Cancer drug controversy;NEWLN:UPI SCIENCE: Snake drug divides Argentine cancer experts


BUENOS AIRES, Argentina -- As far as experimental anti-cancer drugs go, Dr. Juan Carlos Vidal's potion is subject to more skepticism than most.

Called 'crotoxina,' the medicine is composed of a chemical mixture, 68 percent diluted venom from Argentine rattlesnakes along with a limited amount of cobra venom and other chemical agents.


Moreover, the substance is found only in South American rattlesnakes, and not in the poison of their North American counterparts.

That makes crotoxina the type of drug mainstream cancer research scientists and doctors would normally laugh off without much thought.

Only in Argentina, nobodyis laughing.

'The cancer patient is like a prisoner in a jail cell,' said Maria Cecilia Centurion, 38, in an interview. She herself is suffering from terminal cancer.

'Any drug that offers a new possibility for life is like an open window in that cell,' she said.


Centurion is secretary of a recently formed lobby called 'Crotoxina: Hope for Life,' composed of cancer patients and their relatives, who are pressuring the government to continue research into the drug through human experiments.

The controversy has bitterly divided the Argentine medical profession, mobilized human rights groups and political parties in a national debate, and threatened President Raul Alfonsin with a miniature political crisis.

Government cancer experts, after analyzing the cases of 83 patients treated with the drug, said in a preliminary report they could not find a single instance where Crotoxina was definitely the medicine that led to improvement. Their report on Aug. 18 said 23 of the 83 patients died since May, and from 32 to 48 of the other patients were deteriorating. It said investigators could not get enough data to evaluate the remainder of the cases.

However, the report did not discredit the drug altogether and said testing will continue.

The three doctors administering the drug and the 'Crotoxina: Hope for Life' committee have claimed that the medicine can be effective in 40 percent of the cases.

Vidal, a prestigious biochemist and toxicologist who also has a medical degree, is credited with discovering the drug Crotoxina through a laboratory accident in 1979.


Convinced of the substance's possiblities as an anti-cancer agent that would work in a way similar to chemotherapy without the latter's side effects, such as loss of hair, he collaborated in its experimental production and administration for the past five years with a reduced number of doctors, scientists, technicians and patients.

In April, he and three medical doctors quietly patented the medicine, a move unnoticed by the public at the time.

Vidal traveled to Chicago in June to undertake research on the effect of toxic substances on the nervous system at the department of biochemistry and molecular biology at the University of Chicago, where he works under the direction of Dr. Paul Siegler.

In his absence, he and the medical team in Buenos Aires became sudden celebrities, both hailed as medical pioneers and condemned as quacks.

What precipitated the uproar was the sudden withdrawal of crotoxina from the 83 patients receiving it in Buenos Aires on an experimental basis.

The director of Argentina's Neurobiology Institute, Juan Tramezzani, ordered production halted in the institute's facilities, calling its distribution 'fraudulent,' something vigorously denied by Vidal and his collaborators.

But the biggest outcry came from the patients who were receiving the drug and were convinced it gave them at least a chance to live.


They appealed to newspapers, radio and television stations, and magazines for a resumption of the drug's production and distribution.

Two of those who went public, saying crotoxina saved their lives, were Mauricio Olemberg, a psychiatrist, and dentist Celia Vintas.

Two of Argentina's major human rights groups, the Mothers of the Plaza de Mayo and the Center for Legal and Social Studies, backed the patients and demanded resumption of drug production, at least for controlled experiments.

Three street demonstrations in favor of the drug were mobilized, the largest turning out 2,000 persons.

Leaders of the opposition Peronist party backed the pro-Crotoxina forces.

Health Minister Conrado Storani, fearing political fallout from human rights groups and the political opposition, ordered drug production and distribution resumed for the survivors of the 83-member pilot patient group, giving government scientists time to complete an investigation.

The National Council of Scientific and Technical Investigations, a government body, on Aug. 14 issued a communique condemning Vidal and the three doctors who administered crotoxina, accusing them of using irregular and improper experimentation techniques and of failing to test crotoxina first on animals.

Yet the council also recognized the need for further research into the drug 'by working groups with the right experience.'


Vidal, 45, has called crotoxina 'one more weapon' in the arsenal against cancer, but he has warned that it is an experimental drug 'whose results can not be guaranteed.'

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