Maxim Plunges, Colgate Slips in Pre-Trade  NEW YORK (Reuters) - Maxim Pharmaceuticals Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MAXM.O target=/stocks/quickinfo/fullquote"&gt;MAXM.O&lt;/A&gt;  shares plunged nearly 60 percent on Monday after the company  said its experimental liver cancer drug failed to show an  improvement in patient survival rates during a clinical trial.