1.1 Treatment of Osteoporosis in Postmenopausal Women

Alendronate sodium tablets, USP are indicated for the treatment of osteoporosis in postmenopausal women. In postmenopausal women, alendronate sodium tablets, USP increase 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 Prevention of Osteoporosis in Postmenopausal Women

Alendronate sodium tablets, USP are indicated for the prevention of postmenopausal osteoporosis [see Clinical Studies (14.2)] .

1.3 Treatment to Increase Bone Mass in Men with Osteoporosis

Alendronate sodium tablets, USP are indicated for treatment to increase bone mass in men with osteoporosis [see Clinical Studies (14.3)] .

1.4 Treatment of Glucocorticoid-Induced Osteoporosis

Alendronate sodium tablets, USP are indicated for the treatment of glucocorticoid-induced osteoporosis in men and women receiving glucocorticoids in a daily dosage equivalent to 7.5 mg or greater of prednisone and who have low bone mineral density [see Clinical Studies (14.4)] .

1.5 Treatment of Paget's Disease of Bone

Alendronate sodium tablets, USP are indicated for the treatment of Paget's disease of bone in men and women. Treatment is indicated in patients with Paget's disease of bone who have alkaline phosphatase at least two times the upper limit of normal, or those who are symptomatic, or those at risk for future complications from their disease. [See Clinical Studies (14.5).]

1.6 Important Limitations of Use

The optimal duration of use has not been determined. The safety and effectiveness of alendronate sodium tablets, USP 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.

2.1 Treatment of Osteoporosis in Postmenopausal Women

The recommended dosage is:

2.2 Prevention of Osteoporosis in Postmenopausal Women

The recommended dosage is:

2.3 Treatment to Increase Bone Mass in Men with Osteoporosis

The recommended dosage is:

2.4 Treatment of Glucocorticoid-Induced Osteoporosis

The recommended dosage is one 5 mg tablet once daily, except for postmenopausal women not receiving estrogen, for whom the recommended dosage is one 10 mg tablet once daily.

2.5 Treatment of Paget's Disease of Bone

The recommended treatment regimen is 40 mg once a day for six months.

2.6 Important Administration Instructions

Instruct patients to do the following:

• Take alendronate sodium tablets at least one-half hour before the first food, beverage, or medication of the day with plain water only [see Patient Counseling Information (17.2)] . Other beverages (including mineral water), food, and some medications are likely to reduce the absorption of alendronate sodium tablets [see Drug Interactions (7.1)] . Waiting less than 30 minutes, or taking alendronate sodium tablets with food, beverages (other than plain water) or other medications will lessen the effect of alendronate sodium tablets by decreasing its absorption into the body.
• Take alendronate sodium tablets upon arising for the day. To facilitate delivery to the stomach and thus reduce the potential for esophageal irritation, an alendronate sodium tablet should be swallowed with a full glass of water (6-8 ounces). Patients should not lie down for at least 30 minutes and until after their first food of the day. Alendronate sodium tablets should not be taken at bedtime or before arising for the day. Failure to follow these instructions may increase the risk of esophageal adverse experiences [see Warnings and Precautions (5.1) and Patient Counseling Information (17.2)] .

2.7 Recommendations for Calcium and Vitamin D Supplementation

Instruct patients to take supplemental calcium 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.

Patients treated with glucocorticoids should receive adequate amounts of calcium and vitamin D.

2.8 Administration Instructions for Missed Doses

If a once-weekly dose of alendronate sodium tablet is missed, instruct patients to take one dose on the morning after they remember. They should not take two doses on the same day but should return to taking one dose once a week, as originally scheduled on their chosen day.

5.1 Upper Gastrointestinal Adverse Reactions

Alendronate sodium, like other bisphosphonates administered orally, may cause local irritation of the upper gastrointestinal mucosa. Because of these possible irritant effects and a potential for worsening of the underlying disease, caution should be used when alendronate sodium is given to patients with active upper gastrointestinal problems (such as known Barrett's esophagus, dysphagia, other esophageal diseases, gastritis, duodenitis, or ulcers).

Esophageal adverse experiences, such as esophagitis, esophageal ulcers and esophageal erosions, occasionally with bleeding and rarely followed by esophageal stricture or perforation, have been reported in patients receiving treatment with oral bisphosphonates including alendronate sodium. In some cases these have been severe and required hospitalization. Physicians should therefore be alert to any signs or symptoms signaling a possible esophageal reaction and patients should be instructed to discontinue alendronate sodium and seek medical attention if they develop dysphagia, odynophagia, retrosternal pain or new or worsening heartburn.

