Dallas plaintiffs lawyer Fred Baron is battling multiple myeloma, a blood cancer, and his physician is fighting a pharmaceutical company in an effort to use a medication to treat Baron’s illness that the Federal Drug Administration has not yet approved for that purpose.

News of Baron’s condition surfaced on Oct. 14 when Baron’s son Andrew posted a letter online that he had sent to James C. Mullen, the chief executive officer of Cambridge, Mass.-based Biogen Idec Inc. In the letter, Andrew Baron seeks to reverse Biogen’s decision to deny his father’s physician’s request to give Baron a medication that Andrew Baron argues could save his father’s life. Andrew Baron, the founder of New York City-based Rocketboom, did not respond to e-mail requests for comment.