We’re usually not big on one-drug biotech firms, as any hint of competition or a raised eyebrow from regulators can cause the stock to tumble — but Intra-Cellular Therapies (ITCI) could be the exception, suggests Mike Cintolo, editor of Cabot Top Ten Trader.

Its drug — Caplyta — is looking like a huge blockbuster that will drive sales through the roof in the years ahead (and, who knows, possibly attract a suitor). To recap, Caplyta was approved for schizophrenia a couple of years ago, and the potential there is solid (2.4 million people have the disease) and sales grew nicely because of that.

But it was the drug’s broad approval for Bipolar (approved for both I and II either with some other drugs or by itself) that is the real attraction — in fact, Caplyta is the only drug approved for Bipolar II in conjunction with other drugs.

In addition, its only competition as a monotherapy for Bipolar II is something originally launched back in 1997 that has drawbacks (Caplyta is one dose per day, doesn’t have to be taken with food, doesn’t have any weight gain effects and patients don’t need to gradually ramp up usage).

There are some other potential indications down the road (Phase III testing is ongoing for Major Depressive Disorder, which is a giant market), but the Bipolar potential is what’s driving things today: Caplyta has all the makings of a blockbuster.

The company sees revenues leaping from $26 million in Q4 to $35 million in Q1 (new prescriptions jumped north of 60% during that time) and analysts see the top line totaling $223 million this year and $438 million next, both of which are probably going to be conservative. We like it.

Technically, ITCI is one of the few stocks out there that’s set up in a legitimate launching pad and could get going if the market can get out of its own way. The stock actually pushed higher earlier this year before finally giving way to the market’s downturn in April and early May.

Impressively, however, shares bounced back strongly after earnings and have traded rather tightly for a few weeks. If you want in, we’re OK with a nibble here, or just keep it on your watch list and look for an eventual breakout.

Subscribe to Cabot Top Ten Trader here…