The 24-year-old woman was hit around 8:20 a.m. at the intersection of Hampshire Street and Portland Street, the Middlesex District Attorney said.
The woman's name was not released as police notified her next of kin.
An initial investigation revealed that the bike and truck were traveling in the same direction on Hampshire Street and crashed when the truck turned right onto Portland Street.
Paramedics rushed the woman to Massachusetts General Hospital, where she died of her injuries.
The driver remained on the scene.
Cambridge police are investigating the crash.
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