Earnings, a Food and Drug Administration warning and clinical updates blotted the biotech sector Tuesday, but health indices lay flat.

Genentech ( DNA) reported late Monday third-quarter earnings of 73 cents a share, or $778 million, before items, compared to 59 cents a share, or $637 million, in 2006.

Analysts surveyed by Thomson financial were looking for 72 cents a share on revenue of $2.93 billion. Genentech reported revenue of $2.91 billion before items (and including $3 million associated with the acquisition of Tanox), a 22% increase over operating revenue of $2.38 billion in the third quarter of 2006. Shares were down $2.39, or 3.1%, at $ 75.11 on Tuesday.

Forest Laboratories ( FRX) on Tuesday reported earnings that were affected by a $70 million licensing charge (equating to 15 cents a share net of tax) to Microbia for the right to co-develop and co-market constipation treatment linaclotide. The company reported earning 71 cents a share for the second quarter of fiscal 2008. Analysts surveyed by Thomson Financial had expected 74 cents a share.

Forest Labs shares fell 4.8% to $38.46. The stock is a component of the Amex Pharmaceutical index, which was down 3.70, or 1.1%, to 347.85.

Up on earnings, biotechnology company Enzo Biochem ( ENZ) reported that its fiscal fourth-quarter (ended July 31) loss narrowed due to a rise in sales at its clinical lab segment and new product revenue from its acquisition of Axxora Life Sciences. The company reported a loss of $3.3 million, or 9 cents a share, compared to a loss of $4.5 million, or 14 cents a share, in the year-ago quarter. Analysts surveyed by Thomson Financial expected a loss of 12 cents a share on revenue of $16.3 million. Enzo said its revenue rose 81% to $17.9 million from $9.9 million in 2006. Shares climbed 13.4% to $13.14.

Meanwhile, the FDA on Tuesday issued an alert , warning that Amylin Pharmaceuticals' ( AMLN) Byetta for type II diabetes may be linked with cases of acute pancreatitis.

The FDA said Amylin has agreed to include information about acute pancreatitis in the precautions section of the product label. The San Diego-based company has a collaboration agreement with Eli Lilly ( LLY) and Alkermes ( ALKS) to develop a sustained release version of Byetta for type II diabetes.

Amlyin shares fell $2.45, or 5.1%, to $45.41; Eli Lilly was down 79 cents, or 1.4%, to $57.15; and Alkermes fell 73 cents, or 4.2%, to $16.74.

On the clinical front, Repros Therapeutics ( RPRX) said that it will refile for a clinical trial for secondary hypogonadism (testosterone deficiency) treatment Androxal as it has met with the FDA to determine study goals. Repros said it agreed that trial endpoints associated with male sexuality weren't appropriate. Shares rose $1.96, or 18.2%, to $12.69.

Exelixis ( EXEL) fell $1.18, or 9.9%, to $10.79, after reporting that a midstage study on proteinuria associated with diabetic kidney disease failed. The study missed its primary endpoint of decreasing proteinuria, the presence of excess protein in the urine, which is an indicator of renal disease. The company said it will provide an update on its plans once it's done analyzing the data.

Elsewhere, Aastrom Biosciences ( ASTM), which develops technology to repair tissue cells, said it plans to raise about $13.5 million in a registered direct offering of 11.8 million units to a group of institutional investors. The price of the offering is $1.14 per unit -- each unit consists of one share of the company's common stock and a warrant to buy 0.5 shares of Aastrom stock at $1.59 per share, a 25% premium to the stock's closing price on Oct. 15. It expects the offering to close soon. Shares dropped 17 cents, or 13.4%, to $1.10.