Sanofi-Aventis has posted a 4.8% rise in fourth-quarter sales, as top-selling drugs Plavix and Lovenox put in another good showing and its Sanofi Pasteur vaccines business charged ahead.

The company said it now expects earnings per share to grow by around 25% for 2005, better than its earlier forecast of 20% growth.

Fourth-quarter sales came in at 7 billion euros ($8.5bn), with antiplatelet drug Plavix (clopidogrel) contributing 518 million euros, up 17%, and anticoagulant Lovenox (enoxaparin) rising 9% to 572 million euros. For the full year, group sales were 27.3 billion euros, up 9.3%.

The strong performance by Sanofi-Aventis’ biggest products helped offset a 59% reduction in sales of allergy drug Allegra (fexofenadine), which is suffering as a result of generic competition from Teva Pharmaceutical Industries and Barr Laboratories in the USA. Last week, a US court denied efforts by Sanofi-Aventis to stop sales of the low-cost rivals.

Generic competition also bit into sales of diabetes drug Amaryl (glimepiride), which slumped 29% to 135 million euros in the quarter. And, in the longer-term, Sanofi-Aventis’ prospects are clouded by the threat of generic competition to both Plavix and Lovenox, said analysts.

Sanofi Pasteur put in a stellar performance, with sales up 50% to 643 million euros, helped by the launches in the USA last year of the meningitis vaccine Menactra, the diphtheria and tetanus vaccine Decavac and the tetanus, diphtheria and pertussis booster vaccine Adacel. Fears about a flu pandemic also helped drive the market for seasonal influenza vaccines, and US sales of these products rose 35% for 2005 as a whole.

Looking ahead to 2006, Sanofi-Aventis said it was looking forward to a good contribution by recently-approved sustained-release insomnia treatment Ambien CR (zolpidem), which should help protect the franchise - which grew 20% overall to 430 million euros in the fourth quarter - from generic competition due in the USA later in 2006.

The company said it is also starting clinical trials in children which could help secure an additional six months' exclusivity for Ambien in the USA.

Meanwhile, Sanofi-Aventis also has a blockbuster-in-waiting in the form of Acomplia (rimonabant), an obesity drug currently under review in the USA and Europe, and could also see approval this year for another potential big seller, the arrhythmia drug dronedarone.