"You've got this huge gap between your current product and the products behind it," said Michael King, biotechnology analyst at Rodman & Renshaw.

But Peter Drake, a biotechnology analyst at Vector Securities, said the approval would make only a small difference in sales of the drug.

Some biotechnology analysts and executives said the F.D.A. was being overly cautious or not giving clear enough guidance.

His father is a first vice president and biotechnology analyst at Merrill Lynch in New York.

With biotechnology companies routinely reporting scientific breakthroughs, Bernstein has no biotechnology analyst.

It is actively seeking a biotechnology analyst.

But they may also have heard biotechnology analysts warn that it is foolish to pay much attention to feats whose commercial benefits are so speculative and distant.

Health care analysts say that Mr. Harris never really made a mark as a biotechnology analyst.

"No one liked that except a few academic scientists," said Rebecca Goldberg, a biotechnology analyst for the Environmental Defense Fund.

"People are buying products," said Rachel Leheny, biotechnology analyst at Lehman Brothers.