Jan 2002 PES Bulletin

Focus: CLINICAL TRIALS & MEDICAL RESEARCH in PORPHYRIA

     There are many avenues in clinical trials where a porphyria patient can be part of ongoing medical research and on the "cutting edge" of tomorrow's treatment protocols for various types of porphyria. The most frequent area of patient involvement is with that of investigational drugs.

     Remember that porphyria patients can test in drugs for other medical conditions and at the same time be contributing to the understanding of that drug on a porphyria patient. As the old saying goes, "Killing two birds with one stone."

     Before a pharmaceutical company can initiate testing in humans, the pharmaceutical manufacturer must conduct extensive preclinical or laboratory research. Most often there are years of experiments in animal and human cells. The compounds are also extensively tested in animals.

     When this stage of testing has been deemed successful, a pharmaceutical company then presents this statistical data to the Food and Drug Administration (FDA). At this point they are requesting approval to begin testing the drug in humans. This is called an Investigational New Drug application (IND). Each step in the process is quite lengthy, but assures us of many checks and balances along the way. However even after a drug is approved it is very often contraindicated in porphyrics.

     Many porphyria patients wonder about the costs of research and clinical trials. Porphyria patients are interested in clinical research but wonder how much is the cost. So the questions remains: Who pays for clinical research?

     Funding for clinical research comes from both the federal government and from private industry. Much of private industry includes the chemical companies which produce everything from petroleum, paints, drugs and other bio-tech.

     In the United States the US Government entity for medical research is known as the National Institutes of Health.

     The NIH as it is often referred to, sponsors of a specified research hire physicians, who may work in a wide variety of health-care settings, to conduct the clinical trial. The physicians are typically paid on a per-patient basis. The medical care is often provided free to the patient. Patients may also be paid a small fee to participate in a clinical trial.

     Clinical trials cover a lot of different aspects and testing of experimental drugs is one of the top priorities. Clinical testing of experimental drugs is usually completed in three phases.

     Each individual successive phase involves a larger number of Once the FDA has granted a New Drug Approval (NDA), the pharmaceutical companies also conduct a post marketing or what they call a late phase three/phase four study.

     The first part of the studies deal with safety. Phase I studies are primarily concerned with assessing the drug's safety. This initial phase of testing in humans is done in a small number of healthy volunteers (20 to 100). These volunteers are usually paid for participating in the study.

     The reason for this study is to determine what happens to the drug in the human body. This is to ascertain how it is absorbed, metabolized, and excreted. In the initial study it will investigate side effects that occur as dosage levels are increased.

     This takes several months. About 70 percent of experimental drugs pass this initial phase of testing.

     The second phase is known as efficacy. Once a drug has been shown to be safe, it must be tested for efficacy. This second phase of testing may last from several months to two years, and involve up to several hundred patients. This usually consists of randomized trials. One group of patients will receive the experimental drug, while a second "control" group will receive a standard treatment or placebo. Often these studies are "blinded"--neither the patients nor the researchers know who is getting the experimental drug. By doing it in this fashion, the study can provide the pharmaceutical company and the FDA comparative information about the relative safety of the new drug, and its effectiveness. Only about one-third of experimental drugs successfully complete both phase I and phase II studies.

     Most importantly is looking for the adverse reactions of a drug. Looking for adverse reactions happens in the third phase study. Hundreds or thousands may be tested during this phase.

     This large-scale testing provides the pharmaceutical company and the FDA with a more thorough understanding of the drug's effectiveness, benefits, and the range of possible adverse reactions. The majority of phase III studies are randomized and blinded trials. It will last usually for several years. About 70 to 90 percent of drugs that enter phase III studies successfully complete this phase of testing. Once this phase study is successfully completed, a pharmaceutical company can request FDA approval for marketing the drug.

     The fourth phase is known as the pos- marketing phase. It is also the last phase of testing.

     In last phase studies, pharmaceutical companies have several objectives. The objectives include that:(1) studies often compare a drug with other drugs already in the market; (2) studies are often designed to monitor a drug's long-term effectiveness and impact on a patient's quality of life; and(3) many studies are designed to determine the cost-effectiveness of a drug therapy relative to other traditional and new therapies.

     People participate in clinical trials for a number of reasons. People who volunteer for phase II and phase III trials can gain access to promising drugs long before these compounds are approved for the marketplace. For instance at the present time heme arginate which is deemed better Intervention Therapy for treatment of acute porphyria attacks is now undergoing trials in the United States, although all ready approved in Europe and Australia.

     Volunteers typically will get excellent care from the physicians during the course of the study. This care will most likely be free.

     The patient's rights and safety are protected in two important ways. First, any physician awarded a research grant by a pharmaceutical company or the NIH must obtain approval to conduct the study from an Institutional Review Board.

     The review board, which is usually composed of physicians and lay people. This review board is charged with examining the study's protocol to ensure that the patient's rights are protected, and that the study does not present an undue or unnecessary risk to the patient. Second, anyone participating in a clinical trial in the United States is required to sign an "informed consent" form.

     This "informed consent" form details the nature of the study. The form clearly states the risks involved, and what may happen to a patient in the study. The informed consent tells patients that they have a right to leave the study at any time.

     Patients considering participating in clinical research should talk about it with their physicians and medical caregivers. Also if you are considering participating you should also seek to understand the credentials and experience of the individuals and the facility involved in conducting the study.

     Other questions to ask include:
How long will the trial last?
Where is the trial being conducted?
What treatments will be used and how?
What is the main purpose of the trial?
How will patient safety be monitored?
Are there any risks involved?
What are the possible benefits?
What are the alternative treatments besides the one being tested in the trial?
Who is sponsoring the trial?
Do I have to pay for any part of the trial?
What happens if I am harmed by the trial?
Can I opt to remain on this treatment, even after termination of the trial?

