Shares of drugmaker Eli Lilly and Co. continued climbing Tuesday before markets opened, a day after the stock's price topped $50 for the first time in more than four years.
The Indianapolis company's shares gained more than 5 percent Monday after researchers said combined results from two studies of its experimental Alzheimer's drug suggest it might modestly slow mental decline, especially in patients with mild cases of the disease.
Late-stage studies of the drug, solanezumab, missed their main goals of significantly slowing the disease when evaluated separately. But a secondary analysis of pooled results found 34 percent less mental decline in mild Alzheimer's patients compared to those on a fake treatment for 18 months.
Researchers have been trying for years to find a better treatment for the mind-robbing disease, and analysts say such a drug could be especially lucrative for the company that develops it. Current medicines such as Aricept and Namenda just temporarily ease symptoms. There is no known cure.
About 35 million people worldwide have dementia, and Alzheimer's is the most common type. In the U.S., about 5 million have Alzheimer's.
The growth in Lilly's share price comes even though doctors and analysts who cover Lilly caution that the solanezumab results, while encouraging, indicated a relatively small benefit for patients.
"We did not get the impression that any experts saw this as a breakthrough clinical treatment option," Jefferies analyst Jeffrey Holford said in a research note.
Lilly will probably have to conduct another late-stage trial that involves as many as 2,000 patients with mild cases of Alzheimer's, Leerink Swann analyst Seamus Fernandez said in another research note. He said that study, which could last two to three years, may be needed in order for the company to make a case for reimbursement of a costly, once-monthly intravenous treatment that "delivers a limited functional benefit after 18 months."
Lilly's shares rose 67 cents to $51.45 Tuesday in premarket trading. The stock has climbed about 20 percent since it released preliminary results of the solanezumab studies in late August.