AC Immune and Piramal Imaging are betting that an Alzheimer's imaging agent focused on tau proteins will be more valuable and successful in a market in which amyloid-β imaging agents designed to help diagnose the neurodegenerative disease have struggled to gain traction. The two companies sealed a deal focused on developing and commercializing a positron emission tomography (PET) tracer to track early tau buildup in the brain, something the market currently lacks.
Piramal Imaging, based in Switzerland, Germany and Massachusetts, focuses on molecular imaging technology and tools, and is part of the Indian conglomerate Piramal. AC Immune is a Switzerland-based biotech and in January launched the first trial of a tau-targeting Alzheimer's vaccine.
Neither side is discussing financial details of their new arrangement. But the partnership involves a global license agreement for Piramal focused on research, development and commercialization of AC Immune's tau protein positron emission tomography tracers to help diagnose and treat Alzheimer's as well as other tau-related disorders. The deal secures an undisclosed upfront payment for AC Immune, though it will also be eligible for milestone payments down the line, plus tiered royalties on any products that come out of the partnership. Initially, the focus will be on advancing tau PET tracers currently at the late preclinical stage.
Piramal CEO Ludger Dinkelborg told FierceDiagnostics, through a spokesperson via email, that a tau protein PET tracer will offer an important difference in the marketplace versus amyloid-β imaging, because it focuses on an arguably more relevant set of markers for Alzheimer's diagnostics.
"The advantage of tau is the growing clinical validation and acceptance that the presence of tau tangles [in the brain] correlates directly with [Alzheimer's disease] progression, making it a critical biomarker for the early diagnosis of [Alzheimer's] patients," Dinkelborg said.
He added that an imaging agent enabling this "will lead to more effective clinical and care management of this patient group," and that such a diagnostic tool should even help lower healthcare costs, spurring government agencies and payers to accept "broad reimbursement coverage of a tau PET agent."
That would be in contrast to amyloid-β imaging agents, which have made some market progress but are hampered by reimbursement uncertainty, regulatory caution and the lack of viable Alzheimer's drugs. At the end of April, GE Healthcare ($GE) launched Vizamyl, an imaging agent that lights up amyloid-β plaque in brain scans, in the U.S. But the FDA granted limited approval, signing off on its use only in conjunction with other tests in an effort to determine an Alzheimer's diagnosis. The company cautions that a positive scan can't be used on its own to determine Alzheimer's and that a negative one only reduces the likelihood of Alzheimer's-related cognitive impairment. Similar regulatory limits in the U.S. have hamstrung Eli Lilly's ($LLY) Amyvid.
Piramal Imaging's Neuraceq amyloid-β PET tracer is in a similar boat, having just received limited FDA approval in March, a few weeks after gaining approval to market in Europe. (AC Immune has used Neuraceq for imaging amyloid-β plaques in the brains of patients testing its Alzheimer's vaccine.)
So how will a tau PET imaging agent make better traction in the push for better Alzheimer's diagnostics despite regulatory, insurance payment and drug development challenges that remain?
Andrea Pfeifer, CEO of AC Immune, told FierceDiagnostics through a spokesperson that earlier diagnosis of Alzheimer's still matters and should enable better drug development down the line.
"The earlier and more relevant the diagnosis the greater the opportunity to treat the disease process, particularly with respect to forthcoming disease modifying therapies," Pfeifer told FierceDiagnostics. "There are several of these therapies in clinical development, and with each development, the clinical community's understanding of the clinical requirements for disease modifying therapies is broadened."
Pfeifer added that a tau PET tracer "will be critical in guiding clinical trials for such disease modifying treatments, and could provide a validated clinical marker for treatment response, which is lacking now."
Of course, this isn't the only tau-PET Alzheimer's imaging agent project in the pipeline. Both companies note that Eli Lilly and GE Healthcare are also hard at work on their own versions, among other competitors.
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