The risk of severe esophageal adverse experiences appears to be greater in patients who lie down after taking oral bisphosphonates including alendronate sodium and/or who fail to swallow oral bisphosphonates including alendronate sodium with the recommended full glass (6-8 ounces) of water, and/or who continue to take oral bisphosphonates including alendronate sodium after developing symptoms suggestive of esophageal irritation. Therefore, it is very important that the full dosing instructions are provided to, and understood by, the patient [see Dosage and Administration (2.6)] . In patients who cannot comply with dosing instructions due to mental disability, therapy with alendronate sodium should be used under appropriate supervision.

There have been post-marketing reports of gastric and duodenal ulcers with oral bisphosphonate use, some severe and with complications, although no increased risk was observed in controlled clinical trials [see Adverse Reactions (6.2)] .

5.2 Mineral Metabolism

Hypocalcemia must be corrected before initiating therapy with alendronate sodium [see Contraindications (4)] . Other disorders affecting mineral metabolism (such as vitamin D deficiency) should also be effectively treated. In patients with these conditions, serum calcium and symptoms of hypocalcemia should be monitored during therapy with alendronate sodium.

Presumably due to the effects of alendronate sodium on increasing bone mineral, small, asymptomatic decreases in serum calcium and phosphate may occur, especially in patients with Paget's disease, in whom the pretreatment rate of bone turnover may be greatly elevated, and in patients receiving glucocorticoids, in whom calcium absorption may be decreased.

Ensuring adequate calcium and vitamin D intake is especially important in patients with Paget's disease of bone and in patients receiving glucocorticoids.

5.3 Musculoskeletal Pain

In post-marketing experience, severe and occasionally incapacitating bone, joint, and/or muscle pain has been reported in patients taking bisphosphonates that are approved for the prevention and treatment of osteoporosis [see Adverse Reactions (6.2)] . This category of drugs includes alendronate. Most of the patients were postmenopausal women. The time to onset of symptoms varied from one day to several months after starting the drug. Discontinue use if severe symptoms develop. Most patients had relief of symptoms after stopping. A subset had recurrence of symptoms when rechallenged with the same drug or another bisphosphonate.

In placebo-controlled clinical studies of alendronate sodium, the percentages of patients with these symptoms were similar in the alendronate sodium and placebo groups.

5.4 Osteonecrosis of the Jaw

Osteonecrosis of the jaw (ONJ), which can occur spontaneously, is generally associated with tooth extraction and/or local infection with delayed healing, and has been reported in patients taking bisphosphonates, including alendronate sodium. Known risk factors for osteonecrosis of the jaw include invasive dental procedures (e.g., tooth extraction, dental implants, boney surgery), diagnosis of cancer, concomitant therapies (e.g., chemotherapy, corticosteroids, angiogenesis inhibitors), poor oral hygiene, and co-morbid disorders (e.g., periodontal and/or other pre-existing dental disease, anemia, coagulopathy, infection, ill-fitting dentures). The risk of ONJ may increase with duration of exposure to bisphosphonates. For patients requiring invasive dental procedures, discontinuation of bisphosphonate treatment may reduce the risk for ONJ. Clinical judgment of the treating physician and/or oral surgeon should guide the management plan of each patient based on individual benefit/risk assessment.

Patients who develop osteonecrosis of the jaw while on bisphosphonate therapy should receive care by an oral surgeon. In these patients, extensive dental surgery to treat ONJ may exacerbate the condition. Discontinuation of bisphosphonate therapy should be considered based on individual benefit/risk assessment.Patients who develop osteonecrosis of the jaw while on bisphosphonate therapy should receive care by an oral surgeon. In these patients, extensive dental surgery to treat ONJ may exacerbate the condition. Discontinuation of bisphosphonate therapy should be considered based on individual benefit/risk assessment.

5.5 Atypical Subtrochanteric and Diaphyseal Femoral Fractures

Atypical, low-energy, or low trauma fractures of the femoral shaft have been reported in bisphosphonate-treated patients. These fractures can occur anywhere in the femoral shaft from just below the lesser trochanter to above the supracondylar flare and are transverse or short oblique in orientation without evidence of comminution. Causality has not been established as these fractures also occur in osteoporotic patients who have not been treated with bisphosphonates.

Atypical femur fractures most commonly occur with minimal or no trauma to the affected area. They may be bilateral and many patients report prodromal pain in the affected area, usually presenting as dull, aching thigh pain, weeks to months before a complete fracture occurs. A number of reports note that patients were also receiving treatment with glucocorticoids (e.g. prednisone) at the time of fracture.