Dr. Robert Johnson M.D.
Retired clinician

FOCUS: DETERMINING PORPHYRIA PN

     Peripheral Neuropathy [PN] can be determined testing by a neurologist. In porphyria based PN often test results will be inconclusive because much porphyric PN is transient and for the most part in most neurological testing only permanent paralysis can be noted.

     First there is the simple pin sticking checking for nerve impulse.Then the rubber tipped hammer to check for tendon reflexes.Then the biggie... an EMG [Electromyography].

     Electromyography is a diagnostic neurolic test to study the potential [electrically measured activity] of muscle at rest, the reaction to contraction, and the response of muscle to insertion of a needle. The test is an aid in ascertaining whether a patient's illness is directly affecting the spinal cord, muscles or peripheral nerves.

     How is the test performed?

The patient lies at rest while the peripheral nerves in various are stimulated through electrodes, and the electrical activity in the muscle at rest, on insertion of the needle, and during the muscle contraction. The test is sometimes employed as a measure of the muscle tension produced by nervous stress, usually, the muscles of the forehead are tested, since they can indicate relaxation of generalized body tension.

     Electromyoneurogra[hy is the combined use of electromyography and neurography. The two tests offer a more precise means of finding the exact location of nerve damage or disorder.

     Dynomometry testing uses a dynomometer [most often a dial guage attached to a spring mechanism that measures the strength of muscles] to ascertain certain physical abilities such as holding an object in the hand. It helps detect diseases of the nerves from the spinal cord to the muscle.

     There is negligible risk factor in running this test. All that is involved is the catheter and needle insertion along with the elctrical instruments.

     The pain and discomfort from the test focuses on the needle insertion, which is usually done without local anesthesia. This can be quite uncomfortable and at times even very painful.

     Interpretation of the tests must be made by a neurologist. In the normal values, when the muscle is at rest, no electrical activity is observed. When the muscles contract, the electromyography will show a smooth graphic wavelike representation of each contraction. The graph lines are amplified with the increase in strength of each contraction.

     When the values are abnormal, muscle disease will produce a spiked wave pattern. The shape of the spike depends on the particular disease. Muscle weakness produces a diminished wave. With myasthenia gravis, for instance, the waves disappear for a few minutes. Nerve involvement, as oposed to muscle involvement, usually shows a decreased frequency of contractions.

     Current costs of this test runs from$150 to $350 depending on how many muscles or nerves are tested. If all of the extremities are tested, the fee can run to $650. Also, when elctromyoneurolography is used the total cost can run to around $500.

     Neurologist consider the test quite reliable and rate it as 90 percent accurate. As stated by a neurologist colleague, "it is quite difficult for a pretender /malingerer to fake to have muscle pathology when muscles respond to electric stimulation.

Dr. George Howell
Neuropsychiatric Sciences

DRUG UPDATE

ALADDIN is a brand name for the generic drug PHENOTOIN. Another name is DILANTIN. It is an antiepileptic drug. It is related to barbiturates in chemical structure. The liver is the chief site of biotransformation of phenytoin; patients with impaired liver function and porphyria should not take this drug.

TRIZOLE is a brand name for the generic drug combination of SULFAMETHOXAZOLE and TRIMETHOPRIM. It contains sulfa as an ingredient. The drug carries a warning against use in persons with the disease porphyria.
br> WELLBUTRIN is a brand name for the generic drug BUPROPION. It is also known as ZYBAN. It is in the classification of Aminoketone and is used as an Anti-depressant and for Smoking cessation.

Side effects include Chills, facial edema, musculoskeletal chest pain, and photosensitivity. and Abnormal liver function, gastric reflux, gingivitis, glossitis, hepatitis, intestinal perforation, liver damage, pancreatitis, and stomach ulcer. In the Endocrine system side effects include hyperglycemia, hypoglycemia, and syndrome of inappropriate antidiuretic hormone. In the Metabolic conditions the side effects include: Edema, increased and peripheral edema. Muscle weakness has also been observed. Due to the Abnormal liver function, gastric reflux, jaundice, stomatitis, gastrointestinal hemorrhage, hepatitis, and liver damage that have been experienced the drug is considered UNSAFE.

PREDNISONE is the GENERIC name for the BRAND NAME[S]: Apo-Prednisone; Adasone; Cartancyl; Colisone; Cordrol; Cortan; Cortancyl; Dacortin; Dacorten; Decortin; Decortisyl; Delcortin; Dellacort; Dellacort A; Delta-Dome; Deltacortene; Deltacortone; Deltasone; Deltison; Deltisona; Di-Adreson; DiAdreson; Econosone; Encorton; Fernisone; Hostacortin; Liquid Pred; Me-Korti; Meticorten; Nisona; Novoprednisone; Orasone; Origen Prednisone; Panafcort; Panasol; Paracort; Parmenison; Pehacort; Predeltin; Prednicen-M; Prednicorm; Prednicort; Prednicot; Prednidib; Predniment; Prednitone; Rectodelt; Sone; Sterapred; Ultracorten; Winpred. Predinsone which is a glucocorticoid, an adrenocortical steroid.

SIDE EFFECTS: Sodium retention, fluid retention, increased intracranial pressure, convulsions, decreased carbohydrate tolerance; manifestations of latent diabetes mellitus; increased requirements for insulin and hypersensitivity reactions have been observed. PRECAUTIONS: There is an enhanced effect of corticosteroids on patients with hypothyroidism and in those with cirrhosis and liver disease. This drug is not recommended for persons with liver disease.