Shareholders can proceed with their claims that AmerisourceBergen Corp.’s directors knew of and failed to stop a subsidiary’s illegal distribution of oncology drugs, the Delaware Court of Chancery ruled.

In a 75-page memorandum opinion, Vice Chancellor Sam Glasscock III determined that plaintiff investors—five pension and retirement plans—adequately met the high threshold set under the Caremark standard for derivative litigation and denied AmerisourceBergen’s motion to dismiss the case in its entirety.