Palatin Technologies, Inc. announced the initiation of a Phase 2 clinical study of bremelanotide (BMT), a melanocortin 4 receptor (MC4R), co-administered with a phosphodiesterase 5 inhibitor (PDE5i), for the treatment of erectile dysfunction (ED) in patients that do not respond to PDE5i monotherapy. Topline data from the Phase 2 clinical study is expected by the end of calendar year 2024. The Phase 2 clinical trial is designed to enroll approximately 50 patients to be treated with BMT co-administered with a PDE5i in an open-label, dose escalation study treating men with ED who are considered non-responders to PDE5i monotherapy treatment. The clinical study is being conducted under an investigator-sponsored Investigational New Drug (IND) and has Food and Drug Administration (FDA) clearance and Institutional Review Board (IRB) approval.

The study's primary objective is to assess the safety and efficacy of BMT co-administered with a PDE5i for the treatment of ED in males who have not adequately responded to prior PDE5i monotherapy. Palatin has conducted multiple clinical studies of monotherapy BMT and combination therapy BMT plus a PDE5i in men with ED and observed statistically significant and clinically meaningful effects on improving erectile function. In addition, sub-cutaneous bremelanotide 1.75 mg (Vyleesi) is approved by the FDA for the treatment of hypoactive sexual desire disorder (HSDD) in pre-menopausal women and has demonstrated an increase in sexual desire and decrease in distress associated with low desire.

Palatin has developed a new co-formulation of bremelanotide and a PDE5i which can be administered as a single injection. An IND for this novel co-formulation for the treatment of ED is expected to be filed with the FDA later this calendar year and a potential Phase 3 clinical study in ED patients who do not respond to PDE5i monotherapy is expected to start in the first half of calendar year 2025.