THOUSAND OAKS, Calif. ( TheStreet) -- Amgen ( AMGN) reported a 13% increase in adjusted second-quarter earnings Monday ahead of an important Food and Drug Administration meeting for its osteoporosis drug denosumab next month. The company also raised 2009 earnings guidance and announced a marketing partnership with drug giant GlaxoSmithKline ( GSK) to sell denosumab in Europe. Net income for the second quarter totaled $1.27 billion, or $1.25 a share, compared to net income of $906 million, or 84 cents a share, in the year-ago quarter. Income in the quarter was partially bolstered by a one-time tax benefit, the company said. On an adjusted basis, Amgen earned $1.29 a share, above the Street's consensus estimate of $1.16 a share, according to Thomson Reuters. June quarter revenue fell 1% year over year to $3.76 billion, but still ahead of the consensus forecast of $3.58 billion. Amgen raised guidance on 2009 adjusted earnings to a range of $4.80 a share to $4.95 a share. Current Street consensus is at $4.57 a share. The company also said revenue for the year was coming in at the high end of its previously stated guidance range of $14.4 billion to $14.8 billion. Amgen's second-quarter earnings report comes as the FDA is set to convene an advisory panel meeting on Aug. 13 to review the company's experimental osteoporosis drug denosumab. A key issue to be debated at the meeting will be denosumab's safety with a particular focus on any association between the drug and an increased risk of infection.