The primary objective of this study is to define the effect of Tysabri in patients with
relapsing-remitting (RR) multiple sclerosis (MS) over 2 years. The investigators will also
explore the extent of remyelination in MS patients treated with Tysabri over 2 years.
A secondary objective of this study is to investigate differences in the capacity for
remyelination between patients who do or do not respond to Tysabri monotherapy during the
same 24 months.
A tertiary objective of this study is to monitor Tysabri effect in MS antiphospholipid
antibodies positive and MS antiphospholipid antibodies negative patients and to determine
perfusion differences according to the antiphospholipid antibodies positivity status.
Minimum age: 18 Years.
Maximum age: 65 Years.
Gender(s): Both.
Inclusion Criteria:
- Patient diagnosed with clinically definite MS according to the Polman criteria
- Age 18-65
- Have a RR disease course
- Have EDSS scores less than or equal to 5. 5 {Kurtzke, 1983 #15}
- Have disease duration less than 20 years
- Fulfilled the TOUCH enrollment requirements and started on Tysabri monotherapy
- Signed informed consent
- None of the exclusion criteria
Exclusion Criteria:
- Primary progressive, secondary progressive, or progressive relapsing MS. Primary
progressive, secondary progressive or progressive relapsing multiple sclerosis.
- A clinically significant infectious illness (e. g., cellulitis, abscess, pneumonia,
septicemia) within 30 days prior to drug start.
- History of, or abnormal laboratory results indicative of, any significant cardiac,
endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary,
gastrointestinal, dermatologic, psychiatric, renal, and/or other major disease that,
in the opinion of the investigator, would preclude the administration of natalizumab
for the duration of the study.
- History of severe allergic or anaphylactic reactions or known drug hypersensitivity.
- Abnormal blood tests, performed at the screening visit, which exceed any of the
limits defined below:
- ALT/ SGPT, or AST/ SGOT > three times the upper limit of normal (i. e., 3xULN).
- Total white blood cell (WBC) count <2,300/mm3.
- Platelet count <100,000/mm3.
- Creatinine > 2xULN.
- Prothrombin time (PT) > ULN.
- Any prior treatment during the 2 weeks prior to study screening with agents such as
IFN-β, GA, IVIG, or on the following immunosuppressant therapies for less than 3
months: mitoxantrone, cyclophosphamide, cladribine, fludarabine, cyclosporine,
azathioprine, methotrexate, Cellcept, etc.
- History of alcohol or drug abuse within 2 years prior to randomization.
- Female subjects who are not postmenopausal for at least 1 year, surgically sterile,
or willing to practice effective contraception (as defined by the investigator)
during the study. The rhythm method is not to be used as the sole method of
contraception.
- Nursing mothers, pregnant women, and women planning to become pregnant while on
study.
- Unwillingness or inability to comply with the requirements of this protocol including
the presence of any condition (physical, mental, or social) that is likely to affect
the subject's ability to comply with the study protocol.
- Any other reasons that, in the opinion of the Investigator, indicate that the subject
is unsuitable for enrollment into this study.