U.S. drugmakers got a strong start to the year with help from the newest cancer medications, which take advantage of cutting-edge research and have the price tags to prove it.

Pfizer Inc., Merck & Co., and Bristol-Myers Squibb Co. all beat Wall Street's earnings projections in the first quarter, with sales of their new oncology drugs surpassing expectations. Analysts estimate each drugmaker will have a multibillion-dollar blockbuster cancer treatment by 2018. Cancer is one of the biggest targets for drugmakers right now, with scientific breakthroughs helping fuel a series of new drugs.

"Their pipelines are going to be a lot stronger than what people have thought," said Tony Scherrer, director of research at Smead Capital Management, which holds both Pfizer and Merck shares. "You're starting to see that come to light this quarter."

With prices for the treatments extending into the six figures for a year of treatment, the drugmakers have drawn criticism from lawmakers, insurers, and patient advocates, who say the cost of medicine is rising too quickly for the health-care system to absorb it. The companies say they are working to make sure sick people have access to the treatments, and that the medications can reduce costs over time by helping patients get healthier and live longer.

Merck and Bristol have introduced therapies that fall into a new class of cancer drugs that trigger the body's immune system to fight tumors. Merck's Keytruda, which costs about $150,000 a year, sold $83 million in the first quarter, compared with analysts' estimates for $72.5 million of sales. Merck was the first company to win U.S. approval to bring what is known as an immunotherapy to the market for the treatment of advanced melanoma.

On Tuesday, Merck stock jumped as much as 5.9 percent after the company raised its profit forecast for the year, and finished the day up 5.04 percent at $59.98. Pfizer finished down 0.32 percent at $34.48. Bristol-Myers Squibb finished down 0.95 percent at $64.54.

The growing optimism over the potential of the new cancer drugs was tempered by a reminder Tuesday that competition will be fierce for some patients. On a conference call, Merck said it was pushing for Keytruda to be approved to treat many different forms of lung cancer, putting it more directly in competition with Bristol-Myers' immunotherapy, Opdivo.

"People are beginning to look at this market as Merck vs. one competitor or two competitors," said Adam Schechter, president of Merck's Global Human Health division. "It's important to look at this as Merck, Bristol-Myers, and other companies fighting against cancer vs. fighting against one another."

Opdivo had $40 million of sales, compared with the $39.2 million average estimate. Opdivo, which also costs $150,000 a year, was approved to treat advanced melanoma in December. The U.S. Food and Drug Administration also approved Opdivo for a form of lung cancer three months ahead of schedule in March. This month, the New York-based company ended an Opdivo study for another form of lung cancer, citing positive results.

Pfizer's breast cancer drug Ibrance, which costs $9,850 a month or $118,200 a year, had $38 million in sales, compared with the $22 million average projection. While not an immunotherapy, Ibrance showed such promising results in breast cancer patients that U.S. regulators approved it for use in February, two months ahead of schedule.