The drug maker Eli Lilly has engaged in a decade-long effort to play down the health risks of Zyprexa, its best-selling medication for schizophrenia, according to hundreds of internal Lilly documents and e-mail messages among top company managers.
The documents, given to The Times by a lawyer representing mentally ill patients, show that Lilly executives kept important information from doctors about Zyprexa’s links to obesity and its tendency to raise blood sugar — both known risk factors for diabetes.
Lilly’s own published data, which it told its sales representatives to play down in conversations with doctors, has shown that 30 percent of patients taking Zyprexa gain 22 pounds or more after a year on the drug, and some patients have reported gaining 100 pounds or more. But Lilly was concerned that Zyprexa’s sales would be hurt if the company was more forthright about the fact that the drug might cause unmanageable weight gain or diabetes, according to the documents, which cover the period 1995 to 2004.
Zyprexa has become by far Lilly’s best-selling product, with sales of $4.2 billion last year, when about two million people worldwide took the drug.
Critics, including the American Diabetes Association, have argued that Zyprexa, introduced in 1996, is more likely to cause diabetes than other widely used schizophrenia drugs. Lilly has consistently denied such a link, and did so again on Friday in a written response to questions about the documents. The company defended Zyprexa’s safety, and said the documents had been taken out of context.
But as early as 1999, the documents show that Lilly worried that side effects from Zyprexa, whose chemical name is olanzapine, would hurt sales.
“Olanzapine-associated weight gain and possible hyperglycemia is a major threat to the long-term success of this critically important molecule,” Dr. Alan Breier wrote in a November 1999 e-mail message to two dozen Lilly employees that announced the formation of an “executive steering committee for olanzapine-associated weight changes and hyperglycemia.” Hyperglycemia is high blood sugar.
At the time Dr. Breier, who is now Lilly’s chief medical officer, was the chief scientist on the Zyprexa program.
In 2000, a group of diabetes doctors that Lilly had retained to consider potential links between Zyprexa and diabetes warned the company that “unless we come clean on this, it could get much more serious than we might anticipate,” according to an e-mail message from one Lilly manager to another.
And in that year and 2001, the documents show, Lilly’s own marketing research found that psychiatrists were consistently saying that many more of their patients developed high blood sugar or diabetes while taking Zyprexa than other antipsychotic drugs.
The documents were collected as part of lawsuits on behalf of mentally ill patients against the company. Last year, Lilly agreed to pay $750 million to settle suits by 8,000 people who claimed they developed diabetes or other medical problems after taking Zyprexa. Thousands more suits against the company are pending.
On Friday, in its written response, Lilly said that it believed that Zyprexa remained an important treatment for patients with schizophrenia and bipolar disorder. The company said it had given the Food and Drug Administration all its data from clinical trials and reports of adverse events, as it is legally required to do. Lilly also said it shared data from literature reviews and large studies of Zyprexa’s real-world use.
“In summary, there is no scientific evidence establishing that Zyprexa causes diabetes,” the company said.
Lilly also said the documents should not have been made public because they might “cause unwarranted fear among patients that will cause them to stop taking their medication.”
As did similar documents disclosed by the drug maker Merck last year in response to lawsuits over its painkiller Vioxx, the Lilly documents offer an inside look at how a company marketed a drug while seeking to play down its side effects. Lilly, based in Indianapolis, is the sixth-largest American drug maker, with $14 billion in revenue last year.
The documents — which include e-mail, marketing material, sales projections and scientific reports — are replete with references to Zyprexa’s importance to Lilly’s future and the need to keep concerns about diabetes and obesity from hurting sales. But that effort became increasingly difficult as doctors saw Zyprexa’s side effects, the documents show.