Before-the-Bell: SuperGen Shares Soar  NEW YORK (Reuters) - Shares of SuperGen Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=SUPG.O target=/stocks/quickinfo/fullquote"&gt;SUPG.O&lt;/A&gt;  jumped more than 24 percent in trading before the market opened  on Wednesday after MGI Pharma Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MOGN.O target=/stocks/quickinfo/fullquote"&gt;MOGN.O&lt;/A&gt; said it would take  a \$40 million stake in the company as part of a cancer drug  license deal.