Articles on Law, Science, and Engineering

Public Policy and the Preemption of State Tort Claims against Medical Device Manufacturers (cont'd)

The Special Problems of Clinical Trials[index]

The clinical trial process is the most legally sensitive phase medical device development. The purpose of the clinical trial is to determine whether the device, as used in a clinical setting, is safe and effective. It is inappropriate to use products liability standards such as defect, unreasonably dangerous, and failure to warn in the clinical trial setting. These standards work for consumer goods such as lawnmowers because consumer goods can be withheld from the public until they are thoroughly tested and refined. This is not possible for medical devices. The public must be involved in clinical trials to gather the data to determine the risks and benefits of the device.

Prescription drugs and medical devices are the two product classes that are at the core of medical care delivery. Prescription drugs provide the best known model for clinical trials because clinical trials were required for drugs long before they were required for medical devices. Under FDA regulations, if a manufacturer wants to have a drug approved for marketing, the drug must go through a three phase clinical trial after extensive testing in animals. In Phase I, very small doses of the drug are given to healthy volunteers. The dose is gradually increased, while a careful watch is kept for adverse side-effects. In Phase II, the drug is given is given to volunteers with the condition that the drug is intended to treat to look for any evidence of beneficial action. In Phase III, the drug is given to randomly selected patients and compared to a control group of patients that either receive a placebo or a different drug. These controlled trials are usually done blind: neither the treating physician nor the patients know who is getting the investigational drug.

For most medical devices used in medical treatment rather than just monitoring, and for all implantables, it is impossible to carry out such carefully controlled clinical trials. There is no low dose of a medical device. The only way to test an implantable device is to implant it. IOLs provide a good example. It would be ethically impermissible to recruit healthy volunteers to have the lenses of their eyes removed and replaced with an IOL, irrespective of how safe it might be know to be.[7] The same would be true of grafts for arterial reconstruction, artificial joints, bone cement, and most other Class III medical devices.

The only ethically permissible candidate for an implantable device undergoing a clinical trial is a person with condition that the device is intended to treat. The device must treat the patient's condition, and must be expected to do so with at least as many benefits and as few risks as approved devices on the market. This is termed therapeutic research because the expectation is that the patient will benefit from the device used in the research. (In contrast, Phase I drug trials are non-therapeutic research because the healthy volunteers can expect no medical benefit from receiving the drug.) As therapeutic research, the device is implanted by patient's treating physician, or under the supervision of the treating physician if the implantation requires special skills or training.

The ethical requirement that implantable medical devices be tested only on persons for whom they may have clinical benefit means that these medical devices cannot be perfected before they are used on the general public. The subjects in clinical trials of medical devices will always receive device with some level of unknown risk. Yet this very lack of information about the risks of an investigational device would make it unreasonably dangerous in products liability analysis. The only defense would be that the patient was properly informed of all potential complications and adverse side-effect and that he/she made a knowing and voluntary assumption of the risks of the procedure.

The problem is that while the full compliment of risks would only be known in hindsight, plaintiffs' would argue that the knowledge of the risks related back to the beginning of the clinical trial and thus should have been explained to all the participants. Given that the information given to the participants in a clinical trial under FDA supervision cannot be change without FDA or Institutional Review Committee approval, it would be expected that there would be unavoidable delays before newly identified risks would be added to the consent forms. Finally, the potential risks that are identified in a clinical trial are not communicated to investigators until it is certain that they are real risks and not artifacts. This has fueled claims by plaintiffs that the manufacturer improperly withheld information from the subjects.

It is the FDA's role to assure that these patients are not subjected to unreasonable risk during clinical trials. Allowing juries to second guess the conduct of the clinical trial based on a hindsight knowledge of the risks of the device would have a chilling effect on innovation. Having to pay litigation costs to defend every device that might have injured a patient in a clinical trial, plus potential awards of punitive damages for not warning the patients fast enough about risks are they were identified, would provide a strong incentive to avoid developing innovative devices. It would send a powerful signal that the only defensible clinical trials would those on devices that so closely resembled existing devices that the clinical trials would not identify any unexpected risks. While this might satisfy plaintiffs' argument that individual safety is the transcendent value to be protected, it would thwart the congressional aim of encouraging the development of new devices to alleviate human suffering.

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