PRX-08066 is a drug developed by EPIX Pharmaceuticals, which acts as a potent and selective antagonist at the serotonin

Serotonin

Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

 5-HT_2B

5-HT2B receptor

5-hydroxytryptamine receptor 2B, also known as HTR2B, is a 5-HT2 receptor, but also denotes the human gene encoding it.-Function:...

 receptor

Receptor (biochemistry)

In biochemistry, a receptor is a molecule found on the surface of a cell, which receives specific chemical signals from neighbouring cells or the wider environment within an organism...

, with a 5-HT_2B binding affinity (K_i) of 3.4nM, and high selectivity over the closely related 5-HT_2A

5-HT2A receptor

The mammalian 5-HT2A receptor is a subtype of the 5-HT2 receptor that belongs to the serotonin receptor family and is a G protein-coupled receptor . This is the main excitatory receptor subtype among the GPCRs for serotonin , although 5-HT2A may also have an inhibitory effect on certain areas such...

 and 5-HT_2C

5-HT2C receptor

The 5-HT2C receptor is a subtype of 5-HT receptor that binds the endogenous neurotransmitter serotonin . It is a G protein-coupled receptor that is coupled to Gq/G11 and mediates excitatory neurotransmission. HTR2C denotes the human gene encoding for the receptor, that in humans is located at the...

 receptors and other receptor targets. PRX-08066 and other selective 5-HT_2B antagonists are being researched for the treatment of pulmonary arterial hypertension, following the discovery that the potent 5-HT_2B agonist norfenfluramine

Norfenfluramine

Norfenfluramine is a psychoactive drug which functions as a serotonin releasing agent and potent 5HT2B receptor agonist. The action of norfenfluramine on 5HT2B receptors on heart valves leads to a characteristic pattern of heart failure following proliferation of cardiac fibroblasts on the...

 produces pulmonary arterial hypertension and subsequent heart valve damage. In animal studies, PRX-08066 has been found to reduce several key indicators of pulmonary arterial hypertension and improved cardiac output, with similar efficacy to established drugs for this condition such as bosentan

Bosentan

Bosentan is a dual endothelin receptor antagonist used in the treatment of pulmonary artery hypertension . It is licensed in the United States, the European Union and other countries by Actelion Pharmaceuticals for the management of PAH under the trade name Tracleer.-Mechanism of action:Bosentan is...

, sildenafil

Sildenafil

Sildenafil citrate, sold as Viagra, Revatio and under various other trade names, is a drug used to treat erectile dysfunction and pulmonary arterial hypertension . It was originally developed by British scientists and then brought to market by the US-based pharmaceutical company Pfizer...

, beraprost

Beraprost

Beraprost is a synthetic analogue of prostacyclin, under clinical trials for the treatment of pulmonary hypertension. It is also being studied for use in avoiding reperfusion injury.-Clinical pharmacology:...

 and iloprost

Iloprost

Iloprost is a drug used to treat pulmonary arterial hypertension , scleroderma, Raynaud's phenomenon and ischemia. It was developed by the pharmaceutical company Schering AG and is marketed by Bayer Schering Pharma AG in Europe and Actelion Pharmaceuticals in the USA.-Clinical pharmacology:Iloprost...

. It is also being researched for potential anti-cancer applications, due to its ability to inhibit fibroblast

Fibroblast

A fibroblast is a type of cell that synthesizes the extracellular matrix and collagen, the structural framework for animal tissues, and plays a critical role in wound healing...

activation.