Shares of Nabi Biopharmaceuticals ( NABI) were among the worst-performing health-related stocks Tuesday, tumbling nearly 72% after the biotechnology company halted development of its staph infection vaccines.

The company decided to discontinue developing the vaccines after its StaphVax product failed to meet the primary endpoint of a Phase III trial. The study found no reduction in S. aureus types 5 and 8 infections in the StaphVax group of patients as compared to a placebo group. "We are obviously surprised and very disappointed with the results of the StaphVax confirmatory Phase III trial," the company said.

In addition to halting further development of StaphVax and withdrawing its application to market StaphVax in the European Union, Nabi said it would also halt development of Altastaph, the company's investigational product for the prevention and treatment of S. aureus infections. Shares were trading down $9.25 to $3.60.

Allergan ( AGN) rose 8% after the eye-care products company posted better-than-expected third-quarter results. The company earned $150.5 million, or $1.12 a share, on sales of $606.1 million. Excluding items, Allergan have earned $112.1 million, or 83 cents a share. Analysts polled by Thomson First Call expected earnings, before items, of 79 cents a share, and sales of $569.6 million. A year earlier, Allergan earned $92 million, or 69 cents a share, on sales of $510.8 million. Excluding items, the company would have earned $89 million, or 67 cents a share, in the year-ago period.

Looking ahead, Allergan forecast fourth-quarter earnings of 88 cents to 89 cents a share, in line with analysts' forecast of 89 cents. The company sees sales of $565 million to $580 million, bracketing analysts' mean estimate of $570 million. Shares recently were up $6.74 to $96.04.

Shares of Health Net ( HNT) rose 1% after the company posted third-quarter results that topped forecasts. The managed-health care company earned $78.2 million, or 67 cents a share, on sales of $3.06 billion. Analysts projected earnings of 64 cents a share, with sales of $3.04 billion. A year earlier, Health Net earned $71.9 million, or 64 cents a share, on sales of $2.94 billion.

Health Net forecast fourth-quarter earnings of 60 cents to 65 cents a share, short of analysts' expectation of 66 cents a share. For all of 2005, the company expects adjusted earnings, which exclude items, of $2.37 to $2.42 a share. Analysts forecast full-year earnings of $2.38 a share. Shares traded up 66 cents to $47.50.

American Pharmaceutical Partners ( APPX) rose 4% after the company posted mixed third-quarter results. The specialty drug company earned $18.2 million, or 25 cents a share, on sales of $128.8 million. Excluding expenses the company incurred for third-party advisory fees, American Pharmaceutical would have earned 30 cents a share. The company also had costs of $9.7 million, or 9 cents a share, that were related to a re-validation process at its Melrose Park facility. Analysts expected earnings of 27 cents a share and higher sales of $137.7 million. A year earlier, the company earned $13.8 million, or 19 cents a share, on sales of $95.6 million. The year-ago results included $2 million, or 2 cents a share, in costs related to the early termination of a credit facility.

For the full year, American Pharmaceutical Partners forecast sales of $505 million to $540 million, shy of analysts' estimate of $540.6 million. The company narrowed the sales projection for its breast cancer drug Abraxane to $125 million to $140 million, shaving the top end off its previous forecast of $125 million to $155 million. Abraxane expenses are expected to be between $55 million and $60 million, down from a prior estimate of $65 million and $70 million. American Pharmaceutical shares recently traded up $1.61 to $44.66.

Shares of Amedisys ( AMED) rose 9% after the company posted third-quarter results that pleased investors. The home-health nursing company earned $7.8 million, or 48 cents a share, on sales of $112.2 million. Results included a write-off of deferred loan costs, which nicked earnings by 2 cents a share, and amortization of severance arrangements that knocked another 2 cents from earnings. Hurricane Katrina hurt results by 2 cents to 3 cents a share. The company also booked a gain of 2 cents a share related to the resolution of certain open Medicare costs reports. Analysts expected earnings of 50 cents a share and sales of $105.3 million. Last year, Amedisys posted third-quarter earnings of $5.2 million, or 39 cents a share, on sales of $58.5 million.

Amedisys continues to expect 2005 earnings of $1.95 to $2.01 a share and fiscal 2006 earnings of $2.52 to $2.64 a share. Analysts currently predict 2005 earnings of $1.99 a share and 2006 earnings of $2.62 a share. Shares were trading up $3.43 to $41.64.

Other health care volume movers included Novavax ( NVAX), up 74 cents to $4.78; Pfizer ( PFE), down 16 cents to $21.58; Merck ( MRK), up 38 cents to $28.60; Schering-Plough ( SGP), down 52 cents to $19.82; Medco ( MHS), down $5.51 to $50.99; Johnson & Johnson ( JNJ), down 54 cents to $62.08; Teva Pharmaceutical ( TEVA), up $1.14 to $39.26; Amgen ( AMGN), down 23 cents to $75.39; and Genentech ( DNA), up $1.14 to $91.74.