Fundamentally, Merck and Pfizer have enjoyed similar long-term success but also have to deal with many of the same obstacles to future growth. In Merck's most recent quarterly report, the company reported sales growth of just 1%, reporting that the strength of the U.S. dollar cost it two percentage points of growth. Adjusted net income climbed about 6%. Merck focused its attention on key drugs like cancer-fighter Keytruda and hepatitis C treatment Zepatier, which it hopes to attain blockbuster status and replace some of the compounds that have gone off-patent over the years. Acquisitions continue to play a vital role in driving growth in pipelines for Merck, but the drug-maker has had to deal with restructuring costs and impairment charges that forced it to cut its earnings guidance for the full year, and falling sales for past blockbusters requires Merck to stay vigilant looking forward.