Cancer drugs which have not been tested on humans are to be given to terminally ill patients by the NHS in England.
Doctors hope to speed up the approval time
London's St Bartholomew's Hospital will be the first to offer the drugs, followed by 18 other centres.
Doctors say patients will only be given the drugs if they have no other hope of recovery, and they will only get small doses of medication to start with.
The Department of Health approved the move in a bid to halve the amount of time it takes to develop new drugs.
With drug approval currently taking on average 10 years, doctors want to speed up the process.
"We're not talking about cutting any corners in terms of patients' safety," Professor John Gribben from Barts and The London NHS Trust said.
"We would argue that for patients who've got cancer 10 years is too long to wait and we've got to try to cut that period down as much as possible."
Blood samples from patients will be analysed within a day and the treatment only continued if it proves effective.
Mr Gribben added: "What we're looking for is drugs that will kill the cancer cells but leave the rest of the patient intact. We're always prepared for very unexpected effects.
"We know for each product that comes along what the potential side effects might be, and we've got staff who spend a lot of time counselling patients before they sign up to make them aware of the risks and potential lack of benefits."
The initiative is being funded by the Department of Health and Cancer Research UK who are providing £400,000 per year.