A new drug to treat erectile dysfunction in men who previously did not respond to the traditional medications Viagra, Cialis or Levitra has completed the first stage of trials successfully.

Palatin Technologies have developed bremelanotide as an experimental treatment for the common condition. The clinical trials were designed to see whether the drug affected blood pressure in men aged between 45 and 65 years old, as well as how repeated doses of the drug affected plasma exposure. The drug is delivered through injections, which is why the company are especially eager to see its result on blood.

The data from the study is to be submitted to the Federal Food and Drug Administration and the company are continuing with stage II trials, which they hope will be completed by 2010.  The trials are taking place in the homes of the participants, who are expected to deliver the injections themselves.

All the men who are taking part in the trials have tried pills such as Viagra and Cialis but have not responded to the treatments.

Palatin President and CEO Carl Spana said in a statement that the firm believes that a large proportion of men with erectile dysfunction are in a similar position. He said,” About 35% of patients with erectile dysfunction do not respond to approved oral therapies, and with limited treatment options these patients are ideal candidates for subcutaneous bremelanotide”.

The drug, a synthetic peptide, is believed to work by activating melanocortin receptors in the central nervous system.  The company have also carried out extensive experiments into whether it can be administered nasally but discovered that it caused an increase in blood pressure, as well as variations in plasma levels. This caused the company to discontinue experiments into this method of delivery.

Clearly, many men will be uncomfortable with the prospect of having to receive injections in order to achieve erection, though there are a number of other treatments which use similar delivery methods, such as MUSE, which is injected directly into the urethra.

Nonetheless, unless scientists come up with a pill which works in a different way to Viagra, Cialis or Levitra (which all have very similar mechanisms) it seems likely that however unpleasant the delivery method, if the clinical trials for bremelanotide continue to be successful, the company are right in thinking there will be a market for the product.

Mr. Spana was bullish about the potential profits for the company, commenting, “The commercial opportunity for bremelanotide is significant with an estimated market of $500 million to $600 million per year.”