Vantas

Before taking Vantas, tell your doctor about all of your medical conditions. Especially tell your doctor if you:

• are allergic to Vantas or to any of its ingredients
• have diabetes
• have cancer that has spread to the spine
• have a urinary obstruction
• have heart problems
• are pregnant or breastfeeding

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X - are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Vantas falls into category X. It has been shown that women taking Vantas during pregnancy may have babies born with problems. There are no situations where the benefits of the medication for the mother outweigh the risks of harm to the baby. These medicines should never be used by pregnant women.

• Store Vantas implants in the refrigerator, between 2 and 8°C (36 and 46°F). The implantation kit should be stored at room temperature.
• Keep this and all medicines out of the reach of children.

Storage

Sub-Q

2–8°C in unopened glass vial, overwrapped in amber plastic pouch and carton.1 May be exposed to 25°C for 7 days.1 Do not freeze.1 Protect from light.1 Store implantation kit only at room temperature.1

In the U.S.

• Supprelin LA
• Vantas

Available Dosage Forms:

• Kit
• Implant

Therapeutic Class: Endocrine-Metabolic Agent

Pharmacologic Class: Gonadotropin Releasing Hormone Agonist

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

The Vantas® form of histrelin should not be used in children.

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of Supprelin® LA in children 2 years of age and older. However, use in children younger than 2 years of age is not recommended. Safety and efficacy have not been established.

Geriatric

No information is available on the relationship of age to the effects of Supprelin® LA or Vantas® in the elderly.

Pregnancy

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Amifampridine
• Amisulpride
• Bepridil
• Cisapride
• Dronedarone
• Mesoridazine
• Pimozide
• Piperaquine
• Saquinavir
• Sparfloxacin
• Terfenadine
• Thioridazine
• Ziprasidone

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

• Alfuzosin
• Amiodarone
• Amitriptyline
• Anagrelide
• Apomorphine
• Aripiprazole
• Aripiprazole Lauroxil
• Arsenic Trioxide
• Asenapine
• Astemizole
• Atazanavir
• Azithromycin
• Bedaquiline
• Chloroquine
• Chlorpromazine
• Ciprofloxacin
• Citalopram
• Clarithromycin
• Clomipramine
• Clozapine
• Crizotinib
• Cyclobenzaprine
• Dabrafenib
• Dasatinib
• Delamanid
• Desipramine
• Deutetrabenazine
• Disopyramide
• Dofetilide
• Dolasetron
• Domperidone
• Donepezil
• Doxepin
• Droperidol
• Ebastine
• Efavirenz
• Eribulin
• Erythromycin
• Escitalopram
• Famotidine
• Felbamate
• Fingolimod
• Flecainide
• Fluconazole
• Fluoxetine
• Formoterol
• Foscarnet
• Fosphenytoin
• Galantamine
• Gatifloxacin
• Gemifloxacin
• Granisetron
• Halofantrine
• Haloperidol
• Hydroquinidine
• Hydroxychloroquine
• Hydroxyzine
• Ibutilide
• Iloperidone
• Imipramine
• Itraconazole
• Ivabradine
• Ketoconazole
• Lapatinib
• Levofloxacin
• Lumefantrine
• Mefloquine
• Methadone
• Metronidazole
• Mifepristone
• Mizolastine
• Moxifloxacin
• Nelfinavir
• Nilotinib
• Norfloxacin
• Octreotide
• Ofloxacin
• Olanzapine
• Ondansetron
• Paliperidone
• Panobinostat
• Paroxetine
• Pasireotide
• Pazopanib
• Pentamidine
• Perphenazine
• Pimavanserin
• Pipamperone
• Pitolisant
• Posaconazole
• Probucol
• Procainamide
• Prochlorperazine
• Promethazine
• Propafenone
• Protriptyline
• Quetiapine
• Quinidine
• Quinine
• Ranolazine
• Ribociclib
• Rilpivirine
• Risperidone
• Ritonavir
• Sertindole
• Sevoflurane
• Sodium Phosphate
• Sodium Phosphate, Dibasic
• Sodium Phosphate, Monobasic
• Solifenacin
• Sorafenib
• Sotalol
• Sulpiride
• Sunitinib
• Tacrolimus
• Tamoxifen
• Telaprevir
• Telavancin
• Telithromycin
• Tetrabenazine
• Tizanidine
• Tolterodine
• Toremifene
• Trazodone
• Trimipramine
• Vandetanib
• Vardenafil
• Vemurafenib
• Venlafaxine
• Vilanterol
• Vinflunine
• Voriconazole
• Vorinostat
• Zuclopenthixol

