Drug delivery device with a cap

A system comprising an integrated cap assembly and a drug delivery device, the integrated cap assembly comprising:

• a cap
• a needle assembly retained within the integrated cap assembly;
• and
• a pre-stressed biasing element disposed between the cap and the needle assembly and configured to bias the needle assembly proximally with respect to the drug delivery device while the cap is secured to a main body of the drug delivery device;
• and
• the drug delivery device comprising:
• one or more locking elements, each of the one or more locking elements comprising a locking member having a locked position and an unlocked position, and a biasing member configured to bias the locking member towards the unlocked position;
• wherein the cap is configured in an initial position to retain the one or more locking members in the locked position and in an intermediate position to release the one or more locking elements to allow the needle assembly to engage with a cartridge located within the main body of the drug delivery device.

A method relating to a drug delivery device, the method comprising:

• rotating a cap relative to a main body to move one or more locking elements, each of the one or more locking elements comprising a locking member having a locked position and an unlocked position, and a biasing member configured to bias the locking member towards the unlocked position;
• upon rotation resulting in unlocking of the one or more locking elements from a needle assembly contained within the cap, a biasing element being released;
• and
• release of the biasing element causing the needle assembly contained within the cap to engage with a cartridge contained within the main body.