Histrelin Subcutaneous Implant in Children With Central Precocious Puberty

Thirty-two (32) patients will receive a histrelin subdermal implant under the anesthesia deemed appropriate by the administering physician. Ten-twelve (10-12) sites will enroll 2-3 patients per site. It is anticipated that half the patients will be receiving GnRH analog treatment and the other half will be treatment naïve. All patients will undergo selective PK sampling post-implantation to assess histrelin profile. At 12 months, provided that the patient continues to meet the safety and efficacy parameters, the original implant will be removed and the patient can receive a new implant. At 13 months, patients who receive new implants will be evaluated at the study site and administratively transferred to the initial extension study. At Month 24), the implants inserted at Month 12 will be removed. At this time, patients who have completed the initial extension study and who wish to continue therapy with the histrelin implant will be eligible to receive a new (ie, third) implant and to enter an additional 12-month extended access phase at the discretion of the investigator. At Month 36, the implants inserted at Month 24 for the Extended Access Phase will be removed. At this time, patients who have completed the Extended Access Phase and who wish to continue therapy with the histrelin implant will be eligible to receive a new (ie, fourth) implant and to enter the Long Term Extended Access Phase (referred to as the Implant Treatment Phase) at the discretion of the investigator. The purpose of this phase is to provide patients with the opportunity to continue to receive a new implant at the end of each 12-month period until the patient no longer requires hormone suppression. Once implant therapy is discontinued, all patients are eligible to enter the Long Term Follow Up Phase (Post Implant Phase) of the study.