Any patient with a history of bisphosphonate exposure who presents with thigh or groin pain should be suspected of having an atypical fracture and should be evaluated to rule out an incomplete femur fracture. Patients presenting with an atypical fracture should also be assessed for symptoms and signs of fracture in the contralateral limb. Interruption of bisphosphonate therapy should be considered, pending a risk/benefit assessment, on an individual basis.

5.6 Renal Impairment

Alendronate sodium is not recommended for patients with creatinine clearance less than 35 mL/min.

5.7 Glucocorticoid-Induced Osteoporosis

The risk versus benefit of alendronate sodium for treatment at daily dosages of glucocorticoids less than 7.5 mg of prednisone or equivalent has not been established [see Indications and Usage (1.4)] . Before initiating treatment, the gonadal hormonal status of both men and women should be ascertained and appropriate replacement considered.

A bone mineral density measurement should be made at the initiation of therapy and repeated after 6 to 12 months of combined alendronate sodium and glucocorticoid treatment.

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.

6.2 Post-Marketing Experience

The following adverse reactions have been identified during post-approval use of alendronate. 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.

Body as a Whole: hypersensitivity reactions including urticaria and angioedema. Transient symptoms of myalgia, malaise, asthenia and fever have been reported with alendronate, typically in association with initiation of treatment. Symptomatic hypocalcemia has occurred, generally in association with predisposing conditions. Peripheral edema.

Gastrointestinal: esophagitis, esophageal erosions, esophageal ulcers, esophageal stricture or perforation, and oropharyngeal ulceration. Gastric or duodenal ulcers, some severe and with complications, have also been reported [see Dosage and Administration (2.6); Warnings and Precautions (5.1)].

Localized osteonecrosis of the jaw, generally associated with tooth extraction and/or local infection with delayed healing, has been reported [see Warnings and Precautions (5.4)].

Musculoskeletal: bone, joint, and/or muscle pain, occasionally severe, and incapacitating [see Warnings and Precautions (5.3)]; joint swelling; low-energy femoral shaft and subtrochanteric fractures [see Warnings and Precautions (5.5)].

Nervous System: dizziness and vertigo.

Pulmonary: acute asthma exacerbations.

Skin: rash (occasionally with photosensitivity), pruritus, alopecia, severe skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis.

Special Senses: uveitis, scleritis or episcleritis. Cholesteatoma of the external auditory canal (focal osteonecrosis)

7.1 Calcium Supplements/Antacids

Co-administration of alendronate sodium and calcium, antacids, or oral medications containing multivalent cations will interfere with absorption of alendronate sodium. Therefore, instruct patients to wait at least one-half hour after taking alendronate sodium 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 greater than 10 mg and aspirin-containing products.

7.3 Nonsteroidal Anti-Inflammatory Drugs

Alendronate sodium may be administered to patients taking nonsteroidal anti-inflammatory drugs (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 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 alendronate sodium.

8.1 Pregnancy

8.2 Lactation

Risk Summary

It is not known whether alendronate is present in human breast milk, affects human milk production, or has effects on the breastfed infant. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for alendronate sodium and any potential adverse effects on the breastfed child from alendronate sodium or from the underlying maternal condition.

8.4 Pediatric Use

Alendronate is not indicated for use in pediatric patients.

The safety and efficacy of alendronate sodium were examined in a randomized, double-blind, placebo-controlled two-year study of 139 pediatric patients, aged 4-18 years, with severe osteogenesis imperfecta (OI). One-hundred-and-nine patients were randomized to 5 mg alendronate daily (weight less than 40 kg) or 10 mg alendronate daily (weight greater than or equal to 40 kg) and 30 patients to placebo. The mean baseline lumbar spine BMD Z-score of the patients was -4.5. The mean change in lumbar spine BMD Z-score from baseline to Month 24 was 1.3 in the alendronate sodium-treated patients and 0.1 in the placebo-treated patients. Treatment with alendronate sodium did not reduce the risk of fracture. Sixteen percent of the alendronate sodium patients who sustained a radiologically-confirmed fracture by Month 12 of the study had delayed fracture healing (callus remodeling) or fracture non-union when assessed radiographically at Month 24 compared with 9% of the placebo-treated patients. In alendronate sodium-treated patients, bone histomorphometry data obtained at Month 24 demonstrated decreased bone turnover and delayed mineralization time; however, there were no mineralization defects. There were no statistically significant differences between the alendronate sodium and placebo groups in reduction of bone pain. The oral bioavailability in children was similar to that observed in adults.

