Arena Pharmaceuticals (NASDAQ:ARNA), a biopharmaceutical company primarily focused on weight control management drug Belviq, this afternoon reported strong sales growth of its lead product in the first quarter, but also produced a much wider net loss than in the prior-year period.

For the quarter, Arena delivered $6.8 million in revenue, up 187% from the prior-year period as it recognized $2.9 million in Belviq net product sales (representing its 31.5% share of partner Eisai Pharmaceuticals' reported $8.4 million in total sales) compared to $0 in Q1 2013, and saw its collaborative revenue with Eisai more than double to $3.3 million from $1.5 million. As noted in the report, Belviq prescriptions written surged 31% to 77,000 in Q1 with more than 60% of people in the U.S. now estimated to be insurance eligible in some way to receive Belviq.

However, costs associated with Belviq and the remainder of Arena's pipeline also rose, sending research and development expenses up to $21 million from $14 million in the year-ago quarter, and pushing total operating expenses higher by 30% to $30.4 million.

Net loss for the quarter widened by 34% to $25.3 million, or $0.12 per share, from $18.9 million, or $0.09 per share in the year-ago quarter. By comparison, Wall Street was anticipating a slightly narrower loss of just $0.10 per share.

Lastly, Arena announced that it ended the quarter with $256.5 million in cash, cash equivalents, and short-term investments, up from the $221.9 million reported in the sequential fourth quarter. 

Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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