Recruitment did not meet sponsors timeline

This is a randomized double-blind controlled trial of intravenous immunoglobulin (IVIg) for glycine receptor antibody positive (GlyRα1) antibody Stiff Person Syndrome (SPS) spectrum disorders. Adult patients will be enrolled over the course of 36 months. Study duration per patient will be 11 weeks. Total study duration will be 39 months. All treatment and study visits will occur at Mayo Clinic in Rochester, MN.

The purpose of this study is to determine whether intravenous immunoglobulin (IVIG) treatment reduces stiffness and spasms in patients with SPS spectrum disorders compared to patients who do not receive any treatment. In this study, investigators want to compare the effects, good and/or bad, of IVIG with placebo on participants with SPS to find out which is better. This is a "randomized, double-blind" study. Which treatment participants will receive is randomly determined. Participants have an equal chance of receiving IVIG or the placebo.

SPS spectrum cohort will include any from the SPS spectrum patient (stiff-limbs, stiff-trunk, stiff-limbs and trunk, and PERM). Study visits will be considered part of clinical care and will occur at: enrollment (will coincide with screening visit), and 11 weeks. IVIg/placebo (saline) treatments will be administered on 2 consecutive days in week 1, week 5, week 9 in all patients.

Inclusion Criteria

• Patient must be 18 years of age or older
• Must have symptoms of SPS for less than 3 years
• If taking corticosteroids, the patients must be on a stabile dose for 30 days prior to enrolment
• Patients will have a diagnosis of SPS spectrum disorder based on both of clinical and serological status

Exclusion Criteria

• Patients on immune suppressants initiated/dose increased in the prior 6 months

• History of thrombotic episodes within the 2 years prior to enrollment

• Known allergic or other severe reactions to blood products including intolerability to previous IVIG

• Previous adequate trial of IVIG as determined by the Principal Investigator

• IgA deficiency

• Reproductive status:

  • Women who are pregnant, breastfeeding
  • Women and men of childbearing potential who are unwilling or unable to use an acceptable method of birth control to avoid pregnancy for the entire study period, as evaluated by the investigator.

• Any surgical procedure within 4 weeks prior to baseline.

• Evidence of serious uncontrolled concomitant diseases that may preclude patient participation; Other nervous system disease, cardiovascular disease, hematologic/hematopoiesis disease, respiratory disease, muscular disease, endocrine disease, renal/urologic disease, digestive system disease, congenital or acquired severe immunodeficiency

• Known active infection within 4 weeks prior to baseline.

• Evidence of chronic active hepatitis B or C.

• Active ischemic heart disease in the past year prior to baseline.

• Patients should not have severe renal or hepatic disease

• Severe hypertension

Randomized double-blind