letrozole 2.5 MG Oral Tablet

INDICATIONS AND USAGE Letrozole tablets are an aromatase inhibitor indicated for: Adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer. ( 1.1 ) Extended adjuvant treatment of postmenopausal women with early breast cancer who have received prior standard adjuvant tamoxifen therapy. ( 1.2 ) First and second-line treatment of postmenopausal women with hormone receptor positive or unknown advanced breast cancer. ( 1.3 ) 1.1 Adjuvant Treatment of Early Breast Cancer Letrozole tablets are indicated for the adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer. 1.2 Extended Adjuvant Treatment of Early Breast Cancer Letrozole tablets are indicated for the extended adjuvant treatment of early breast cancer in postmenopausal women, who have received 5 years of adjuvant tamoxifen therapy. The effectiveness of letrozole tablets in extended adjuvant treatment of early breast cancer is based on an analysis of disease-free survival (DFS) in patients treated with letrozole tablets for a median of 60 months [see Clinical Studies ( 14.2 , 14.3 )]. 1.3 First and Second-Line Treatment of Advanced Breast Cancer Letrozole tablets are indicated for first-line treatment of postmenopausal women with hormone receptor positive or unknown, locally advanced or metastatic breast cancer. Letrozole tablets are also indicated for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy [see Clinical Studies ( 14.4 , 14.5 )] .

DOSAGE AND ADMINISTRATION Letrozole tablets are taken orally without regard to meals ( 2 ): Recommended dose: 2.5.mg once daily ( 2.1 ) Patients with cirrhosis or severe hepatic impairment: 2.5 mg every other day ( 2.5 , 5.3 ) 2.1 Recommended Dose The recommended dose of letrozole tablet is one 2.5 mg tablet administered once a day, without regard to meals. 2.2 Use in Adjuvant Treatment of Early Breast Cancer In the adjuvant setting, the optimal duration of treatment with letrozole is unknown. In both the adjuvant study and the post approval adjuvant study, median treatment duration was 5 years. Treatment should be discontinued at relapse [see Clinical Studies ( 14.1 )]. 2.3 Use in Extended Adjuvant Treatment of Early Breast Cancer In the extended adjuvant setting, the optimal treatment duration with letrozole tablet is not known. The planned duration of treatment in the study was 5 years. In the final updated analysis, conducted at a median follow-up of 62 months, the median treatment duration for letrozole tablets was 60 months. Seventy-one (71%) percent of patients were treated for at least 3 years and 58% of patients completed at least 4.5 years of extended adjuvant treatment. The treatment should be discontinued at tumor relapse [see Clinical Studies ( 14.2 )]. 2.4 Use in First and Second-Line Treatment of Advanced Breast Cancer In patients with advanced disease, treatment with letrozole tablets should continue until tumor progression is evident [see Clinical Studies ( 14.4 , 14.5 )] . 2.5 Use in Hepatic Impairment No dosage adjustment is recommended for patients with mild to moderate hepatic impairment, although letrozole tablets blood concentrations were modestly increased in subjects with moderate hepatic impairment due to cirrhosis. The dose of letrozole tablets in patients with cirrhosis and severe hepatic dysfunction should be reduced by 50% [see Warnings and Precautions ( 5.3 )]. The recommended dose of letrozole tablets for such patients is 2.5 mg administered every other day. The effect of hepatic impairment on letrozole tablets exposure in noncirrhotic cancer patients with elevated bilirubin levels has not been determined. 2.6 Use in Renal Impairment No dosage adjustment is required for patients with renal impairment if creatinine clearance is greater than or equal to 10 mL/min [see Clinical Pharmacology ( 12.3 )] .

