Merck Says FDA Approves Antifungal Cancidas

New York (Reuters) - Merck Co Inc said Monday that U.S. regulators had approved its experimental drug Cancidas, the first member of a new class of medicines meant to battle deadly fungal diseases that are becoming increasingly common in people with weakened immune systems.

The Food and Drug Administration approved Cancidas for treatment of invasive aspergillosis in patients who do not respond to or cannot tolerate other antifungal therapies, including amphotericin B and itraconazole.

Analysts have predicted Cancidas could achieve peak annual sales between $300 million and $500 million, respectable revenues but not quite blockbuster scale for a company like Merck, which has annual revenues of over $40 billion.

Shares of Merck were down 74 cents to $81.51 in afternoon trade on the New York Stock Exchange, amid a slight decline for the large U.S. drugmakers.

Aspergillosis is a common fungus that poses little threat to the average person. But in people with weakened immune systems, it can infect the lungs and spread throughout the body to damage the heart, brain, kidneys and eyes -- a condition called invasive aspergillosis.

"Despite current treatments, the mortality rates in patients with invasive aspergillosis range from 50 to over 90 percent," the company said in a statement.

It is especially dangerous to cancer patients, organ and bone marrow transplant recipients, and patients with HIV/AIDS, Merck said, adding that Cancidas demonstrated effectiveness among patients who had previously failed to benefit from other therapies.

Cancidas, which is given intravenously, is the first member of the new class of antifungals called echinocandins or glucan synthesis inhibitors. They block synthesis of a protein, D-glucan, that is an important component of the fungal cell wall but that is not found in human cells.

"There's no doubt that Cancidas is a very good drug that can save lives of patients who have failed other drugs," said Richard Evans, a Sanford Bernstein pharmaceuticals analyst.

But precisely because Cancidas works for patients with no other hope, he predicted many doctors would set it aside for emergency use rather than prescribing it as a first-use treatment.

"It will be one of those 'behind-the-glass emergency drugs' that doctors won't want to over-use -- in order to prevent pathogens from becoming resistant" to the medicine, said Evans, who predicted Cancidas would achieve peak sales of $350 million.

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Copyright © 2001 At Home Corporation.

This article posted February 16, 2001.