Fred Baron, one of Dallas' biggest Democratic donors, has been treated with the special drug that he'd been prohibited from using in his fight against cancer, Baron's son said in an e-mail.

From his son, Andrew Baron:

Thanks to the persistence and hard work of so many friends, Frederick has received Tysabri. The Mayo Clinic working with the FDA found a legal basis for this use. We have every expectation of a positive result.

The maker of the drug, Biogen, had previously said it wasn't allowed for use on people with cancer -- it's made to treat people with multiple sclerosis and Chron's disease.

A fundraiser was being held at Baron's North Dallas mansion tonight for state Senate candidate Wendy Davis.

More here on Davis and his illness from the DMN.