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InVivo plunges as it pushes back spinal cord study

CAMBRIDGE, Mass. (AP) -- InVivo Therapeutics Holdings Corp. shares fell by more than one-third on Tuesday after the company said it has to push back the first human trial of its experimental treatment of spinal cord injuries.

The Cambridge, Mass., company said the Food and Drug Administration wants to stagger each patient's enrollment by three months. Based on this timeline, the company expects it will take 21 months to enroll all five patients in the test of its biopolymer scaffold device.

The company now expects to enroll its first patient in the first quarter of 2014. The company had said in April that it expected to begin the trial in coming months.

InVivo shares plunged $1.30, or nearly 38 percent, to $2.15 in afternoon trading on five times average volume.

"We remain fully committed to beginning this study as soon as possible. While the study will take additional time, we look forward to bringing this important therapy into the clinic," said Michael Astrue, the company's interim CEO, in a statement.