Yes I have heard of it from well meaning but stupid and gullible friends. The doctor is a total fraud, but very very clever in his misuse of the legal system and FDA arcane systems. Basically his patients DIE. For a nuanced and subtle debunking, Here is Dr Andrew Weil's far too kind expose:
Over the years, Dr. Burzynski claims to have treated more than 8,000 patients, but his success rates are unknown. His Web site states only that he has helped "many" people. If antineoplaston therapy works, we should have scientific studies showing what percentage of patients treated have survived and for how long, as well as evidence showing how Dr. Burzynski's method stacks up against conventional cancer treatment. The only study I know that documents how Dr. Burzynski's patients have fared was done in Canada in 1985. It found that of 36 patients treated, 32 died without showing signs of improvements. One patient died after slight improvement, another died after being stable for a year and, at the time of the study, the other two had widespread cancer.

The cost of antineoplaston therapy at Dr. Burzynski's clinic reportedly ranges from $30,000 to $60,000 per year. After initial treatment there, patients may be able to continue therapy at home with follow up clinic visits every two months.