Amgen’s experimental bone drug reduced the risk of spinal fractures in women with osteoporosis by 68 percent in a pivotal clinical trial.

Genentech said it would spend up to $371 million on retention bonuses to keep its employees from leaving because of the possible acquisition of the company by its majority shareowner, Roche.

The biotechnology giant Genentech turned down a buyout offer from its majority owner Roche, saying the $43.7 billion takeover bid undervalues the company.

Genentech said it had formed a special committee, consisting of its three independent board members, to consider a takeover bid from Roche Holding.

The Swiss drug maker Roche Holding said it was offering about $43.7 billion to acquire the 44 percent of Genentech that it did not already own.

The Swiss drug maker was seeking to acquire the 44 percent of Genentech that it does not already own.

The Swiss drug maker was seeking to acquire the 44 percent of Genentech that it does not already own.

The Swiss pharmaceutical company Roche Holding said none of its pending medicines represent significant improvement over existing drugs.