Vertex Pharmaceuticals (VRTX -0.49%) has a lot going on these days. The biotech company is developing two candidates that could make it even stronger in the billion-dollar cystic fibrosis (CF) treatment market. And Vertex is one step away from entering a new and potentially big market: It's submitting its gene-editing candidate for blood disorders to regulators this month.

Investors clearly are excited about this biotech giant's story. The stock has climbed 38% this year -- and is trading at its highest ever. Sure, the future looks bright. But should we really buy Vertex stock at the high? Let's take a closer look and find out.

Leadership through the 2030s

We'll start with CF. Vertex already is a leader in the market. In fact, the company expects to hold its position until at least the late 2030s. Today, Vertex sells four CF drugs. But the latest, Trikafta, is the biggest moneymaker. It generated $5.6 billion in revenue last year, helping Vertex reach $2.3 billion in profit.

Is there a potential treatment that could unseat Trikafta? Possibly. And here's the good news. It's being developed by... guess who? Vertex. The company is studying its candidate compared to Trikafta in phase 3 trials. Vertex expects to complete trial enrollment by the end of this year.

Trikafta has the ability to help 90% of individuals with CF. What about the other 10%? This is where Vertex's other CF candidate comes in. The candidate, being developed with Moderna, involves programming lung cells to produce a specific protein. The companies plan on applying for authorization to launch clinical trials by the end of the year.

So, Vertex clearly has what it takes to hold onto leadership in the CF market. And now it looks like Vertex is close to expanding into another major treatment area. Vertex and partner CRISPR Therapeutics are submitting their candidate exa-cel to regulatory authorities in the U.S., Europe, and the U.K. this month.

A curative treatment

Exa-cel is an investigational one-time curative treatment for beta thalassemia and sickle cell disease in adults. Today, treatment options for these blood disorders are limited. The idea of a potential cure could be big news. And may result in blockbuster revenue. Vertex takes responsibility for 60% of the costs of the program worldwide -- and would eventually keep 60% of profits. 

Regulatory submissions should be complete by the end of the year in Europe and the U.K. -- and during the first quarter in the U.S. If all goes well during regulatory review, exa-cel could soon become another revenue driver for Vertex. The company's phase 3 trials of exa-cel in kids are ongoing -- and represent additional opportunity.

It's also important to note that Vertex is working on candidates in two areas with much need: pain management and type 1 diabetes (T1D).

Today, treatments for pain are limited to over-the-counter classics like aspirin, acetaminophen, and ibuprofen -- or opioids that have been linked to addiction. Vertex aims to offer an alternative. The company's pain candidate recently began a pivotal trial for moderate-to-severe acute pain.

As for T1D, it's a fast-growing market. The global treatment market, at a compound annual growth rate of more than 17%, is forecast to reach $24 billion by 2029, according to GlobalData. Vertex's T1D candidate is involved in a phase 1/2 trial.

If all goes well in clinical trials, these potential products could contribute to revenue in a major way by the end of the decade.

A look at valuation

Now let's check out valuation. Today, Vertex is trading at 20 times forward earnings estimates. That's more than about 14 last year. But this remains a very reasonable level. It's still lower than the average of 24 for pharmaceutical companies, according to New York University's Stern Business School.

So, should you buy Vertex at the high? Yes. Vertex has a track record of earnings growth. Potential new CF products could keep this going. And exa-cel could open the door to a whole new era of revenue growth through products beyond the CF business.

All of that means there are many exciting chapters ahead. And today's high could lead to even higher highs down the road.