Given that it's a household name and one of the largest businesses in the U.S., it makes sense that Amazon (AMZN -1.11%) is a high performer among growth stocks. Over the last ten years, buoyed by massive sales, its shares returned above 800%, handily beating the market's rise of nearly 200%.

But, over the last few years, the company's stock performance is becoming more in line with the market's, and that could be a sign that other growth stocks will be a better place to park your money. In particular, there's a pair of biomedical businesses that have a shot at beating Amazon's returns over the next three years, though the odds of doing so are much longer -- and the potential rewards much greater -- for the smaller one. Here's why.

Vertex Pharmaceuticals is building multiple new avenues for growth

Vertex Pharmaceuticals (VRTX -0.27%) is likely to outperform Amazon because it has quite a few catalysts and milestones in the works that'll drive its share prices higher, not to mention it's also profitably raking in cash from sales of its medicines that are already on the market. Over the last three years, its trailing-12-month (TTM) net income appreciated by 49%, reaching roughly $3.2 billion, whereas Amazon's earnings were basically flat, with a rise of around 2.3%. To accomplish that, Vertex profitably sold four of its medicines for cystic fibrosis (CF), a rare hereditary pulmonary disease for which the company has so far focused on cornering the market. 

Building on those successes in the market for CF therapies, the company is also constantly working to expand the indications of its previously approved drugs, not to mention developing new ones to treat CF and other conditions like acute pain. And it's diversifying into treating other diseases too. With the help of its collaborator, CRISPR Therapeutics, (CRSP -4.14%) it's hoping to commercialize its gene therapy called exa-cel for sickle cell disease and transfusion-dependent beta thalassemia quite soon. The pair will have their approval packet for regulators finalized by the first quarter of next year, and revenue could start to flow in by the end of 2023.

Between the rest of this year and early next year, Vertex will also be advancing two of its newer programs intended to treat acute pain into their pivotal-stage trials, which implies significant catalysts for the stock when those trials eventually report their results. While that might not be enough for it to outperform Amazon forever, the next few years look extremely promising for the company, and it's practically a slam dunk for continuing to grow its revenue and earnings faster than the internet retailer, just as it did in the last five years.

CRISPR Therapeutics might not have enough catalysts to top Amazon stock

As great as the future looks for Vertex, CRISPR Therapeutics is in a somewhat weaker position, which means it will have a much harder time beating Amazon consistently, even if its collaboration projects get approved for sale and end up making plenty of money. Whereas Vertex has a few products on the market and a few that are on deck, CRISPR doesn't have any way of making revenue outside of collaborations with larger pharmaceuticals and nonprofits.

That means any therapies it manages to commercialize in the near term will be subject to profit-splitting agreements, which will somewhat limit the growth investors can expect. In fact, if Vertex gets the green light from regulators with exa-cel in 2023, CRISPR will be on the hook for 40% of the commercialization costs as well as 40% of the profits, so the unit economics of administering exa-cel may be somewhat of an impediment too. And there aren't any other chances in the pipeline of generating revenue from any other drug launches for quite a while, either.

Of course, don't take that to mean CRISPR isn't working on interesting projects that could pay off big in the future. It's in preclinical testing with at least 10 gene-editing therapies seeking to cure certain hereditary conditions in people by correcting the maladaptive sequences in their genetic code -- something that modern medicine couldn't have dreamed of actually approaching even a decade ago.

But ingenuity alone doesn't drive shareholder returns. Though there's a high chance the biotech's stock will shoot up if exa-cel makes it to the market next year, there aren't many catalysts on the radar to sustain any outperformance. So, it's a much riskier purchase than shares of Vertex, and it's a toss-up whether it'll beat a proven tech-growth stock like Amazon, which only needs to keep executing on its core business model to make its shareholders richer.