AEterna Zentaris has reported that ZEN-019, an oral LHRH antagonist peptidomimetic, demonstrated in vivo activity by suppressing plasma testosterone levels.

The company's in vivo data showed that using ZEN-019 with a single, oral administration (20 mg/kg) in rats, lead to efficient and revocable suppression of plasma testosterone levels for up to 12 hours. Furthermore, a repeat of the dosing of ZEN-019 increased the suppression time without accumulation in the plasma.