Ireland’s Elan Corp has posted a reduction in losses for the fourth quarter and says that its mutiple sclerosis drug multiple sclerosis treatment Tysabri will be the drug that leads the company back to profitability.

Losses for the quarter fell 55% to $26.5 million, or $0.14 per share, helped by what the firm described as an improved operating performance as well as a gain of $49.8 million from King Pharmaceuticals which was ordered to pay the Irish firm in a binding arbitration decision over a dispute concerning the insomnia product Sonata (zaleplon).

Revenues for the quarter rose 18.5% to $166.4 million, though sales of its Maxipime (cefepime) antibiotic slipped 1.3% to $46.2 million ahead of US patent expiry in March. Azactam (aztreonam), another antibiotic, rose 22% to $21.3 million, and its sales are expected to be negatively impacted by generic competition in 2007, although no copycat version has been approved yet. Severe pain treatment Prialt (ziconotide) brought in $3.4 million, up 70%, but the main growth drivers were Elan’s manufacturing revenue and royalties, which increased 15% in the to $67.3 million.

However all eyes were on Tysabri (natalizumab), partnered with Biogen Idec, which had sales of $30.2 million. The drug only returned to the market in July after being pulled off on safety concerns in February 2005, and its reintroduction came with restrictions to monitor patients for symptoms of the rare brain disease PML (progressive multifocal leukoencephalopathy). However nearly 10,000 people have been prescribed with the drug and the company is confident that Tysabri will continue to penetrate the MS market.

Chief financial Officer Shane Cooke said "we are optimistic that Elan will achieve break-even, on an adjusted earnings before interest, tax, depreciation and amortisation basis, by the end of the year” and added that the firm is “confident Tysabri will be a blockbuster drug in MS." A supplemental Biologics License Application was filed with the US Food and Drug Administration in December seeking approval to market Tysabri as a treatment for Crohn's disease.

Elan added that 2007 revenues excluding Tysabri should exceed $500 million, with R&D and other expenses expected to be in the range of $600-$650 million. Much of that sum is likely to go on developing its Alzheimer's programme with Wyeth, notably AAB-001 (bapineuzumab), a humanised monoclonal antibody which is in Phase II clinical trials.