Sophie Thatcher (“Heretic,” “Companion”), Erin Kellyman (“28 Years Later: The Bone Temple,” “Eleanor the Great”) and Joe Alwyn (“The Brutalist,” “Hamnet”) are to star in “Cavendish, an “irreverent and original” thriller set against the witch hunts of 17th-century Britain. From writer-director Christopher Andrews (“Bring Them Down”), “Cavendish” is billed as “blending visceral action with sharp, unexpected humour.” Cornerstone will handle international sales and distribution and will commence sales at Cannes. CAA Media Finance is handling domestic. Set in 1645, the story sees a privileged young bride (Thatcher) accused of witchcraft on her wedding day and pursued by a ruthless witch hunter (Alwyn).…