Alendronate

12.1 Mechanism of Action Animal studies have indicated the following mode of action. At the cellular level, alendronate shows preferential localization to sites of bone resorption, specifically under osteoclasts. The osteoclasts adhere normally to the bone surface but lack the ruffled border that is indicative of active resorption. Alendronate does not interfere with osteoclast recruitment or attachment, but it does inhibit osteoclast activity. Studies in mice on the localization of radioactive [ 3 H]alendronate in bone showed about 10-fold higher uptake on osteoclast surfaces than on osteoblast surfaces. Bones examined 6 and 49 days after [ 3 H]alendronate administration in rats and mice, respectively, showed that normal bone was formed on top of the alendronate, which was incorporated inside the matrix. While incorporated in bone matrix, alendronate is not pharmacologically active. Thus, alendronate must be continuously administered to suppress osteoclasts on newly formed resorption surfaces. Histomorphometry in baboons and rats showed that alendronate treatment reduces bone turnover (i.e., the number of sites at which bone is remodeled). In addition, bone formation exceeds bone resorption at these remodeling sites, leading to progressive gains in bone mass.

1 INDICATIONS AND USAGE BINOSTO is a bisphosphonate indicated for: Treatment of osteoporosis in postmenopausal women ( 1.1 ) Treatment to increase bone mass in men with osteoporosis ( 1.2 ) Limitation of use: Optimal duration of use has not been determined. For patients at low-risk for fracture, consider drug discontinuation after 3 to 5 years of use ( 1.3 ) 1.1 Treatment of Osteoporosis in Postmenopausal Women BINOSTO effervescent tablet 70 mg is indicated for the treatment of osteoporosis in postmenopausal women. For the treatment of osteoporosis, alendronate sodium increases bone mass and reduces the incidence of fractures, including those of the hip and spine (vertebral compression fractures). [See Clinical Studies (14.1) .] 1.2 Treatment to Increase Bone Mass in Men With Osteoporosis BINOSTO is indicated for treatment to increase bone mass in men with osteoporosis [see Clinical Studies (14.2) ] . 1.3 Important Limitations of Use The optimal duration of use has not been determined. The safety and effectiveness of BINOSTO for the treatment of osteoporosis are based on clinical data of four years duration. All patients on bisphosphonate therapy should have the need for continued therapy re-evaluated on a periodic basis. Patients at low-risk for fracture should be considered for drug discontinuation after 3 to 5 years of use. Patients who discontinue therapy should have their risk for fracture re-evaluated periodically.

2 DOSAGE AND ADMINISTRATION 70 mg BINOSTO effervescent tablet once weekly. ( 2.1 , 2.2 ) Instruct patients to: ( 2.3 ) Dissolve one tablet of BINOSTO in approximately half a glass of plain room temperature water (4 oz). Wait at least 5 minutes after the effervescence stops, stir the solution for approximately 10 seconds and consume contents. Swallow solution at least 30 minutes before the first food, beverage, or medication of the day. Avoid lying down for at least 30 minutes after taking BINOSTO and until after the first food of the day. 2.1 Treatment of Osteoporosis in Postmenopausal Women The recommended dosage is one 70 mg effervescent tablet once weekly. 2.2 Treatment to Increase Bone Mass in Men With Osteoporosis The recommended dosage is one 70 mg effervescent tablet once weekly. 2.3 Important Administration Instructions Instruct patients to do the following to assure adequate drug absorption and to decrease the risk of esophageal adverse reactions: Take BINOSTO upon arising for the day and at least 30 minutes before the first food, beverage, or medication of the day. Patients should not swallow the undissolved effervescent tablet, should not chew the effervescent tablet or allow the effervescent tablet to dissolve in their mouths because of the risk for oropharyngeal irritation [see Warnings and Precautions (5.1) ]. Dissolve the effervescent tablet in 4 ounces room temperature plain water only (not mineral water or flavored water). Wait at least 5 minutes after the effervescence stops and then stir the buffered solution for approximately 10 seconds and ingest. Avoid lying down for at least 30 minutes after taking BINOSTO and until after their first food of the day. Do not take BINOSTO at bedtime or before arising for the day. Failure to follow these instructions may increase the risk of esophageal adverse reactions [see Warnings and Precautions (5.1) ] . 2.4 Recommendations for Calcium and Vitamin D Supplementation Instruct patients to take supplemental calcium and vitamin D if dietary intake is inadequate [see Warnings and Precautions (5.2) ] . Patients at increased risk for vitamin D insufficiency (e.g., over the age of 70 years, nursing home-bound, or chronically ill) may need vitamin D supplementation. Patients with gastrointestinal malabsorption syndromes may require higher doses of vitamin D supplementation and measurement of 25-hydroxyvitamin D should be considered. 2.5 Administration Instructions for Missed Doses If the once-weekly dose is missed, instruct patients to take one dose on the morning after they remember. They should not take 2 doses on the same day but should return to taking one dose once a week, as originally scheduled on their chosen day.

