Two most recent IALANA working papers have been posted on the UN website:
https://s3.amazonaws.com/unoda-web/wp-content/uploads/2017/06/A-CONF.229-2017-NGO-WP.37.pdf (prohibitions and preamble)
https://s3.amazonaws.com/unoda-web/wp-content/uploads/2017/06/A-CONF.229-2017-NGO-WP.381.pdf (nuclear-armed states and other issues)
You can get some sense of how the negotiations are going from:
http://reachingcriticalwill.org/disarmament-fora/nuclear-weapon-ban/reports
http://reachingcriticalwill.org/disarmament-fora/nuclear-weapon-ban