Elan generated marginally less revenue than expected in the first quarter from sales of Tysabri, the multiple sclerosis drug that accounts for almost all of its earnings.
But its quarterly revenues grew enough to keep guidance on track.
Elan, which markets the MS drug with US firm Biogen Idec, said sales of the treatment rose 14% to $399m - lower than analyst expectations of $402m.
Shares in the company closed 1.2% higher at €10.55 in Dublin this evening,
Elan said quarterly revenues of $288m put it on track to generate €1.2-1.25 billion in revenue for the year as a whole.
The sales to March 31 compared to $313m a year ago, a figure boosted by Elan's former drug delivery business which it sold in a $960m deal that cut its debt pile by two thirds at the cost of €80m in core earnings a year.
Elan said that excluding the drug delivery business, first quarter sales grew by 17% from $247.1m.
Elan, which adds $100m to its bottom line for every 10,000 extra patients it adds to its MS treatment, has said continued sales growth in Tysabri would lead to overall revenue growth of 15% a year over the next three to five years.
It said expects to make adjusted earnings before interest and taxes of at least $200m for this year compared to the €147m earned in 2011.
"Our first quarter financial performance was solid and represents a good start to the year across all aspects of our business," commented Elan's chief executive Kelly Martin.
He further indicated that the company is clearly focused on becoming the world's leading biotech focused on neurology, noting that "the opportunities and patient need in the broad area of neurology are significant''.
Elan is also keenly awaiting phase three data in the second half of this year on Bapineuzumab, an experimental Alzheimer's drug being developed by Pfizer and Johnson & Johnson in which Elan has a 25% economic interest.
Last month Elan asked outgoing CEO Kelly Martin to stay on beyond an agreed date to stand down so it can first see the key data that it described as "potentially transformational" for the company.
