It has been recently announced that scientists from Japan and South Korea are planning a partial replication of the NTP study. According to what is known now, not all parameters of the NTP study will be used in this Japan/South Korea replication study. It is logical approach. Technological progress, since the time when NTP study was planned and set up, has been swift and exact replication of radiation exposures from some 5 years ago might be of little use for the currently used exposures.
The document of the planned experiments, released by Japanese scientists is in Japanese, but it has a very informative English summary. It appears that not all experimental parameters were already agreed upon and that negotiations are still ongoing.
You can see what Professor Dariusz Lezczynski has to say about this study here.