CIDP What Is The Path Study

Today's post from neuropathy.org (see link below) invites people to join a 'Path' study in their area. This sort of study looks at the effectiveness of immunoglobulin being injected to treat CIDP (chronic inflammatory demyelinating neuropathy. Chronic CIDP is a lesser known form of neuropathy the main symptoms of which are weakness in the arms, legs, hands and feet. Normally this is treated with corticosteroids which are administered in pill form but they are looking into the effectiveness of injected immunoglobulin as an alternative. Now many people with neuropathy (peripheral or otherwise) suffer to some extent from weakness in the limbs and this is often accompanied (or even caused by) muscle decrease. If you feel that the weakness you are feeling is more than could reasonably be expected, it may be worth talking it over with your doctor or neurologist, to see if CIDP is playing a part.

Understanding the "PATH" Study, Assessing Subcutaneous Immunoglobulin, for CIDP  
Neuropathy Association June 18, 2014

Learn more about this clinical
research study...

If you are looking to volunteer or want
information about a study site near you,
please contact the study team at
clinicaltrials@cslbehring.com.

Chronic inflammatory demyelinating polyradiculoneuropathy, or CIDP, is a rare disorder of the peripheral nerves occurring at any age. Although the exact cause is not known, CIDP is considered an autoimmune disorder. It is twice as common in males as in females. The prevalence of CIDP is unclear, but in studies performed worldwide, it has been estimated to range from 1.9 per 100,000 to 7.7 per 100,000.

CIDP is characterized by weakness in the arms and legs which gradually worsens over a period of months. A patient with CIDP may find walking difficult due to weakness, or have difficulty using their arms and hands and/or legs and feet. Children are often diagnosed because of a disturbance in the way they walk, potentially causing them to fall, or by muscle weakness and loss of tendon reflexes. The course of the disease in children may be variable, showing a pattern that changes from worsening (relapsing) of symptoms to improvement (remitting).

1. How is CIDP treated?

Clinical studies in CIDP patients have shown that effective treatments include immunoglobulins or corticosteroids. In the event that neither of these options is effective, plasma exchange may be considered.Patients with CIDP can be treated with immunoglobulins or corticosteroids as first-line therapy. Immunoglobulins can be administered intravenously (IVIg), while corticosteroids may be administered by mouth (orally) or intravenously. A third option, plasma exchange or plasmapheresis (PE) can also be effective. PE is a blood purification procedure used to treat several autoimmune diseases, including CIDP.

It is important to discuss the advantages and disadvantages of these treatment options, as recommended by the guidelines, with your doctor. To ensure the most effective treatment is being used, all patients will have an individualized assessment of their treatment response.

2. What is IgPro20?

IgPro20 is a 20%, ready-to-use, liquid formulation of purified human immunoglobulin for subcutaneous (SCIg) administration. It is manufactured by the same advanced process that is used in the manufacture of 10% intravenous immunoglobulin (IVIg), Privigen. IgPro20 contains a higher immunoglobulin concentration than other SCIg immunoglobulins and IVIg products, giving the potential for a low infusion volume and short infusion time.

SCIg administration involves injection of immunoglobulin under the surface of the skin, and does not require access to a vein. This method of administration provides a convenient alternative to the intravenous route, and is often administered under medical supervision.

CSL Behring is recruiting patients for the Polyneuropathy And Treatment with Hizentra (PATH) study to evaluate the effectiveness of IgPro20 compared with placebo in the treatment of CIDP.

3. What are the potential benefits of subcutaneous administration vs. intravenous?

Although SCIg is not yet labeled for use in CIDP, IVIg is a well-established treatment for CIDP. SCIg products are already widely used in the treatment of primary and secondary immune deficiencies, and the subcutaneous route has a number of proven advantages over intravenous administration.

The IVIg route of administration can produce high Ig levels that may trigger side effects such as headache. With SCIg -- which is administered at lower, more frequent doses -- the headaches are less frequent.

SCIg’s frequent dosing schedule also means that there are less fluctuations in the patients’ Ig levels. Typically, after IVIg treatment, Ig levels rise sharply then decline, tailing off and wearing off, as 3 to 4 weeks elapse. However, with weekly SCIg, a more consistent steady-state Ig levels are seen in patients. The wear-off effects, such as weakness, which some patients experience in between doses of IVIg may therefore be reduced in patients receiving SCIg.

In addition, the SCIg route provides the potential for patients to self-administer. After appropriate training, patients can receive their treatment wherever and whenever it suits, such as in the home, for example while reading or watching television. SCIg may also be administered by a parent or a caregiver. The result is that, compared with IVIg treatment, CIDP patients may have more independence and convenience with SCIg. E.g., Patients do not have to take time off from work or school to receive SCIg.

4. What is the PATH study and what does it involve?

The Polyneuropathy And Treatment with Hizentra (PATH) study is an international clinical trial designed to assess the use of SCIg in the treatment of CIDP. The safety and effectiveness of two different dosages of IgPro20 are evaluated by comparison with placebo.

To be eligible to take part in the study, participants must:

a) have been diagnosed with definite or probable CIDP as defined by the European Federation of Neurological Societies and Peripheral Nerve Society (EFNS/PNS) guidelines;

b) have had repeated treatment with IVIg (four or more infusions) in the previous nine months;

c) have had IVIg treatment in the previous eight weeks; and

d) be at least 18 years old.

The study lasts up to 52 weeks and is divided into four parts:

- Screening Period: During the screening period, medical assessments and a blood draw may be carried out to decide whether the patient is eligible to participate.

- Immunoglobulin Dependency Test Period: During the immunoglobulin dependency test period, the purpose is to test the patient’s dependence on immunoglobulin therapy—to be certain that immunoglobulin treatment is still needed—before the study drug is administered. The patient will be trained and asked to look for signs and symptoms of immunoglobulin dependency, for example, by monitoring ability to perform certain everyday activities.

- Re-Stabilization Period: If a patient experiences a relapse in symptoms during the 12-week dependency test period, they will be asked to visit the clinic to be re-stabilized on IVIg treatment. If symptoms do not worsen, then IVIg may not be needed or a reduced dose may be appropriate. For patients who require re-stabilization, treatment will continue for 10-13 weeks before entering the final SCIg treatment period of the study.

- SCIg Treatment Period: During the SCIg treatment period, study participants will receive weekly infusions of either placebo or the study drug for 25 weeks. The first two SCIg infusions will be performed at the clinic, where a member of the study team will teach patients how to administer the treatment. After that, patients may carry out the infusions themselves at home.

To assist in measuring the effectiveness of IgPro20 in CIDP, the study is carried out double-blinded, meaning that neither the patient nor the doctor will know which treatment is being given. Patients’ symptoms will be closely monitored throughout the study, and any worsening of symptoms will result in IVIg treatment being restarted.

5. How can I find out about taking part in the PATH study?

We are always looking for volunteers to participate in our studies. If you are looking to volunteer or want information about a study site near you, please contact the study team at clinicaltrials@cslbehring.com.

http://www.neuropathy.org/site/News2?page=NewsArticle&id=8699&news_iv_ctrl=1101