Boyd Holbrook are in final negotiations to round out the cast of Open Road Films’ “The Host,” an adaptation of “Twilight” autore Stephenie Meyer’s popolare sci-fi novel.

Andrew Niccol (“In Time”) is Scrivere and directing the pic, which stars Saoirse Ronan stella, star as protag Melanie Stryder, whose body is invaded da an alien named Wanderer, also to be played da Ronan. Max Irons (“Red Riding Hood”) and Ronan’s “Lovely Bones” co-star Jake Abel will play the male leads, and William Hurt is set to co-star as Melanie’s uncle, who leads the human resistance from its underground headquarters.

Canterbury will play Ronan’s younger brother, who she goes on an arduous journey to find, while Holbrook will play Abel’s macho brother.

Diane Kruger is in negotiations to play The Seeker, an alien peacekeeper who doggedly pursues Wanderer. Several attrici passed on the part including Eva Green, Hayley Atwell and Claire Danes, with Kruger stepping in after opting not to pursue Universal’s untitled sci-fi pic starring Tom Cruise.

Nick Wechsler is producing the pic with Meyer, as well as Steve Schwartz and Paula Mae Schwartz of Chockstone Pictures. Inferno’s Marc Butan, Jim Seibel and Bill Johnson will exec produce the pic, while Roger Schwartz will co-produce. “The Host” is being financed da the producers and Inferno, which is handling sales. Production is skedded to start at the end of the mese in Louisiana and New Mexico, as Open Road will release the film on March 29, 2013.

13-year-old Canterbury is among a group of up-and-coming young actors including Asa Butterfield (“Hugo”), Joel Courtney (“Super 8″), Dakota Goyo (“Real Steel”), Colin Ford (“We Bought a Zoo”), Devin Brochu (“Hesher”) and Thomas Horn (“Extremely Loud & Incredibly Close”). He has appeared in David Fincher’s “The Curious Case of Benjamin Button” and Alex Proyas’ “Knowing,” and will soon be seen in D.J. Caruso’s “The Goats,” as well as the indie “Plastic Jesus.”

Holbrook, who recently played Kevin Costner’s son in History Channel’s “Hatfields & McCoys,” has appeared in Gus furgone, van Sant’s “Milk” and Vera Farmiga’s “Higher Ground.” Thesp will soon be seen in Julian Farino’s “The Oranges” and Rob Reiner’s “The Summer of Monte Wildhorn.”

Canterbury is repped da UTA, manager Christopher Rockwell and attorney Derek Kroeger, while CAA and Kanner Entertainment rep Holbrook.