Presided by Kirk D'Amico, Myriad will introduce "Shadow Girl" to buyers at the Cannes Film Market.
Targeting a still underserved YA and adult female audience which has made a large hit of such titles as "Me Before You," "Shadow Girl," marks a move towards the mainstream for Claudia Myers who broke through to attention with "Fort Bliss" - a "solid, affecting drama," Variety said.
Billed as a magical love story and from an original screenplay by Myers which also has coming of age elements, "Shadow Girl" stars Mamet as a girl, Holly, who has literally faded with the death of her mother until near invisible - until she meets Shane, a disgraced MMA champ, who can make her out. But Holly discovers she bears more responsibility than she imagined for Shane's downfall and her own fate.
"Claudia has written a uniquely original story with strong, fully-developed characters. We believe that together with Scott, Zosia and the rest of the cast that she will bring her ultimately romantic vision to the big screen in a beautiful way," said Myriad president D'Amico.
The stage producers of "Natasha, Pierre amp; the Great Comet of 1812," Hipzee's Tara Sickmeier and Rob Baunoch III, produce with Boundary Stone's Mark Schacknies and Khris Baxter. D'Amico will serve as an executive producer for Daylight Media.
Myers, best known for her starring role alongside Lena Dunham in HBO's "Girls," is managed by Echo Lake Ent.
Speedman, who can currently be seen as Barry "Baz" Blackwell in TNT family crime drama series "Animal Kingdom," is represented by United Talent Agency (UTA) and Gary Goddard Agency.
Myriad's Cannes slate also includes Sundance-selected "Red Dog: True Blue," the prequel to 2011 international box office smash hit "Red Dog," which reunites the creative team behind the original "Red Dog" of writer Daniel Taplitz ("Chaos Theory"), producer Nelson Woss ("Ned Kelly") and director Kriv Stenders ("Kill Me Three Times") and Penelope Cruz'-starrer "The Queen of Spain," directed by Academy Award winning Fernando Trueba ("Belle Epoque"), which reprises the characters of "The Girl of My Dreams" 18 years on, in an impoverished Spain of the 1950s.
Also sold by Myriad, and a Special Presentation at Sundance: "Mark Pellington's "The Last Word," starring Shirley MacLaine as a retired but still control-freak businesswoman.