The overall safety profile of alendronate sodium in osteogenesis imperfecta patients treated for up to 24 months was generally similar to that of adults with osteoporosis treated with alendronate sodium. However, there was an increased occurrence of vomiting in osteogenesis imperfecta patients treated with alendronate sodium compared to placebo. During the 24-month treatment period, vomiting was observed in 32 of 109 (29.4%) patients treated with alendronate sodium and 3 of 30 (10%) patients treated with placebo.

In a pharmacokinetic study, 6 of 24 pediatric osteogenesis imperfecta patients who received a single oral dose of alendronate sodium 35 or 70 mg developed fever, flu-like symptoms, and/or mild lymphocytopenia within 24 to 48 hours after administration. These events, lasting no more than 2 to 3 days and responding to acetaminophen, are consistent with an acute-phase response that has been reported in patients receiving bisphosphonates, including alendronate sodium. [See Adverse Reactions (6.2).]

8.5 Geriatric Use

Of the patients receiving alendronate sodium in the Fracture Intervention Trial (FIT), 71% (n=2302) were greater than or equal to 65 years of age and 17% (n=550) were greater than or equal to 75 years of age. Of the patients receiving alendronate sodium in the United States and Multinational osteoporosis treatment studies in women, osteoporosis studies in men, glucocorticoid-induced osteoporosis studies, and Paget's disease studies [see Clinical Studies (14.1), (14.3), (14.4), (14.5)] , 45%, 54%, 37%, and 70%, respectively, were 65 years of age or over. No overall differences in efficacy or safety were observed between these patients and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

8.6 Renal Impairment

Alendronate sodium is not recommended for patients with creatinine clearance less than 35 mL/min. No dosage adjustment is necessary in patients with creatinine clearance values between 35-60 mL/min [see Clinical Pharmacology (12.3)] .

8.7 Hepatic Impairment

As there is evidence that alendronate is not metabolized or excreted in the bile, no studies were conducted in patients with hepatic impairment. No dosage adjustment is necessary [see Clinical Pharmacology (12.3)].

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 [ 3H]alendronate in bone showed about 10-fold higher uptake on osteoclast surfaces than on osteoblast surfaces. Bones examined 6 and 49 days after [ 3H]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.

12.2 Pharmacodynamics

Alendronate is a bisphosphonate that binds to bone hydroxyapatite and specifically inhibits the activity of osteoclasts, the bone-resorbing cells. Alendronate reduces bone resorption with no direct effect on bone formation, although the latter process is ultimately reduced because bone resorption and formation are coupled during bone turnover.

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Harderian gland (a retro-orbital gland not present in humans) adenomas were increased in high-dose female mice (p=0.003) in a 92-week oral carcinogenicity study at doses of alendronate of 1, 3, and 10 mg/kg/day (males) or 1, 2, and 5 mg/kg/day (females). These doses are equivalent to approximately 0.1 to 1 times the highest recommended clinical daily dose of 40 mg based on surface area, mg/m 2. The relevance of this finding to humans is unknown.

Parafollicular cell (thyroid) adenomas were increased in high-dose male rats (p=0.003) in a 2-year oral carcinogenicity study at doses of 1 and 3.75 mg/kg body weight. These doses are equivalent to approximately 0.3 and 1 times the 40 mg clinical daily dose based on surface area, mg/m 2. The relevance of this finding to humans is unknown.

Alendronate was not genotoxic in the in vitro microbial mutagenesis assay with and without metabolic activation, in an in vitro mammalian cell mutagenesis assay, in an in vitro alkaline elution assay in rat hepatocytes, and in an in vivo chromosomal aberration assay in mice. In an in vitro chromosomal aberration assay in Chinese hamster ovary cells, however, alendronate gave equivocal results.

Alendronate had no effect on fertility (male or female) in rats at oral doses up to 5 mg/kg/day (approximately 1 times the 40 mg clinical daily dose based on surface area, mg/m 2).

13.2 Animal Toxicology and/or Pharmacology

The relative inhibitory activities on bone resorption and mineralization of alendronate and etidronate were compared in the Schenk assay, which is based on histological examination of the epiphyses of growing rats. In this assay, the lowest dose of alendronate that interfered with bone mineralization (leading to osteomalacia) was 6000-fold the antiresorptive dose. The corresponding ratio for etidronate was one to one. These data suggest that alendronate administered in therapeutic doses is highly unlikely to induce osteomalacia.

