Genzyme is touting new data from a 253-patient study that shows clear benefits from a single dose of its Synvisc osteoarthritis drug compared to a placebo. Synvisc is currently approved to be given in three doses over three weeks. The new data supports Genzyme's contention that a single dose can improve symptoms. Genzyme is disputing a decision by CMS to reimburse Synvisc at an equal rate with all viscosupplementation therapies. Report