FDA Rejects AstraZeneca's Exanta  NEW YORK (Reuters) - AstraZeneca Plc &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AZN.L target=/stocks/quickinfo/fullquote"&gt;AZN.L&lt;/A&gt; &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AZN.N target=/stocks/quickinfo/fullquote"&gt;AZN.N&lt;/A&gt; on  Friday said U.S. regulators did not approve its anti-clotting  drug Exanta.