Cartridge assembly for a drug delivery device and drug delivery device

A drug delivery device comprising:

• a housing;
• and
• a cartridge assembly releasably connected to the housing;
• wherein the cartridge assembly comprises:
• a cartridge containing a drug,
• a cartridge holder, the cartridge holder defining an interior cartridge holding section, wherein the cartridge is arranged within the cartridge holding section, wherein the cartridge holder comprises a distal region with a needle connector arranged at a distal end of the distal region and a main body region,
• a fixing feature arranged at the distal region, and
• a region with a reduced mechanical stiffness compared to a stiffness of the main body region, wherein the region with the reduced mechanical stiffness is integrated into the distal region and arranged between the needle connector and the fixing feature, such that, when the cartridge is moved in a proximal direction, an emerging load is transferred from the cartridge to the fixing feature and further to the main body region in the proximal direction;
• wherein the drug comprised in the cartridge is a medicament,
• wherein the fixing feature comprises a continuous mechanical connection to the distal region of the cartridge holder in a circumferential direction, and
• wherein the fixing feature is arranged such that movement of the cartridge in a proximal direction causes a radial inward deflection of the fixing feature.