For the first quarter of 2011, the Company reported a net loss of $10.1 million, or $0.17 per share, compared with a net loss of $5.6 million, or $0.16 per share for the first quarter of 2010. Cash, cash equivalents and marketable securities as of March 31, 2010 were $46.4 million.

Revenue for the three months ended March 31, 2011 was $65,000, compared with revenue of $74,000 for the three months ended March 31, 2010. Revenue in both periods consisted primarily of reimbursed costs under the Company's collaboration with Gilead Sciences, Inc.

Research and development expenses were $8.0 million in the first quarter of 2011, compared with $4.0 million for the same period of 2010. Research and development expenses were primarily related to costs incurred from the ongoing Phase 2 clinical trial with ACH-1625 and preparations to advance the Company's two additional HCV compounds, ACH-2684 and ACH-2928, into clinical trials during the first half of 2011. As the Company continues to advance its three HCV compounds in the clinic, it expects that research and development expenses will remain consistent with first quarter levels during the remaining quarters of 2011.

For the three months ended March 31, 2010, general and administrative expenses totaled $2.2 million, increased slightly from $1.7 million for the same period in 2010.