Get your patient on Vabrinty - Leuprolide Acetate injection, Suspension, Extended Release (Leuprolide Acetate)

VABRINTY is administered subcutaneously and provides continuous release of leuprolide acetate over a one-, three-, four-, or six-month treatment period (Table 1). VABRINTY must be administered by a healthcare provider. The injection delivers the dose of leuprolide acetate incorporated in a polymer formulation.

Table 1. VABRINTY Recommended Dosing

As with other drugs administered by subcutaneous injection, the injection site should vary periodically.  The specific injection location should be an area with sufficient soft or loose subcutaneous tissue.  In clinical trials, the injections were administered in the upper- or mid-abdominal area.  Avoid areas with brawny or fibrous subcutaneous tissue or locations that could be rubbed or compressed (i.e., with a belt or clothing waistband).

In patients treated with GnRH analogues for prostate cancer, treatment is usually continued upon development of metastatic castration-resistant prostate cancer.

Use aseptic technique throughout the procedure.  As with other similar agents, the use of gloves is recommended during mixing and administration.  Allow the product to reach room temperature before mixing.  Once mixed, the product must be administered within 30 minutes or it should be discarded.

VABRINTY is packaged in a carton containing:

• Tray containing pre-connected syringe system and desiccant pack
• Prescribing information
• Sterile safety needle and cap (located under the tray in carton)

Follow the detailed instructions below to ensure correct preparation of VABRINTY prior to administration:

Step 1 On a clean field open the tray by tearing off the foil from the corner and remove the contents. Discard the desiccant pack. Remove the pre-connected syringe system from the tray. Open the sterile safety needle package by peeling back the paper tab. Note: Syringe A and Syringe B should not be lined-up yet. The product should only be administered with the co-packaged, sterile safety needle.
Step 2 Grasp the latching button on the coupling device with your finger and thumb and press until you hear a snapping sound. The two syringes will be aligned. Do not bend the pre-connected syringe system.
Step 3 Holding the syringes in a horizontal position, transfer the liquid contents of Syringe A into the leuprolide acetate powder contained in Syringe B. Thoroughly mix the product for 60 cycles by pushing the contents back and forth between both syringes to obtain a uniform suspension. A cycle is one push of the Syringe A plunger and one push of the Syringe B plunger. When thoroughly mixed, the suspension will appear light tan to tan (VABRINTY 7.5 mg) or colorless to pale yellow (VABRINTY 22.5 mg, 30 mg, and 45 mg). Note: Product must be mixed as described; shaking will NOT provide adequate mixing. Do not bend.
Step 4 After mixing, hold the syringes vertically (upright) with Syringe B (wide syringe) on the bottom. The syringes should remain securely coupled. Transfer all of the mixed product into Syringe B by depressing the Syringe A plunger and slightly withdrawing the Syringe B plunger.
Step 5 While ensuring the Syringe A plunger is fully pushed down, hold the coupling device and unscrew Syringe B. This will disconnect Syringe B from the coupling device. Syringe A will remain attached to the coupling device. Note: Small air bubbles will remain in the formulation – this is acceptable. Do not purge the air bubbles from Syringe B as product may be lost!
Step 6 Continue to hold Syringe B upright with the open end at the top. Hold back the white plunger on Syringe B to prevent loss of the product, and attach the safety needle and cap (the safety needle is located under the tray). Gently screw clockwise with approximately a three-quarter turn until the safety needle and cap are secure. Do not overtighten, as the needle hub may become damaged which could result in leakage of the product during injection. The safety shield may also be damaged if the safety needle and cap are screwed with too much force.
Step 7 Move the safety shield away from the needle and towards the syringe. Pull off the cap immediately prior to administration.

Note: Should the needle hub appear to be damaged, or leak, the product should NOT be used. The damaged safety needle and cap should NOT be replaced and the product should NOT be injected. In the event of damage to the needle hub, use a new replacement VABRINTY carton.

Risk Summary
Based on findings in animal studies and mechanism of action, VABRINTY may cause fetal harm when administered to a pregnant woman [see Clinical Pharmacology (12.1 )] . There are no available data in pregnant women to inform the drug-associated risk. Expected hormonal changes that occur with VABRINTY treatment increase the risk for pregnancy loss. In animal developmental and reproductive studies, major fetal abnormalities were observed after administration of leuprolide acetate throughout gestation in rats. Advise pregnant patients and females of reproductive potential of the potential risk to the fetus (see Data) .

Data

Animal Data
In animal developmental and reproductive studies, major fetal abnormalities were observed after administration of leuprolide acetate throughout gestation.  There were increased fetal mortality and decreased fetal weights in rats and rabbits.  The effects of fetal mortality are expected consequences of the alterations in hormonal levels brought about by this drug.

The safety and efficacy of VABRINTY have not been established in females. There is no information regarding the presence of VABRINTY in human milk, the effects on the breastfed child, or the effects on milk production. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in a breastfed child from VABRINTY, a decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.

