Derek Cianfrance, writer-director of the HBO limited series “I Know This Much Is True,” has set a two-year overall deal with HBO.

The deal calls for the helmer to develop a range of projects for the pay TV powerhouse.

The pact comes a few days before the six-episode series bows on May 10. Cianfrance partnered with “IKTMIT” executive producer and star Mark Ruffalo to tackle the adaptation of the acclaimed 1998 novel by Wally Lamb about the lives of two twin brothers, one of whom struggles with mental illness. The cast also features Melissa Leo, Rosie O’Donnell, Archie Panjabi, Imogen Poots, Bruce Greenwood, Juliette Lewis and Kathryn Hahn.

In an interview with Variety in March, Cianfrance discussed the process of filming “IKTMIT” with Ruffalo playing both brothers. “He just became both guys,” Cianfrance said. “When he was Dominick, he was an alpha male and a little more angsty. He was a bear to wrestle with. When he was Thomas, he was so fragile that I had to approach him with kid gloves. It was like working with two different people.”

Cianfrance is known as the writer-director by the 2010 drama “Blue Valentine,” starring Ryan Gosling and Michelle Williams, and 2012’s “The Place Beyond the Pines,” toplined by Gosling, Bradley Cooper and Eva Mendes. His most recent film was 2016’s “The Light Between Oceans,” which starred Michael Fassbender, Alicia Vikander, and Rachel Weisz.

Before breaking into features, Cianfrance worked in commercials, music videos and documentaries. He earned a DGA Award in 2017 for the Nike Golf commercial “Chase.” He’s also served as a cinematographer and editor.

Cianfrance is repped by CAA, manager Jamie Patricof at Hunting Lane Films and attorney Michael L. Schenkman at Bloom Hergott.