PUBLISHED ONInvalid Date Invalid Date
SINGAPORE - A surgeon friend recently told me about a brain tumour patient who had sought out unorthodox treatment from a Texas-based doctor who uses his own special drugs called "anti-neoplastons" (ANPs).
The patient had seemingly recovered when last seen on his return.
The doctor in question, Dr Stanislaw Burzynski, 70, says he first derived ANPs from human urine. He is wont to portray himself as a maverick persecuted by the oncologist fraternity for using ANPs.
His supporters like to claim that the money-grubbing "cancer industry" of oncologists just would not let patients have "natural cures", never mind that Dr Burzynski charges very high fees.
A relative, having read online patient testimonies about ANPs being a miracle cancer cure, urged me to send my mother who has terminal lung cancer to Dr Burzynski. Whether I should or not depends on what ANPs are.
Since the molecular structures of the two main ones that Dr Burzynski uses, which he calls AS-2.1 and A-10, are given at his website, one can see what they really are.
If you ingest sodium phenylbutyrate, your body breaks it down to phenylacetic acid (PA), which breaks down further into phenylacetyl glutamine (PAG), which is then excreted in the urine.
Now A-10 is PAG while AS-2.1 is a mix of PA and PAG. But what is sodium phenylbutyrate itself?
It is an infant drug made for patients with a rare genetic mutation (that causes a lack of one of the six enzymes in the urea cycle which helps to remove ammonia from the blood stream).
An infant drug, in turn, is one made for a rare disorder. It is fast-tracked for approval because makers cannot make money from it, there being few such patients globally, a fact that also makes recruiting subjects for rigorous, large drug trials impractical, too.
In sum, ANPs are merely compounds the body produces by the breakdown of an infant drug called phenylbutyrate.
But when a patient takes it, only very low blood levels of PA result because most of the PA is broken down to PAG within four hours: PAG itself is quite an inactive compound.
Nevertheless, Dr Burzynski claims that his ANPs (which are PA and PAG) offer "targeted therapy" against 100 cancer genes.
By contrast, "targeted therapy" conventionally refers to a drug that hits one or just a couple of gene products only. That is, the targets in question are quite few.
For example, gefitinib (marketed as Iressa, which my mother is taking) targets the Her1(erb-B1), Her2(erb-B2) and Her3(erb-B3) gene products in some lung cancers. Trastuzumab (marketed as Herceptin) targets Her2 gene products in some breast cancers.
So if ANPs hit 100 gene products in blunderbuss fashion, they can hardly be a targeted therapy.
But even if they are not, is there scientific evidence that ANPs do work? Dr Burzynski apparently has had clinical trials ongoing for about 15 to 20 years, all using AS-2.1 and A-10. These should help answer that very question.
Note that a phase I trial is done to study if a new drug is safe to use in humans; a phase II trial is a small and preliminary one done to show if a drug is effective in humans; and a phase III trial is the final definitive stage of testing on large numbers of subjects before a drug is approved for marketing.
However, Dr Burzynski has never published even one report of any phase II trial and he has never initiated a phase III trial.
Instead, he offers only abstracts and anecdotal case reports in marginal publications like Journal of Cancer Therapy which is not indexed by PubMed, where all reputable journals are included.
A search at www.ClinicalTrials. gov for studies of whether phenylbutyrate works in cancer does turn up many completed studies. But none involves Dr Burzynski.
These studies have published their results like a National Cancer Institute (NCI) trial of phenylbutyrate in glioma (a brain tumour) published in Neuro-Oncology in 2005, which reported the drug as safe but with just a 5 per cent response rate.
A separate NCI review of ANP data noted Dr Burzynski "often reported remissions but other investigators have not been successful in duplicating these results".
Interviewed for Knockout (2010), a book by TV actress Suzanne Somers, Dr Burzynski claimed cure rates of 85 per cent in breast cancer and 50 per cent in advanced brain tumours. But his claims have never been submitted for peer scrutiny and critique.
The reason could be that he does not really carry out clinical trials at all. According to Mr Richard Jaffe, Dr Burzynski's lawyer got him off when he faced Food and Drug Administration (FDA) action in the 1990s.
Mr Jaffe wrote Galileo's Lawyer (2008), in which he noted: "All of his current patients (are) covered in a single clinical trial called CAN-1. As far as clinical trials go, it was a joke. Clinical trials test the safety or efficacy of a drug for one disease: CAN-1 had a dozen different types of cancers...
"It was all an artifice... Burzynski personally put together 72 protocols to treat every type of cancer (he) had treated and everything (he) wanted to treat in the future… Miracle of miracles, all his patients were now on FDA-approved clinical trials, and he would be able to treat almost any patient he would want to treat!"
Because of patient complaints against him, Dr Burzynski was investigated by the authorities in 2009.
The FDA warned him in writing that his trials did not meet "statutory requirements and FDA regulations governing the protection of human subjects". Last year, it warned him for advertising ANPs in press releases, online videos and websites as "safe and effective", which was unproven.
But if the desperate patient wants to try ANPs anyway, she should not be making a beeline for Texas. Instead, she could request her oncologist to administer phenylbutyrate as an off-label prescription.
When a drug approved for certain indications is used for an unapproved indication or age group or dosage or form of administration, it is said to be used off-label.
Doctors are permitted to write such prescriptions but must do so wisely based on sound science reasons.
Try ANPs if you must but do so here at home.
andyho@sph.com.sg
Get a copy of The Straits Times or go to straitstimes.com for more stories.