Natalizumab long-term remission results

Elan and Biogen Idec announced that a trial has found that natalizumab (sold as TYSABRI) maintained remission in Crohn's disease patients treated for longer than 2 years.

93% of TYSABRI patients who were in remission at month 12 of ENACT-2, were still in remission following 6 additional TYSABRI infusions in the open-label extension study and 86% were still in remission after 12 additional infusions.

These results were based on approximately 90 patients who were in remission after 15 months of continuous TYSABRI therapy in the ENACT-1 and ENACT-2 trials and elected to enroll in an open-label extension trial. A subpopulation of 22 patients was previously exposed to infliximab therapy. In this subpopulation, 91% were in remission after additional 6 and 12 infusions of TYSABRI, and 82% who had previously failed therapy with infliximab were in remission at the same time points.

"What is truly exciting is that patients who enter remission on TYSABRI may remain in remission in the long-term without loss of efficacy over time. These data are a significant advance for the field and suggest that TYSABRI may be an alternative biologic outside the anti-TNF class for patients suffering from Crohn's disease," said Remo Panaccione MD, Director, Inflammatory Bowel Disease Clinic, University of Calgary, Calgary, Canada, who presented the data at UEGW.

Natalizumab, like infliximab, is a monoclonal antibody (all generic medicine names ending in -mab are monoclonal antibodies). It is also used to treat multiple sclerosis, but was withdrawn from market in 2005 due to safety concerns. In mid 2006 it was reapproved for use in the US and Europe. More details are in the Wikipedia.