A drug delivery device comprising: a housing retaining a primary drug delivery assembly configured to receive a primary reservoir containing a primary medicament and a secondary drug delivery assembly configured to receive a secondary reservoir containing a secondary medicament, wherein the primary drug delivery assembly comprises a primary dose setting mechanism for setting a dose of the primary medicament and wherein the secondary drug delivery assembly comprises a secondary dose setting mechanism for setting a dose of the secondary medicament, wherein the secondary dose setting mechanism comprises a biasing member adapted to reset the secondary dose setting mechanism in a resetting movement and a trigger button for releasing the biasing member, wherein the trigger button is movable from a first into a second position; and a setting element movable between a first position and a second position and connected to the secondary dose setting mechanism such that during the resetting movement of the secondary dose setting mechanism, the setting element is moved from the second position into the first position; characterized by an actuator movable relative to the housing, wherein the actuator engages a primary dose dispensing mechanism of the primary drug delivery assembly during an actuation movement such that a set dose of the primary medicament is dispensed through a dispense interface, wherein the actuator comprises a first engagement section configured to engage a second engagement section provided by an actuation collar such that the actuation movement of the actuator is transferred to the actuation collar, wherein the actuation collar is moveable relative to the actuator between a first position where the first engagement section and the second engagement section are not engaged and a second position relative to the actuator where the first engagement section and the second engagement section are engaged such that the actuation movement of the actuator is transferred to the actuation collar such that the actuation collar engages the trigger button and moves the trigger button into the second position, wherein when the trigger button moves towards the second position, the trigger button releases the biasing member, wherein the biasing member is connected to the setting element such that the biasing member moves the setting element from the second into the first position when the biasing member relaxes, wherein the setting element is configured to drive the actuation collar out of engagement with the actuator when moving from the second position into the first position. a housing retaining a primary drug delivery assembly configured to receive a primary reservoir containing a primary medicament and a secondary drug delivery assembly configured to receive a secondary reservoir containing a secondary medicament, wherein the primary drug delivery assembly comprises a primary dose setting mechanism for setting a dose of the primary medicament and wherein the secondary drug delivery assembly comprises a secondary dose setting mechanism for setting a dose of the secondary medicament, wherein the secondary dose setting mechanism comprises a biasing member adapted to reset the secondary dose setting mechanism in a resetting movement and a trigger button for releasing the biasing member, wherein the trigger button is movable from a first into a second position; and a setting element movable between a first position and a second position and connected to the secondary dose setting mechanism such that during the resetting movement of the secondary dose setting mechanism, the setting element is moved from the second position into the first position; characterized by an actuator movable relative to the housing, wherein the actuator engages a primary dose dispensing mechanism of the primary drug delivery assembly during an actuation movement such that a set dose of the primary medicament is dispensed through a dispense interface, wherein the actuator comprises a first engagement section configured to engage a second engagement section provided by an actuation collar such that the actuation movement of the actuator is transferred to the actuation collar, wherein the actuation collar is moveable relative to the actuator between a first position where the first engagement section and the second engagement section are not engaged and a second position relative to the actuator where the first engagement section and the second engagement section are engaged such that the actuation movement of the actuator is transferred to the actuation collar such that the actuation collar engages the trigger button and moves the trigger button into the second position, wherein when the trigger button moves towards the second position, the trigger button releases the biasing member, wherein the biasing member is connected to the setting element such that the biasing member moves the setting element from the second into the first position when the biasing member relaxes, wherein the setting element is configured to drive the actuation collar out of engagement with the actuator when moving from the second position into the first position.