Air carrier First Officer reported the loss of aircraft pressurization during descent.

Narrative

PRESSURIZATION EVENTApproximately six minutes prior to top of descent (TOD); the descent checklist had been completed; including setting the destination landing altitude. We had been cleared to descend at pilots discretion to FL250. Shortly after initiating descent; a CABIN ALTITUDE warning was annunciated on the EICAS.We immediately donned oxygen masks; performed the memory items; and requested priority handling with ZZZZ Center. We then proceeded with the QRC and QRH procedures for CABIN ALTITUDE.While executing the checklist; we received an AUTO INOP EICAS caution and noticed the associated light illuminated above the cabin altitude mode selector. We completed the QRH items and leveled off at FL250; as cleared. ZZZZ Center subsequently cleared us to descend to FL170 and contact ZZZZ Approach.As we descended through FL170; the AUTO INOP caution extinguished and the cabin began descending with the status message CABIN ALT AUTO 2 displayed. Cabin altitude was observed near 15;000 ft; and gradually returned toward the preselected value of 8;360 ft. The warning message extinguished once cabin altitude dropped below 10;000 ft.After verifying the cabin altitude was stabilized and below 10;000 ft; I removed my oxygen mask; followed by the Captain to improve communication. It appeared that CABIN ALT AUTO 1 had resumed control and stabilized the pressurization system.ZZZZ Approach asked if further assistance was required. We declined and downgraded the priority handling; eventually cancelling it altogether. The approach was completed without further incident and the aircraft landed safely.Both the CABIN ALTITUDE WARNING and CABIN ALT AUTO 2 status messages were documented in the aircraft logbook.