"A script is indeed in development, but I’m afraid that’s all I can say. Thanks for your good wishes and support all these years," is what Mr. Spotnitz shared. Our source also indicates that both David Duchovny and Gillian Anderson are interested in reprising their roles from the previous film and the cult-favorite Fox series.
No word yet on if it’ll be a "connected" sequel or more like a James Bond "separate adventure" concept — but hopefully we can get some of those pesky questions answered!
Source: Sci-Fi Wire