A drug delivery device having a trigger biasing member that provides dispense assistance. The drug delivery device includes a variable dose setting mechanism that is operably coupled to a primary reservoir holding a first medicament. The drug delivery device also includes a fixed dose setting mechanism that is operably coupled to a secondary reservoir holding a second medicament. The fixed dose setting mechanism comprises a trigger biasing member or spring. In addition, the drug delivery device includes a mechanical coupling that operably couples the variable dose setting mechanism and the fixed dose setting mechanism. During dose setting, activation of a single dose setter sets a variable dose of the first medicament. Setting of a minimum dose of the first medicament causes a fixed dose of the second medicament to be automatically set, and, during dispense, the trigger spring at least assists with the dispense of the fixed dose of the second medicament.