FDA's approval of Elan Corp. plc's and Biogen Idec Inc.'s Tysabri natalizumab to treat relapsing remitting multiple sclerosis marks the first big change to the competitive dynamics of the MS marketplace in years. It also offers the prospect that the stimulus of intense marketing battles will greatly expand the number of patients being treated for the disease.
BIIB and ELN plan to target Tysabri (Antegren) at all patients with this form of the disease: newly diagnosed patients and those who have never been treated, those who have quit other MS therapies, and those who might benefit from switching to Tysabri monotherapy or even adding Tysabri to their existing regimen. The primary marketing message will be the attractions of once-monthly dosing and fewer side effects than interferons. The partners initially hope to "bring back the quitters" and thereby grow the market.
Serono S.A., whose Rebif beta interferon will be the primary competitor affected by Tysabri, plans to counter with a message that clinical data for Tysabri are not comparable to Rebif data and that the long-term safety and efficacy of Tysabri are unknown. The company also will show doctors data, based on the percentage of patients who are relapse-free, that could be interpreted as showing that Rebif is the better drug.
Tysabri's label allows its use in front-line patients or patients who are failing other MS therapies, either as monotherapy or in combination with other MS drugs. In addition to Rebif, these include two other beta interferons - Avonex from BIIB and Betaseron from Berlex Laboratories Inc. (Mountville, N.J.) - and a non-interferon drug, Copaxone glatiramir from Teva Pharmaceutical Industries Ltd. (TEVA, Jerusalem, Israel).
Although ELN and BIIB say they are going to target the roughly 50,000 U.S.