I concur with the answer from Brightbladesanswer from Brightblades, which addresses the lack of clinical evidence.
That leaves the question about the legal situation.
From the Wikipedia page references, I found a decision for case NO. 03-95-00222-CV at the Texas Court of Appeals, in the case between Burzynski and the Texas State Board of Medical Examiners.
Its summary states:
Appellant Texas State Board of Medical Examiners ("the Board") ordered that appellee Dr. Stanislaw Burzynski's license to practice medicine be suspended and that such suspension be stayed with Dr. Burzynski being placed on probation for ten years under certain conditions. (1) Upon judicial review of the Board's order, the district court reversed the order in its entirety and dismissed the cause. In two points of error, the Board asserts that the trial court erred in finding that TMPA section 5.09(a) authorizes Dr. Burzynski's use of antineoplastons in Texas and that the false advertising statute is unconstitutional. We will reverse the judgment of the trial court and render judgment in accordance with the order of the Board.
To summarise the summary:
- The Board suspended his license.
- The District Court reviewed and reversed the suspension.
- The Texas Court of Appeals reversed the reversal, leaving his license suspended again.
This confusing back-and-forth explains why the difference sources appear to be contradicting each other.