A. P. Pharma Inc. uncovered that U. S. health regulators disapproved its experimental drug designed to treat nausea and vomiting induced by chemotherapy, revealing concerns related to the drug's administration system.

The decision was extended on March 18 and in anticipation of the drug's approval, the stock registered a rise of 32% to $2.06 yesterday. In pre-market trading Friday, following the FDA rejection, the stock fell over 63% to $0.75.

APF530, is designed to prevent both acute and delayed onset CINV, is a long-acting formulation of the anti-nausea drug granisetron and is delivered by a subcutaneous injection.

The company has revealed that the U. S. Food and Drug Administration has ordered for the re-presentation and re-analysis of select existing phase III clinical trial data, however, it has not asked for any further clinical efficacy studies.

FDA is reported to have indentified certain deficiencies during inspections of the company and several of its contract manufacturing facilities.

The issues posed by FDA's is related to the two-syringe administration system for the drug include issues related to the transfer of material from one syringe to another and with the potential risk of improper administration of the drug as well.