Wednesday's Health Winners & Losers

After Tuesday's rally, the health sector delivered a blasé performance Wednesday, as stocks aired clinical and earnings news and weathered analyst actions.

Pfizer (PFE Quote) halted a phase III study of melanoma treatment tremelimumab after an interim review found that the drug would not prolong survival any more than currently prescribed chemotherapy. Pfizer's shares traded roughly flat, edging 0.2% higher to $21.43 in recent trading, but the news weighed heavily on Medarex (MEDX Quote), which is developing a drug in same class.

The drug that Medarex and partner Bristol-Myers Squibb (BMY Quote) are developing failed a late-stage study in December, but the companies said they will still file the drug for approval with U.S. regulators before the middle of the year. Investors guessing that the Medarex drug -- because of its similarities to the Pfizer drug -- is equally doomed took shares down $1.80, or 19.3%, to $7.52. Bristol's shares edged down 1% to $21.66.

Smaller-cap biotech Ista Pharmaceuticals (ISTA Quote) dove after announcing Tuesday post close that a new formulation of its anti-inflammatory drug was no more effective than the original. Shares retracted 69 cents, or 33%, to $1.38.

Separately, Ista said it hired Cowen and Co. to help it evaluate opportunities such as potential mergers.

Punk, Ziegel & Co. downgraded the stock to sell from market perform and chopped its price target to $1.79 from $4. Roth Capital also slashed its price target, to $3.50 from $7, and RBC Capital Markets lowered its target to $4 from $7.

The stock is a component of the Nasdaq biotechnology index, which was down 0.4% at 802.31.

In earnings, Immucor (BLUD Quote) shares added $2.34, or 9.9%, to $25.87, Wednesday after the company posted a third-quarter earnings beat and reaffirmed guidance. The company said Tuesday post-close that net income climbed to $19.3 million, or 27 cents a share, from $15 million, or 21 cents a share, in the 2006 quarter. Revenue increased 17% to $67 million. Analysts surveyed by Thomson Financial were looking for 22 cents a share.

The company also reaffirmed expectations for 2008 earnings of between 92 cents and 96 cents a share on revenue of $249 million and $257 million. Wall Street analysts had targeted 92 cents a share on $255 million in revenue.

Elsewhere, Wall Street analysts weighed in on stocks. UBS analyst Annabel Samimy upgraded hepatitis and HIV drug developer Pharmasset (VRUS Quote) to buy from neutral. Pharmasset shares rose 91 cents, or 4.8%, to $19.99.

Meanwhile two analysts upped their price targets for HIV drug company Gilead (GILD Quote) -- Lehman Brothers to $57 from $53 and BWS Financial to $60 from $50 -- but it did little for the stock. Shares were down $1, or 1.9%, to $51.88.

AstraZeneca (AZN Quote), also down a bit -- 21 cents, or 0.5%, to $40.39 -- received an upgrade and a downgrade. Citigroup upgraded the stock to buy from hold, and HSBC Securities downgraded the stock to neutral from overweight.