Immunex

(IMNX)

reported lower first-quarter profits Monday, although sales of its rheumatoid arthritis drug. Enbrel, met expectations.

The Seattle, Wash.-based biotech firm, in the midst of a merger with

Amgen

(AMGN) - Get Report

, said first-quarter net income totaled $34.9 million, or 6 cents per share, compared to net income of $39.8 million, or 7 cents per share in the year-ago quarter. Immunex blamed lower profits on higher tax rates, although earnings beat Wall Street estimates by a penny.

Total revenue for the quarter rose 25% to $272 million. More importantly, Enbrel sales in the quarter totaled $216 million, in line with analyst estimates of between $215 million to $218 million. Enbrel sales were flat with the fourth quarter 2001, however, as Immunex continues to deal with much-publicized supply constraints.

And last month, Immunex warned that already short supplies of Enbrel would be even shorter in April and May due to changes in the drug's production schedule. The company told doctors and patients to expect delays in filling Enbrel prescriptions that could last from several days to a few weeks. Immunex has not yet disclosed whether this new delay would force it to change earnings guidance for the current quarter.

Shares of Immunex closed Monday down 39 cents to $28.51.