Palatin Begins Phase 2 Study of Bremelanotide with PDE5i for ED Treatment

Palatin Technologies, Inc., a company specializing in the development of innovative treatments based on the modulation of melanocortin receptors, has announced the commencement of a Phase 2 clinical trial. This study focuses on bremelanotide (BMT), a melanocortin 4 receptor (MC4R) agonist, co-administered with a phosphodiesterase 5 inhibitor (PDE5i) for the treatment of erectile dysfunction (ED) in patients who do not respond to PDE5i monotherapy. The topline data from this trial is projected to be available by the end of 2024.

Erectile dysfunction affects a significant number of men, with approximately 30-40% of patients showing little to no response to PDE5i monotherapy, including common drugs like Viagra, Cialis, and Levitra. Carl Spana, Ph.D., President and CEO of Palatin, highlighted the substantial unmet need for effective ED treatments, noting that PDE5i monotherapy, despite its significant market presence with over $4 billion in annual sales, fails to work for a considerable portion of patients. He expressed optimism that the combination of BMT and a PDE5i could provide a synergistic and clinically meaningful solution for these non-responding patients.

The Phase 2 trial aims to enroll around 50 participants and will involve an open-label, dose-escalation study. This study targets men with ED who have not responded adequately to PDE5i monotherapy. It has received both FDA clearance and Institutional Review Board (IRB) approval. The primary goal of the study is to evaluate the safety and efficacy of the combined treatment in this specific patient group.

Jed Kaminetsky, MD, FACS, a urologist and the lead investigator of the study, emphasized the growing prevalence of ED, particularly among younger adults, and its significant impact on quality of life. He pointed out that patients with more severe ED often seek better treatment outcomes and have limited non-surgical options. Dr. Kaminetsky has previously used bremelanotide in his practice and believes that its combination with a PDE5i could offer an effective treatment for PDE5i non-responders.

Palatin has previously conducted multiple clinical studies involving both monotherapy with BMT and combination therapy with BMT and a PDE5i, observing statistically significant improvements in erectile function. Additionally, bremelanotide, marketed as Vyleesi® at a subcutaneous dose of 1.75 mg, is FDA-approved for treating hypoactive sexual desire disorder (HSDD) in pre-menopausal women, showing increased sexual desire and reduced distress related to low desire.

The company has developed a new co-formulation of bremelanotide and a PDE5i, which can be administered as a single injection. They plan to file an Investigational New Drug (IND) application for this novel formulation with the FDA later this year. A Phase 3 clinical trial for ED patients who do not respond to PDE5i monotherapy is anticipated to begin in the first half of 2025.

Erectile dysfunction, defined as the consistent inability to achieve and maintain an erection sufficient for sexual intercourse, affects an estimated 30 million men in the United States. Standard therapies with PDE5 inhibitors, such as sildenafil (Viagra®), vardenafil (Levitra®), and tadalafil (Cialis®), are ineffective for about 30-40% of patients. For these non-responders, therapeutic options are limited to direct penis injections, urethral suppositories, surgical implants, and various devices.

Palatin Technologies is committed to developing first-in-class medicines targeting diseases with significant unmet medical needs and commercial potential. Their strategy involves forming marketing collaborations to maximize the commercial potential of their products.