VANTAS Implant Ref.[50376] Active ingredients: Histrelin

5.1 Transient Increase in Serum Testosterone

VANTAS causes a transient increase in serum concentrations 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.

5.2 Spinal Cord Compression and Urinary Tract Obstruction

Cases of spinal cord compression, which may result in paralysis, and ureteral obstruction, which may cause renal impairment, have been reported with GnRH agonists. Patients with metastatic vertebral lesions and/or with urinary tract obstruction should be closely observed during the first few weeks of therapy.

5.3 Difficulty Locating or Removing Implant

In all clinical trials combined, an implant was not recovered in 8 patients. For two of these [see Clinical Studies (14)], serum testosterone rose above castrate level and the implant was neither palpable nor visualized with ultrasound. These two implants were believed to have been extruded without appreciation by the patients. In the other six, serum testosterone remained below the castrate level, but the implant was not palpable. No further diagnostic tests were conducted. One of these patients underwent in-clinic surgical exploration that did not locate the implant.

Implant insertion is a surgical procedure. Careful adherence to the Recommended Procedure for Implant Insertion and Removal [see Dosage and Administration (2.2)] is advised to minimize the potential for complications and for implant expulsion. In addition, patients should be instructed to refrain from wetting the arm for 24 hours and from heavy lifting or strenuous exertion of the inserted arm for 7 days after implant insertion.

5.4 Hyperglycemia and Diabetes

Hyperglycemia and an increased risk of developing diabetes have been reported in men receiving GnRH agonists. Hyperglycemia may represent development of diabetes mellitus or worsening of glycemic control in patients with diabetes. Monitor blood glucose and/or glycosylated hemoglobin (HbA1c) periodically in patients receiving a GnRH agonist and manage with current practice for treatment of hyperglycemia or diabetes.

5.5 Cardiovascular Disease

Increased risk of developing myocardial infarction, sudden cardiac death and stroke has been reported in association with use of GnRH agonists in men. The risk appears low based on the reported odds ratios, and should be evaluated carefully along with cardiovascular risk factors when determining a treatment for patients with prostate cancer. Patients receiving a GnRH agonist should be monitored for symptoms and signs suggestive of development of cardiovascular disease and be managed according to current clinical practice.

5.6 Laboratory Tests

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

Results of testosterone determinations are dependent on assay methodology. It is advisable to be aware of the type and precision of the assay methodology to make appropriate clinical and therapeutic decisions.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety of VANTAS was evaluated in 171 patients with prostate cancer treated for up to 36 months in two clinical trials. The pivotal study (Study 1) consisted of 138 patients, while a separate supportive study (Study 2) consisted of 33 patients.

VANTAS, like other GnRH analogs, caused a transient increase in serum testosterone concentrations during the first week of treatment. Therefore, potential exacerbations of signs and symptoms of the disease during the first few weeks of treatment are of concern in patients with vertebral metastases and/or urinary obstruction or hematuria. If these conditions are aggravated, it may lead to neurological problems such as weakness and/or paresthesia of the lower limbs or worsening of urinary symptoms [see Warnings and Precautions (5.1)].

In the first 12 months after initial insertion of the implant(s), an implant extruded through the incision site in eight of 171 patients in the clinical trials (see the Recommended Procedure for correct implant placement).

In the pivotal study (Study 1) a detailed evaluation for implant site reactions was conducted. Out of the 138 patients in the study, 19 patients (13.8%) experienced local or insertion site reactions. All these local site reactions were reported as mild in severity. The majority were associated with initial insertion or removal and insertion of a new implant, and began and resolved within the first two weeks following implant insertion. Reactions persisted in 4 (2.8%) patients. An additional 4 (2.8%) patients developed application-site reactions after the first two weeks following insertion.

Local reactions after implant insertion included bruising (7.2% of patients) and pain/soreness/tenderness (3.6% of patients). Other, less frequently reported, reactions included erythema (2.8% of patients) and swelling (0.7% of patients). In this study, two patients had events described as local infections/inflammations, one that resolved after treatment with oral antibiotics and the other without treatment.

Local reactions following insertion of a subsequent implant were comparable to those seen after initial insertion.

