An advisory panel to the Food and Drug Administration on Monday night shot down Matrix Pharmaceutical's ( MATX)experimental cancer treatment. The advisory panel members voted 9 to 3, with one abstention, to recommend against approval of IntraDose. The recommendation will now be forwarded to the FDA for a final decision. The agency normally follows the panel's recommendation. Despite the negative vote, one observer of Matrix's FDA advisory committee meeting said many panel members seemed to believe that IntraDose may be effective, but that the company did a poor job of designing tests to prove it. Matrix's failure Monday was no big surprise given the highly negative tone of an FDA staff report released last Friday. Trading in Matrix has been halted since last Thursday, when shares closed at $6.79 a share. Matrix officials will be holding a conference call Tuesday morning to discuss the panel's decision.