1 Reason I'll Never Sell Vertex Pharmaceuticals Stock

Vertex Pharmaceuticals (NASDAQ: VRTX) has proven itself to be an excellent long-term investment, advancing 91% over the past five years. This is as the company has delivered steady growth in revenue thanks to a market-leading franchise.

Vertex is the global leader in cystic fibrosis (CF) drugs, and the company's products have both revolutionized the treatment of this disease and generated blockbuster revenue. This biotech player also has expanded its research into other disease areas and scored two wins in recent years, with approvals of Casgevy for blood disorders and Journavx for pain management.

So, even though Vertex stock may not soar every year, I'm optimistic about the stock's long-term prospects. Here's one reason I'll never sell this biotech giant.

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Vertex's expansion

Before I talk about that, though, it's important to note that Vertex's move to expand into a broad range of treatment areas was a wise one. This offers the company additional revenue streams and the potential to become a leader in these and possibly other markets over time. Vertex's growing portfolio also could make the company more attractive to investors who aim to get in on a big biotech player.

But the one reason I'll never sell Vertex is due to its dominance in the CF market, ensured by patents that the company has said should prolong its leadership until the late 2030s. Vertex has developed a portfolio of therapies known as CFTR modulators, which are meant to fix a faulty protein produced by the CFTR gene. These have been life-changing treatments for CF patients, and importantly, Vertex's offerings can treat almost 95% of CF patients.

Vertex's progress in CF

Why can't Vertex treat 100% of patients? CF involves various mutations, and each CFTR modulator can treat cases stemming from specific ones. Reaching coverage of almost 95% of patients is huge, and Vertex is working on a candidate in a phase 1/2 trial that would address patients who can't be helped by CFTR modulators. Meanwhile, the biotech company's current CFTR modulators continue to gain patients through new approvals and reimbursement agreements.

Vertex's CF portfolio drove an 11% increase in revenue to more than $3 billion in the latest quarter, and the company expects full-year revenue in the range of $11.9 billion to $12 billion. And considering Vertex's secure leadership in CF and its innovation, this business could continue powering revenue growth well into the future.

So, I think it's fantastic that Vertex has expanded into other therapeutic areas -- and it was a necessary growth move for the company. But the one reason I won't sell Vertex is for its dominance in CF, as this should be a multibillion-dollar revenue driver shareholders can count on over the long term.

Adria Cimino has positions in Vertex Pharmaceuticals. The Motley Fool has positions in and recommends Vertex Pharmaceuticals. The Motley Fool has a disclosure policy.