Given that this is the sticky for those people who are contemplating Tysabri might review, it's probably as good a place as any to store all NMSS warnings/bulletins that come out along the way (like this recent liver one).
I am aware of two other warnings that have come out previously:
Research
Bulletins
Bulletins Archive
Researchers Report that Stopping Tysabri Increased MRI-Detected Disease Activity in Some Patients, September 14, 2007
Researchers from one site involved in the pivotal studies of Tysabri® (natalizumab, Biogen Idec and Elan Pharmaceuticals) in relapsing forms of MS report that stopping the drug may lead to an increase in the number of new and enlarging lesions (areas of damage or disease activity) detected on magnetic resonance imaging scans. They compared before-treatment scans with scans from a 15-month period after 21 participants stopped taking the drug. No substantial increase of clinical activity, such as relapses, was noted. These findings of “rebound” activity occurring in a small sample of patients warrant confirmation in independent, larger groups of people before recommendations can be made concerning Tysabri administration. Drs. Machteld Vellinga, Chris Polman (VU University Medical Center, Amsterdam, the Netherlands) and colleagues report the findings in the online edition of the journal Neurology (published online September 12, 2007).
Background: Tysabri was approved by the FDA for relapsing MS based on its ability to slow disability progression and reduce relapses in two pivotal clinical trials, called AFFIRM (which compared Tysabri alone to inactive placebo in 942 people with relapsing MS) and SENTINEL (which tested Tysabri plus interferon beta-1a or Tysabri plus placebo in 1171 people with relapsing MS). Detailed results were published in The New England Journal of Medicine 2006;354:899-910 and 2006;354:911-923).
These studies were suspended when two cases of PML (progressive multifocal leukoencephalopathy, a rare and frequently fatal disease of the central nervous system) were diagnosed in those on combination therapy. One of those cases was fatal. A third case of PML, also fatal, was uncovered in another person who had taken Tysabri during a clinical trial for Crohn’s disease.
“Rebound” findings: When dosing was suspended in these studies at the VU University Medical Center in Amsterdam, the neuroradiologist reviewing post-treatment MRI scans noticed an increase in lesions among participants. The team analyzed “T2” lesions, which show cumulative damage, from 21 people who had MRI scans of their brains taken before taking Tysabri and again within a 15-month interval after discontinuing the drug. Participants were divided into two groups: one group took the drug for an average of three years, and the other group took the drug for an average of two months.
Their findings show that the total group of participants developed more than three times as many lesions in the 15-month period after discontinuing the drug than before they started taking it. This increase was mainly driven by those who took the drug for an average of two months, who experienced five times as many brain lesions after stopping the drug. Clinical relapses did not increase following suspension of the drug.
These findings of “rebound” activity occurred in a small sample of patients, and warrant confirmation in independent, larger groups of people so that their potential significance to clinical practice in terms of the administration of Tysabri can be determined.
http://www.nationalmssociety.org/sit...rch_2007sept14
Research
Bulletins
Bulletins Archive
Two Cases of Melanoma (Skin Cancer) Reported in People Taking Tysabri for MS, February 7, 2008
Physicians in Boston have reported two cases of melanoma (skin cancer) that developed in women in their practice who were administered Tysabri® (natalizumab, Biogen Idec and Elan Pharmaceuticals) to treat their multiple sclerosis. John T. Mullen, MD, and two colleagues (Beth Israel Deaconess Hospital, Boston) reported the cases in the New England Journal of Medicine (2008;358[6]:647-8). The melanomas developed early in the course of treatment, but it cannot be confirmed from these case reports that Tysabri caused them. However, the authors advise against treating individuals with Tysabri when there is a personal or family history of melanoma or in patients with atypical moles or ocular nevus (spot at the back of the eye).
Background: Tysabri is a laboratory-produced monoclonal antibody that is approved for patients with relapsing forms of MS to delay the accumulation of physical disability and reduce the frequency of clinical exacerbations. It is designed to hamper movement of potentially damaging immune cells from the bloodstream, across the "blood-brain barrier" into the brain and spinal cord.
Details: Dr. Mullen’s team reports that a 46-year-old woman developed a melanoma shortly after receiving her first dose of Tysabri, and an ocular nevus developed into a melanoma after several doses in a 45-year-old woman with a family history of melanoma . A case of melanoma also appeared in the AFFIRM study which involved 942 individuals with relapsing MS, who received either Tysabri or inactive placebo by intravenous infusions every four weeks for more than two years in a patient with a history of malignant melanoma.
It cannot be confirmed from these reports that there is a causal link between Tysabri administration and the occurrence of melanoma. However, given these occurrences, the authors recommend that Tysabri not be administered to people with a history or family history of melanoma.
“These reports raise concern and they underscore the importance of carefully tracking patients on powerful medications like Tysabri,” said Dr. John R. Richert, executive vice president of research and clinical programs at the National MS Society. “This drug is relatively new to the market, and as experience grows we are bound to learn more about its benefits as well as possible adverse events,” Dr. Richert added.
http://www.nationalmssociety.org/sit...earch_2008feb7
Previous conversation here about this topic:
http://neurotalk.psychcentral.com/sh...hlight=tysabri
Cherie