Patent Challenge Muddles Merck Picture

Merck (MRK Quote) can't catch a break. Saddled with an anemic drug pipeline and having botched its Medco spinoff, the well-known pharma must also deal with the unclear patent status of one of its flagship products, Fosamax.

Fosamax, also known as alendronate sodium, was approved by the FDA in 1995 in daily dosages to treat bone thinning in osteoporosis patients. The drug has been a huge success, generating just over $2 billion in annual sales. ...