It looks like the manga publisher Del Rey has canceled the second volumes of its X-Men: Misfits and Wolverine: Prodigal Son. The news broke in a conversation on Twitter, where manga blogger Deb Aoki tweeted a tip that the books had been canceled and Lissa Pattillo noted that they had been taken down from retail sites.

Dave Roman, who co-wrote the X-Men books with his wife, Raina Telgemeier, confirmed this in two tweets of his own:

Wow! News travels fast! @goraina and I super disappointed since it was written as a 2-part story and it will be unfair to readers.

We only found out last week. We still don't have a lot of the details beyond it being a cost of licensing vs. profits issue. :/

Roman added that he had seen some of the pencils and assumed that the artist, Anzu, was "far along, but still deep into it."

Antony Johnston, the writer of Wolverine: Prodigal Son, confirmed that book's demise on his blog:

Unfortunately, the simple truth is that not enough people bought them. Despite WOLVERINE being praised by readers and selected for two library YA lists, despite MISFITS making it onto the New York Times bestseller list, and not least despite all the efforts of Del Rey themselves and our editors there, there just weren’t enough readers to justify the costs. This is, sadly, more common than you might think in comics.

According to the Bookscan chart, the first volume of X-Men: Misfits sold 4,042 copies in bookstores in 2009, which put it at number 720 in the top-750 chart. By contrast, not a single Viz Signature title (including the Eisner-nominated Pluto and 20th Century Boys) made the top 750. Diamond lists 1,655 copies sold in September 2009, the date of its release, meaning the book's sales were respectable by manga standards. And it made the 2010 Great Graphic Novels for Teens list.

The Wolverine manga, by contrast, doesn't seem to have cracked the Bookscan chart, although Diamond lists 1,906 copies sold in April 2009.

Don't cry for these creators, though. Johnston continues working on his Daredevil series, Telgemeier is still promoting her successful graphic novel Smile, and Roman tweeted last week that he turned in the final version of Astronaut Elementary, which will be published by First Second.