Shares of Wyeth (WYE) sank Friday after the Food and Drug Administration rejected the company's application for a schizophrenia treatment and said more testing would be needed for approval. Separately, Wyeth and a partner stopped a midstage clinical trial combining an experimental drug with two existing treatments for Hepatitis C, a blood-borne viral infection caused primarily by needle-sharing among drug users. Some patients receiving the experimental drug had elevated liver enzymes, a signal for potential liver damage.

Standard & Poor's Ratings Services on Friday lowered its long-term credit rating on Thornburg Mortgage (TMA), a prime mortgage lender, and placed the rating on CreditWatch Negative to reflect the unsteady state of the secured financing capital market. S&P downgraded Thornburg to "B" from "BB." Both ratings are junk bond ratings. (AP)

Marchex (MCHX) got hammered after the online advertising company posted second-quarter results that fell short of expectations. The company earned $354,000, or a penny a share, on revenue of $34.7 million. Excluding items, the company earned 10 cents a share. Analysts expected earnings of 11 cents a share on revenue of $35.1 million. Looking ahead, Marchex sees third-quarter revenue of more than $32.5 million. Analysts project revenue of $37 million.

Shares of ViroPharma (VPHM) and Wyeth (WYE) fell hard on news that they decided to discontinue dosing of its HCV-796, a Hepatitis C candidate, in combination with pegylated interferon and ribavirin in the current phase II study because of issues with liver toxicity.

Shares of Symmetricom (SYMM) tumbled 24.5%, after the provider of software services posted a fiscal fourth-quarter earnings miss and warned that first-quarter results would be well below expectations. The company posted adjusted earnings of $4 million, or 9 cents a share, on revenue of $57.4 million. Analysts expected earnings of 10 cents a share. Looking ahead, Symmetricom sees first-quarter adjusted earnings of 1 cent to 6 cents a share on revenue of $48 million to $53 million. Analysts project earnings of 11 cents a share on revenue of $55.7 million. For the full year, the company sees adjusted earnings of 24 cents to 34 cents a share on revenue of $210 million to $220 million. Analysts project earnings of 51 cents a share on revenue of $229.8 million. This is the pick for Monday 8-13-07. Opened 8-13-07 at $5.06.