While Fosamax is the undisputed leading product in the osteoporosis market, many challengers in all of the major product classes are set to attempt to unseat Merck from atop the market.  Companies such as Pfizer, Wyeth, Roche, GSK, Novartis, NPS Pharmaceuticals, and Servier are set to enter the market with new products and battle for revenues.  Will these drugs drive the osteoporosis market to new heights?
Osteoporosis is a generalized, progressive disease characterized by low bone mass and structural deterioration of bone tissue, which leads to bone fragility or skeletal weakness and an increased susceptibility to fractures and chronic bone pain.

  According to the National Osteoporosis Foundation, an estimated 10 million Americans suffer from osteoporosis and almost 34 million have low bone mass, placing them at increased risk for developing osteoporosis.  Incidence of osteoporosis increases with age, and is most common in postmenopausal women.  Women account for 80 percent of all cases.

The osteoporosis market in the United States is currently experiencing tremendous growth mainly due to the success of Fosamax from Merck.  Fosamax is the gold standard in osteoporosis treatment due to its excellent efficacy in slowing bone loss and reducing fractures.  Four key product classes dominate treatment regimens: bisphosphonates, selective estrogen receptor modulators (SERMs), calcitonins and anabolic agents such as parathyroid hormones (PTHs).
Despite the fact that the osteoporosis market is in its growth phase, a major factor keeping the market depressed to some extent is that currently available therapeutics are not totally satisfying patients.  Antiresorptives are most effective if you catch the disease early enough before there is significant bone loss, but once patients reach a severe stage these products are often ineffective.  The bulging pipeline for osteoporosis confirms the high unmet medical need still existing among patients.
Even though bisphosphonates dominate the market, they have several shortcomings that present opportunities for new market entrants.  Patient compliance is an issue with Fosamax and Actonel due to gastrointestinal side effects.  Also, their long-term effect on bone structure is unknown and raises safety concerns.  Most importantly, like every other product on the market, they only slow the rate of bone loss and do not build bone.  There are several products over the next three years set to be introduced that could capitalize on these defects and dramatically inflate market revenues.  Boniva and Zometa hope to offer patients bisphosphonate products that improve patient compliance due to their intermittent dosing intervals, yet maintain efficacy similar to Fosamax and Actonel.
Lasofoxifene and basedoxifene are SERMs that could treat women with breast cancer who enter early menopause due to chemotherapy and are highly susceptible to premature bone loss.  Some women have been shown to lose up to 8 percent of their spine bone mass in just one year, following the onset of early menopause.  A number of studies are being conducted to evaluate the therapeutic benefit of SERMs in halting bone loss caused by chemotherapy-induced menopause.  The market potential for osteoporosis drugs as an adjuvant to chemotherapy is substantial, considering that around 200,000 new cases of breast cancer are diagnosed each year.
Parathyroid hormones offer the most promise in terms of expanding the market since they work by stimulating the bone replacement function in the remodeling process.  This is crucial for severe osteoporotic patients who have already lost significant bone mass and suffered a fracture.  What is needed for these patients is a drug that replaces the lost bone and restores the patient to a healthy condition. Bisphosphonates, while very effective in the prevention of osteoporosis, do not serve this patient base well.  The treatment of these seriously osteoporotic patients, usually those people over 65, is the market segment products such as Forteo, Preos, and Protos can target.  It is projected that this will be the fastest growing market segment as more baby boomers reach that age group and life expectancy increases.
As more companies enter the market, they should drive revenue growth just because there is more noise surrounding the market as new products become available and clinical trials are being conducted, bringing heightened visibility to the overall market.  The introduction of several new products in these classes with expanded indications and improved dosing regimens ensures that this market will continue to expand for years to come as general awareness surrounding osteoporosis grows and physicians better comprehend the seriousness of this disease.