The Hachette Book Group lists the first volume of Ryohgo Narita and Akiyo Satorigi's Durarara!! Saika Arc manga from Yen Press on its website. ANN is awaiting Hachette's response to a request for comment.
Satorigi launched this continuation of the first Durarara!! manga in Square Enix's Monthly G Fantasy magazine in 2011, and Square Enix will publish the second volume next month.