Treatment with TYSABRI reduces the rate of hospitalization in Crohn’s patients

Elan Corporation, plc (NYSE: ELN) and Biogen Idec (NASDAQ: BIIB) today announced data showing that treatment with TYSABRI^® (natalizumab) significantly reduced the rate of hospitalization compared with placebo in patients with moderate–to–severe Crohn’s disease during both induction and maintenance treatment. These results were obtained from retrospective subset analyses of three registrational Phase 3 trials (ENACT-1 [Efficacy of Natalizumab as Active Crohn’s Therapy]), (ENACT-2 [Evaluation of Natalizumab as Continuous Therapy] and ENCORE [Efficacy of Natalizumab in Crohn’s Disease Response and Remission]), and one open-label study (ENABLE [Evaluation of the Natalizumab Antibody for Long-term Efficacy]). The data were presented for the first time in an oral session at the American College of Gastroenterology Annual Scientific Meeting in San Diego.

“Hospitalization accounts for a large proportion of the cost of Crohn’s disease management,” said Corey A. Siegel, M.D., director, Inflammatory Bowel Disease Center, Dartmouth-Hitchcock Medical Center in Lebanon, N.H., and lead author of the subset analysis. “Therefore, we were encouraged to see that TYSABRI reduced hospitalization rates, particularly in the more difficult-to-treat subsets of patients previously treated with anti-TNFα therapy.”

The retrospective subset analysis evaluated the effect of TYSABRI on the rate of hospitalization during induction and maintenance treatment using pooled data from the ENACT-1 and ENCORE trials. In those trials, patients with Crohn’s disease were randomized to intravenous TYSABRI 300 mg or placebo every four weeks for three doses. The maintenance analysis was conducted on TYSABRI responders in ENACT-1 who were re-randomized and followed for an additional 48 weeks of therapy in ENACT-2. Data on patients losing response in ENACT-2 who rolled over to an open-label study (ENABLE) supplemented the ENACT-2 data. Rates of all-cause hospitalization and Crohn’s disease-related hospitalization per 100 patients over the 84-day induction period and the 336-day maintenance periods were evaluated.

Results of the subset analysis showed that hospitalization rates were significantly lower in patients treated with TYSABRI when compared with placebo. Two physicians, blinded to treatment, reviewed all data to determine hospitalizations and surgeries and whether they were, or were not, related to Crohn’s disease. Out of the approximately 1500 patients involved in these trials, the total number of all-cause hospitalizations was>) during the induction period and 44%>) during the maintenance period. The total number of Crohn’s disease-related hospitalizations was>p<0.001) during the induction period and 58%>) during the maintenance period.

In patients who had received prior anti-TNF therapy, a more difficult-to-treat patient population, the benefit of TYSABRI was higher. During the induction period, the total number of all-cause hospitalizations was>) and Crohn’s disease-related hospitalization>. During the maintenance period, all-cause hospitalization rate was reduced by 60%>) and the Crohn’s disease-related hospitalization rate was reduced by 75%>).

“The results of this analysis showing reduced hospitalization rates, together with subset data previously announced at Digestive Disease Week in May, provide additional support that TYSABRI is an important treatment option for patients with this chronic and debilitating disease who have failed anti-TNFα therapies,” said Elan President Carlos V. Paya, M.D., Ph.D. “TYSABRI continues to show benefits in improving quality of life, in CD patients, as well as in multiple sclerosis patients who also exhibit benefits across clinical and radiological measures.”

Natalizumab Reduces the Rate of Hospitalization in Moderate to Severe Crohn’s Patients: Data from the ENACT and ENCORE Trials, Siegel, CA, Sands BE, Feagan B, et al. Presented at the American College of Gastroenterology Annual Scientific Meeting, October 27, 2009.