Independent FDA panel votes 6-1 against Stryker’s bone-growth putty


Outside experts recommended against the company’s request for expanded use of OP-1 in a wider population.

An advisory panel to the U.S. Food and Drug Administration, voted on Tuesday, 31 March, against an expanded approval of Stryker Corp’s bone-growth putty for spinal surgery.

OP-1, a genetically engineered protein, had already been cleared by the FDA in 2004, for limited use in certain spine surgeries to treat back pain under the Humanitarian Device Exemption programme. The product, indicated for
posterolateral spinal fusion procedures in skeletally mature patients with lumbar spondylolisthesis who have failed at least six months of conservative nonsurgical treatment, currently has approval for use in 4,000 or fewer patients per year.

While the company was seeking to expand that base,the independent panel to the U.S. drug regulators had concerns about bias having crept in to the company’s clinical trial. They also found and lack of scientific rigour in establishing the safety and effectiveness of the product.

Stryker’s first three analyses of its main study, which sought to prove “non-inferiority”, and compared the putty to a procedure in which surgeons used an autograft to fuse the vertebrae, showed that the putty failed to perform as well as the autograft.

The FDA advisory committee said that control subjects in the study “had a higher rate of bone formation” than those who had received the OP-1 Putty.

The company said in a statement that it was disappointed with the vote and that it was reviewing options for the drug. “We are very disappointed by the FDA advisory panel’s vote,” said a release from Stryker. “We believe the clinical evidence that we submitted and the long history of OP-1’s use demonstrate OP-1’s proven safety record,” it said.

Reports find that panel members said a new study would likely be required to win approval.

The FDA typically goes by recommendations from its advisory panels, but is not required to do so.