Goldman Sachs analyst Terence Flynn recommends using today's post-earnings selloff in shares of Amgen as a buying opportunity. The stock in premarket trading is down 4%, or $8.13, to $218.02. The midpoint of company's 2020 earnings per share guidance of $15.22 is 6% below consensus, which could drive share weakness, but Amgen typically guides conservatively, Flynn tells investors in a post-earnings research note. The analyst is confident that similar to prior years, Amgen will ultimately exceed the initial earnings guidance. In addition, three significant late-stage pipeline readouts this year have the potential to expand Amgen's multiple if successful, including AMG510 for lung and colon cancer, Tezepelumab for asthma and Omecamtiv for heart failure, Flynn contends. The analyst keeps a Conviction Buy rating on the shares with a price target of $273.