CRISPR companies down after immunity concerns

Shares of CRISPR companies fell Monday after data published last week suggested many people may have pre-existing immunity to the Cas9 enzymes commonly used in CRISPR-based therapeutics.

Intellia Therapeutics Inc. (NASDAQ:NTLA) tumbled $2.68 (12%) to $20.03, Editas Medicine Inc. (NASDAQ:EDIT) fell $3.57 (11%) to $30.02 and CRISPR Therapeutics AG (NASDAQ:CRSP) lost $0.74 (3%) to $26.07. By comparison, the NASDAQ Biotechnology Index (NBI) fell 1.4% on Monday...