: Sientra stock rockets to pace premarket gainers after FDA clearance of tissue expander

Shares of Sientra Inc. SIEN skyrocketed 82.3% toward a seven-month high on heavy volume to pace all premarket gainers Friday after the medical aesthetics company after the U.S. Food and Drug Administration granted 510(k)-clearance for its AlloX2 Pro Tissue Expander. Trading volume ballooned to 4.2 million shares, compared with the full-day average of about 328,900 shares. The 510(k) clearance means Sientra’s device is “substantially equivalent” to another device that has been cleared for marketing. “This innovation allows the AlloX2 Pro to be labeled as MRI-conditional, making it the only tissue expander cleared in the United States for exposure to magnetic resonance imaging, an important screening tool for breast reconstruction patients,” said AlloX2 inventor Thomas McClellan. The stock has dropped 13.8% year to date through Thursday, while the S&P 500 has gained 11.8%.

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