NEW YORK--(BUSINESS WIRE)--Callisto Pharmaceuticals, Inc. (OTC BB:CLSP.OB), a developer of new drugs to treat cancer and gastrointestinal disorders, announced today that Synergy Pharmaceuticals (OTC BB: SGYP), its majority-owned subsidiary, successfully completed the Phase I clinical trial of SP-304 in healthy volunteers that was initiated in June, 2008. This first study was a double-blind, placebo-controlled, randomized single, oral, ascending dose trial performed in 71 healthy male and female volunteers. The primary objective of the Phase I clinical trial with SP-304 was to characterize the safety, tolerability, pharmacokinetic and pharmacodynamic effects of the drug in healthy volunteers.