HTC is about to present a new high-end devices. This probably happened at Mobile World Congress 2015. The information we have at the moment is that the A55 will be series Desire.
Upleaks announced that the A55 will be a 5.5-inch QHD display, MediaTek MT6795 eight-core 64-bit chipset. In terms of memory, the device comes with 3 GB RAM and 32GB internal memory. Back camera is 20MP, 13MP is the front and the battery is less than 3000 mAh. A55 will work with HTC Sense 7.0 and Android 5.0.Source: GSMARENA