Came across this on Yahoo:
1. Arthritis Panel to Revisit Safety with TNF Inhibitors. The FDA’s Arthritis Advisory Committee will
discuss the postmarketing update to the safety of Immunex’s and J&J’s TNFa inhibitors, Enbrel and
Remicade, at its meeting on Friday, August 17. An FDA transcript containing briefing information for
the meeting was posted on the FDA’s website today at
fda.gov. We reviewed this transcript and present
our conclusions below. The majority of the transcript described the reasons behind past revisions to
the package inserts. These revisions concerned the possible association of Enbrel and Remicade to
multiple sclerosis, seizures, aplastic anemia, intestinal perforation and cutaneous lupus. In our view,
these issues seem to have been addressed already as the revisions described have already been
instituted.
2. Remicade May Substantially Increase TB. In our view, the main issue to be discussed at the FDA
meeting involves the increased incidence of tuberculosis (TB) and possibly other opportunistic
infections in patients taking TNF inhibitors. The incidence of reported cases were mostly from patients
on Remicade. As of May 2001, 70 patients on Remicade were reported to have developed TB after
starting treatment with Remicade. A good number (54) of these patients were reported to have
received another immunosuppressive agent, such as methotrexate or corticosteroids. The most
concerning point was that the types of TB reported were unusual. Most patients (56%) had
extrapulmonary TB, TB that does not affect the lungs. Generally, TB is a disease of the lungs, which
may uncommonly affect other organs. Furthermore, 24% of patients had disseminated TB, a severe
form of the disease where multiple organs and tissues throughout the body are affected. While such
postmarketing surveillance may bias toward a reporting of more serious cases of disease, such a
pattern of disease forms is abnormal, in our view. The transcript did not mention such a recent
increase in TB cases with Enbrel. According to the FDA transcript, cases of other opportunistic
infections (infections that occur when the immune system is suppressed) were reported for both
Remicade and Enbrel. However, most cases were in patients on Remicade, with only a few in patients
on Enbrel. Nine patients on Remicade were reported to have histoplasmosis, a fungal infection,
compared to one on Enbrel. Eleven on Remicade were reported to have Listeria infections compared
to one on Enbrel. And 15 on Remicade had PCP infections compared to 5 on Enbrel. We believe that,
while these data are subject to strong bias, they do suggest that more infections have occurred with
Remicade than Enbrel. Such a difference can be explained by the fact that Remicade kills TNF-producing
cells and Enbrel does not. |
