Pfizer beat Wall Street expectations for first-quarter profit thanks to reduced spending on operations and legal costs, along with strong sales of key new drugs and longtime blockbuster pain treatment Lyrica. [...] the top U.S. drugmaker had a disappointing revenue dip of 1 percent as competition hurt overseas sales of the immune disorder drug Enbrel. Pfizer continued its aggressive pursuit of companies that can boost its sales and its pipeline of future drugs, completing three significant deals — two purchases and a sale — since January of 2016.