Thursday, April 13, 2006

What Did Parexel Tell the Participants in the TGN 1412 Trial?

We previously posted about the disastrous trial, implemented by Parexel International , of a new monoclonal antibody designated TGN 1412, manufactured by TeGenero AG. All six healthy volunteers who got the antibody soon became critically ill. We recently reported an account of an interview with one of the participants which serious questions about whether research subjects were adequately informed about the nature of the trial and its possible risks, and why the investigators continued to administer the drug after the first subjects had begun to experience adverse effects (see post here).

Bloomberg news just reported on the consent form used in the trial, raising even more issue about what the participants were told or understood about what could happen to them. These issues are summarized below.

Risks Not Revealed - Bloomberg showed the form to several medical ethicists. Michael Goodyear stated, "they [the trial investigators] failed to to adequately disclose the degree of uncertainty around a first-in-man trial. The risks were well known. They were not disclosed in the consent form." Arthur Caplan, of the Center for Bioethics at the University of Pennsylvania, said, "they hid the most serious threats with bland language." Parexel countered only by saying that the UK Medicines and Healthcare Products Regulatory Agency (MHRA) "has done an exhaustive inquiry of Parexel and confirmed that the trial was run according to the approved protocol." However, Bloomberg noted "the agency says its investigation didn't include a review of the consent form."

Participants Questions Deflected - Bloomberg reported that study participant Raste Khan claimed that Parexel staff deflected questions, saying "we're in a bit of a push. Can you sign now, and I'll explain it all to you."

Proportion of Patients to Receive Placebo Not Explained - Khan also said, "They didn't tell us how many placebos there were, so I just thought it was 50/50." Caplan called this a "'major' ethical violation to withhold the actual chance of receiving the drug."

Drug Not Described Clearly in Lay Terms - The drug was described as "a 'monoclonal antibody,' which means that it is an antibody (a naturally produced protein) that has been designed by scientists to target a particular type of cell -- in this case, a type of white blood cell called T-cells.'' Caplan retorted, "I've read a lot of consent forms and I don't understand this." Goodyear noted that the consent form never clearly said what the drug would do, specifically never stating that the drug would stimulate the immune system, and suggested that comparing the drug to aspirin and ibuprofen was also misleading.

Adverse Effects Minimized - "Parexel's consent form says the drug, called TGN 1412, was designed to treat arthritis, other inflammatory illnesses and leukemia. The form says that 'no significant side effects had been seen in the animal studies.' "I think it was misleading not to tell participants that that this drug was genetically engineered from hamster cells and that it was designed to alter their immune system,"' commented Goodyear. "Reasonable people would think twice before allowing an experimental drug to change their immune system.''
Furthermore, the form described a cytokine burst as akin to hives. Goodyear responded, "Since monoclonal antibodies are know to cause Cytokine Release syndrome, which can be fatal, and Parexel was not even planning for this, the subjects should have been warned." Parexel's response, again was "the MHRA found no deficiencies during its inspection of Parexel's Phase I unit at Northwick Park Hospital that would have contributed to the adverse reactions experienced by the study volunteers.''

Possible Coercion - "Ethicists say the consent document exploited the participants' need for cash. The first page of the consent document says participants can leave the trial at 'any time without giving a reason and my rights will not be affected.'' On page 9, the document says, 'If you leave the study and exercise your right not to give a reason or are required to leave the study for non-compliance, no payment need be made to you.'
'That's very coercive language,'' says Greg Koski, 56, a physician and former head of the U.S. Office for Human Subject Protection, interviewed by phone April 5. 'It's a bait and switch.'"

Failure to Identify Ethics Committee Which Approved the Trial - " Parexel's TGN 1412 consent form omitted the name and contact information for the Brent Medical Ethics Committee, which approved the consent form and supervised the trial." Caplan noted, "The participant needs to know who to contact. There has to be a source of independent advice. They are defeating the entire purpose of having an ethics committee if you can't find it.'' The MHRA investigation did not cover the role of the ethics committee.

Referral to an Irrelevant Pamphlet - " Parexel's consent form advised subjects to read a pamphlet published by Consumers for Ethical Research, a London-based advocacy group. Naomi Pfeffer, chair of the organization, says the booklet shouldn't be used for healthy volunteers as it was written as advice to sick people considering treatment through a clinical trial."

Revelations about how Parexel failed to inform, or misinformed subjects in the calamitous TGN 1412 trial, coupled with previous reports about how SFBC International, another contract research organization, treated its trial subjects (most recent post here), suggest that commercial contract research organizations need to be much more closely regulated and supervised than they are now. And it may be time to question the whole notion of commercial firms doing clinical trials of drugs and devices.

Addendum (14 April, 2006): The Lancet just published a lead editorial that summarized the TNG 1412 trial, and concluded, "the TGN 1412 events indicate that urgest change is needed in the approval processes and regulation of phase I trials of biologic agents." [Anonymous. Urgent changes needed for authorisation of phase I trials. Lancet 2006; 367: 1214.]

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