In a translated interview at NeoGaf.com (via Games Radar) Dark Souls III director Miyazaki has indicated that the latest game is the last in the series with "no plans right now for any sequels, spin-offs or tie-ins".
"What is certain for now is, to me personally, Dark Souls is over. So rather than make another sequel, I think it’s time we take a step to a new direction. Development of a new IP has already begun”.
Miyazaki also opined that any other games in the series would be developed by an outside studio.
Dark Souls III will see two DLC released, one this fall and one in early 2017.
Read the full translation of the interview at the link above.