(ShareCast News) - AstraZeneca posted a drop in first-quarter earnings but a rise in revenue as core research and development costs increased, reflecting recent acquisitions.Core earnings per share fell 7% at constant currency and 12% in dollar terms to 95 cents, while revenue was up 5% at constant currency to $6.1bn, or 1% in dollar terms.Consensus estimates were for revenue of $5.95bn.Core operating profit, meanwhile, fell 12% in dollar terms to $1.59bn, with core R&D costs up 15% to $1.43bn as the company continued to focus on its pipeline. This reflected the number of potential medicines in pivotal trials and the absorption of the R&D costs of ZS Pharma and Acerta Pharma.Chief executive officer Pascal Soriot said: "We delivered a first-quarter performance in line with expectations, with the growth in total revenue underpinned by the performance of the growth platforms. I was particularly pleased with the results in China, where we continued to deliver double-digit sales growth, and with the progress of our New Oncology launches."Strong advances were made in our late-stage pipeline, with regulatory approvals for Bevespi Aerosphere in the US for COPD, Brilique in the EU for post-myocardial infarction and Tagrisso in Japan for lung cancer. Looking ahead, we anticipate increased newsflow across the pipeline, including a number of regulatory decisions and data readouts, particularly in Oncology.AstraZeneca reaffirmed its full year 2016 guidance for a low to mid single-digit percentage decline in total revenue and core earnings per share.