Medtronic's Infuse Studies Under Scrutiny

Doctors say Medtronic Bone Graft failed to disclose serious risks after payoffs

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) A major U.S. medical journal has published several articles criticizing Medtronic Inc.'s Infuse, used to spur bone growth after spinal surgery, for failing to disclose potentially life-threatening side effects.

In 13 trials that involved 780 patients, no adverse events from use of the product were reported, according to the study by Dr. Eugene Carragee, chief of spinal surgery at Stanford School of Medicine and editor of The Spine Journal, which published the scathing reports. Medtronic funded the studies.

However information provided to U.S. regulators shows that up to 50 percent of patients suffered a range of side effects including back and leg pain, infection, neurological injury, cyst formation and cancer, authors said.

"Talk to your surgeon if you've had spinal fusion and Infuse therapy."

Infuse was approved in 2002, the same year reports of side effects began surfacing. Carragee last month published a study demonstrating that the bone product could leave men infertile. U.S. Food and Drug Administration officials also issued a safety warning about the product in 2008.

Infuse combines a protein that sparks bone growth by use of a device that delivers protein to the spine. It is used in spinal fusion operations for stability, often after an injury.

Last week the U.S. Senate Finance Committee requested that Medtronic detail payments to physicians who conducted research on the bone device. Carragee said that in each Infuse study at least one author received at least $10 million in royalties.

"The original estimate of ICBG harvesting morbidity was based on invalid assumptions and methodology. This in turn may have exaggerated the benefit or underestimated the morbidity of rhBMP-2 in the clinical situations tested," Carragee wrote in review published in the journal.

"In conclusion, it is important to consider that identification of problems during the early industry-sponsored lumbar trials may have averted (or at least raised concerns about) complications before significant morbidity and mortality were eventually seen with widespread use. As it was, the presentation of rhBMP-2 morbidity in the original industry-sponsored publications did not fully reflect the data available from those trials as reviewed in FDA documents and subsequent clinical reports."

The Spine Journal devoted a plethora of space to Infuse including in its journal two studies, two reviews and an editorial.

In a statement, Omar Ishrak, chairman and chief executive officer of Medtronic, Inc., said that integrity and patient safety remain high priorities and that the company is committed to ongoing safety and efficacy studies.

“While the Spine Journal articles raise questions about researchers’ conclusions in their published peer-reviewed literature, the articles do not raise questions about the data Medtronic submitted to the FDA in the approval process or the information available to physicians today through the instructions for use brochure attached to each product sold," Ishrak said.

Reviewed by: 
Review Date: 
June 28, 2011
Last Updated:
June 28, 2011