CTN has offered to review testing protocols for drug development. Such reviews too often occur after protocols have been cemented, even though, in several cases, companies submitted protocols much earlier than their clinical testing started.
FDA is another key player in promoting standardization. In December 2009, the agency approved cGMP regulations for PET drugs marketed for clinical use. That touched off a two-year period during which PET drug makers were required to apply for NDAs and ANDAs for their radiopharmaceuticals. Those applications are due December 12, 2011.
The regulation completes a process dating back to 1995, when the agency said it intended to regulate PET drugs under the Federal Food, Drug, and Cosmetic Act. In 1997, Congress passed the FDA Modernization Act, which clarified that PET drugs are subject to FDA regulation but allowed for a phasing-in of rules.
“Throughout these proceedings, we’ve tried to be sensitive to the fact that we are bringing under regulatory control an industry that had been largely unregulated and an industry with special characteristics, given the short half-lives of the materials involved and the fact that they are often used onsite or within a relatively short distance from the production site because of their half-lives,” Jane A. Axelrad, associate director for policy at FDA’s Center for Drug Evaluation and Research, said at a March 2 public meeting.
Also working on standardization efforts is the Quantitative Imaging Biomarkers Alliance (QIBA), organized in 2007 by the Radiological Society of North America (RSNA) to unite researchers, healthcare professionals, and industry stakeholders in the advancement of quantitative imaging and the use of biomarkers in clinical trials and practice.
Most recently, on June 28, QIBA released for public comment a “profile” or technical document from its Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) Technical Committee. It offers basic standards for site and scanner qualification, subject preparation, contrast agent administration, imaging procedure, image post-processing, image analysis, image interpretation, data archival, and quality control.
CTN says it is close to completing a protocol for the use of fluorodeoxyglucose (FDG), a radiopharmaceutical used in PET imaging. It has obtained some consensus from industry and professionals, CTN reports. Protocols for other PET imaging agents will follow, and rules will differ from one radiopharmaceutical to another. “For instance, the fluorothymidine (FLT) protocol is going to be significantly different than the FDG protocol, though, there will be areas where they are identical,” Dr. Graham said.
“There are other agents that we’ve been talking about. For instance, some of the hypoxia imaging agents are likely to be ones that we work on relatively soon,” he explained.
Amyloid imaging agents, for which clinical trials are getting under way, may be another area of concentration for future CTN protocols. The network’s ultimate direction on which future protocols to pursue won’t be made until after talks with biopharma industry representatives. Dr. Graham added that FDA can help advance standardization by simplifying toxicological requirements for imaging agents, since some have already been used in thousands of patients without incident.