Puzo novels that were never turned into films

Curiously, for an author who wrote one of the greatest bestsellers of all-time, The Godfather, many of Puzo's works were not made into films.

Such as...

The Dark Arena
Fools Die
The Fourth K
Omerta
The Family

I would think that Hollywood would have been all over Fools Die, particularly as it was Puzo's follow-up to The Godfather.

Does anyone know if anyone tried to make movies based on these books and they just died in development hell?

I am wondering if they made a film for The Fortunate Pilgrim. This is Puzo's favorite book. It makes me almost cry to see that no one cares about this story. I read it and loved it. It is probably because I am more interested in Puzo himself rather than the whole Mafia buzz (the Fortunate Pilgrim is novelization of Puzo's life; it is some sort of autobiography).

A TV movie was made in the mid-eighties starring Sophia Loren. Never saw it, but it was made. I don't believe it's available on DVD or VHS.

There's always the possibility it could show up on TV somewhere, so don't give up hope! :p