14.1 Treatment of Osteoporosis in Postmenopausal Women

Daily Dosing

The efficacy of alendronate 10 mg daily was assessed in four clinical trials. Study 1, a three-year, multicenter, double-blind, placebo-controlled, US clinical study enrolled 478 patients with a BMD T-score at or below minus 2.5 with or without a prior vertebral fracture; Study 2, a three-year, multicenter, double blind, placebo controlled Multinational clinical study enrolled 516 patients with a BMD T-score at or below minus 2.5 with or without a prior vertebral fracture; Study 3, the Three-Year Study of the Fracture Intervention Trial (FIT) a study which enrolled 2027 postmenopausal patients with at least one baseline vertebral fracture; and Study 4, the Four-Year Study of FIT: a study which enrolled 4432 postmenopausal patients with low bone mass but without a baseline vertebral fracture.

Effect on Fracture Incidence

To assess the effects of alendronate sodium on the incidence of vertebral fractures (detected by digitized radiography; approximately one third of these were clinically symptomatic), the U.S. and Multinational studies were combined in an analysis that compared placebo to the pooled dosage groups of alendronate (5 or 10 mg for three years or 20 mg for two years followed by 5 mg for one year). There was a statistically significant reduction in the proportion of patients treated with alendronate sodium experiencing one or more new vertebral fractures relative to those treated with placebo (3.2% vs. 6.2%; a 48% relative risk reduction). A reduction in the total number of new vertebral fractures (4.2 vs. 11.3 per 100 patients) was also observed. In the pooled analysis, patients who received alendronate sodium had a loss in stature that was statistically significantly less than was observed in those who received placebo (-3.0 mm vs. -4.6 mm).

The Fracture Intervention Trial (FIT) consisted of two studies in postmenopausal women: the Three-Year Study of patients who had at least one baseline radiographic vertebral fracture and the Four-Year Study of patients with low bone mass but without a baseline vertebral fracture. In both studies of FIT, 96% of randomized patients completed the studies (i.e., had a closeout visit at the scheduled end of the study); approximately 80% of patients were still taking study medication upon completion.

Fracture Intervention Trial: Three-Year Study (patients with at least one baseline radiographic vertebral fracture)

This randomized, double-blind, placebo-controlled, 2027-patient study (alendronate sodium, n=1022; placebo, n=1005) demonstrated that treatment with alendronate sodium resulted in statistically significant reductions in fracture incidence at three years as shown in Table 6.

Table 6: Effect of Alendronate Sodium on Fracture Incidence in the Three-Year Study of FIT (patients with vertebral fracture at baseline)

	Percent of Patients
	Alendronate Sodium (n=1022)	Placebo (n=1005)	Absolute Reduction in Fracture Incidence	Relative Reduction in Fracture Risk %
* Number evaluable for vertebral fractures: Alendronate sodium, n=984; placebo, n=966 † p<0.001, ‡ p=0.007, § p<0.01, ¶ p<0.05
Patients with:
Vertebral fracture (diagnosed by X-ray) *
≥1 new vertebral fracture	7.9	15.0	7.1	47 †
≥2 new vertebral fractures	0.5	4.9	4.4	90 †
Clinical (symptomatic) fractures
Any clinical (symptomatic) fracture	13.8	18.1	4.3	26 ‡
≥1 clinical (symptomatic) vertebral fracture	2.3	5.0	2.7	54 §
Hip fracture	1.1	2.2	1.1	51 ¶
Wrist (forearm) fracture	2.2	4.1	1.9	48 ¶

Furthermore, in this population of patients with baseline vertebral fracture, treatment with alendronate sodium significantly reduced the incidence of hospitalizations (25.0% vs. 30.7%).

In the Three-Year Study of FIT, fractures of the hip occurred in 22 (2.2%) of 1005 patients on placebo and 11 (1.1%) of 1022 patients on alendronate sodium, p=0.047. Figure 1 displays the cumulative incidence of hip fractures in this study.

Figure 1: Cumulative Incidence of Hip Fractures in the Three-Year Study of FIT (patients with radiographic vertebral fracture at baseline)

Fracture Intervention Trial: Four-Year Study (patients with low bone mass but without a baseline radiographic vertebral fracture)

This randomized, double-blind, placebo-controlled, 4432-patient study (alendronate sodium, n=2214; placebo, n=2218) further investigated the reduction in fracture incidence due to alendronate sodium. The intent of the study was to recruit women with osteoporosis, defined as a baseline femoral neck BMD at least two standard deviations below the mean for young adult women. However, due to subsequent revisions to the normative values for femoral neck BMD, 31% of patients were found not to meet this entry criterion and thus this study included both osteoporotic and non-osteoporotic women. The results are shown in Table 7 for the patients with osteoporosis.

