Eli Lilly and Co. has acquired two investigational PET imaging agents from Siemens Healthcare in an effort to boost its commitment to Alzheimer's disease research and development. Both tracers have been clinically proven to selectively target neurofibrillary tangles (NFTs), or tau, a diagnostic biomarker for Alzheimer's disease.

Neurofibrillary tangles of tau protein are one of two critical protein abnormalities associated with Alzheimer's disease; the other is amyloid plaque. Both pathologies are considered to be targets for therapeutic intervention, in addition to being biomarkers for diagnostic in vivo imaging agents.

Edgar Alvarez, global marketing for Siemens PETNET solutions, told DOTmed News that at this point scientists theorize that having both the amyloid tracer and the tau agent for determining Alzheimer's would give clinicians a good picture of whether Alzheimer's was present or not.
Use of a tau tangle tracer could enable tailoring and early identification of at-risk patients, as well as potentially provide a marker for treatment response, according to Lilly.

At this early stage of the acquisition, Lilly said it will initially focus on incorporating this new technology into its anti-amyloid and anti-tau R&D program, with the option to commercialize the tracers later on. The tracers will have to go through several different clinical phases before they can be submitted for U.S. Food and Drug Administration approval.

The financial terms of the deal with Siemens are not being disclosed.

Hartmuth Kolb, vice president of biomarker research at Siemens, told DOTmed News last year that they have made around 800 compounds altogether for Alzheimer's biomarkers, and two have been most promising — T807 and T808. These are the ones Lilly has acquired.

He said tau could be an additional imaging biomarker for Alzheimer's because it can point to the degree of cognitive impairment and neuronal circuitry deterioration associated with Alzheimer's and dementia. Amyloid plaque build-up cannot provide these particulars.

"The expression of tau is more in synch with the actual symptoms of dementia," said Kolb. "Amyloid might be useful for early detection and tau might be useful for measuring the progression of the disease."

Lilly is already a step ahead with imaging amyloid plaque. In November 2011, it entered a deal with PETNET Solutions, a Siemens subsidiary, to manufacture and distribute Amyvid, an amyloid plaque PET imaging agent approved by the FDA in April.

Back to HCB News

More Industry Headlines