Dose setting mechanism for a drug delivery device and drug delivery device

A drug delivery device comprising:

• a primary drug delivery assembly for delivery of a primary medicament;
• and
• a secondary drug delivery assembly for delivery of a secondary medicament, and
• a dose setting mechanism comprising
• a primary dose dial component for setting a primary dose in the primary drug delivery assembly;
• and
• a secondary dose dial component for setting a secondary dose in the secondary drug delivery assembly, wherein the primary dose dial component and the secondary dose dial component are configured to rotate during dose setting, and
• a gear mechanism configured such that
• rotation of the primary dose dial component is transferred to the secondary dose dial component during a first phase of the dose setting, and
• the secondary dose dial component is decoupled from the primary dose dial component during a second phase of the dose setting, thereby inhibiting rotation of the primary dose dial component from being transferred to the secondary dose dial component, for further setting the primary dose in the primary drug delivery assembly without changing the secondary dose in the secondary drug delivery assembly.

A method of operating a drug delivery device, the method comprising:

• setting a dose of a primary medicament to be delivered from the drug delivery device and a dose of a secondary medicament to be delivered from the drug delivery device, the dose of the primary medicament being adjustable and the dose of the secondary medicament being fixed, wherein the dose of the primary medicament and the dose of the secondary medicament are set during a first phase of dose setting;
• adjusting the dose of the primary medicament during a second phase of the dose setting;
• and
• dispensing a combined dose from the drug delivery device, the combined dose including the dose of the primary medicament and the dose of the secondary medicament,
• wherein the first phase of dose setting includes causing the rotation of a primary dose dial component to transfer to a secondary dose dial component, and
• wherein the second phase of dose setting includes causing the secondary dose dial component to decouple from the primary dose dial component such that rotation of the primary dose dial component is inhibited from being transferred to the secondary dose dial component, for further setting the dose in a primary drug delivery assembly without changing the dose in a secondary drug delivery assembly.