Says TV Guide, "Sources tell us it was Pinkner's decision to exit the series in order to pursue other projects and that it was an amicable split. Pinkner will not retain his executive producer credit and Wyman will be the sole showrunner for the final season."
Executive producer/co-creator JJ Abrams issued the following statement: "We're so excited to begin work on a fifth season of Fringe and to be able to deliver the 13 final episodes to our passionate and devoted fans. For four years, J.H. Wyman and Jeff Pinkner have worked tirelessly as a team to keep all the worlds in order on Fringe. We're thankful for the invaluable contributions Jeff has made to the show and of course wish him well and look forward to working together in the future. J.H. Wyman's importance to Fringe cannot be overstated, however, and I'm thrilled that he will continue as showrunner for the concluding chapters of our story. We can't wait for our fans to see what we have in store for them in the wild conclusion of Fringe."