Fosbretabulin (Combretastatin A4 phosphate, CA4P) is the lead compound of a relatively new class of agents termed vascular disrupting agents that target existing tumor blood vessels. Rapid tumor blood flow shutdown has been demonstrated in preclinical models and patients by various techniques such as dynamic contrast-enhanced MRI, perfusion computed tomography and PET scans following CA4P infusion. CA4P typically induces rapid tumor necrosis in the center of the tumor and leaves a rim of viable cells in the periphery. In oncology, CA4P does not appear to be that active by itself, but may be more efficacious when combined with chemotherapy, antiangiogenic therapy and radiation therapy. Combretastatin was initially isolated from the root bark of the South African Bush willow Combretum caffrum in 1982 by Pettit and colleagues at the Arizona State University (AZ, USA). Combretastatin A4 phosphate binds avidly to tubulin at the colchicine-binding site to inhibit microtubule assembly and destabilize the cytoskeleton. CA4P is a tubulin-binding agent that binds at or near the colchicine binding site of β-tubulin (Kd = 0.40 uM), inhibits tubulin assembly with IC50 of 2.4 uM. Fosbretabulin has orphan drug status in the EU and the US for the treatment of ATC (Anaplastic Thyroid Cancer). Later the development of this drug was discontinued.

Bromofenofos is an anthelminthic agent used in veterinary medicine to treat common liver fluke (Fasciola hepatica) infections in cattle and sheep.

Perifosine is an orally active alkyl-phosphocholine compound with potential antineoplastic activity. Perifosine is an Akt inhibitor, which targets the pleckstrin homology domain of Akt, thereby preventing its translocation to the plasma membrane. Perifosine exerts Akt-dependent and Akt-independent effects, and although many preclinical studies have documented Akt inhibition by perifosine, clinical validation of these findings is lacking. Perifosine is in phase II and III clinical trials for the treatment of neuroblastoma, glioblastoma multiforme and other solid tumors.

Fosopamine (also known as Sim 2055), is a prodrug of epinine was studied for the treatment of renal failure and of essential hypertension. However, phase II of clinical trials in Italy was discontinued in 1995. Information about the current development of this drug is not available.

Eritoran (E-5564) is a synthetic lipid A analog that has been designed to antagonize the effects of lipopolysaccharide (LPS) and has been found to do this by interacting with Toll-like receptor 4, the cell surface receptor for LPS. Preclinical in vitro and in vivo studies of eritoran tetrasodium indicate it can limit excessive inflammatory mediator release associated with LPS and improve survival in sepsis models. Clinically, eritoran was being investigated for the treatment of severe sepsis, septic shock, and other endotoxin-mediated indications. Eritoran development has been discontinued.

Edelfosine is a synthetic alkyl-lysophospholipid, a potent immunomodulator and an effective inhibitor of tumor cell proliferation. The cytotoxic effect of edelfosine has been evaluated in a large variety of both tumor (leukemic and solid) and normal cell types, showing a high degree of selectivity towards tumor cells. Like all alkyl-lysophospholipids, Edelfosine incorporates into the cell membrane and does not target the DNA. In many tumor cells, Edelfosine causes selective apoptosis, sparing healthy cells. Edelfosine can activate the Fas/CD95cell death receptor, can inhibit the MAPK/ERK mitogenic pathway and the Akt/protein kinase B (PKB) survival pathway. Edelfosine apoptosis-inducing abilities were studied with several types of cancer, among them multiple myeloma and non-small and small cell lung carcinoma cell lines. In vivo activity against human solid tumors in mice was shown against malignant gynecological tumor cells, like ovarian cancer, and against breast cancer. In vivo biodistribution studies demonstrated a “considerably higher” accumulation of Edelfosine in tumor cells than in other analyzed organs. Several clinical trials were conducted. Among them, a phase I trials with solid tumors or leukemias and phase II with non-small-cell lung carcinomas (NSCLC). In Phase II clinical trial for use of Edelfosine in treating leukemia with bone marrow transplants, it was found to be safe and 'possibly effective'. A phase II trial for the treatment of brain cancers was also reported. It showed encouraging results in stopping the growth of the tumor and a considerable improvement in the “quality of life” of the patients. A phase II trial on the effect of Edelfosine on advanced non-small-cell bronchogenic carcinoma had a “remarkable” “high proportion of patients with stationary tumor status” as result, stable disease after initial progression in 50% of the patients.

Metronidazole phosphate is a water-soluble prodrug of metronidazole.

Triamcinolone acetonide- 21-dihydrogen phosphate is the long-acting derivative of a synthetic glucocorticoid triamcinolone. Triamcinolone acetonide has eight times more potency than prednisolone. Triamcinolone acetonide- 21-dihydrogen phosphate used for intravenous injection. It is supposed to be hydrolyzed rapidly in the body to form the free corticoid alcohol.

SR 202 is an antagonist of peroxisome proliferator-activated receptor γ (PPARγ) transcriptional activity induced by troglitazone but not of basal PPARγ activity. It is selective for PPARγ, not affecting basal or agonist-induced transcriptional activity of PPARα, PPARβ, or the farnesoid X receptor (FXR). It inhibits PPARγ-dependent differentiation of preadipocyte 3T3-L1 cells in a dose-dependent manner. SR 202 (400 mg/kg) decreases the amount of weight gained and white adipose tissue mass accumulated by mice fed a standard or high-fat diet for ten weeks and is associated with lower PPARγ mRNA levels. It protects against high-fat diet-induced insulin resistance in wild-type mice and improves insulin sensitivity in ob/ob mice.