WARNINGS AND PRECAUTIONS This product contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions (including bronchial asthma) in certain susceptible persons. Although the overall incidence of FD&C Yellow No. 5 (tartrazine) sensitivity in the general population is low, it is frequently seen in patients who also have aspirin hypersensitivity. Decreases in bone mineral density may occur. Consider bone mineral density monitoring (5.1) Increases in total cholesterol may occur. Consider cholesterol monitoring. (5.2) Fatigue, dizziness and somnolence may occur. Exercise caution when operating machinery (5.4) Embryo-Fetal toxicity: Can cause fetal harm when administered to pregnant women. Obtain a pregnancy test in females of reproductive potential. Advise females of reproductive potential to use effective contraception (5.6 , 8.1 , 8.3) 5.1 Bone Effects Use of letrozole may cause decreases in bone mineral density (BMD). Consideration should be given to monitoring BMD. Results of a safety study to evaluate safety in the adjuvant setting comparing the effect on lumbar spine (L2 to L4) BMD of adjuvant treatment with letrozole to that with tamoxifen showed at 24 months a median decrease in lumbar spine BMD of 4.1% in the letrozole arm compared to a median increase of 0.3% in the tamoxifen arm (difference = 4.4%) ( P < 0.0001) [ see Adverse Reactions (6) ]. Updated results from the BMD substudy (MA-17B) in the extended adjuvant setting demonstrated that at 2 years patients receiving letrozole had a median decrease from baseline of 3.8% in hip BMD compared to a median decrease of 2.0% in the placebo group. The changes from baseline in lumbar spine BMD in letrozole and placebo treated groups were not significantly different [ see Adverse Reactions (6) ]. In the adjuvant trial (BIG 1-98) the incidence of bone fractures at any time after randomization was 14.7% for letrozole and 11.4% for tamoxifen at a median follow-up of 96 months. The incidence of osteoporosis was 5.1% for letrozole and 2.7% for tamoxifen [ see Adverse Reactions (6) ]. In the extended adjuvant trial (MA-17), the incidence of bone fractures at any time after randomization was 13.3% for letrozole and 7.8% for placebo at a median follow-up of 62 months. The incidence of new osteoporosis was 14.5% for letrozole and 7.8% for placebo [ see Adverse Reactions (6) ]. 5.2 Cholesterol Consideration should be given to monitoring serum cholesterol. In the adjuvant trial (BIG 1-98), hypercholesterolemia was reported in 52.3% of letrozole patients and 28.6% of tamoxifen patients. Grade 3 to 4 hypercholesterolemia was reported in 0.4% of letrozole patients and 0.1% of tamoxifen patients. Also in the adjuvant setting, an increase of greater than or equal to 1.5 x upper limit of normal (ULN) in total cholesterol (generally nonfasting) was observed in patients on monotherapy who had baseline total serum cholesterol within the normal range (i.e., less than = 1.5 x ULN) in 155/1843 (8.4%) patients on letrozole vs 71/1840 (3.9%) patients on tamoxifen Lipid lowering medications were required for 29% of patients on letrozole and 20% on tamoxifen [ see Adverse Reactions (6) ]. 5.3 Hepatic Impairment Subjects with cirrhosis and severe hepatic impairment who were dosed with 2.5 mg of letrozole tablets experienced approximately twice the exposure to letrozole as healthy volunteers with normal liver function [ see Clinical Pharmacology (12.3) ]. Therefore, a dose reduction is recommended for this patient population. The effect of hepatic impairment on letrozole exposure in cancer patients with elevated bilirubin levels has not been determined [ see Dosage and Administration (2.5) ]. 5.4 Fatigue and Dizziness Because fatigue, dizziness, and somnolence have been reported with the use of letrozole, caution is advised when driving or using machinery until it is known how the patient reacts to letrozole use. 5.5 Laboratory Test Abnormalities No dose-related effect of letrozole on any hematologic or clinical chemistry parameter was evident. Moderate decreases in lymphocyte counts, of uncertain clinical significance, were observed in some patients receiving letrozole 2.5 mg. This depression was transient in about half of those affected. Two patients on letrozole developed thrombocytopenia; relationship to the study drug was unclear. Patient withdrawal due to laboratory abnormalities, whether related to study treatment or not was infrequent. 5.6 Embryo-Fetal Toxicity Based on postmarketing reports, findings from animal studies and the mechanism of action, letrozole can cause fetal harm and is contraindicated for use in pregnant women. In postmarketing reports, use of letrozole during pregnancy resulted in cases of spontaneous abortions and congenital birth defects. Letrozole caused embryo-fetal toxicities in rats and rabbits at maternal exposures that were below the maximum recommended human dose (MHRD) on a mg/m 2 basis. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during therapy with letrozole and for at least 3 weeks after the last dose [ see Adverse Reactions (6.2) , Use in Specific Populations (8.1 , 8.3) and Clinical Pharmacology (12.1) ]. 5.7 Risk of Allergic Reactions due to Tartrazine This product contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions (including bronchial asthma) in certain susceptible persons. Although the overall incidence of FD&C Yellow No. 5 (tartrazine) sensitivity in the general population is low, it is frequently seen in patients who also have aspirin hypersensitivity.

CONTRAINDICATIONS Pregnancy: Letrozole can cause fetal harm [see Use in Specific Populations ( 8.1 )] . Pregnancy: Letrozole can cause fetal harm [see Use in Specific Populations ( 8.1 )] . Pregnancy: Letrozole can cause fetal harm [see Use in Specific Populations ( 8.1 )] . Pregnancy: Letrozole can cause fetal harm [see Use in Specific Populations ( 8.1 )] . Known hypersensitivity to the active substance, or to any of the excipients [see Adverse Reactions ( 6 )] . Known hypersensitivity to the active substance, or to any of the excipients [see Adverse Reactions ( 6 )] . Known hypersensitivity to the active substance, or to any of the excipients [see Adverse Reactions ( 6 )] . Known hypersensitivity to the active substance, or to any of the excipients [see Adverse Reactions ( 6 )] . Pregnancy ( 4 ) Known hypersensitivity to the active substance, or to any of the excipients ( 4 )

Mechanism of Action The growth of some cancers of the breast is stimulated or maintained by estrogens. Treatment of breast cancer thought to be hormonally responsive (i.e., estrogen and/or progesterone receptor positive or receptor unknown) has included a variety of efforts to decrease estrogen levels (ovariectomy, adrenalectomy, hypophysectomy) or inhibit estrogen effects (antiestrogens and progestational agents). These interventions lead to decreased tumor mass or delayed progression of tumor growth in some women. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue itself can therefore be achieved by specifically inhibiting the aromatase enzyme. Letrozole is a nonsteroidal competitive inhibitor of the aromatase enzyme system; it inhibits the conversion of androgens to estrogens. In adult nontumor- and tumor-bearing female animals, letrozole is as effective as ovariectomy in reducing uterine weight, elevating serum LH, and causing the regression of estrogen-dependent tumors. In contrast to ovariectomy, treatment with letrozole does not lead to an increase in serum FSH. Letrozole selectively inhibits gonadal steroidogenesis but has no significant effect on adrenal mineralocorticoid or glucocorticoid synthesis. Letrozole inhibits the aromatase enzyme by competitively binding to the heme of the cytochrome P450 subunit of the enzyme, resulting in a reduction of estrogen biosynthesis in all tissues. Treatment of women with letrozole significantly lowers serum estrone, estradiol and estrone sulfate and has not been shown to significantly affect adrenal corticosteroid synthesis, aldosterone synthesis, or synthesis of thyroid hormones.