Table 7: Effect of Alendronate Sodium on Fracture Incidence in Osteoporotic * Patients in the Four-Year Study of FIT (patients without vertebral fracture baseline)

	Percent of Patients
	Alendronate Sodium (n=1545)	Placebo (n=1521)	Absolute Reduction in Fracture Incidence	Relative Reduction in Fracture Risk %
* Baseline femoral neck BMD at least 2 SD below the mean for young adult women † Number evaluable for vertebral fractures: Alendronate sodium, n=1426; placebo, n=1428 ‡ p<0.001, § p=0.035, ¶ p=0.01, # Not significant. This study was not powered to detect differences at these sites.
Patients with:
Vertebral fracture (diagnosed by X-ray) †
≥1 new vertebral fracture	2.5	4.8	2.3	48 ‡
≥2 new vertebral fractures	0.1	0.6	0.5	78 §
Clinical (symptomatic) fractures
Any clinical (symptomatic) fractures	12.9	16.2	3.3	22 ¶
≥1 clinical (symptomatic) vertebral fracture	1.0	1.6	0.6	41 (NS) #
Hip fracture	1.0	1.4	0.4	29 (NS) #
Wrist (forearm) fracture	3.9	3.8	-0.1	NS #

Fracture Results Across Studies

In the Three-Year Study of FIT, alendronate sodium reduced the percentage of women experiencing at least one new radiographic vertebral fracture from 15.0% to 7.9% (47% relative risk reduction, p<0.001); in the Four-Year Study of FIT, the percentage was reduced from 3.8% to 2.1% (44% relative risk reduction, p=0.001); and in the combined U.S./Multinational studies, from 6.2% to 3.2% (48% relative risk reduction, p=0.034).

Alendronate sodium reduced the percentage of women experiencing multiple (two or more) new vertebral fractures from 4.2% to 0.6% (87% relative risk reduction, p<0.001) in the combined U.S./Multinational studies and from 4.9% to 0.5% (90% relative risk reduction, p<0.001) in the Three-Year Study of FIT. In the Four-Year Study of FIT, alendronate sodium reduced the percentage of osteoporotic women experiencing multiple vertebral fractures from 0.6% to 0.1% (78% relative risk reduction, p=0.035).

Thus, alendronate sodium reduced the incidence of radiographic vertebral fractures in osteoporotic women whether or not they had a previous radiographic vertebral fracture.

Effect on Bone Mineral Density

The bone mineral density efficacy of alendronate 10 mg once daily in postmenopausal women, 44 to 84 years of age, with osteoporosis (lumbar spine bone mineral density [BMD] of at least 2 standard deviations below the premenopausal mean) was demonstrated in four double-blind, placebo-controlled clinical studies of two or three years' duration. Figure 2 shows the mean increases in BMD of the lumbar spine, femoral neck, and trochanter in patients receiving alendronate 10 mg/day relative to placebo-treated patients at three years for each of these studies.

Figure 2: Osteoporosis Treatment Studies in Postmenopausal Women Increase in BMD Alendronate 10 mg/day at Three Years

At three years significant increases in BMD, relative both to baseline and placebo, were seen at each measurement site in each study in patients who received alendronate 10 mg/day. Total body BMD also increased significantly in each study, suggesting that the increases in bone mass of the spine and hip did not occur at the expense of other skeletal sites. Increases in BMD were evident as early as three months and continued throughout the three years of treatment. (See Figure 3 for lumbar spine results.) In the two-year extension of these studies, treatment of 147 patients with alendronate 10 mg/day resulted in continued increases in BMD at the lumbar spine and trochanter (absolute additional increases between years 3 and 5: lumbar spine, 0.94%; trochanter, 0.88%). BMD at the femoral neck, forearm and total body were maintained. Alendronate sodium was similarly effective regardless of age, race, baseline rate of bone turnover, and baseline BMD in the range studied (at least 2 standard deviations below the premenopausal mean).

Figure 3: Osteoporosis Treatment Studies in Postmenopausal Women Time Course of Effect of Alendronate 10 mg/day Versus Placebo: Lumbar Spine BMD Percent Change From Baseline

In patients with postmenopausal osteoporosis treated with alendronate 10 mg/day for one or two years, the effects of treatment withdrawal were assessed. Following discontinuation, there were no further increases in bone mass and the rates of bone loss were similar to those of the placebo groups.

