Scientists Question Data Behind an Experimental Alzheimers Drug

Studies linked to Cassava Sciences, once a stock market favorite, have been retracted or challenged by medical journals.

A small biotech company that trumpeted an exciting new treatment for Alzheimers disease is now under fire for irregularities in its research results, after several studies related to its work were retracted or questioned by scientific journals.

The company, Cassava Sciences, based in Austin, Texas, announced last summer that its drug, simufilam, improved cognition in Alzheimers patients in a small clinical trial, describing it as the first such advance in treatment of the disease. Cassava later initiated a larger trial.

The drugs potential garnered enormous attention from investors. Alzheimers disease affects roughly six million Americans, a number that is expected to double by 2050, and an effective treatment would be lucrative. Cassavas stock soared, by more than 1,500 percent at one point. The company was worth nearly $5 billion last summer.

But many scientists have been deeply skeptical of the companys claims, asserting that Cassavas studies were flawed, its methods opaque and its results improbable.

Families of some trial participants have said they see improvements. But critics noted that the trial reporting better cognition due to simufilam lacked a placebo group, and asserted that the Alzheimers patients were not followed long enough to confirm that any improvements in cognition were genuine.

Some experts went further, accusing the company of manipulating its scientific results.