/PRNewswire-FirstCall/ -- Palatin Technologies, Inc. (NYSE Amex: PTN) today announced positive results of a Phase 1 clinical trial of subcutaneously administered bremelanotide, its melanocortin agonist drug candidate for treatment of male erectile dysfunction (ED) and female sexual dysfunction (FSD). The results demonstrate that with subcutaneous administration consistent therapeutic blood plasma levels can be obtained without sustained clinically significant blood pressure effects and support the continued development of bremelanotide.
As part of the analysis of the effects of bremelanotide on blood pressure, the Company engaged an independent panel of cardiovascular experts to evaluate both study results and an integrated cardiovascular safety analysis conducted on data from completed bremelanotide studies. Based on recommendations from the outside panel and its own internal review, Palatin intends to engage the Food and Drug Administration (FDA) in discussions regarding clinical trial designs to further study bremelanotide for the treatment of sexual dysfunction.
Palatin expects to meet with the FDA in the fourth quarter of calendar year 2010 to discuss initiation of a Phase 2 study of subcutaneously administered bremelanotide, as a monotherapy and as a combination therapy with a PDE-5 inhibitor such as sildenafil (Viagra®), for men with ED who are not responsive or inadequately responsive to PDE-5 inhibitor therapies alone.
The objective of the placebo-controlled, randomized, double-blind, cross over safety study was evaluation of blood pressure effects of subcutaneous bremelanotide in healthy male volunteers between 45 and 65 years old. The study also evaluated dose-to-dose consistency of plasma exposure of bremelanotide. A total of 49 subjects were dosed in the safety study; nineteen of the subjects were enrolled in a sub-study and completed a graded exercise treadmill test as a surrogate for the cardiovascular effects of sexual activity.
"The commercial opportunity of bremelanotide for sexual dysfunction is significant. About 35% of patients with ED do not respond to approved oral therapies, and with limited treatment options these patients are ideal candidates for subcutaneous bremelanotide," stated
, Ph.D., President and CEO of Palatin. "Plus, we have an additional opportunity with female sexual dysfunction (FSD), which also represents a large market opportunity with no FDA approved drugs."
About Erectile Dysfunction (ED)
Erectile dysfunction is the consistent inability to attain and maintain an erection sufficient for sexual intercourse. Up to 35% of men are non-responsive to standard therapies with phosphodiesterase-5 inhibitors such as sildenafil (Viagra®), vardenafil (Levitra®) and tadalafil (Cialis®). The current worldwide market for ED drugs is over
. There are limited therapeutic options for ED patients non-responsive to phosphodiesterase-5 inhibitor therapy, including alprostadil for direct penis injection or urethral suppositories, surgical penile implants and various devices.
About Female Sexual Dysfunction (FSD)
FSD includes four disorders, hypoactive sexual desire disorder, female sexual arousal disorder, sexual pain disorder and orgasmic disorder. To establish a diagnosis of FSD, these syndromes must be associated with personal distress, as determined by the affected woman. A
February 10, 1999
study published in the
Journal of the American Medical Association
, titled, "Sexual Dysfunction in
the United States
: Prevalence and Predictors," states that approximately 43% of women suffer from some form of FSD. There are no drugs in
the United States
approved for FSD indications.
Bremelanotide, a synthetic peptide developed and solely owned by Palatin Technologies, is believed to act through activation of melanocortin receptors in the central nervous system. Nasal formulations of bremelanotide have been extensively studied, including Phase 2B studies for erectile dysfunction in both non-diabetic and diabetic patients and Phase 2A studies for female sexual dysfunction in both pre- and post-menopausal women. Increases in blood pressure observed in some patients receiving nasally administered bremelanotide, coupled with significant variation in plasma levels, lead to discontinuation of nasally administered bremelanotide as a first-line therapy for sexual dysfunction. Palatin is developing subcutaneous bremelanotide as a therapeutic for treatment of men with erectile dysfunction who are non-responsive to standard therapies with phosphodiesterase-5 inhibitors such as sildenafil and for treatment of women with female sexual dysfunction.