Bone Histology

Bone histology in 270 postmenopausal patients with osteoporosis treated with alendronate sodium at doses ranging from 1 to 20 mg/day for one, two, or three years revealed normal mineralization and structure, as well as the expected decrease in bone turnover relative to placebo. These data, together with the normal bone histology and increased bone strength observed in rats and baboons exposed to long-term alendronate treatment, support the conclusion that bone formed during therapy with alendronate sodium is of normal quality.

Effect on Height

Alendronate sodium, over a three- or four-year period, was associated with statistically significant reductions in loss of height vs. placebo in patients with and without baseline radiographic vertebral fractures. At the end of the FIT studies the between-treatment group differences were 3.2 mm in the Three-Year Study and 1.3 mm in the Four-Year Study.

14.2 Prevention of Osteoporosis in Postmenopausal Women

Daily Dosing

Prevention of bone loss was demonstrated in two double-blind, placebo-controlled studies of postmenopausal women 40-60 years of age. One thousand six hundred nine patients (alendronate 5 mg/day; n=498) who were at least six months postmenopausal were entered into a two-year study without regard to their baseline BMD. In the other study, 447 patients (alendronate 5 mg/day; n=88), who were between six months and three years postmenopause, were treated for up to three years. In the placebo-treated patients BMD losses of approximately 1% per year were seen at the spine, hip (femoral neck and trochanter) and total body. In contrast, alendronate 5 mg/day prevented bone loss in the majority of patients and induced significant increases in mean bone mass at each of these sites (see Figure 4). In addition, alendronate 5 mg/day reduced the rate of bone loss at the forearm by approximately half relative to placebo. Alendronate 5 mg/day was similarly effective in this population regardless of age, time since menopause, race and baseline rate of bone turnover.

Figure 4: Osteoporosis Prevention Studies in Postmenopausal Women

Bone Histology

Bone histology was normal in the 28 patients biopsied at the end of three years who received alendronate at doses of up to 10 mg/day.

14.3 Treatment to Increase Bone Mass in Men with Osteoporosis

The efficacy of alendronate sodium in men with hypogonadal or idiopathic osteoporosis was demonstrated in two clinical studies.

14.4 Treatment of Glucocorticoid-Induced Osteoporosis

The efficacy of alendronate 5 and 10 mg once daily in men and women receiving glucocorticoids (at least 7.5 mg/day of prednisone or equivalent) was demonstrated in two, one-year, double-blind, randomized, placebo-controlled, multicenter studies of virtually identical design, one performed in the United States and the other in 15 different countries (Multinational [which also included alendronate 2.5 mg/day]). These studies enrolled 232 and 328 patients, respectively, between the ages of 17 and 83 with a variety of glucocorticoid-requiring diseases. Patients received supplemental calcium and vitamin D. Figure 5 shows the mean increases relative to placebo in BMD of the lumbar spine, femoral neck, and trochanter in patients receiving alendronate 5 mg/day for each study.

Figure 5: Studies in Glucocorticoid - Treated Patients Increase in BMD Alendronate 5 mg/day at One Year

After one year, significant increases relative to placebo in BMD were seen in the combined studies at each of these sites in patients who received alendronate 5 mg/day. In the placebo-treated patients, a significant decrease in BMD occurred at the femoral neck (-1.2%), and smaller decreases were seen at the lumbar spine and trochanter. Total body BMD was maintained with alendronate 5 mg/day. The increases in BMD with alendronate 10 mg/day were similar to those with alendronate 5 mg/day in all patients except for postmenopausal women not receiving estrogen therapy. In these women, the increases (relative to placebo) with alendronate 10 mg/day were greater than those with alendronate 5 mg/day at the lumbar spine (4.1% vs. 1.6%) and trochanter (2.8% vs. 1.7%), but not at other sites. Alendronate sodium was effective regardless of dose or duration of glucocorticoid use. In addition, alendronate sodium was similarly effective regardless of age (less than 65 vs. greater than or equal to 65 years), race (Caucasian vs. other races), gender, underlying disease, baseline BMD, baseline bone turnover, and use with a variety of common medications.

Bone histology was normal in the 49 patients biopsied at the end of one year who received alendronate at doses of up to 10 mg/day.

Of the original 560 patients in these studies, 208 patients who remained on at least 7.5 mg/day of prednisone or equivalent continued into a one-year double-blind extension. After two years of treatment, spine BMD increased by 3.7% and 5.0% relative to placebo with alendronate 5 and 10 mg/day, respectively. Significant increases in BMD (relative to placebo) were also observed at the femoral neck, trochanter, and total body.

