Tuesday's Winners & Losers: Onyx Pharmaceuticals

Onyx Pharmaceuticals(ONXX) was left choking on a clinical trial news.

Onyx and partner Bayer AG said Tuesday that they halted a late-stage trial of their drug Nexavar in lung cancer patients after an independent monitoring board concluded that the study had no chance to succeed. Onyx also said on a conference call that it is unable to forecast a profit for 2008. Shares shed $10.69, or 24%, to $34.25.

Sony(SNE) gained $2.12, or 4.7%, to $46.90 on news that rival Toshiba has abandoned its HD DVD high-definition video format, leaving Sony's Blu-ray format the winner. All Sony PlayStation 3 video game consoles ship with a Blu-ray player.

Premier Exhibitions (PRXI), an Atlanta-based developer of touring exhibitions about the Titanic and the human body, jumped 17.7% to $5.05 after announcing it had appointed Harold "Bud" Ingalls to replace Steven Couture as CFO. Over the weekend, the company also issued an open letter to TV show 20/20 and its own shareholders. Premiere Exhibitions expects 20/20 to air an episode that displays its traveling show Bodies in a misleading and sensationalized light, according to the company.

Chipmaker Sigma Designs(SIGM) fell $4.56, or 10.1%, to $40.39 after an analyst at Robert W. Baird cut his rating on the stock to neutral from outperform and lowered his price target to $50 from $75. Sigma could see its revenue dip in the first half of 2008 because macroeconomic concerns could lead to a slowdown in orders from manufacturers, the analyst said.

On the losing side, Lincoln, Neb., bank TierOne (TONE) took a hit after CapitalSource (CSE) authorized its CEO to either back out of a previously announced $652 million purchase of TierOne or to renegotiate the agreement. Shares lost 14% to $15.

Elsewhere, UBS analyst Annabel Samimy downgraded Pharmasset(VRUS) to neutral from buy, but raised her price target to $23 from $17 a share. She believes that the value of the company's hepatitis B and C drugs, clevudine and R7128, is now reflected in the stock price. Shares of Pharmasset fell $1.53, or 7.1%, at $19.97.

>To order reprints of this article, click here: Reprints