Shares of

Cubist Pharmaceuticals

(CBST)

were among the best-performing health-related stocks Friday, jumping 21% after the biopharmaceutical company received an expanded approval from the

Food and Drug Administration

for Cubicin.

In addition to treating skin infections with the treatment, Cubicin can now be marketed for treating bloodstream and heart infections as well. "The approval received today provides the clinicians who treat these complicated infections with an alternative therapy backed by prospectively collected, controlled, and comparative clinical data," the company said. "Based on the expanded label approved today, we are very comfortable confirming our previously issued U.S. net product revenue guidance for 2006 of between $190 million and $205 million." Shares were trading up $4.62 to $25.87.

NWH

( NWIR) soared 32% after the health information company agreed to be acquired by a unit of

UnitedHealth

(UNH) - Get Report

for about $54 million in cash. The unit, Ingenix, will pay $18.24 a share for NWH, which represents a 35% premium over the Thursday closing price of $13.51. The deal is expected to close during the third quarter. Shares of NWH were trading up $4.29 to $17.80.

Shares of

SuperGen

( SUPG) fell 2%, even though the company said it would receive a $20 million milestone payment, which was triggered by the first commercial shipment of Dacogen. SuperGen said that its partner,

MGI Pharma

( MOGN), released the first shipment of Dacogen, a treatment of myelodysplastic syndromes, to wholesale drug distributors earlier this week. In addition to receiving the milestone payment, SuperGen will also be eligible to receive royalties tied to specific sales targets. Shares of SuperGen were down 7 cents to $4.20.

Cyberonics

(CYBX)

jumped 19% after the medical-device maker posted better-than-expected fourth-quarter results. For the quarter ended April 28, the company reported a loss of $5.2 million, or 21 cents a share, on revenue of $36 million. Analysts polled by Thomson First Call expected a wider loss of 30 cents a share and revenue of $35.2 million. A year earlier, the company's loss totaled $6.5 million, or 26 cents a share, on revenue of $26.7 million.

Cyberonics said it expects to return to profitability, excluding stock-based compensation costs, during the second quarter of fiscal 2007. Meanwhile, the company continues to project quarterly sales of more than $50 million by the fourth quarter of fiscal 2007. Cyberonics also said its board authorized the repurchase of about 3 million shares. The company's shares were recently up $4.22 to $26.83.

Shares of

Weight Watchers International

(WTW) - Get Report

rose 3% after the company announced an expanded share repurchase plan and declared a quarterly dividend. The company will repurchase an additional $250 million in stock as part of its ongoing stock buyback plan, the company said. As for the dividend, Weight Watchers will pay 17.5 cents on July 14 to shareholders of record on June 30. Shares were trading at $42.37, up $1.35.

Other health care volume movers included

Pfizer

(PFE) - Get Report

, up 11 cents to $23.96;

Elan

(ELN)

, up 42 cents to $18.55; UnitedHealth, up 82 cents to $43.24;

Boston Scientific

(BSX) - Get Report

, up 27 cents to $20.16;

Omnicare

(OCR)

, up $1.63 to $46.09;

Medtronic

(MDT) - Get Report

, down 35 cents to $50.25;

Johnson & Johnson

(JNJ) - Get Report

, up 16 cents to $60.61;

Amgen

(AMGN) - Get Report

, up 56 cents to $68.72;

Schering-Plough

( SGP), up 6 cents to $19.36;

Teva Pharmaceutical

(TEVA) - Get Report

, up 62 cents to $37.27; and

Bristol-Myers Squibb

(BMY) - Get Report

, up 33 cents to $24.94.