When it comes to AbbVie (ABBV 0.01%), investors have been worrying about one thing: an eventual drop in sales of its blockbuster Humira. The immunosuppressive drug is used for various diseases, including rheumatoid arthritis.

Last year, Humira generated more than $20 billion in sales. But as of next year, competition may start eating away at Humira's market share.

That may look like terrible news, but there's a big silver lining around this dark cloud. And the following two charts offer us the details.

An investor smiles while looking at something on a laptop.

Image source: Getty Images.

20 key products

First, it's important to note that Humira is a major drug for AbbVie. But AbbVie isn't a one-product-only company. In fact, it sells about 20 key products in various treatment areas, from immunology to neuroscience and aesthetics. And it expects its immunology drugs Rinvoq and Skyrizi to together surpass Humira's peak sales.

Let's look at our first chart. It shows a forecast for the top 10 pharmaceutical products by sales in 2026, and two AbbVie products make the list. Rinvoq is No. 10, with expectations for nearly $8.9 billion in annual sales at that time. Last year, Rinvoq brought in $1.6 billion. Clearly, there's a lot of growth ahead for this drug.

This chart shows forecasts for the top pharmaceutical products by sales.

Image source: Statista.

The second AbbVie drug on this list comes in higher up. It's Imbruvica, an oncology drug that's part of a partnership with Johnson & Johnson. This product is No. 6 on this list with a forecast for annual revenue of more than $10 billion. This chart shows AbbVie as the seller of two of the world's biggest drugs.

Prescription-drug market share

Let's move along to our second chart. This one shows the top pharmaceutical companies worldwide by prescription-drug market share in 2019 -- and forecasts for 2026. In 2019, AbbVie was No. 7 on the list, but by 2026, the company is forecast to take the top spot.

AbbVie is expected to hold 4.2% of the market by then. That's while today's giants such as Roche and Novartis see their share shrink.

This chart shows the top pharmaceutical companies by prescription drug market share.

Image source: Statista.

These two charts add to the evidence that AbbVie's growth story is far from over. In fact, the company is set to become an even bigger presence in the industry than before. I mentioned earlier AbbVie's goals for Rinvoq and Skyrizi. How will the company make these drugs together stronger than Humira?

AbbVie is adding new indications. And soon, these two drugs will be sold "across all of Humira's major indications plus atopic dermatitis," AbbVie says.

All of this means that -- even with Humira rivals on the horizon -- AbbVie's revenue looks unstoppable.