Supprelin LA (histrelin acetate) subcutaneous implant is indicated for the treatment of children with central precocious puberty (CPP).

Children with CPP (neurogenic or idiopathic) have an early onset of secondary sexual characteristics (earlier than 8 years of age in females and 9 years of age in males). They also show a significantly advanced bone age that can result in diminished adult height attainment.

Prior to initiation of treatment a clinical diagnosis of CPP should be confirmed by measurement of blood concentrations of total sex steroids, luteinizing hormone (LH) and follicle stimulating hormone (FSH) following stimulation with a GnRH analog, and assessment of bone age versus chronological age. Baseline evaluations should include height and weight measurements, diagnostic imaging of the brain (to rule out intracranial tumor), pelvic/testicular/adrenal ultrasound (to rule out steroid secreting tumors), human chorionic gonadotropin levels (to rule out a chorionic gonadotropin secreting tumor), and adrenal steroids to exclude congenital adrenal hyperplasia.

Recommended Dose

The recommended dose of Supprelin LA is one implant every 12 months. Each implant contains 50 mg histrelin acetate. The implant is inserted subcutaneously in the inner aspect of the upper arm and provides continuous release of histrelin acetate (65 mcg per day) for 12 months of hormonal therapy. Supprelin LA must be removed after 12 months of therapy (the implant has been designed to allow for a few additional weeks of histrelin acetate release in order to allow flexibility of medical appointments). At the time an implant is removed, another implant may be inserted to continue therapy. Discontinuation of Supprelin LA should be considered at the discretion of the physician and at the appropriate time point for the onset of puberty (approximately 11 years for females and 12 years for males).

Insertion Procedure

The implant should be kept refrigerated (2-8°C) until the day of the procedure. The insertion tool, supplied as part of the implantation kit, does not require refrigeration. All other supplies necessary to insert and/or remove the implant will be provided in the implantation kit.

It is important to use aseptic techniques to minimize any chance of infection. Sterile gloves are required for the insertion procedure and subsequent removal of the implant.

The implant is inserted using the procedure outlined below:

Identifying the Insertion Site

The patient should be on his/her back, with the arm least used (e.g., left arm for a right-handed person) flexed so the physician has ready access to the inner aspect of the upper arm. Prop the arm with pillows so the patient can easily hold that position. The optimum site for insertion is approximately half way between the shoulder and the elbow and in the crease between the bicep and triceps.

Loading the Insertion Tool

Load the insertion tool prior to prepping the insertion field and insertion site. Remove the insertion tool from its sterile bag. The tool is shipped with the cannula fully extended. Verify this by inspecting the position of the green retraction button. The button should be all the way forward, towards the cannula, away from the handle. Remove the metal band from the vial, remove the rubber stopper, and use a mosquito clamp to grasp either tip of the implant. Avoid grabbing or clamping the middle of the implant to prevent distortion of the implant.

Insert the implant into the cannula of the insertion tool. The implant will rest in the cannula so that just the tip is visible at the bottom of the bevel.

Inserting the Implant

1. Swab the insertion area with povidone-iodine swabs, then lay a fenestrated drape over the insertion site (for clarity of illustration, the accompanying photos do not show the drape).

Anesthetic

2. The method of anesthesia (i.e., local, conscious sedation or general) utilized should be determined at the discretion of the physician and/or surgeon performing the procedure. After determining the absence of known allergies to the anesthetic agent, a topical lidocaine or lidocaine/epinephrine cream can be used to anesthetize the area prior to injection of local anesthetic. Inject a few milliliters of the anesthetic, starting at the planned incision site, then infiltrating up to the length of the implant, 32 mm, in a fan-like fashion.

Incision

3. Using a scalpel, make a 2-3 mm incision immediately subcutaneous and perpendicular to the shoulder.

Insertion

4. Grasp the insertion tool by its handle, as shown.

5. Insert the tip of the insertion tool into the incision with the bevel up and advance the tool subcutaneously along the path of the anesthetic, up to the inscribed line on the cannula. Pull back the tool about an inch, almost to the tip, while keeping the insertion path just immediately subcutaneous. Keep the insertion tool extended and locked while pulling back the insertion tool. Push the tool back into the arm, up to the black line. This will create a “pocket” for the implant. To ensure subcutaneous placement, the insertion tool should visibly raise the skin at all times during insertion. Be sure that the insertion tool doesn't enter the muscle tissue.

6. Hold the insertion tool in place as you move your thumb to the green retraction button. Press the button down to release the locking mechanism, then draw the button back to the back stop, all the while holding the tool in place. The cannula will withdraw from the incision, leaving the implant in the dermis. Withdraw the insertion tool from the incision. Release of the implant can be checked by palpation.