After one year, 2.3% of patients treated with alendronate 5 or 10 mg/day (pooled) vs. 3.7% of those treated with placebo experienced a new vertebral fracture (not significant). However, in the population studied for two years, treatment with alendronate (pooled dosage groups: 5 or 10 mg for two years or 2.5 mg for one year followed by 10 mg for one year) significantly reduced the incidence of patients with a new vertebral fracture (alendronate sodium 0.7% vs. placebo 6.8%).

14.5 Treatment of Paget's Disease of Bone

The efficacy of alendronate 40 mg once daily for six months was demonstrated in two double-blind clinical studies of male and female patients with moderate to severe Paget's disease (alkaline phosphatase at least twice the upper limit of normal): a placebo-controlled, multinational study and a U.S. comparative study with etidronate disodium 400 mg/day. Figure 6 shows the mean percent changes from baseline in serum alkaline phosphatase for up to six months of randomized treatment.

Figure 6: Studies in Paget's Disease of Bone Effect on Serum Alkaline Phosphatase of Alendronate 40 mg/day Versus Placebo or Etidronate 400 mg/day

At six months the suppression in alkaline phosphatase in patients treated with alendronate sodium was significantly greater than that achieved with etidronate and contrasted with the complete lack of response in placebo-treated patients. Response (defined as either normalization of serum alkaline phosphatase or decrease from baseline greater than or equal to 60%) occurred in approximately 85% of patients treated with alendronate sodium in the combined studies vs. 30% in the etidronate group and 0% in the placebo group. Alendronate sodium was similarly effective regardless of age, gender, race, prior use of other bisphosphonates, or baseline alkaline phosphatase within the range studied (at least twice the upper limit of normal). Bone histology was evaluated in 33 patients with Paget's disease treated with alendronate 40 mg/day for 6 months. As in patients treated for osteoporosis [see Clinical Studies (14.1)], alendronate sodium did not impair mineralization, and the expected decrease in the rate of bone turnover was observed. Normal lamellar bone was produced during treatment with alendronate sodium, even where preexisting bone was woven and disorganized. Overall, bone histology data support the conclusion that bone formed during treatment with alendronate sodium is of normal quality.

How Supplied

Alendronate sodium tablets USP, 35 mg (alendronate), are modified oval, white to off-white tablets; one side debossed 'AP207', the other side blank.

NDC 60723-207-31 blister packs of 4 with child resistant package.



NDC 60723-207-32 unit-of-use packages of 12 with child resistant package.



NDC 60723-207-33 unit dose packages of 20. This package not intended for household use. For institutional use only.

Alendronate sodium tablets USP, 70 mg (alendronate), are modified oval, white to off-white tablets; one side debossed 'AP205', the other side blank.

NDC 60723-205-31 blister packs of 4 with child resistant package.



NDC 60723-205-32 unit-of-use packages of 12 with child resistant package.



NDC 60723-205-33 unit dose packages of 20. This package not intended for household use. For institutional use only.

Storage

Store in a well-closed container at 20° - 25°C (68° - 77°F); excursions permitted to 15° - 30°C (59° - 86°F) [see USP Controlled Room Temperature].

17.1 Osteoporosis Recommendations, Including Calcium and Vitamin D Supplementation

Instruct patients to take supplemental calcium and vitamin D, if daily dietary intake is inadequate. Weight-bearing exercise should be considered along with the modification of certain behavioral factors, such as cigarette smoking and/or excessive alcohol consumption, if these factors exist.

17.2 Dosing Instructions

Instruct patients that the expected benefits of alendronate sodium may only be obtained when it is taken with plain water the first thing upon arising for the day at least 30 minutes before the first food, beverage, or medication of the day. Even dosing with orange juice or coffee has been shown to markedly reduce the absorption of alendronate sodium [see Clinical Pharmacology (12.3)].

Instruct patients not to chew or suck on the tablet because of a potential for oropharyngeal ulceration.

Instruct patients to swallow each tablet of alendronate sodium with a full glass of water (6-8 ounces) to facilitate delivery to the stomach and thus reduce the potential for esophageal irritation.

Instruct patients not to lie down for at least 30 minutes and until after their first food of the day.

Instruct patients not to take alendronate sodium at bedtime or before arising for the day. Patients should be informed that failure to follow these instructions may increase their risk of esophageal problems.

Instruct patients that if they develop symptoms of esophageal disease (such as difficulty or pain upon swallowing, retrosternal pain or new or worsening heartburn) they should stop taking alendronate sodium and consult their physician.

If patients miss a dose of once weekly alendronate sodium tablet, instruct patients to take one dose on the morning after they remember. They should not take two doses on the same day but should return to taking one dose once a week, as originally scheduled on their chosen day.