The positive CHMP opinion for approval of LEMTRADA was based on data from the CARE-MS I and CARE-MS II trials, in which LEMTRADA was significantly more effective than Rebif® (subcutaneous interferon beta-1a 44 mcg three times weekly) at reducing relapse rates. In CARE-MS II, accumulation of disability was significantly slowed in patients given LEMTRADA vs. Rebif, and importantly, patients treated with LEMTRADA were significantly more likely to experience improvement in pre-existing disability.
LEMTRADA has a novel dosing and administration schedule of two annual treatment courses. The first treatment course of LEMTRADA is administered via intravenous infusion on five consecutive days, and the second course is administered on three consecutive days, 12 months later.
The LEMTRADA clinical development program included two randomized Phase III studies comparing treatment with LEMTRADA to Rebif in patients with relapsing-remitting MS who had active disease and were either new to treatment (CARE-MS I) or who had relapsed while on prior therapy (CARE-MS II), as well as an ongoing extension study. A large randomized Phase II study provided the foundation for the Phase III program.
Safety results were consistent across both the CARE-MS I and CARE-MS II studies. The most common adverse events associated with LEMTRADA were infusion-associated reactions, including headache, rash, fever, nausea and hives. Infections were common in both the LEMTRADA and Rebif groups. Infections more common on LEMTRADA treatment included upper respiratory and urinary tract infections, herpes viral infections, and influenza. Most infusion-associated reactions and infections were mild to moderate in severity and responded to standard treatments.
In both CARE-MS I and CARE-MS II, the incidence of serious adverse events was similar between the two treatment arms. As previously reported, autoimmune disorders were more frequent in patients treated with LEMTRADA, primarily autoimmune thyroid disease which was observed in an estimated 36% of patients during extended follow-up. Immune thrombocytopenia (ITP) developed in 1.4 percent of LEMTRADA-treated patients through extended follow-up and 0.3% developed glomerulonephritis. Autoimmune disorders were detected soon after onset through a monitoring program, and were generally managed using standard treatments.