A two year trial has demonstrated the efficacy of Tysabri in RRMS.
February 18, 2005 4:35 PM GMT (Datamonitor) - Biogen-IDEC [BIIB] and Elan [ELA.L] have announced that Tysabri has demonstrated significant improvements in disability progression and reduction in the rate of relapse in relapse-remitting multiple sclerosis (RRMS). The outlook for the drug is therefore extremely bright, and it could cannibalize revenues of rival RRMS products significantly. Tysabri may yet herald a new dawn in RRMS treatment.
Biogen-IDEC and Elan have announced that Tysabri (natalizumab) achieved the two-year end-point of slowing the progression of disability in patients with RRMS, in the AFFIRM monotherapy trial. Tysabri therapy demonstrated a 42% reduction in the risk of disability progression as compared to a placebo and also led to a 67% reduction in the rate of clinical relapse over two years. Additional MRI and immunogenicity data are also similar to that observed at one year, with hypersensitivity reactions occurring in less than 1% of patients; and serious infection occurring in 3.2% of treated patients compared to 2.6% of those receiving placebo.
The results of the trial demonstrate a significant improvement on the reduction in relapse rates of the leading beta-interferons of Serono's Rebif and Biogen's Avonex (interferon-beta 1a). Furthermore the positive data will no doubt assuage physician's hesitation in prescribing the drug based on the one year data supporting the FDA approval of the drug and will bolster its already rapid uptake in the US market.
Biogen-IDEC/Elan expects to present the full two-year data at the American Academy of Neurology meeting in April 2005, with full two year data from SENTINEL, the Tysabri Avonex combination study, expected later in the year. Furthermore, in December 2004 the companies announced the initiation of a study known as STARS comparing the safety and efficacy of Tysabri against Rebif.
Following the strong clinical data, Tysabri could see prescriptions rise upwards of 70% in treatment naive patients, and it will replace Copaxone (glatiramer acetate) as an alternative option for interferon-beta resistant patients, demolishing Copaxone revenues. Furthermore, Tysabri will offer a significant advantage over the once weekly Avonex and three-times-a-week Rebif with a once-monthly dosage, heavily impacting interferon-beta revenues with many patients switching to Tysabri.
The future for Tysabri is extremely promising, and if it demonstrates superiority in the STARS trial, it could signal the end of an era for beta-interferon therapy in RRMS.