Past performance isn't a guarantee of future success, and that's as true in life as it is in the stock market. But past performance isn't meaningless either; investing in a company capable of replicating a winning strategy is a pretty good bet. With that in mind, let's look at pharma giant AbbVie (ABBV 0.90%).

Unlike most of its peers in the pharmaceutical industry, this drugmaker has outperformed the broader market in the past nine years. The bears will point to declining sales of AbbVie's rheumatoid arthritis drug Humira in Europe as evidence that its growth days are well behind it.

Yet there is much more to the story than that. Let's consider whether it's still worth purchasing AbbVie's shares today.

ABBV Chart

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Results remain strong 

On the financial front, AbbVie's business seems pretty healthy. In the third quarter, the company generated $14.3 billion in revenue -- 11.2% higher than the year-ago period -- and most business segments saw strong sales increases.

The company's immunology business, which is home to Humira and other key growth drivers, posted total sales of $6.8 billion, 15.3% higher than a year ago. Meanwhile, sales within AbbVie's oncology segment rose 8.4% year over year to $1.9 billion. On the bottom line, AbbVie's earnings soared 38% to $1.78 per share.

AbbVie also continues to generate loads of cash. In the third quarter, free cash flow totaled $21.7 billion, a 282% increase from last year. AbbVie boasts a price-to-free cash flow ratio of 10.3, which is on the low end of its historical range .

Doctor shaking patient's hand.

Image source: Getty Images.

AbbVie's growth days aren't over

Now, let's take a look at the business itself. One way pharmaceutical companies maintain their edge is through patents that protect their drugs from competition and grant them some degree of pricing power. But once these patents expire, cheaper versions from other companies -- known as biosimilars -- are bound to eat up a medicine's market share.

That's what's going on with Humira, which lost patent exclusivity in Europe in 2018. As a result, the drug's international sales dropped by 14.6% to $812 million in the third quarter and its total sales only grew by 5.6% to $5.4 billion. Humira's patent protection in the U.S. expires in 2023.

But AbbVie is replenishing its lineup. Products such as immunosuppressants Skyrizi and Rinvoq, cancer drug Venclexta, and skin treatment Botox (added to the lineup through AbbVie's $63 billion acquisition of Allergan) are all performing well. For example, Botox saw sales of $645 million in the third quarter, 23% higher than the year-ago period. And sales of Rinvoq more than doubled to $453 million.

It is worth noting that Rinvoq has been under regulatory scrutiny recently. It belongs to a group of drugs known as JAK inhibitors. After studies revealed that these drugs carry risks of cardiovascular events and cancer, the U.S. Food and Drug Administration announced in September that JAK inhibitors would now come with a label warning patients of these risks.

Still, management remains confident that Rinvoq can continue to perform well and, along with Skyrizi, team up to replace Humira. As CEO Rick Gonzalez said in the company's third-quarter earnings conference call:

Skyrizi and Rinvoq have established very strong launch trajectories. These two assets are either approved, under regulatory review, or in late-stage development across all of Humira's major indications, and we remain confident that they will both be significant contributors to AbbVie's long-term growth.

So far, things are going according to plan on that front, and that's excellent news for AbbVie's future.

Multiple reasons to get in on the action

So do AbbVie shares make a good investment? Well, the company still boasts a solid lineup of drugs that can drive top- and bottom-line growth, cash generation, and eventually fill in the gaping hole that Humira will leave once it starts facing biosimilar competition in the U.S. in 2023.

The drugmaker is also an excellent option for dividend-seeking investors, offering a yield of 4.14% -- far higher than the S&P 500's yield of 1.30%. AbbVie is also a Dividend Aristocrat, having raised its dividends 49 years in a row, and it will likely join the exclusive rank of Dividend Kings next year.

Finally, the shares are attractively priced, trading at a forward price-to-earnings ratio of 9.9 vs. a pharma industry average of 13.5. In a market where rich valuation metrics tend to be the norm, investors shouldn't ignore a company like AbbVie that trades at reasonable levels. 

In short, no, it isn't too late to get in on this excellent pharma stock