AbbVie Inc (NYSE:ABBV) just announced that it has picked up approval for  one of its lead development candidates, but the company has failed to really move on the announcement. For a company of AbbVie’s size, that’s not really too much of a surprise. Whereas a drug approval might induce high double-digit or triple digit gains in a company worth a couple of hundred million dollars, for one worth $100 billion, a single approval isn’t going to make that much difference.

With that said, however, it’s still good news, and – if the drug lives up to its potential –  there is a potential billion-dollar-plus market on offer.

For us, and even for a company of the size of AbbVie, that is a substantial number, and as such – we think there is an opportunity to pick up an exposure to this relatively low risk healthcare asset ahead of the drug in question’s commercialization execution.

Here is what you need to know.

The drug is called Imbruvica, and the FDA just approved it as a therapy to treat a rare form of non-Hodgkin lymphoma called relapsed/refractory (R/R) marginal zone lymphoma (MZL).  Around 72,000 people will be diagnosed with non-Hodgkin lymphoma this year in the US alone, and a little over 12% of these will develop MZL. There is currently no treatment available (outside of some standard of care NHL treatments, but these aren’t particularly effective) and the prognosis is not great regardless of the stage at which the condition is discovered. That means, in the US, there are just shy of 9000 individuals that will develop MZL this year.

The drug in question, Imbruvica, is already approved across a spate of other oncology indications revolving around NHL, and even without the latest approval, analysts expect revenues derived from its sales to reach $5 billion by 2020. During the third quarter of 2016, the company generated $501 million from the drug.

So what is the impact of this latest approval?

Well, the cost right now is a little over $130,000 annually. We aren’t going to get into a debate over the ethics of charging this much for an oncology drug here, especially in a rare indication, but it is worth noting that there is some potential for this cost to lower across the coming decade with political input. However, that is just speculation at his point, and we think that – for the next five years at least – drug prices will remain pretty stable, political input or not.

So, let’s do some math.

$130,000 annually spread across 9000 patients that will develop MZL in the US, and that will have no alternative treatment outside of current standard of care first-line, totals out at a market potential of just short of $1.2 billion annually. That’s a significant ramp-up in sales for any company, and even with AbbVie generating more than $22 billion annually during 2015, and looking set to beat this number by around $2-3 billion for 2016 total revenues, it is still a 5% growth in annual sales. Of course, we are assuming full market saturation when we use numbers, and it’s highly unlikely that the company will achieve this level of saturation (even though it is a rare disease and there are no current effective options) but as illustrative of impact, the numbers are valid.

Beyond the US, of course, there is also the potential for expansion into this market in Europe, Asia and Africa. The European market is of a relatively similar size to that of the US, representing another $1 billion plus in potential revenues based on this latest approval. Asian markets are slightly smaller for NHL, but still significant. All told, there are around $3 billion worth of potential revenues to be had just on this indication if the company can expand on the FDA approval and pick up similar approvals from the relevant authorities in the above-mentioned regions.

At time of writing, midmorning US session, the company has picked up a bit of strength, likely on the approval notice, but nothing significant, and we think there is still an opportunity to get to discount as highlighted in the introduction to this piece.