An Eli Lilly & Co. logo is seen on the cap of a pill bottle in this arranged photograph at a pharmacy in Princeton, Illinois. Daniel Acker | Bloomberg | Getty Images

Shares of pharmaceutical giants Pfizer and Merck both rose by about 1% Tuesday after reporting first-quarter financial results that beat Wall Street's expectations. However, shares of drug giant Eli Lilly dropped as much as 3.5% after releasing first-quarter earnings that topped profit expectations, but missed on revenue. Sales of two of Lilly's key drugs, Trulicity and Alimta, fell short of Wall Street's forecasts. Merck's earnings got a slight lift from sales of cancer immunotherapy drug Keytruda and vaccines — amid the worst measles outbreak since health officials declared the disease eradicated from the U.S. in 2000.

Health care has been the worst-performing sector in the stock market this year on concerns about drug price reform and "Medicare for All" proposals from Democratic lawmakers. The Health Care Select Sector SPDR Fund, an ETF that tracks the health-care industry's biggest companies, had risen by just 2.7% year to date as of Monday, significantly lagging the broader market indexes. The Dow Jones Industrial Average was up 13% over the same period, and the S&P 500 was 17% higher.

Eli Lilly

Eli Lilly posted earnings $1.33 per share on revenue of $5.09 billion. Analysts had expected earnings of $1.31 a share on revenue of $5.12 billion. The company said it expects further price declines in the United States this year as well as increased competition from generics, including for erectile dysfunction drug Cialis. Trulicity, the company's top-selling diabetes drug, brought in $879.7 million in the quarter. That was an increase of 30% compared with the first quarter of 2018 but below the $952 million analysts had expected. Sales of cancer drug Alimta came in flat compared with last year at $499 million. The U.S. drugmaker now expects full-year revenue between $22 billion and $22.5 billion, lower than a previous forecast of of $25.1 billion to $25.6 billion. However, it raised its adjusted full-year earnings forecast by 5 cents to $5.60 to $5.70 per share. Lilly has been facing pressure from Congress to lower prescription drug costs. In March, the company disclosed for the first time what it charges wholesalers versus what many patients typically pay. It also announced plans to sell a half-price version of insulin injection Humalog.

Merck

The company reported first-quarter earnings of $1.22 per share, beating analysts' expectations of $1.06 a share. Revenue came in at $10.81 billion, topping estimates of $10.48 billion. Merck said sales of Keytruda surged 55% in the quarter to $2.27 billion. Keytruda, which boosts the immune system to attack cancer, has driven growth for Merck and put pressure on Bristol-Myers Squibb's rival drug Opdivo.

Merck's Gardasil vaccine to prevent certain types of cancer also had a good quarter with sales up 27% to $838 million. Sales of children's vaccines, which includes the company's MMR vaccine for measles, jumped 27% to $496 million. The drug giant raised its earnings guidance for the year. It now expects full-year adjusted earnings per share of between $4.67 and $4.79, up from its prior forecast of $4.57 to $4.72.

Pfizer