Infertility
Males
Based on mechanism of action, VABRINTY may impair fertility in males of reproductive potential [see Clinical Pharmacology (12.1 )] .

The safety and effectiveness of VABRINTY in pediatric patients have not been established.

The majority of the patients (approximately 70%) studied in the clinical trials were age 70 and older.  Clinical studies of VABRINTY did not include sufficient numbers of younger adult patients to determine if patients 65 years of age and older respond differently than younger adult patients.

VABRINTY 7.5 mg, 22.5 mg, and 30 mg like other GnRH agonists, causes a transient increase in serum concentrations of testosterone during the first week of treatment. VABRINTY 45 mg causes a transient increase in serum concentrations of testosterone during the first two weeks of treatment. Patients may experience worsening of symptoms or onset of new signs and symptoms during the first few weeks of treatment, including bone pain, neuropathy, hematuria, or bladder outlet obstruction.

Cases of ureteral obstruction and/or spinal cord compression, which may contribute to paralysis with or without fatal complications, have been observed in the treatment of advanced prostate cancer using GnRH agonists.

Patients with metastatic vertebral lesions and/or with urinary tract obstruction should be closely observed during the first few weeks of therapy. If spinal cord compression or ureteral obstruction develops, standard treatment of these complications should be instituted.

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.

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.

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.

Postmarketing reports of convulsions have been observed in patients on leuprolide acetate therapy. These included patients with a history of seizures, epilepsy, cerebrovascular disorders, central nervous system anomalies or tumors, and in patients on concomitant medications that have been associated with convulsions such as bupropion and SSRIs. Convulsions have also been reported in patients in the absence of any of the conditions mentioned above. Patients receiving a GnRH agonist who experience convulsion should be managed according to current clinical practice.

Severe cutaneous adverse reactions (SCARs), including Steve-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), and erythema multiforme, occurred in patients receiving VABRINTY [see Adverse Reactions (6.2 )] .

Monitor patients for the development of SCARs. Advise patients of the signs and symptoms of SCARs (e.g., a prodrome of fever, flu-like symptoms, mucosal lesions, progressive skin rash, or lymphadenopathy).

If a SCAR is suspected, interrupt VABRINTY until the etiology of the reaction has been determined. Consultation with a dermatologist is recommended. If a SCAR is confirmed, or for other grade 4 skin reactions, permanently discontinue VABRINTY.

Monitor VABRINTY response by periodic measurement of serum concentrations of testosterone and prostate specific antigen.

In the majority of patients, testosterone levels increased above Baseline during the first week, declining thereafter to Baseline levels or below by the end of the second or third week.  Castrate levels were generally reached within two to four weeks.

Castrate testosterone levels were maintained for the duration of the treatment with VABRINTY 7.5 mg.  No increases to above the castrate level occurred in any of the patients.

Castrate levels were generally maintained for the duration of treatment with VABRINTY 22.5 mg.

Once castrate levels were achieved with VABRINTY 30 mg, most (86/89) patients remained suppressed throughout the study.

Once castrate levels were achieved with VABRINTY 45 mg, one patient (< 1%) experienced a breakthrough, with testosterone levels > 50 ng/dL.

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.

Drug/Laboratory Test Interactions: Therapy with VABRINTY results in suppression of the pituitary-gonadal system.  Results of diagnostic tests of pituitary gonadotropic and gonadal functions conducted during and after VABRINTY therapy may be affected.

Based on findings in animal studies and mechanism of action, VABRINTY may cause fetal harm when administered to a pregnant woman. In animal developmental and reproductive studies, major fetal abnormalities were observed after administration of leuprolide acetate throughout gestation in rats. Advise pregnant patients and females of reproductive potential of the potential risk to the fetus [see Use in Specific Populations (8.1), Clinical Pharmacology (12.1 )] .

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 all VABRINTY formulations was evaluated in clinical trials involving patients with advanced prostate cancer.  In addition, the safety of VABRINTY 7.5 mg was evaluated in 8 surgically castrated males (Table 4).  VABRINTY, like other GnRH analogs, caused a transient increase in serum testosterone concentrations during the first one to two weeks of treatment.

Therefore, potential exacerbations of signs and symptoms of the disease during the first 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 (5.7 )] .

During the clinical trials, injection sites were closely monitored.  Refer to Table 3 for a summary of reported injection site adverse reactions.

Table 3. Reported Injection Site Adverse Reactions

These localized adverse reactions were non-recurrent over time.  No patient discontinued therapy due to an injection site adverse reaction.

The following possibly or probably related systemic adverse reactions occurred during clinical trials with VABRINTY, and were reported in > 2% of patients (Table 4).  Reactions considered not drug-related are excluded.

Table 4. Summary of Possible or Probably Related Systemic Adverse Reactions Reported by > 2% of Patients Treated with VABRINTY

In addition, the following possibly or probably related systemic adverse reactions were reported by < 2% of the patients treated with VABRINTY in these clinical studies.

