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After persistent pressure and a threat of legal action from an eminent
critic of genetic engineering, the US National Institutes of Health has
agreed to suspend the enrolment of children in two clinical trials of synthetic
human growth hormone.

In a legal petition delivered to the NIH at the end of June, Jeremy
Rifkin’s Foundation on Economic Trends, and the Physicians’ Committee for
Responsible Medicine, threatened legal action if the NIH did not respond
within 20 days to their concerns about the safety and ethics of the trials.
In a letter delivered to the foundation last week, Bernadine Healy, director
of the NIH, said that after considering the issues raised in the petition,
the NIH would call on independent experts to review its research on human
growth hormone.

The independent reviewers meet next week and will report their findings
to Healy within three months, says Marsha Love, a spokeswoman for the National
Institute for Child Health and Human Development, which is overseeing the
trials. Healy will then provide a ‘substantive response’ to Rifkin’s petition
based on their findings. In the meantime, the trials will continue, but
no new children will be enrolled.

Synthetic versions of the human growth hormone produced by genetically-engineered
bacteria are marketed in the US by Genentech and Eli Lilly. The Food and
Drug Administration has approved the drug only for the treatment of children
with pituitary dwarfism, who do not produce enough of the hormone themselves,
but some paediatricians are giving the drug to children who are simply short.

The NIH is supporting two separate trials of the hormone. One is a study
of the effect of growth hormone on girls with Turner’s syndrome, a chromosomal
abnormality which results in extremely short stature. The other trial is
designed to test the effects on children who are very short for their age
but have normal levels of growth hormone and normal growth hormone receptors.
Boys in the study are projected to reach an adult height of no more than
160 centimetres, and girls no more than 145 centimetres, putting them in
the bottom percentile for their age group.

In the trial, the children are given three injections a week of either
the hormone or a saline placebo. The children are also given regular X-rays,
blood tests and psychological testing. They are photographed naked each
year to record growth. The study continues for each child for 10 years or
until they reach their adult height.

The foundation’s petition calls for a complete halt of the trial of
healthy short children, and of the placebo arm of the Turner’s syndrome
trial. Lawyers for the foundation argue that giving these children a placebo
violates federal regulations governing the participation of children in
clinical trials. ‘This has been a laborious behind-the-scenes pursuit since
1989, but we thought we finally had a compelling legal case,’ says Rifkin.

The foundation’s legal reasoning is modelled on a report published in
1989 by a team from the University of Nebraska Medical Center’s Institutional
Review Board, the body which reviews all research on human subjects. Researchers
at the university had been asked to participate in a multi-centre trial
of human growth hormone in girls with Turner’s syndrome, similar to the
trial at NIH. Nebraska’s review board concluded that the research did not
comply with federal regulations, because the risks to the children given
a placebo were greater than minimal, the placebo offered no benefit, and
the research was not likely to yield vital knowledge.

According to Ernest Prentice, vice-chairman of the review board: ‘There
are situations where the utilisation of a placebo is simply not justified.
The trial is not going to be as scientific without a placebo, but when you’re
talking about injecting children with saline hundreds of times, which is
painful, maybe we have to compromise a little bit.’

At the NIH, Love counters that ‘there is no way to really confirm the
effect, particularly if the effects are modest, without a placebo arm in
the trial’.

The NIH argues that paediatricians are already giving the hormone to
healthy, short children, and that therefore the government has an obligation
to determine whether the drug is safe and effective for this purpose. ‘If
you’re going to have a large demand for a drug, and there’s no restriction
on getting it, we have to know what the effects of the drug are in order
to protect our children,’ says Love.

Rifkin believes that the NIH has no business conducting research on
what he sees as a social problem. ‘If these kids are abnormal just because
society discriminates against them, then obese people, African-Americans,
perhaps even women would also be defined as abnormal,’ says Rifkin. ‘These
kids are not sick. What’s sick is the attitudes of our society.’