Amgen Inc. stock surged almost 6 percent Wednesday, the first day of trading after the company surprised investors during its second-quarter earnings report late Tuesday. The Thousand Oaks biotech let drop during Tuesday’s conference call that a colorectal and appendiceal cancer drug, AMG510, has shown promise. In June Amgen said the drug may be effective against lung cancer, and the company said Tuesday that it plans to begin a trial later this year. The news helped boost the company’s shares by 3 percent in extended trading Tuesday. Amgen beat estimates as well, reporting an adjusted net income of $2.2 billion ($3.97 a share) for the quarter. Revenue totaled $5.9 billion, a decrease of 3 percent compared to the second quarter for 2018. This decrease reflects increasing competition due to patent expirations, Amgen said. Analysts on average expected second quarter net income of $3.59 a share on revenue of $5.6 billion, according to Yahoo Finance. In terms of individual drug sales, newer products such as Prolia increased 14 percent from the year-ago quarter, due to higher demand. Blincyto sales increased 30 percent for the fourth quarter. However, total product revenue decreased 2 percent from last year’s second quarter; an increase in demand for newer products was offset by biosimilar competition for older products. Amgen expects the approval of more biosimilars to contribute to total revenues. Mvasi and Kanjinti, biosimilar drugs for cancer treatment, were approved by the Food and Drug Administration earlier this month. Amgen’s stock on Wednesday closed up $10.13, an increase of 5.7 percent, to $186.58 on the Nasdaq.