This study will identify an appropriate dose of MK5442 that will produce an osteoanabolic (bone-building) effect without causing high blood calcium levels.

• Drug: MK5442
  MK5442 2.5 mg, 5 mg, 7.5 mg, 10 mg, or 15 mg tablet once daily for 24 months. There will be a 2-week period during which all patients will receive placebo.
• Drug: Comparator: Placebo
  Matching placebo to MK5442 once daily for 24 months.
• Dietary Supplement: Comparator: Vitamin D3
  Vitamin D3, two 400 IU tablets daily throughout the study.
• Dietary Supplement: Comparator: calcium carbonate
  Patients who have a calcium intake less than 1200 mg/day will receive a daily 500 mg calcium supplement throughout the study. A Dietary Calcium Questionnaire will be repeated at Month 12 if the patient indicates at that time that her diet has changed significantly over the past year with respect to milk products.

• 1: Experimental
  MK5442 2.5 mg
  Interventions:

  • Drug: MK5442
  • Dietary Supplement: Comparator: Vitamin D3
  • Dietary Supplement: Comparator: calcium carbonate
• 2: Experimental
  MK5442 5 mg
  Interventions:

  • Drug: MK5442
  • Dietary Supplement: Comparator: Vitamin D3
  • Dietary Supplement: Comparator: calcium carbonate
• 3: Experimental
  MK5442 7.5 mg
  Interventions:

  • Drug: MK5442
  • Dietary Supplement: Comparator: Vitamin D3
  • Dietary Supplement: Comparator: calcium carbonate
• 4: Experimental
  MK5442 10 mg
  Interventions:

  • Drug: MK5442
  • Dietary Supplement: Comparator: Vitamin D3
  • Dietary Supplement: Comparator: calcium carbonate
• 5: Experimental
  MK5442 15 mg
  Interventions:

  • Drug: MK5442
  • Dietary Supplement: Comparator: Vitamin D3
  • Dietary Supplement: Comparator: calcium carbonate
• 6: Placebo Comparator
  Placebo
  Interventions:

  • Drug: Comparator: Placebo
  • Dietary Supplement: Comparator: Vitamin D3
  • Dietary Supplement: Comparator: calcium carbonate

Inclusion Criteria:

• Patient has been postmenopausal for at least 5 years
• Patient has no history of fragility fracture, unless she is unwilling to take or is not a candidate for marketed osteoporosis therapy
• Patient agrees not to use medications for osteoporosis except that provided by the study
• The patient has an areal BMD T-score <-2.5 at one or more of the following 4 BMD sites: total hip, femoral neck, trochanter, or lumbar spine and is >= -3.5 at all 4 BMD sites. Patients unwilling to take or ineligible for marketed osteoporosis therapy may have one or more areal BMD T-scores < -3.5

Exclusion Criteria:

• Patient has used oral bisphosphonates in the 6 months prior to screening, for more than 3 months in the past 2 years, or lifetime use for more than 6 months total
• Patient has used IV bisphosphonates, strontium, or growth hormone at any time
• Patient is currently using phenytoin, raloxifene, or heparin
• Patient is using pioglitazone or rosiglitazone at screening
• Patient has had prior neck surgery with a total thyroidectomy
• Patient is known to be HIV-positive
• Patient has had cancer within 5 years of screening, except for certain skin or cervical cancers
• Patient currently uses any illicit drug and/or has a history of alcohol abuse