Bremelanotide

What Is PT-141 (Bremelanotide)?

Bremelanotide was formerly known as PT-141 and is a peptide drug originally developed by Palatin Technologies. Bremelanotide has been put forth as a treatment for everything from hemorrhagic shock to female sexual dysfunction. It derives its effects through stimulation of melanocortin receptors and is a derivative of the well-known drug melanotan II (melanotan 2). Bremelanotide is considered more tolerable than melanotan 2 and is known to have fewer side effects like sweating and yawning1,2.

Bremelanotide Properties

Bremelanotide (PT-141) is a member of the large class of molecules known as melanocortins, molecules that exert effects through binding to several melanocortin receptors (MCRs). Which receptors a particular melanocortin binds to determines the properties of that agent. Bremelanotide primarily binds to MCR(4) and thus influences male and female sexual function.

In truth, bremelanotide, much like the Sermorelin peptide, binds to all of the MCRs, with the exception of MCR(2), though with lower affinity than to MCR(1) and MCR(4). This means it avoids the unpleasant side effects associated with stimulating the adrenal glands. It plays a role in reducing inflammation and in reducing ischemia.

Development

Bremelanotide (PT-141) was originally developed as a nasal spray and was undergoing clinical testing in the early part of the twenty-first century as a potential treatment for female sexual dysfunction. Unfortunately, it was found to produce high blood pressure and the trials were halted. Palatin reformulated the drug to be injected and the high blood pressure side effect was reduced. Clinical trials resumed, but the FDA expressed concern and the development of Bremelanotide was discontinued in 2008.

Bremelanotide

In 2009, Palatin began to develop a slightly modified version of Bremelanotide, called PL-6983, as a treatment for hemorrhagic shock3. Its actions on the MCR(1) and MCR(4) receptors mean the drug reduces ischemia and thus protects tissues derived of adequate blood supply. Once again, this drug was administered via injection through the subcutaneous route. It was found to have no hypertensive effects and has completed phase IIb human trials with very positive results. This drug will likely be used off-label in the future as a treatment for female sexual dysfunction providing it receives FDA approval as a treatment for hemorrhagic shock, continue reading this at http://www.streetinsider.com/Conference+Calls/Palatin+Technologies+(PTN)+Announces+Bremelanotide+Phase+3+Met+co-Primary+Endpoints+in+HSDD/12193963.html

Resources

  1. Safarinejad, M. R. & Hosseini, S. Y. Salvage of Sildenafil Failures With Bremelanotide: A Randomized, Double-Blind, Placebo Controlled Study. J. Urol.179, 1066-1071 (2008).
  1. Safarinejad, M. R. Evaluation of the Safety and Efficacy of Bremelanotide, a Melanocortin Receptor Agonist, in Female Subjects with Arousal Disorder: A Double-Blind Placebo-Controlled, Fixed Dose, Randomized Study. J. Sex. Med.5, 887-897 (2008).
  1. Rössler, A.-S. et al. The melanocortin agonist, melanotan II, enhances proceptive sexual behaviors in the female rat. Pharmacol. Biochem. Behav.85, 514-521 (2006).