This state is to finalize the data is not received at either side(UE,eNB). Here data can be from any channels like PDSCH/PDCCH/PUCCH/PUSCH. if eNB/UE is not able to decode the data or CRC error means it is NACK. but if eNB/UE is not even able to receive or see the data means then it is DTX.
In this case eNB/UE will be in OFF and ON combination for battery saving purpose.
DTX is data loss or no transmission. DRX is purposeful sleep combination.