Pfizer reportedly approached Cellectis with a deal that could value it at about $1.64 billion, the Financial Times reported.
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Dan Mangan is a reporter covering health care for CNBC.com.
Meg Tirrell joined CNBC in April 2014 as a general assignment reporter focusing on biotechnology and pharmaceuticals.
Bertha Coombs is a general assignment reporter for CNBC, covering financial markets and business news stories.