Ganirelix

INDICATIONS AND USAGE Ganirelix Acetate Injection is indicated for the inhibition of premature LH surges in women undergoing controlled ovarian hyperstimulation.

CLINICAL PHARMACOLOGY The pulsatile release of GnRH stimulates the synthesis and secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The frequency of LH pulses in the mid and late follicular phase is approximately 1 pulse per hour. These pulses can be detected as transient rises in serum LH. At midcycle, a large increase in GnRH release results in an LH surge. The midcycle LH surge initiates several physiologic actions including: ovulation, resumption of meiosis in the oocyte, and luteinization. Luteinization results in a rise in serum progesterone with an accompanying decrease in estradiol levels. Ganirelix acetate acts by competitively blocking the GnRH receptors on the pituitary gonadotroph and subsequent transduction pathway. It induces a rapid, reversible suppression of gonadotropin secretion. The suppression of pituitary LH secretion by ganirelix acetate is more pronounced than that of FSH. An initial release of endogenous gonadotropins has not been detected with ganirelix acetate, which is consistent with an antagonist effect. Upon discontinuation of ganirelix acetate, pituitary LH and FSH levels are fully recovered within 48 hours. Pharmacokinetics The pharmacokinetic parameters of single and multiple injections of ganirelix acetate in healthy adult females are summarized in Table I . Steady-state serum concentrations are reached after 3 days of treatment. The pharmacokinetics of ganirelix acetate are dose-proportional in the dose range of 125 to 500 mcg. TABLE I: Mean (SD) pharmacokinetic parameters of 250 mcg of ganirelix acetate following a single subcutaneous (SC) injection (n=15) and daily SC injections (n=15) for seven days. t max Time to maximum concentration t ½ Elimination half-life C max Maximum serum concentration AUC Area under the curve; Single dose: AUC 0–∞ ; multiple dose: AUC 0–24 V d Volume of distribution † Based on intravenous administration CL Clearance = Dose/AUC 0–∞ F Absolute bioavailability t max h t 1/2 h C max ng/mL AUC ng•h/mL CL/F L/h V d /F L Ganirelix Acetate single dose 1.1 (0.3) 12.8 (4.3) 14.8 (3.2) 96 (12) 2.4 (0.2) † 43.7 (11.4) † Ganirelix Acetate multiple dose 1.1 (0.2) 16.2 (1.6) 11.2 (2.4) 77.1 (9.8) 3.3 (0.4) 76.5 (10.3) Absorption Ganirelix acetate is rapidly absorbed following subcutaneous injection with maximum serum concentrations reached approximately one hour after dosing. The mean absolute bioavailability of ganirelix acetate following a single 250-mcg subcutaneous injection to healthy female volunteers is 91.1%. Distribution The mean (SD) volume of distribution of ganirelix acetate in healthy females following intravenous administration of a single 250 mcg dose is 43.7 (11.4) liters (L). In vitro protein binding to human plasma is 81.9%. Metabolism Following single-dose intravenous administration of radiolabeled ganirelix acetate to healthy female volunteers, ganirelix acetate is the major compound present in the plasma (50–70% of total radioactivity in the plasma)

