Merck Serono has won approval from European regulators to sell a new formulation of its blockbuster Rebif for the treatment of relapsing multiple sclerosis.

The European Commission has granted marketing authorisation for the new formulation of Rebif (interferon beta-1a) which improves injection tolerability “while targeting an improved immunogenicity profile”, Merck Serono said. The approval covers all 27 countries of the European Union as well as Iceland, Liechtenstein and Norway.

The firm added that the new formulation has been developed in the same strengths and pharmaceutical forms as currently registered (8.8, 22 and 44 mcg) as a solution for injection in pre-filled syringes and “originates from an innovative approach, using state-of-the-art technologies”. The approval is based on a Phase III study which showed that the new formulation leads to a rate of injection-site reactions in MS patients treated with Rebif over one year that is three times lower, compared with historical data from previous trials.

Merck Serono will be hoping that regulators across the Atlantic take notice of the European approval as the US Food and Drug Administration asked for more information about the new formulation in February. The original is a big earner for the company and sales in the second quarter reached a record high of 312 million euros, up 8.2%.