Optimization of lead candidates for an on-demand male contraceptive

Mammalian sperm are stored in the epididymis in a dormant state; they are immotile and unable to fertilize the egg. Upon ejaculation, sperm begin swimming and initiate a process called capacitation, where they become competent to fertilize. An initial event in capacitation and activation of motility is the HCO3- induced stimulation of soluble adenylyl cyclase (sAC: ADCY10). Men and male mice with the sAC gene knocked out are infertile, and pharmacological inhibitors specific for sAC block in vitro fertilization and temporarily render male mice infertile. Thus, sAC is a genetic and pharmacologically validated, non-hormonal target essential for male fertility. The overall hypothesis tested in this application is that sAC inhibitors can be designed which can be appropriately dosed to block sperm functions while minimizing undesirable side effects. We propose to test a series of potent, selective sAC inhibitors, using in vitro and in vivo studies of efficacy, safety, and pharmacokinetics, to identify the most well-developed, potent, selective, drug-like, non-toxic sAC inhibitors. The goal of this Project is to advance a compound from this series into preclinical development candidates suitable for development partners to apply for an FDA Investigational New Drug (IND) for a novel oral, non-hormonal contraceptive.