DOSAGE AND ADMINISTRATION After initiating FSH therapy on Day 2 or 3 of the cycle, ganirelix acetate injection 250 mcg may be administered subcutaneously once daily during the mid to late portion of the follicular phase. By taking advantage of endogenous pituitary FSH secretion, the requirement for exogenously administered FSH may be reduced. Treatment with ganirelix acetate should be continued daily until the day of hCG administration. When a sufficient number of follicles of adequate size are present, as assessed by ultrasound, final maturation of follicles is induced by administering hCG. The administration of hCG should be withheld in cases where the ovaries are abnormally enlarged on the last day of FSH therapy to reduce the chance of developing OHSS (Ovarian Hyperstimulation Syndrome). Directions for Using Ganirelix Acetate Injection Ganirelix acetate injection is supplied in a single dose, sterile, prefilled syringe and is intended for SUBCUTANEOUS administration only. Air bubble(s) may be seen in the pre-filled syringe. This is expected, and removal of the air bubble(s) is not needed. Wash hands thoroughly with soap and water. The most convenient sites for SUBCUTANEOUS injection are in the abdomen around the navel or upper thigh. The injection site should be swabbed with a disinfectant to remove any surface bacteria. Clean about two inches around the point where the needle will be inserted and let the disinfectant dry for at least one minute before proceeding. With syringe held upward, remove needle cover. Pinch up a large area of skin between the finger and thumb. Vary the injection site a little with each injection. The needle should be inserted at the base of the pinched-up skin at an angle of 45–90° to the skin surface. When the needle is correctly positioned, it will be difficult to draw back on the plunger. If any blood is drawn into the syringe, the needle tip has penetrated a vein or artery. If this happens, withdraw the needle slightly and reposition the needle without removing it from the skin. Alternatively, remove the needle and use a new, sterile, prefilled syringe. Cover the injection site with a swab containing disinfectant and apply pressure; the site should stop bleeding within one or two minutes. Once the needle is correctly placed, depress the plunger slowly and steadily, so the solution is correctly injected and the skin is not damaged. Pull the syringe out quickly and apply pressure to the site with a swab containing disinfectant. Use the sterile, prefilled syringe only once. Discard the unused portion and dispose of it properly.

ADVERSE REACTIONS The safety of ganirelix acetate was evaluated in two randomized, parallel-group, multicenter controlled clinical studies. Treatment duration for ganirelix acetate ranged from 1 to 14 days. Table IV represents adverse events (AEs) from first day of ganirelix acetate administration until confirmation of pregnancy by ultrasound at an incidence of ≥ 1% in ganirelix acetate-treated subjects without regard to causality. TABLE IV: Incidence of common adverse events (Incidence ≥ 1% in ganirelix acetate-treated subjects). Completed controlled clinical studies (All-subjects-treated group). Adverse Events Occurring in ≥ 1% Ganirelix Acetate N=794 % (n) Abdominal Pain (gynecological) 4.8 (38) Death Fetal 3.7 (29) Headache 3.0 (24) Ovarian Hyperstimulation Syndrome 2.4 (19) Vaginal Bleeding 1.8 (14) Injection Site Reaction 1.1 (9) Nausea 1.1 (9) Abdominal Pain (gastrointestinal) 1.0 (8) During post-marketing surveillance, rare cases of hypersensitivity reactions, including anaphylaxis (including anaphylactic shock), angioedema and urticaria have been reported with ganirelix acetate, as early as with the first dose (see PRECAUTIONS ). Congenital Anomalies An observational study in more than 1,000 newborns compared the incidence of congenital anomalies in newborns of women administered ganirelix acetate to historical controls of a GnRH agonist. This study demonstrated that the incidence of congenital anomalies in children born after COH treatment in women using ganirelix acetate was comparable with that reported after a COH treatment cycle using a GnRH agonist. The incidence of congenital malformations after some Assisted Reproductive Technologies (ART) [specifically in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI)] may be slightly higher than after spontaneous conception. This slightly higher incidence is thought to be related to differences in parental characteristics (e.g., maternal age, maternal and paternal genetic background, sperm characteristics) and to the higher incidence of multi-fetal gestations after IVF or ICSI. The causal relationship between these congenital anomalies and ganirelix acetate injection is unknown.

WARNINGS Ganirelix acetate injection should be prescribed by physicians who are experienced in infertility treatment. Before starting treatment with ganirelix acetate, pregnancy must be excluded. Safe use of ganirelix acetate during pregnancy has not been established (see CONTRAINDICATIONS and PRECAUTIONS ).

CONTRAINDICATIONS Ganirelix acetate is contraindicated under the following conditions: Known hypersensitivity to ganirelix acetate or to any of its components including dry natural rubber/latex (see HOW SUPPLIED ). Known hypersensitivity to GnRH or any other GnRH analog. Known or suspected pregnancy (see PRECAUTIONS ).

OVERDOSAGE There have been no reports of overdosage with ganirelix acetate in humans.