6 ADVERSE REACTIONS The following clinically significant adverse drug reactions are described elsewhere in the labeling: Upper Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.1) ] Mineral Metabolism [see Warnings and Precautions (5.2) ] Musculoskeletal Pain [see Warnings and Precautions (5.3) ] Osteonecrosis of the Jaw [see Warnings and Precautions (5.4) ] Atypical Fractures Including Femoral Fractures [see Warnings and Precautions (5.5) ] Renal Impairment [see Warnings and Precautions (5.6) ] Patients sensitive to High Sodium Intake [see Warnings and Precautions (5.7) ] The most common adverse reactions (incidence greater than or equal to 3%) are abdominal pain, acid regurgitation, constipation, diarrhea, dyspepsia, musculoskeletal pain, and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Radius Health, Inc. at 1-855-672-3487 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience 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 clinical practice. The safety of BINOSTO (alendronate sodium) effervescent tablet 70 mg is based on clinical trial data of alendronate sodium 10 mg daily and alendronate sodium 70 mg weekly. Treatment of Osteoporosis in Postmenopausal Women Daily Dosing The safety of alendronate sodium 10 mg daily in the treatment of postmenopausal osteoporosis was assessed in four clinical trials that enrolled 7453 women aged 44-84 years. Study 1 and Study 2 were identically designed, three-year, placebo-controlled, double-blind, multicenter studies (United States and Multinational n=994); Study 3 was the three year vertebral fracture cohort of the Fracture Intervention Trial [FIT] (n=2027) and Study 4 was the four-year clinical fracture cohort of FIT (n=4432). Overall, 3620 patients were exposed to placebo and 3432 patients exposed to alendronate. Patients with pre-existing gastrointestinal disease and concomitant use of non-steroidal anti-inflammatory drugs were included in these clinical trials. In Study 1 and Study 2 all women received 500 mg elemental calcium as carbonate. In Study 3 and Study 4 all women with dietary calcium intake less than 1000 mg per day received 500 mg calcium and 250 IU Vitamin D per day. Among patients treated with alendronate 10 mg or placebo in Study 1 and Study 2, and all patients in Study 3 and Study 4, the incidence of all-cause mortality was 1.8% in the placebo group and 1.8% in the alendronate group. The incidence of serious adverse events was 30.7% in the placebo group and 30.9% in the alendronate group. The percentage of patients who discontinued the study due to any clinical adverse event was 9.5% in the placebo group and 8.9% in the alendronate group. Adverse reactions from these studies considered by the investigators as possibly, probably, or definitely drug related in greater than or equal to 1% of patients treated with either alendronate or placebo are presented in Table 1. Table 1 Osteoporosis Treatment Studies in Postmenopausal Women Adverse Reactions Considered Possibly, Probably, or Definitely Drug Related by the Investigators and Reported in Greater Than or Equal to 1% of Patients United States/Multinational Studies Fracture Intervention Trial Alendronate Sodium 10 mg/day for three years Placebo Alendronate Sodium 5 mg/day for 2 years and 10 mg/day for either 1 or 2 additional years Placebo % (N = 196) % (N = 397) % (N = 3236) % (N = 3223) Gastrointestinal Abdominal pain 6.6 4.8 1.5 1.5 Nausea 3.6 4.0 1.1 1.5 Dyspepsia 3.6 3.5 1.1 1.2 Constipation 3.1 1.8 0.0 0.2 Diarrhea 3.1 1.8 0.6 0.3 Flatulence 2.6 0.5 0.2 0.3 Acid regurgitation 2.0 4.3 1.1 0.9 Esophageal ulcer 1.5 0.0 0.1 0.1 Vomiting 1.0 1.5 0.2 0.3 Dysphagia 1.0 0.0 0.1 0.1 Abdominal distention 1.0 0.8 0.0 0.0 Gastritis 0.5 1.3 0.6 0.7 Musculoskeletal Musculoskeletal (bone, muscle or joint) pain 4.1 2.5 0.4 0.3 Muscle cramp 0.0 1.0 0.2 0.1 Nervous system/psychiatric Headache 2.6 1.5 0.2 0.2 Dizziness 0.0 1.0 0.0 0.1 Special senses Taste perversion 0.5 1.0 0.1 0.0 Rarely, rash and erythema have occurred. Gastrointestinal Adverse Reactions: One patient treated with alendronate sodium (10 mg/day), who had a history of peptic ulcer disease and gastrectomy and who was taking concomitant aspirin developed an anastomotic ulcer with mild hemorrhage, which was considered drug related. Aspirin and alendronate sodium were discontinued and the patient recovered. In the Study 1 and Study 2 populations, 49-54% had a history of gastrointestinal disorders at baseline and 54-89% used nonsteroidal anti-inflammatory drugs or aspirin at some time during the studies [ see Warnings and Precautions (5.1) ]. Laboratory Test Findings: In double-blind, multicenter, controlled studies, asymptomatic, mild, and transient decreases in serum calcium and phosphate

7 DRUG INTERACTIONS Calcium supplements, antacids or oral medications containing multivalent cations interfere with absorption of alendronate. ( 7.1 ) Use caution when co-prescribing aspirin/nonsteroidal anti- inflammatory drugs that may worsen gastrointestinal irritation. ( 7.2 , 7.3 ) 7.1 Calcium Supplements/Antacids Co-administration of BINOSTO and calcium, antacids, or oral medications containing multivalent cations will interfere with absorption of BINOSTO. Therefore, instruct patients to wait at least one-half hour after taking BINOSTO before taking any other oral medications. 7.2 Aspirin In clinical studies, the incidence of upper gastrointestinal adverse events was increased in patients receiving concomitant therapy with daily doses of alendronate sodium greater than 10 mg and aspirin-containing products. 7.3 Nonsteroidal Anti-inflammatory Drugs (NSAIDs) BINOSTO may be administered to patients taking NSAIDs. In a 3-year, controlled, clinical study (n=2027) during which a majority of patients received concomitant NSAIDs, the incidence of upper gastrointestinal adverse events was similar in patients taking alendronate sodium 5 or 10 mg/day compared to those taking placebo. However, since NSAID use is associated with gastrointestinal irritation, caution should be used during concomitant use with BINOSTO. 7.4 Levothyroxine The bioavailability of alendronate was slightly decreased when BINOSTO and levothyroxine were co-administered to healthy subjects [see Clinical Pharmacology (12.3) ] .