Biogen blueprints a big Phase III effort for its Alzheimer's hopeful

Riding high on some promising Phase I data, Biogen ($BIIB) has mapped out a big late-stage program for its Alzheimer's disease treatment, making a risky bet that it can reverse decades of failure in the field.

The treatment, aducanumab, is an antibody targeting beta amyloid proteins, buildups in the brain widely believed to contribute to the disease's neurodegenerative effects. In Phase I data unveiled last month, Biogen's treatment did what no candidate of its kind managed before, notching a statistically significant improvement in cognition. The data, from just 166 patients, were enough to spur a great deal of renewed optimism around the industry, and now Biogen is taking the plunge on Phase III.

Biogen R&D chief Doug Williams

In the second half of 2015, the Big Biotech is planning to launch two 18-month studies on roughly 1,350 patients each, taking a page from its Phase I success and targeting Alzheimer's sufferers with early-stage disease. In the next few months, Biogen expects to get final signoff from the FDA on its trial design, clearing the way for recruitment. The company won't divulge much detail until then, R&D chief Doug Williams said on a call with analysts, but the company is broadly looking to replicate the treatment effect it found in Phase I.

In the earlier trial, three out of four dosage levels of BIIB037 led to statistically significant reductions in beta amyloid compared to placebo after 26 weeks, and, for the two doses with enough data to measure, that effect was even greater at week 54. More importantly, that reduction in beta amyloid correlated with statistically significant improvements over placebo on two common measures of cognition, a result many say affirms the hypothesis that the protein is to blame for Alzheimer's memory-destroying effects.

Of course, Biogen isn't the first drugmaker to take an anti-amyloid agent into Phase III with big ambitions. Eli Lilly's ($LLY) solanezumab and Pfizer ($PFE) and Johnson & Johnson's ($JNJ) bapineuzumab each flamed out spectacularly in late-stage trials, and the dismal record of failure in Alzheimer's R&D otherwise speaks for itself. But Biogen and its supporters contend that the company's combination of a potentially best-in-class antibody and a strategy of targeting patients with mild Alzheimer's could make this time different.

Meanwhile, Biogen is settling in for the long haul in Alzheimer's development. In addition to its lead amyloid effort, the company is also working on treatments that target tau and BACE proteins, two other potential culprits in neurodegeneration. Biogen believes mixing and matching multiple approaches could be the key to fighting Alzheimer's down the line, Williams said, and the company is at work on preclinical studies to tease out that promise.

"Long term, our view is that this will become a combination market, and we're exploring a number of what I'd characterize as obvious combinations to look at right up front," Williams said.

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