Radiochemicals, Chemists, & a Potential Alzheimer’s Breakthrough
The NYTimes has a great piece today on a potential new dye that can detect amyloid plaque, the telltale sign of Alzheimer’s disease. As we’ve written, the pipeline is chock full of drugs to prevent amyloid from building up on the brain, but many neurologists believe those efforts could be for naught if the drugs aren’t tested early on in the progression of the disease. The problem is that its hard to separate dementia caused by Alzheimer’s from other neurological disorders. And by the time doctors can comfortably say that a person has Alzheimer’s, an awful lot of neurons have died. To date, there’s been no way to tell if someone showing signs of memory loss will indeed go on to develop the disease. Bottom line: this new dye could help identify the right patients, earlier on, ideally improving outcomes for drugs in development and ultimately patients.
The Times piece highlights the work of Daniel Skovronsky, CEO of Avid Radiopharmaceuticals, who along with University of Pennsylvania chemist Hank Kung developed a radioactive dye based on fluorine 18. Results from what could be a groundbreaking study will of the dye’s ability to detect amyloid plaque are going to be unveiled on July 11th at Alzheimer’s Association’s annual meeting.
We wanted to point readers to a piece our own Beth Halford wrote back in 2008 highlighting the genesis of three imaging agents labeled with 18F, including Kung and Avid’s dye and products by Bayer and GE Healthcare. More importantly, we wanted to point out some of the potential stumbling blocks to the development of newer agents and the field in general. While the NYTimes article discusses some of the ethical hurdles associated with developing and testing imaging agents for Alzheimer’s, Halford highlighted some of the larger picture worries—namely, a lack of basic research around nuclear medicine:
A report released last year by the National Academy of Sciences concluded that there was a "loss of federal commitment" to nuclear medicine. The Department of Energy, which has supported the bulk of nuclear medicine research since the 1950s, cut back its funding for the field by 85% from 2005 to 2006, and funding levels haven't made any appreciable gains in the past two years.
PET researchers' other chief complaint has particular relevance to C&EN readers. "What we're missing in this field are chemists," says Gilles Tamagnan, laboratory R&D director at Molecular NeuroImaging and associate professor of psychiatry at Yale University. "There's plenty of nice chemistry to be done. There just aren't enough people doing it," he says.
PET researchers say more radiochemists are required to staff the rapidly growing number of PET centers (see page 68). They also note that only a handful of synthetic chemists are working on new methods to incorporate radionuclides into molecules. Medicinal chemists are also needed to expand the limited list of radiotracers currently available. "There are less than 20 teams developing new radiolabeled compounds for the brain," Tamagnan notes, "and the brain is very big."
In an entirely separate issue, the number of suppliers of radiochemicals has been shrinking, a situation that has some worried about the long-term availability of radiochemicals. As our own Mike McCoy wrote earlier this year, two major suppliers—Sigma-Aldrich and GE—exited the radiochemical business in 2008, moves that don’t exactly bode well for the long-term health of the industry. Although McCoy found several smaller suppliers that vouched for the stability of supply, a number of researchers, including Penn’s Kung, were feeling neglected. As McCoy writes:
There was a time when commercial radiochemical firms would replicate diagnostics developed in Kung’s lab and offer them to other scientists for use in research. But during the 2000s they lost interest in this business, he says, leaving his fellow researchers in the lurch. “I try to help them out, but I’m not set up to supply them on a regular basis,” he explains.
On a happier note, Kung says commercial supply houses seem a little more invested in helping out these days. Perhaps news of a breakthrough diagnostic is helping them to see the light. So chemists that use radiochemicals: are you having any trouble getting them? And do you buy into Tamagnan’s assertation that there’s a market for radiochemists out there?