NDAs FOR PET RADIOPHARMACEUTICALS WOULD COVER USE OF CYCLOTRONS

NDAs FOR PET RADIOPHARMACEUTICALS WOULD COVER USE OF CYCLOTRONS and "black boxes" under a current FDA proposal, FDA Medical Imaging Drugs Group Leader Eric Jones, MD, said at a March 5 FDA public hearing on regulatory approaches to Positron Emission Tomographic (PET) radiopharmaceuticals. "Accelerators and cyclotrons used to produce radioactive atoms for PET radiopharmaceuticals [would be] considered components of processing to produce PET radiopharmaceuticals and be embodied within the NDA," Jones said. "The automated synthesis systems [black boxes] would also follow a similar approach [as] we would have those [embedded] within the NDA...and we would seek consultation from [CDRH] as needed." The current proposal differs from one contained in a paper for comment recently released by the agency. The hearing was held to get feedback on the paper, which sets out FDA's plan for regulating these products. The prior proposal called for a 510(k) or a premarket approval application (PMA) to be submitted for the processing equipment in addition to an NDA for the PET radiopharmaceutical. FDA is also proposing that PET radiopharmaceuticals be regulated as "new drugs" and therefore in need of INDs and NDAs or ANDAs. At the hearing, FDA issued a statement saying that the agency has "an NDA for a finished PET radiopharmaceutical in which the cyclotron and associated...black box are described in the NDA as components of the manufacturing process." The Methodist Medical Center in Peoria, Ill. filed an NDA on Jan. 15 for the widely-used PET radiopharmaceutical, fludeoxyglucose F 18 (FDG). The agency's Medical Imaging Drugs Advisory Committee determined at its May 1992 meeting that FDG is effective in evaluating many conditions including suspected brain tumors based on a clinical drug master file (DMF) submitted to FDA by the Institute for Clinical PET (ICP) ("The Pink Sheet" June 1, 1992, T&G-1). Steven Zigler, PhD, operational director at Methodist's PET center, commented negatively on the length of time required to put the FDG regulatory package together. "The development of our NDA at Methodist has easily required five man-years of effort since October 1991, Zigler said, adding: "I believe the collective effort to assemble our NDA and see it through to conclusion... has literally strained the resources of the entire PET community." FDA Medical Imaging Drugs Division Supervisory Chemist Eric Sheinin, PhD, asked past ICP president Edward Coleman, MD, if the lessons learned from the FDG NDA would make it easier for the next application. Coleman responded that "we have learned that the efforts that we have made have not been met with equal efforts by the FDA to have any compromise." The major limitations, Coleman continued, "relate to GMP standards; we are not manufacturers of drug products," and FDA has "not been able to show any leniency in the hospitals producing these products concerning GMP standards." He added: "As a matter of fact, the mechanisms that are put before us today...are even more stringent than we were working with in 1988." FDA's Jones pointed out that "documents for FDA field investigators allow for modified GMP requirements as they apply to PET radiopharmaceuticals and will include separate, alternative procedures for inspections." ICP President Henry Wagner, MD, said PET producers and users have recommended that FDA appoint a working group of staffers and outside experts to develop specific recommendations and standards for PET. CDRH Office of Health Affairs Director Gordon Johnson, MD, said: "I think Dr. Wagner's suggestion of putting some people together...is helpful."