Writer-director Michael J. Gallagher’s Heaven’s Gate cult biopic The Leader , starring Vera Farmiga , Tim Blake Nelson and Jim Parsons , has been sold into the U.K. and Canada ahead of a world premiere at the Tribeca Festival next month. As part of distribution deals negotiated by Brian O’Shea at Voltage/The Exchange, the thriller about the infamous messiahs of the religious UFO cult whose followers in 1997 committed the largest mass suicide on American soil will be released by Altitude Films in Britain and Sphere Films in the Canadian market. “Michael Gallagher has crafted a powerful and thought-provoking film anchored by extraordinary performances. We look forward to sharing this compelling true story with Canadian audiences,” Victor Rego of Sphere Films said in a statement.…