A University City start-up is working on radioactive compounds that can be scanned to identify plaque in the brain believed to be related to Alzheimer's and other neurodegenerative diseases - long before any symptoms occur.

Avid Radiopharmaceuticals Inc. was spun out of research at the University of Pennsylvania. It has just raised $26 million in venture financing, led by Safeguard Scientifics Inc., of Wayne, and AllianceBernstein Venture Fund, of New York.

About 5.1 million Americans are diagnosed with Alzheimer's, a memory-robbing disease that generally afflicts those over 65.

Avid employees are working with Penn scientists to develop compounds that bind to amyloid plaque in the brain. When a patient is imaged with a PET scanner, researchers say they can detect changes in the brain that could be early signs of Alzheimer's and Parkinson's disease.

The technology - already tested in early-stage human studies - was developed after a decade of work by Hank Kung, a University of Pennsylvania chemist, who worked with Penn neuropathologist Daniel Skovronsky.

The injected compounds emit radioactive particles that bind to amyloid plaque. Avid also is developing a compound that binds to certain neurons in the brain; the loss of these neurons is associated with Parkinson's disease.

The use of radiopharmaceuticals to diagnose and monitor Alzheimer's, Parkinson's, and other neurological disorders is potentially a big market, as the U.S. population ages.

"We are not alone in this field," said Kung, who is still at Penn and is Avid's chief scientific adviser.

GE Healthcare, the medical division of General Electric Co., has licensed compounds including one, dubbed "Pittsburgh Compound B," from the University of Pittsburgh Medical Center, he said.

"GE Health is actively developing similar imaging agents for Alzheimer's disease," Kung said. "Both the university and GE have done quite a few clinical studies in patients using Pittsburgh Compound B."

The Penn researchers collaborate with Avid's 15 employees from laboratories at 3700 Market St., part of the University City Science Center. Avid's offices and labs are across the street, at 3624 Market.

In July 2005, Skovronsky left Penn to become Avid Radiopharmaceuticals' first employee and its chief executive officer.

A year later, in July 2006, Avid signed a collaboration deal with Germany-based Schering AG to further develop one of its compounds for diagnosing Alzheimer's. In return for funding the work, the firm, now called Bayer Schering Pharma AG, gets the option for exclusive rights to commercialize the compound.

"Currently, there are four drugs approved to treat Alzheimer's disease," Skovronsky said. "We hope that by identifying patients earlier and more accurately, we can get them on the right therapies sooner."

"It's just as important to identify patients who don't have Alzheimer's," Skovronsky said. "If someone shows up with memory impairment and cognitive dysfunction, about one-third won't have Alzheimer's. They will have other causes of dementia. We need to discover what it is and get them on the right treatment."

Avid is developing five radioactive imaging drugs and plans to use the $26 million in new financing to pay for large midstage clinical trials.

In 2005, Avid raised $500,000 from BioAdvance, the Philadelphia region's life-sciences greenhouse, and in 2006 raised an additional $8.9 million.

The original investors - Pfizer Inc.'s Strategic Investments Group; Lilly Ventures, the venture-capital group of Eli Lilly & Co.; RK Venture Group; and BioAdvance - all invested in the latest financing. Safeguard Scientifics invested $7.3 million of the $26 million and will gain a seat on Avid's board.

Contact staff writer Linda Loyd at 215-854-2831 or lloyd@phillynews.com.