Biogen Idec Inc has seen its market value quadruple in three years to more than $100 billion on the back of its successful multiple sclerosis drugs. Now it has new ambitions in its sights.

The Massachusetts-based company, which made headlines last week when it announced better-than-expected clinical trial results for its experimental Alzheimer's drug, aducanumab, said that it will drop Idec from its name as of Monday and adopt a new logo. The company merged with Idec Pharmaceuticals more than a decade ago.

Chief Executive George Scangos says that going forward he will keep Biogen focused on developing drugs for some of the hardest-to-treat diseases.

"Five years down the road, with some luck, we'll have an Alzheimer's drug that's getting approved,” Scangos told Reuters. "I hope we can transform the treatment of MS. By that time, we will have made substantial progress on ALS and other nerve degenerative diseases, spinal muscular atrophy in kids. All that stuff is on our plate," he said.

"I am sure of two things," he added. "Not all of it is going to work, and some of it will."

Investors, excited by the aducanumab news, sent Biogen shares up 9.7 percent on Friday, and the company's stock touched an all-time high of $480.18 during the session.

The small trial showed the treatment significantly slowed cognitive impairment in patients with mild symptoms, a rare bit of good news in a field littered with high profile failures from the likes of Pfizer Inc and Eli Lilly and Co

But some patients, especially those with a gene predisposing them to Alzheimer's, developed localized brain swelling. The symptom was most common among patients with the gene who were receiving the highest doses of aducanumab, leading about 1/3 of the participants in that category to discontinue the treatment. The company said the swelling was generally "asymptomatic or with mild, transient symptoms."

Biogen plans to begin a larger trial later this year. "If they can replicate the Alzheimer's data in Phase III, they could conceivably have the biggest drug on the planet," JMP Securities analyst Michael King said. As many as 75 million people are expected to develop the disease by 2030.

For Biogen, which is also working on Alzheimer's drugs that use other mechanisms of action, research on dementia drugs represents an expansion of the company's potential reach.

"If the Alzheimer's thing works, then we're not just an MS company. We are broadly focused on neuro-degenerative diseases," Scangos said.

The company is also developing a drug it hopes will address not just symptoms but the cause of MS, potentially changing the way the disease is treated.

"The future looks pretty exciting for us," said Scangos, who became Biogen CEO in July 2010 following a period of upheaval in which activist investor Carl Icahn pushed for management changes and the sale of the company. Scangos, who previously led the tiny biotech firm Exelixis Inc, was recommended for the CEO post by Icahn lieutenants on the Biogen board.

BIGGER MOVE INTO BIOSIMILARS

As it works on new medicines for unmet needs, Biogen is also planning a bigger move into the fledgling field of biosimilars, manufacturing cheaper versions of older biotech drugs as they lose patent protection. Health regulators this month approved the first such drug for the U.S. market, a biosimilar version of Amgen Inc's white blood cell booster Neupogen.

Biogen previously disclosed plans to develop six biosimilar drugs in collaboration with Samsung. "We will expand that to include more," Scangos said.

It has filed for European approval of biosimilars of two blockbuster rheumatoid arthritis drugs, Amgen's Enbrel and Johnson & Johnson's Remicade.

Scangos shrugged off the potential impact to Biogen of biosimilars that replicate its own products, even though such competition could result in far cheaper alternatives to its drugs.

"I view biosimilars as a good thing," he said. "When they come for our drugs, they come."

Biogen's ambitions are not without risk. The company saw a "spectacular failure," as Scangos put it, with a large trial of an ALS drug a few years ago, highlighting the challenge ahead.

"There was no effect at all," Scangos said. "We've gone back to the drawing board."