Doctors choose the more expensive drug more than half a million times every year, a choice that costs the Medicare program, the largest single customer, an extra $1 billion or more annually.
Spending that much may make little sense for a country burdened by ever-rising health bills, but as is often the case in American health care, there is a certain economic logic: Doctors and drugmakers profit when more-costly treatments are adopted.
Genentech, a division of the Roche Group, makes both products but reaps far more profit when it sells the more expensive drug. Although Lucentis is about 40 times as expensive as Avastin to buy, the cost of producing the two drugs is similar, according to scientists familiar with the drugs and the industry.