* Data are from a pivotal, open-label, multicenter study evaluating 138 patients with advanced prostate cancer and mean baseline serum levels of 388.3 ng/dL for testosterone and 83.6 ng/mL for PSA. Patients were treated with a single VANTAS implant and were evaluated for at least 60 weeks. Of the 138 patients, 37 had Jewett stage C disease, 29 had stage D disease, and 72 had an elevated or rising serum PSA after definitive therapy for localized disease. Ninety percent of patients were 65 years of age. Efficacy was determined by the number (%) of patients who attained the criterion level of chemical castration (defined as serum testosterone 50 ng/dL) at week 4 and maintained this level through week 52.

† At each follow-up endpoint, the number of patients who were evaluated for efficacy defined the observed cases for that visit.

‡ Data are from a 17-patient pharmacokinetic subset of the pivotal study. Not all 17 patients were evaluated at each endpoint. Histrelin was administered by subcutaneous route using a single 50 mg VANTAS implant.

VANTAS is indicated in the palliative treatment of advanced prostate cancer.

VANTAS is contraindicated in patients with hypersensitivity to GnRH, GnRH agonist analogs, or any components in VANTAS. VANTAS is contraindicated in women and pediatric patients and was not studied in women or children. VANTAS, like other LHRH agonists, causes a transient increase in serum concentration of testosterone during the first week of treatment. Patients may experience worsening of symptoms or onset of new symptoms including bone pain, neuropathy, hematuria, or ureteral or bladder outlet obstruction. Cases of ureteral obstruction and spinal cord compression, which may contribute to paralysis with or without fatal complications, have been reported with LHRH agonists. If spinal cord compression or renal impairment develops, standard treatment of these complications should be instituted.

The most common systemic side effects were hot flashes (65.5%), asthenia (9.9%), implant site reaction (5.8%), testicular atrophy (5.3%), and renal impairment (4.7%). Five of the 8 patients had only a single occurrence of mild renal impairment (defined as creatinine clearance 30 and < 60 mL/min), which returned to a normal range by the next visit. The most common local side effects were bruising (7.2%), and pain/soreness/tenderness (3.6%).

Once serum testosterone concentrations at or below castrate level ( 50 ng/dL) were achieved, a total of 4 patients (3%) demonstrated breakthrough during the study. In one patient, a serum testosterone level of 63.1 ng/dL was reported at week 44; this patient's serum testosterone level returned to 8.1 ng/dL at the next reading. In another patient, a serum testosterone level of 3,340 ng/dL was reported at week 40. This aberrant value was possibly related to lab error. In two patients, serum testosterone rose above castrate level and the implant could neither be palpated nor visualized with ultrasound.

Response to VANTAS should be monitored by measuring serum concentrations of testosterone and PSA periodically, especially if the anticipated clinical or biochemical response to treatment has not been achieved.