A merger, an FDA holdup and management musical-chairs yanked health care stocks in different directions Monday, resulting in a flat day for the biotech and pharmaceutical indices.

Women's health company Hologic ( HOLX - Get Report) announced a $6.2 billion deal to buy Cytyc , which manufactures cervical cancer screening equipment. Hologic, which manufactures mammography and breast care products, expects to complete the transaction in the third calendar quarter of 2007. Hologic said the combined companies' annual revenues would be more than $1.7 billion, while adjusted earnings per share would be between $2.35 and $2.40. Hologic's shares fell $3.67, or 6.9%, to $53.94, while Cytyc's shares were up $7.80, or 22%, to $42.85.

Point Therapeutics , Cleveland BioLabs ( CBLI - Get Report) and Nektar Therapeutics ( NKTR - Get Report) were affected by differing study results.

Point Therapeutics fell 30 cents, or 69%, to 14 cents, after the Food and Drug Administration placed the clinical program for talabostat on hold. The company recommended stopping two phase III studies as a potential treatment for patients with advanced non-small-cell lung cancer because neither of two endpoints demonstrated improvement over the placebo groups.

Cleveland BioLabs said a study for Protectan CBLB612 showed blood from healthy mice treated with the drug helped mice issued a normally lethal dose of radiation survive past the 60-day mark. The company said the experiment demonstrated effectiveness in stimulation and mobilization of stem cells. Shares rose 37 cents, or 3.4%, to $9.27.

Nektar Therapeutics shares rose 2.5% after announcing that its phase IIa study of NKTR-061 showed success in treating mechanically ventilated patients who have hospital-acquired pneumonia. The treatment, which is the first in a series of antibiotic products that use the company's micropump technology to deliver antibiotics to the deep lungs, is being tested for safety and tolerability. Shares were up 26 cents to $11.66.

The Nasdaq Biotechnology index, which includes Nektar Therapeutics, was up 4.75, or 0.6%, to 827.10

On a separate note, National Medical Health Card Systems announced a slew of management changes Monday. Chairman Thomas Erickson is replacing James Smith as president and CEO on an interim basis while the company looks for Smith's replacement.

Furthermore, the company said Tery Baskin, Jonathan Friedman and Bill Masters have all left their respective positions as CMO, Chief Legal Officer and CIO. Marty Magill, the senior vice president of sales, will become chief marketing officer. George McGinn, former general counsel for Surgis, will become general counsel for National Medical Card Systems. Patrick Maroney, former chief information officer at Health Care Service Corp., will take over as chief information officer. National Medical Card Systems expects that it will incur a cost of approximately $1.8 million in connection with these management changes.

"Today's actions commence what we hope will be an on-going process of cost and service improvements for our customers and shareholders," Erickson said in a press release. Shares were up 16 cents, or 0.9%, to $16.09.