Aussie researchers find imaging agent for early diagnosis of melanoma
Australian scientists have developed a potential new material for diagnosing malignant melanoma, according to a study in the Sept. 10 issue of the Journal of Medicinal Chemistry.

Ivan Greguric, PhD, of the Radiopharmaceuticals Research Institute at the Australian Nuclear Science and Technology Organization in Sydney, Australia, and colleagues noted that melanoma is the most dangerous form of skin cancer and results in most of the deaths related to skin cancer. Survival depends on early detection and cure by surgical resection, the authors said, noting that metastatic malignant melanoma is refractory to most therapies with a five-year survival rate of less than 5 percent. One problem with early diagnosis is that PET can still miss small cancers, delaying diagnosis and treatment.

The Australian researchers, working with the Cooperative Research Consortium for Biomedical Imaging Development—a program funded by the Australian government—focused on fluoronicotinamides as imaging agents.

The researchers prepared a series of fluoronicotinamide analoges with enhanced melanin binding and uptake, rapid clearance, and high in vivo stability.

“It was found that the fluoronicotinamide structures are not only excellent bioisosteres of previously reported halogenated benzamides but the nicotinamides also possess superior radiolabeling properties,” the authors said. Combining fluoronicotinic acid with N,N-diethylethylenediamine led the researchers to discover [F18]2, “which possessed the highest target-to-nontarget ratio, high in vivo stability, and rapid whole-body clearance.”

This “novel radiotracer for PET melanoma imaging” is currently being evaluated in preclinical studies for progression into clinical trials to assess the responsiveness of therapeutic agents,” the authors said.

Clinical trials with the new agent are scheduled for 2010.