According to a TASS report, Alexander Nevskiy submarine of the Project 955 class left its temporary base in Gadzhievo in mid-August for the permanent base in Vilyuchinsk in the Pacific. An analysis done by the "7 Feet Beneath the Keel" blog strongly suggests that the submarine sailed on or shortly after August 18, 2015. It is expected to arrive to Vilyuchink around September 7.
Alexander Nevskiy was reported to have the full complement of SLBMs on board in April 2015. The plan to transfer the submarine to the Pacific in August-September 2015 was announced shortly thereafter.
Following the Alexander Nevskiy news, it was confirmed that the third Project 955 submarine, Vladimir Monomakh, will remain with the Northern Fleet until late 2016, as previously planned. It is expected to conduct a Bulava launch from the Barents Sea in October-November 2015.
UPDATE 09/09/15: Subsequent reports suggested that the transfer will probably not be completed before the end of September. However, the reports are rather contradictory.