Merck KGaA has posted a strong set of figures for the fourth quarter of 2012, driven by sales of its multiple sclerosis blockbuster Rebif.

The Darmstadt, Germany-based group noted that net profits more than doubled to 271.8 million euros, helped by favourable one-time effects on income tax. Revenues increased 8% to 2.83 billion euros and sales at the Merck Serono drugs unit rose 5.0% to 1.52 billion euros.

Growth was driven by Rebif (interferon beta-1a) which climbed 9.6% to 471.3 million euros, helped by price increases in the USA. The colorectal/head and neck cancer drug Erbitux (cetuximab) dipped 0.6% to 223.8 million euros.

The fertility drug Gonal-f (follitropin) increased 10% to 153.2 million euros. Merck's Glucophage (metformin) diabetes products leapt 17% to 104.4 million euros, while the beta blocker Concor (bisoprolol) franchise fell 10.7% to 92.6 million euros. The growth hormone treatment Saizen (somatropin) rose 11.4% to 62.6 million euros.

The firm is undergoing a major reorganisation and during 2012, it realised around 115 million euros in net savings. Two-thirds of the restructuring costs of 504 million euros incurred in 2012 were reported in the Merck Serono division.

Merck chairman Karl-Ludwig Kley said that "not only did we make progress with one of the most extensive change programmes in the 345-year history of the company, we also succeeded in further expanding our business in a challenging economic environment".