Mike Snider, and Kevin McCoy

USA TODAY

Pharmaceutical giant Eli Lilly said Wednesday that medical testing showed that its trial drug for treatment of mild dementia from Alzheimer’s disease did not slow memory loss in patients.

Patients treated with the drug called solanezumab "did not experience a statistically significant slowing in cognitive decline compared to patients treated with a placebo" in results of a phase 3 clinical trial, the company said in a statement. Although the study results "directionally favored" the drug, "the magnitudes of treatment differences were small," the company said.

As a result, Eli Lilly (LLY) said it would not submit the drug for U.S. regulatory approval. The company plans to present the clinical findings on Dec. 8 during the ninth Clinical Trials on Alzheimer's Disease meeting.

Shares of the Indianapolis-based drug firm fell 11.7% to $67.09 in morning trading, recovering somewhat from a 15% plunge before U.S. financial markets opened.

The results also appeared to impact the pharmaceutical research sector. Shares of Biogen (BIIB) dropped more than 5% to $301.48, while investors sent shares of Merck (MRK) 1.2% lower to $60.95 in morning trading.

Separately, shares of Juno Therapeutics (JUNO) plunged more than 30% to $20.64 after the Seattle-based biopharmaceutical company issued an announcement that one patient had died and another was not expected to recover from tests of a trial medication to treat a form of acute leukemia. The company said it notified the U.S. Food and Drug Administration that testing of the drug known as JCAR015 had been put on hold.

The Eli Lilly announcement represents the latest in a string of trial medications that have failed to achieve a potential medical breakthrough for treating Alzheimer's disease. Eli Lilly said the brain ailment has stricken an estimated 47 million people worldwide. The company, which has invested more than $3 billion on Alzheimer's disease research over nearly 30 years, said it "remains committed" to finding an effective drug for the disease.

Solanezumab also failed in two previous large studies of people with mild-to-moderate forms of Alzheimer's. Lilly's latest trial sought to show that drug could slow the cognitive decline in patients with mild cases of the disease — people who have lost some memory but otherwise could handle daily tasks. Analysts were skeptical.

"As far back as ... 2012, we’ve said solanezumab was a very high risk program that was likely to fail," Tim Anderson, a pharmaceuticals analyst for Sanford C. Bernstein LLC, wrote Wednesday in a note to investors.

Despite the failed test, Eli Lilly has "strong growth prospects without solanezumab," said David Ricks, who next month will become the company's CEO. He currently is president of Lilly Bio-Medicines. "Driven by new product launches, we continue to expect to grow average annual revenue by at least 5% between 2015 and 2020. Over that time frame, we also expect to increase our margins and provide annual dividend increases to our shareholders," he said in a statement.

Next Eli Lilly CEO's reign centers on Alzheimer's drug

However, the study outcome is expected to result in a fourth-quarter charge of roughly $150 million, pre-tax, or approximately 9 cents a share after-tax, the company said. Eli Lilly plans to provide updated 2016 financial guidance and announce its 2017 outlook on Dec. 15.

"The results ... were not what we had hoped for and we are disappointed for the millions of people waiting for a potential disease-modifying treatment for Alzheimer's disease," John Lechleiter, the company's current CEO, chairman and president, said in a statement.

Contributing: James Briggs of the Indianapolis Star

Follow Mike Snider on Twitter: @MikeSnider