The death of a vCJD patient who had shown a “remarkable” improvement after starting a controversial drug treatment will not affect preparations for clinical trials of the treatment in the US and UK, authorities say.
Rachel Forber was diagnosed with the human form of mad cow disease in June 2001. In August, she flew to the laboratory of Stanley Prusiner at the University of California, San Francisco for treatment with chloropromazine, an anti-psychotic, and quinacrine, which is conventionally used against malaria. Laboratory studies had suggested that both drugs can block the formation of prions, which cause vCJD.
Within three weeks, Forber showed such an improvement that the UK government announced it would fast-track a trial to evaluate the efficacy and side-effects of quinacrine on patients with vCJD and related sporadic CJD. But Forber was taken off quinacrine after suffering liver damage. She died of causes unrelated to that damage on 30 November.
Peter Smith, deputy chair of the UK government’s Spongiform Encephalopathy Advisory Committee (SEAC), says that most of the science community had been sceptical that quinacrine was a miracle cure. “I guess most people won’t be surprised that the unfortunate woman died,” he told New Scientist.
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Families’ dismay
Smith adds: “There had been some in-vitro evidence it would work, but that’s a long way away from patient trials.
“Patients and their relatives are often prepared to take risks when faced with a fatal disease, when really we would be happier if drugs were tried out in a cellular system first.”
Forber’s death has dismayed families of patients with vCJD and sporadic CJD, says Francis Hall of the UK’s Human BSE Foundation, who knew the Forber family. “It’s terrible for hope to be given and then snatched away like that. We’re right back where we started with no cure.”
Memory improvement
Three weeks after starting treatment, Forber was no longer confined to a wheelchair. She was again able to clothe and feed herself and showed improvements in memory and alertness. But some vCJD experts suggested that she might have experienced a “natural” improvement in her condition, rather than one triggered by the drugs.
Prusiner’s team is planning to start full-scale trials of both drugs on US patients with sporadic CJD within the next three months.
The UK’s Medical Research Council also plans to start full-scale clinical trials of quinacrine at St Mary’s Hospital in London in January 2002. But UK vCJD and CJD patients who request the drug are currently being given it, St Mary’s says.
“Clearly we already know a lot about quinacrine and its side-effects,” says Janet Derbyshire, head of the MRC’s Clinical Trials Unit. “With malaria, the risks outweigh the benefits, so we treat patients with newer drugs, but CJD has no cure.”
But the small number of vCJD cases will make it difficult to evaluate the drug, say critics. “Even though trials will also be carried out with sporadic CJD, that still amounts to only about 40 cases a year and those patients only tend to live about five months after diagnosis,” Smith says.
Of the 113 people identified with definite or probable vCJD since 1996, eight are still alive.
