoma xenografts results in dose-dependent antitumor activity associated with depletion of S1P levels in the tumors and progressive tumor cell apoptosis. Therefore, this newly developed SK2 inhibitor provides an orally available drug candidate for the treatment of cancer and other diseases. ABC-294640 has completed multiple successful pre-clinical studies in inflammatory, GI, radioprotection and oncology models, as well as a Phase I clinical study in cancer patients with advanced solid tumors.

Metenkephalin (Met-enkephalin) is an endogenous opioid peptide that acts as an agonist at μ-opioid receptors (μORs) and δ-opioid receptors (δORs). Met-enkephalin exhibits neuromodulatory, antinociceptive/analgesic, antidepressant, and gastrointestinal motility modulating activities. Like other endogenous opioids, met-enkephalin modulates expression of opioid receptors and plays a role in reward/reinforcement signaling. Met-enkephalin is also involved in exercise-induced reversal of neuropathic pain and in animals undergoing the forced swim test, decreases immobility time. Met-enkephalin inhibits gastrointestinal muscle contractility, inhibiting motility and gastric emptying. Additionally, analogs of this peptide display anticancer and antiepileptic/anticonvulsant activities.

CPI-613 is a lipoate derivative synthesized to be catalytically inert but to potentially mimic lipoate catalytic intermediates. The drug is in phase II of clinical trials for the treatment of Myelodysplastic syndromes; Pancreatic cancer; Small cell lung cancer; Solid tumors; Bile duct cancer; Acute Myeloid leukemia. The mechanism of CPI-613 action can be explained by (I) inhibition of tumor cell pyruvate dehydrogenase complex (PDC) through activation of pyruvate dehydrogenase kinases leading to inactivating phosphorylation of the E1alpha-subunit of PDC; and (II) inhibition of alpha-ketoglutarate dehydrogenase.

Racemetirosine is an orally active inhibitor of the enzyme tyrosine 3-monooxygenase, and consequently of the synthesis of catecholamine. At dosages of 600 to 3500mg daily, it is effective in controlling the hypertensive episodes and symptoms of catecholamine excess in phaeochromocytoma during preparation for surgery. Oral Racemetirosine is well absorbed and absorption appears constant in each individual over a wide dosage range. The drug is largely excreted via the kidneys, but extrarenal elimination has not been studied. Case reports on the clinical use of Racemetirosine in phaeochromocytoma indicate that the drug controls hypertension and symptoms of catecholamine excess in most patients during preparation for surgical removal of a tumor. In some cases, the addition of Racemetirosine to phenoxybenzamine plus propranolol has resulted in adequate control of symptoms previously unresponsive to the adrenergic blocking regimen. Drowsiness and sedation have been the most frequently reported side effects of Racemetirosine treatment.

2-Cyano-3,12-dioxooleana-1,9-diene-28-oic acid (CDDO, also known as Bardoxolone) is a synthetic triterpenoid that displays potent anti-inflammatory and antitumorigenic activities. CDDO was in the clinical trial phase I for the treatment patients with Solid tumors and leukemia, but that studies were discontinued. It is known, that CDDO blocks the cellular synthesis of inducible nitric oxide synthase and inducible COX-2. In addition, was discovered, that CDDO disrupted intracellular redox balance and thereby induce apoptosis. Moreover, CDDO is a ligand for peroxisome proliferator-activated receptor that it induces genes regulated by Nrf2, including heme oxygenase-1 and eotaxin-1, which play a role in antioxidant response element signaling activity.

Talabostat is a prolineboronate ester derivative patented by Boehringer Ingelheim Pharmaceuticals, Inc. as an antineoplastic agent. Talabostat inhibits dipeptidyl peptidases, such as fibroblast activation protein (FAP), resulting in the stimulation of cytokine and chemokine production and specific T-cell immunity and T-cell dependent activity. Talabostat has been shown to cause caspase-1 activation and IL-1β induction in macrophages, which in turn causes upregulation of the cytokines and chemokines that characterize the responses to talabostat, both in vitro and in tumor-bearing mice. Talabostat may also stimulate the production of colony stimulating factors, such as granulocyte colony stimulating factor (G-CSF), resulting in the stimulation of hematopoiesis. In clinical trials, the combination of talabostat and cisplatin was well tolerated compared to historical data using cisplatin alone. The most frequent adverse events were nausea, vomiting, fatigue, anemia, edema, and constipation. Unfortunately was no evidence that Talabostat enhanced the clinical activity of other anticancer drugs and further development was discontinued.