Being the last line of defense isn't usually a way to make big bucks. Drugmakers have to wait for patients to trickle through other medications and many patients will be sopped up by the other drugs. It's better used as a way to get your foot in the door, as Novartis
But Symbyax isn't your typical second-line treatment. Depression is a gloomy disease with up to 35% of patients failing to respond to two different treatments. That'll leave quite a few patients/customers still seeking treatment after trying drugs like Pfizer's Zoloft, GlaxoSmithKline's
More importantly, Prozac is approved as a front-line treatment for depression, so the combination drug makes for an easy transition for doctors and their patients. Adding Zyprexa to a patient who is already taking Prozac may be an easier solution than changing medications all together.
Second-line treatments often aren't all they're cracked up to be, but for Eli Lilly, the research-and-development costs to expand Symbyax's label should be well worth the investment.