The first human trial for gene transfer therapy for the treatment of erectile dysfunction: Preliminary results

Objective: To test the safety of a single intracavernous injection of a plasmid vector (hMaxi-K) that expresses the hSlo gene, that encodes the alpha-subunit of the Maxi-K channel, for the treatment of erectile dysfunction (ED). Methods: Six men, thus far have fulfilled the entry criteria of the protocol and had gene transfer with hMaxi-K. Three received a dose of 500 mu g and three received a dose 1000 mu g of the gene product, injected intracavernously as naked DNA. Dosing at 5000 mu g and higher is planned. Results: The primary end point of the phase I trial is safety. No drug-related adverse events or significant laboratory changes have occurred after the gene transfer. Moreover, there is no evidence of the gene in semen at the one copy per mu g total DNA in any of the participants. Conclusion: Preliminary results indicate that, in a single dose escalation study, ion channel gene transfer with hMaxi-K can be administered safely to men with ED without adverse events. (c) 2005 Elsevier B.V. All rights reserved.