Biotechnology stocks have been among the market's top performers this year, with the iShares Nasdaq Biotechnology ETF's 36% gain handily outpacing the S&P 500's 14% return. That heady return, however, comes with one potential drawback: It might be tough to figure out which biotech stocks will continue climbing next year. With that in mind, here are three large-cap biotech stocks that I believe could be top performers again in 2015.

Source: Amgen

1. Good things coming
Amgen 
(AMGN -0.19%) is one of biotech's biggest companies, and it's also the only large biotech to offer investors a dividend. But those are not the only reasons investors might want to own shares next year.

Amgen's stable of top-selling medicines drove sales up by 6% to $5 billion in the third quarter, year over year, while earnings per share grew 9% to $2.30. And that product lineup is about to get bigger.

The company might have as many as four new product launches next year, including evolocumab, a bad cholesterol-beating drug that could become a big seller. Statins have been the dominant medicine for curbing cholesterol over the past 20 years, and many of those statins have become multibillion-dollar blockbusters. For instance, Pfizer's Lipitor raked in $13 billion in sales per year at its peak.

If evolocumab gets Food and Drug Administration approval, it will join Amgen's Blincyto (formerly known as blinatumomab), which on Dec. 3 received early approval as a treatment for relapsing acute lymphocytic leukemia. In February, Amgen will also find out whether ivabradine, its treatment for chronic heart failure that is already being sold abroad, wins FDA approval. Additionally, Amgen also expects a regulatory decision from both the FDA and the European Union for its melanoma drug T-Vec in 2015.

If that isn't enticing enough, Amgen might also soon file for FDA approval of brodalumab, a treatment for psoriasis. Amgen just reported phase 3 data in which brodalumab performed better than Johnson & Johnson's $2 billion-a-year Stelara.

It won't be all clear sailing for Amgen. The company will have to overcome the risk of patent expiration on its top-selling Neulasta in October 2015. But since Neulasta is a tough-to-copy biologic, it's not clear just how much market share it will lose if a generic biosimilar is approved. So far, biosimilars in other markets have captured between 30% and 40% of sales.

Regardless, since Amgen has already told investors its plans include a 30% increase in its dividend payout, beginning in 2015, and committed to buying back $2 billion in stock by the end of next year, it could be worth giving the company the benefit of the doubt.

2. Building a franchise
Celgene
's (CELG) Revlimid is the top-selling treatment for relapsing multiple myeloma, and the drug is on pace to deliver more than $5 billion in sales next year.

Revlimid's success is providing plenty of cash flow that the company has used to acquire new products, such as Abraxane, develop new drugs, including Pomalyst, and partner with emerging biotechnology companies, including Agios and Acceleron.

Those moves should reward investors with revenue and profit growth in 2015. Sales of Abraxane grew 25% year over year in the third quarter, to $212 million, and sales of Pomalyst, a third-line treatment for multiple myeloma launched in 2013, rose 102% to $181 million.

But those drugs aren't the only reason Celgene shares could head higher in 2015. The company should also next year begin reporting meaningful sales for its latest drug, Otezla. Celgene thinks Otezla, which is approved for psoriasis and psoriatic arthritis, has billion-dollar blockbuster potential. Additionally, Revlimid sales could also get a boost if the FDA approves its use as a front-line therapy. A decision is expected in February.

Source: Gilead Sciences.

3. Establishing a beachhead
Shares in Gilead Sciences (GILD 0.07%) have recently given back some of their 2014 gains, but investors should not dismiss the potential for upside again in 2015.

Gilead Sciences' success this year stems from its hepatitis C drugs Sovaldi and Harvoni. Sovaldi won FDA approval last December and produced more than $8 billion in sales during the first nine months of this year. Harvoni, which received FDA approval in October, is expected to post similar results in 2015.

Although AbbVie could get the FDA green light for its own hepatitis C therapy this month, Gilead Sciences is likely to remain the market leader. That's because the once-daily Harvoni has an easier dosing schedule than the three-pill AbbVie cocktail, and because Harvoni posted arguably better results during clinical trials, without the help of side effect-laden ribavirin.

AbbVie could win some market share, especially if it undercuts Gilead Sciences on pricing, but Harvoni will still be one of the planet's best-selling drugs next year given that there are more than 150 million people with chronic hepatitis C worldwide, and Gilead Sciences has treated just 117,000 of them in 2014.

There are other reasons to be optimistic about Gilead's outlook in 2015. The company has a robust HIV drug franchise that includes five separate products that could each post sales of more than $1 billion this coming year. Gilead Sciences also has cardiovascular and respiratory drugs that produce $1 billion in annualized sales, and the company launched its first oncology drug this past summer. Couple those opportunities with a rock-solid balance sheet flush with cash and you get a compelling argument for shares to head higher in 2015.

And another thing
None of these stocks are immune to the market's inevitable fits and starts, and no one can say with any certainty that a stock will surely rise, or fall, in any specific time period. But each of these companies is a market leader in its field, with a solid balance sheet and catalysts that could support rising share prices. That suggests each could be worthy of consideration for investors willing to take some risk and own biotechnology stocks next year.