The Food and Drug Administration has accepted for review an application from Amgen Inc. for a biosimilar drug to compete with AbbieVie Inc.’s Humira. Amgen in Thousand Oaks calls its drug ABP 501. Humira, technically known as adalimumab, is used to treat chronic inflammatory conditions such as rheumatoid arthritis and Crohn’s disease. Biosimilars copy established bioengineered medications, but because they are made in living cells, they cannot be exact replicas of the original. Yet, to be approved by the FDA, they must be “highly similar” to the drug they are aiming to replace, meaning there must be no meaningful differences in safety and effectiveness. “If approved, we believe ABP 501 could serve as an important additional approved therapeutic option for patients with chronic inflammatory conditions,” said Dr. Sean E. Harper, executive vice president at Amgen. “We look forward to potentially expanding our robust portfolio of approved products, and further demonstrating our continued commitment to delivering high-quality medicines to patients worldwide.” The FDA has set a target date of Sept. 25 to decide on ABP 501. Amgen shares closed up 35 cents or a fraction of a percent to $153.78 on the Nasdaq.