The US Food and Drug Administration wants digital imaging technologies to become a larger part of the drug-approval process, especially in tracking the response of cancer patients to potential therapies in clinical trials, according to a senior agency official.
"We lack a mechanism for rapidly — or even slowly — tracing the response of cancer patients [to potential therapies] in clinical trials," Janet Woodcock, acting deputy commissioner for operations at the FDA, said last week at the Molecular Medicine Tri-Conference in San Francisco. "We want to see imaging technologies put to use here" to gauge such endpoints as tumor size reduction.
Woodcock's comments could be regarded as the FDA waving a flag to start a race that could create new molecular biology tools that may allow in vitro data into the drug-discovery — and eventually drug-approval — process.
"The FDA is saying we need to move out on this now," Woodcock told BioCommerce Week in a telephone interview this week. "It's time to really start moving in the utilization of technologies — MRI, CT, and the probes used with them. But we can't force the choice of technology."
This speech is clearly welcomed at GE Healthcare and rivals Siemens and Philips, companies that are leaders in the commercialization of digital imaging technology and the development of new imaging modalities, and probes.
Woodcock's singling out of imaging technology was unusual and important in that it raises awareness of the tools and appears to put today's imaging instruments and contrast agents, and in-development, higher resolution modalities, on a faster track at the regulatory agency, similar to the agency's adoption of genomic data derived from microarrays, for example.
"Imaging technologies are at the forefront of our efforts," Woodcock said.
CT, MRI, and PET are well-established diagnostic technologies, and efforts are underway at GE and competitors to create new imaging technologies with greater resolution under the rubric of "molecular imaging," which is a general term used to describe new generations of imaging technology being developed with the goal of providing higher resolution insights into biology at the molecular level.
Woodcock said her remarks were not specific to a particular technology, but rather a call to action.
George Mills, director of CDER's medical imaging and radiopharmaceutical drug products unit, told BioCommerce Week that the imaging technology available today may take as many as five years for the agency to get to the point where it is comfortable with the precision and reproducibility of imaging data to be systematically used in the regulatory process, and even still more time for it to become a part of the drug development process and enter the approval process (see Q&A).
The technology that the FDA is focusing on is positron emission tomography, whose images capture the metabolism of radiopharmaceuticals absorbed by tissue in the body. Some 700,000 PET scans were performed at some 1,500 sites in the US in 2003, with 93 percent of PET studies conducted for oncology purposes, and 7 percent for cardiology and neurology applications, according to research published by IMV Medical Information Division, a Des Plaines, Ill., market research firm.
"No doctor is going to tell you for sure that you have cancer if you only have a PET scan, they have to do the histology; but PET is the gold standard in pathological analysis," Antonio Garcia, research manager for medical imaging for Frost and Sullivan, told BioCommerce Week.
GE Healthcare has been the market leader of the $2 million combination PET/CT instruments that are dominating PET equipment sales now, followed by Siemens and Philips Electronics, respectively, Garcia said. The company's April 2004 acquisition of Amersham, and its portfolio of contrast agents used in imaging, has greatly augmented GE's leadership by bringing together the leading platform seller with a leader in contrast technologies.
The PET/CT market was estimated at $496.5 million in 2004. Additionally, the firm estimates the radiopharmaceutical market, where Amersham claimed it held a 35-percent market share in 2002, at $1.4 billion in 2004.
Already GE is benefiting from the Amersham acquisition by being able to charge a premium price for its imaging instruments, according to Nicholas Heymann, an analyst for Prudential Equity Group.
In a research note in December, Heymann wrote that the addition of genomic information and Amersham's imaging agents are being factored into the development of GE's healthcare products — including CT, PET, MR and ultrasound — and the addition of Amersham's imaging agents are helping GE now charge premium prices for those products. But, for PET, GE customers have to go elsewhere for FDG, as the company does not manufacture it, according to Gail Prochaska, vice president of vendor sales at the IMV.
GE Healthcare will launch new CT and MRI products in the second half of the year and expects to charge a premium of 10 percent to 15 percent more for those products, GE executives said in the company's recent first-quarter conference call (see BCW 4/21/2005).
Siemans and Philips are moving to shore up their positions against GE in this emerging market.
Siemens is making investments in molecular imaging pharmaceuticals and has obtained a share of a distribution channel of the key tracer used in PET.
Siemans Venture Capital last week announced its participation in a syndicate investing $28 million in Series C funding for Cambridge, Mass.-based Molecular Insight Pharmaceuticals, a firm developing imaging pharmaceuticals and radiotherapeutics. The funds will be used to take the company's lead compound, BMIPP, into Phase 3 clinical trials, Molecular Insight said in a statement. BMIPP is a molecular imaging pharmaceutical that enables the detection of cardiac ischemia based on changes in cardiac cell metabolism, the company said.
Additionally, Seimens, which created a molecular imaging unit in 2003, in March anted up $1.3 billion to buy CTI Molecular Imaging, its partner in an 18-year-old joint venture, CPS Innovations of Knoxville, Tenn.
Before the acquisition offer, Siemens served as the distribution arm for CTI's PET scanning technology and provided the PET imaging systems sold by Hitachi. It is unclear whether the acquisition of CTI Molecular Imaging may leave Hitachi without a PET system. Hitachi declined comment.
With the acquisition of CTI Molecular Imaging, Siemans also obtains FDG Petnet, a network of cyclotrons that manufacture FDG, the radioactive tracer used in PET, to service areas of high PET instrument concentration.
Meantime, Philips has spent about $6.5 billion over three years buying businesses including the medical systems units of Marconi and Agilent Technologies to increase its overall positioning in the diagnostic-imaging devices.
"There's a few more opportunities in the imaging area that we think we can expand, that are more full impact areas and special technologies than huge acquisitions here," Gerard Kleisterlee, president and CEO of Royal Philips Electronics told analysts in the company's fourth quarter conference call in January. It wasn't clear if that meant that Philips will look to acquire radiopharmaceutical technologies or other imaging modalities.
Woodcock described as a "trickle" the pipeline of imaging-related applications moving through the FDA approval process and pointed to the agency's work on fluorodeoxyglucose, the radioactive tracer used in PET procedures. In 1999, the FDA approved F-18 fluorodeoxyglucose for the diagnosis of all cancers, cardiovascular disease, and epilepsy.
"We had to do that work ourselves and publish a Federal Register note," she said. "That was an emerging technology and there was nobody big enough to take it."
FDG has to be manufactured and used before the half-life of the radioactive substance in it decays beyond being able to produce a detectable signal. That's one reason that the Mayo Institute recently opted to purchase its own cyclotrons to manufacture its own FDG and have a consistent supply — uninterruptible by Minnesota's winters.
Garcia said he didn't expect new technologies to easily make their way through the FDA.
"The FDA has pretty high standards in terms of what technology they will accept," he said. "[New] technologies are going to have to provide more than marginal benefit to go against decades of data and the established modalities that are out there and I don't think the FDA is in a hurry to displace those. I wouldn't be surprised if there was a push there to increase the uses of PET."
Imaging is also part of the FDA's Critical Path initiative, a document issued last March that highlights the FDA's belief that medical product development has failed to keep track with advances in basic sciences.
"New imaging technologies will ultimately contribute important biomarkers and surrogate end points, but how soon these new tools will be available for use will depend on the effort invested in developing them specifically for this purpose," the FDA said in the document, which is available online.
— Mo Krochmal ([email protected])