Alternatively, the implant can be inserted manually by creating a pocket with the mosquito clamp large enough to allow insertion of the implant. Procedures for incision and closure are the same as instructed above.

NOTE: Do not try to push the tool in deeper once the retraction process has started to avoid severing the implant. If you wish to re-start the process, withdraw the tool, grasp the implant by the tip to extract it, reset the retraction button to its most forward position, reload the implant, and start again.

After placement, sterile gauze may be used to apply pressure briefly to the insertion site to ensure hemostasis.

Closing the Incision

7. To close the incision, use one or two sutures (optional), knots facing inside the incision. Apply a light coating of antibiotic ointment directly onto the incision. The incision can also be closed with two surgical strips. Apply one or two of the gauze pads over the incision and secure with an adhesive elastic bandage.

Removal Procedure and New Implant Insertion

Supprelin LA must be removed after 12 months of therapy. The techniques and instruments required are the same as for implantation. Assemble all the necessary implements prior to the procedure.

Locating the Implant

The implant may be located by palpating the area near the incision from the prior year. Generally, the implant is readily palpated. Press the distal end of the implant to determine the proximal tip's location relative to the old incision.

In the event the implant is difficult to locate, ultrasound can be used. If ultrasound fails to locate the implant, other imaging techniques such as CT or MRI may be used to locate it (plain films are not recommended as the implant is not radiopaque).

Preparing the Site

1. Patient position and site preparation are the same as for the initial insertion. Swab the area above and around the implant with the povidone-iodine swabs. Drape the area with a fenestrated drape.

Anesthetic

2. After determining the absence of known allergies to the anesthetic agent, press down on the implant tip furthest from the old incision to determine the location of the tip closest to the incision. Inject a small amount of lidocaine/epinephrine at the tip near the incision, then advance the needle along the length, but beneath the implant, steadily injecting a small amount of anesthetic along the way. The anesthetic will raise the implant up within the dermis. If you are inserting a new implant, you have the option of either placing the new one in the same “pocket” as the removed one, or using the same incision; insert the new implant in the opposite direction. If placing the new implant in the opposite direction, inject a few milliliters of the anesthetic, starting at the planned incision site, then infiltrating up to the length of the location of the new implant, 32 mm, in a fan-like fashion. Apply anesthetic prior to removal of the old implant.

Incision/Implant Removal

3. Using a scalpel, make a 2-3 mm incision near the tip and about 1-2 mm deep. Generally, the tip of the implant will be visible through a pseudocapsule of tissue. If not, push down on the distal tip of the implant and massage it forward towards the incision. Carefully nick the pseudocapsule to reveal the polymer tip. Insert the mosquito clamp into the hole created in the pseudocapsule and expand by opening the clamp. Widening the opening of the pseudocapsule helps ease the extraction of the old implant.

4. Grasp the tip with the mosquito clamp and extract the implant.

5. Dispose of the implant in a proper manner, treating it like any other bio-waste.

If inserting a new implant - proceed according to “Loading the Insertion Tool”, “Insertion”, and “Closing the Incision” sections above.

The new implant may be placed through the same incision site. Alternatively, the contralateral arm may be used. 6. Provide the patient with the Patient Labeling material.

Dosage forms and Strength

Supprelin LA is a sterile, nonbiodegradable, diffusion-controlled reservoir drug delivery system designed to deliver histrelin acetate continuously for 12 months after subcutaneous implantation. The sterile histrelin acetate implant contains 50 mg histrelin acetate and delivers approximately 65 mcg histrelin acetate per day over 12 months.

And Storage and Handling

Supprelin LA (NDC 67979-002-01) is supplied in a carton containing 2 inner cartons: a small one for the vial containing the Supprelin LA implant, which is shipped with a cold pack in a polystyrene cooler and must be refrigerated upon arrival, and one for the implantation kit for use with Supprelin LA.

The Supprelin LA implant carton contains an amber plastic pouch. Inside the pouch is a glass vial with a Teflon-coated stopper and an aluminum seal, containing the implant immersed in 2 mL of 1.8% sterile sodium chloride. The sterile insertion tool is part of the implantation kit.

Supprelin LA is stable when refrigerated under the recommended storage conditions (2-8ºC) for up to 2 years. Do not freeze. Protect from light. The implantation kit should be stored at room temperature.

Manufactured for: Indevus Pharmaceuticals, Inc. 33 Hayden Avenue, Lexington, MA 02421
FDA rev date: 5/3/2007

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