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Bladder blockage or
• Diabetes or
• Heart attack, history of or
• Heart disease or
• Hyperglycemia (high blood sugar) or
• Kidney problems (reduced urine flow) or
• Nerve problems in the spine from cancer lesions in the bones or
• Problems passing urine or
• Spinal cord problems or
• Stroke, history of—Use with caution. May make these conditions worse in men.

• Brain tumor, history of or
• Seizures or epilepsy, history of—Use with caution. May cause side effects to become worse.

• Congestive heart failure or
• Electrolyte imbalance or
• Heart rhythm problems (eg, congenital long QT syndrome)—May cause side effects to become worse.

• Depression, history of or
• Mental illness, history of—Use with caution. May make these conditions worse.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Irritation where implant was placed.
• Feeling tired or weak.
• Hard stools (constipation).

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Vantas is indicated for the palliative treatment of advanced prostate cancer.

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.

5.7  Effect on QT/QTc Interval

Androgen deprivation therapy may prolong the QT/QTc interval. Providers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities, and in patients taking drugs known to prolong the QT interval. Electrolyte abnormalities should be corrected. Consider periodic monitoring of electrocardiograms and electrolytes. 

Vantas® (histrelin acetate) implant is a sterile, non-biodegradable, diffusion-controlled hydrogel polymer reservoir containing histrelin acetate, a synthetic nonapeptide analog of the naturally occurring gonadotropin releasing hormone (GnRH). Vantas is designed to deliver approximately 50 mcg histrelin acetate per day (equivalent to approximately 41 mcg histrelin per day) over 12 months.

The sterile Vantas implant looks like a small thin flexible tube and consists of a 50-mg histrelin acetate drug core inside a 3.5 cm by 3 mm, cylindrical hydrogel polymer reservoir (Figure A). The implant may appear partially to completely full with variation in color from off-white to light brown. The color may be uneven within the core.

Figure A. Vantas Implant diagram (not to scale)

Histrelin acetate is chemically described as: 5-oxo-L-prolyl-L-histidyl-L-tryptophyl-L-seryl-L-tyrosyl-Ntbenzyl-D-histidyl-L-leucyl-L-arginyl-N-ethyl-L-prolinamide acetate (salt) [C66H86N18O12 (1.7-2.8 moles) CH3COOH, (0.6-7.0 moles) H2O], with the molecular weight of 1443.70 (or 1323.50 as histrelin base).

Histrelin acetate has the following structural formula:

The drug core also contains the inactive ingredient stearic acid NF. The hydrogel polymer reservoir is a hydrophilic cartridge composed of 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, trimethylolpropane trimethacrylate, benzoin methyl ether, Perkadox-16, and Triton X-100. Each implant is packaged hydrated in a glass vial containing 2 mL of sterile 1.8% sodium chloride solution. The implant is primed for immediate release of the drug upon insertion.

A single use, sterile Insertion Tool is provided along with the implant that may be used for the placement of the implant into the subcutaneous tissue of the inner aspect of the upper arm. The Insertion Tool is enclosed in a sterile bag and is provided separately from the implant in the Implantation Kit [see Dosage and Administration (2.2)].