The following possibly or probably related systemic adverse events occurred during clinical trials of up to 24 months of treatment with VANTAS, and were reported in ≥2% of patients (Table 1).

Table 1. Incidence () of Possibly or Probably Related Systemic Adverse Events Reported by ≥2 of Patients Treated with VANTAS for up to 24 Months:

Hot flashes were the most common adverse event reported (65.5% of patients). In terms of severity, 2.3% of patients reported severe hot flashes, 25.4% of patients reported moderate hot flashes and 37.7% reported mild hot flashes. In addition, the following possibly or probably related systemic adverse events were reported by <2% of patients using VANTAS in clinical studies.

Blood and Lymphatic System Disorders: Anemia

Cardiac Disorders: Palpitations, ventricular extrasystoles

Gastrointestinal Disorders: Abdominal discomfort, nausea

General Disorders: Feeling cold, lethargy, malaise, edema peripheral, pain, pain exacerbated, weakness, weight decreased

Hepatobiliary Disorders: Hepatic disorder

Injury, Poisoning and Procedural Complications: Stent occlusion

Laboratory Investigations: Aspartate aminotransferase increased, blood glucose increased, blood lactate dehydrogenase increased, blood testosterone increased, creatinine clearance decreased, prostatic acid phosphatase increased

Metabolism and Nutrition Disorders: Appetite increased, fluid retention, food craving, hypercalcaemia, hypercholesterolemia

Musculoskeletal and Connective Tissue Disorders: Arthralgia, back pain, back pain aggravated, bone pain, muscle twitching, myalgia, neck pain, pain in limb

Nervous System Disorders: Dizziness, tremor

Psychiatric Disorders: Depression, irritability

Renal and Urinary Disorders: Calculus renal, dysuria, hematuria aggravated, renal failure aggravated, urinary frequency, urinary frequency aggravated, urinary retention

Reproductive System and Breast Disorders: Breast pain, breast tenderness, genital pruritus male, gynecomastia aggravated, sexual dysfunction

Respiratory, Thoracic and Mediastinal Disorders: Dyspnea exertional

Skin and Subcutaneous Tissue Disorders: Contusion, hypotrichosis, night sweats, pruritus, sweating increased

Vascular Disorders: Flushing, hematoma

Changes in Bone Density: Decreased bone density has been reported in the medical literature in men who have had orchiectomy or who have been treated with a GnRH agonist analog. It can be anticipated that long periods of medical castration in men will have effects on bone density.

The following adverse reactions have been identified during post approval use of VANTAS. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Pituitary Apoplexy: Cases of pituitary apoplexy (a clinical syndrome secondary to infarction of the pituitary gland) have been reported after the administration of gonadotropin-releasing hormone agonists. In a majority of these cases, a pituitary adenoma was diagnosed with a majority of pituitary apoplexy cases occurring within 2 weeks of the final dose, and some within the first hour. In these cases, pituitary apoplexy has presented as sudden headache, vomiting, visual changes, opthalmoplegia, altered mental status, and sometimes cardiovascular collapse. Immediate medical attention has been required.

Drug-Induced Liver Injury: Severe liver injury has been reported in association with VANTAS. The toxicity was reversible with the removal of the VANTAS implant.

Nervous System Disorders: Convulsions.

Overview

No pharmacokinetic-based drug-drug interaction studies were conducted with VANTAS [see Clinical Pharmacology (12.3)].

Drug-Laboratory Test Interactions

Therapy with histrelin results in suppression of the pituitary-gonadal system. Results of diagnostic tests of pituitary gonadotropic and gonadal functions conducted during and after histrelin therapy may be affected.

Pregnancy Category X. [see Contraindications (4.2)].

VANTAS is contraindicated in females who are or may become pregnant. VANTAS can cause fetal harm when administered to a pregnant woman. The possibility exists that spontaneous abortion may occur. Major fetal abnormalities were observed in rabbits but not in rats after administration of histrelin acetate throughout gestation. There were increased fetal mortality and decreased fetal weights in rats and rabbits. These effects on fetal mortality are expected consequences of the alterations in hormonal levels brought about by this drug. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.

VANTAS is not indicated for use in women. It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from VANTAS, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

VANTAS is not indicated for use in pediatric patients.