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 VABRINTY. 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 - During postmarketing surveillance, rare 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 first dose, and some within the first hour. In these cases, pituitary apoplexy has presented as sudden headache, vomiting, visual changes, ophthalmoplegia, altered mental status, and sometimes cardiovascular collapse. Immediate medical attention has been required.

Nervous System - Convulsions

Respiratory System - Interstitial lung disease

Skin reactions- Erythema multiforme, SJS/TEN

Leuprolide acetate, a gonadotropin releasing hormone (GnRH) agonist, acts as an inhibitor of gonadotropin secretion when given continuously in therapeutic doses.  Animal and human studies indicate that after an initial stimulation, chronic administration of leuprolide acetate results in suppression of testicular and ovarian steroidogenesis.  This effect is reversible upon discontinuation of drug therapy.

Following initial administration, VABRINTY causes an initial increase in serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels with subsequent increases in serum levels of testosterone.  Administration of VABRINTY leads to sustained suppression of pituitary gonadotropins, and serum levels of testosterone consequently fall into the range normally seen in surgically castrated men approximately 21 days after initiation of therapy. Continuation of therapy with leuprolide acetate in patients with prostate cancer maintained testosterone below the castrate level for up to five years.

Following the first dose of VABRINTY, mean serum testosterone concentrations transiently increased, then fell to below castrate threshold ( < 50 ng/dL) within three weeks, and generally remained below castrate threshold levels throughout treatment for all VABRINTY concentrations. Mean serum testosterone concentrations fell to < 20 ng/dL within five weeks for all VABRINTY concentrations.

Absorption
VABRINTY 7.5 mg
Following a single injection of VABRINTY 7.5 mg for 1-month administration in patients, the mean peak plasma concentration was 25.3 ng/mL (C _max ) at 5 hours;at the end of the 4 week dosing interval the mean concentration declined to 0.42 ng/mL.

VABRINTY 22.5 mg
Following a single injection of VABRINTY 22.5 mg for 3-month administration in patients, the mean peak plasma concentration was 127 ng/mL (C _max ) at 5 hours; at the end of the 12 week dosing interval the mean concentration declined to 0.34 ng/mL.

VABRINTY 30 mg
Following a single injection of VABRINTY 30 mg for 4-month administration in patients, the mean peak plasma concentration was 150 ng/mL (C _max ) at 3.3 hours; at the end of the 16 week dosing interval the mean concentration declined to 0.1 ng/mL.

VABRINTY 45 mg
Following a single injection of VABRINTY 45 mg for 6-month administration in patients, the mean peak plasma concentration was 82 ng/mL at 4.5 hours (C _max ); at the end of the 24 week dosing interval the mean concentration declined to 0.2 ng/mL.

There was no evidence of significant accumulation during repeated dosing.

Distribution
The mean steady-state volume of distribution of leuprolide following intravenous bolus administration to healthy male volunteers was 27 L. In vitro binding to human plasma proteins ranged from 43% to 49%.

Elimination
After the initial increase following each subcutaneous injection, serum concentration range was 0.1 – 2.00 ng/mL.

In healthy male volunteers, a 1-mg bolus of leuprolide administered intravenously revealed that the mean systemic clearance was 8.34 L/h, with a terminal elimination half-life of approximately 3 hours based on a two compartment model.

Metabolism
No drug metabolism study was conducted with VABRINTY.  Upon administration with different leuprolide acetate formulations, the major metabolite of leuprolide acetate is a pentapeptide (M-1) metabolite.

Excretion
No drug excretion study was conducted with VABRINTY.

Specific Populations
Geriatrics [see Use in Specific Populations (8.5 )]

Race
In patients studied, mean serum leuprolide concentrations were similar regardless of race.  Refer to Table 6 for distribution of study patients by race.

Table 6.  Race Characterization of VABRINTY Study Patients (n)

Renal and Hepatic Insufficiency
The pharmacokinetics of VABRINTY in hepatically and renally impaired patients have not been determined.

Two-year carcinogenicity studies were conducted with leuprolide acetate in rats and mice.  In rats, a dose-related increase of benign pituitary hyperplasia and benign pituitary adenomas was noted at 24 months when the drug was administered subcutaneously at high daily doses (0.6 to 4 mg/kg).  There was a significant but not dose-related increase of pancreatic islet-cell adenomas in females and of testicular interstitial cell adenomas in males (highest incidence in the low dose group).  In mice, no leuprolide acetate-induced tumors or pituitary abnormalities were observed at a dose as high as 60 mg/kg for two years. Patients have been treated with leuprolide acetate for up to three years with doses as high as 10 mg/day and for two years with doses as high as 20 mg/day without demonstrable pituitary abnormalities. No carcinogenicity studies have been conducted with VABRINTY.

Mutagenicity studies have been performed with leuprolide acetate using bacterial and mammalian systems and with VABRINTY 7.5 mg in bacterial systems.  These studies provided no evidence of a mutagenic potential.