SAN DIEGO, Jan. 3, 2013 (GLOBE NEWSWIRE) -- Zogenix Inc. (Nasdaq:ZGNX), a pharmaceutical company commercializing and developing products for the treatment of central nervous system disorders and pain, today announced positive single-dose pharmacokinetic (PK) results from the Phase 1 clinical trial of Relday™, an investigational candidate of a proprietary, once-monthly subcutaneous formulation of risperidone for the treatment of schizophrenia. Adverse events in the Phase 1 trial in patients diagnosed with schizophrenia were generally mild to moderate and consistent with other risperidone products. Based on the favorable safety and PK profile demonstrated with the 25 mg and 50 mg once-monthly doses tested in the Phase 1 trial, Zogenix has extended the current study to include a 100 mg dose of the same formulation. The addition of this dose arm to the study will enable evaluation of dose proportionality across the full dose range that would be anticipated to be used in clinical practice. Positive results from this study extension would better position Zogenix to begin a multi-dose clinical trial, which would provide the required steady-state PK and safety data prior to initiating Phase 3 development studies. Zogenix expects to complete the extension of the Phase 1 clinical trial during the second quarter of 2013. Roger L. Hawley, chief executive officer of Zogenix, said, "The positive results from the first Relday study provide proof-of-concept for a novel, long-acting, subcutaneous formulation of an established antipsychotic to provide psychiatrists and their patients with an improved treatment option. Because the PK profile, overall safety results and injection site reactions were all favorable, we can now begin discussions with potential partners for rest-of-world development and commercialization as we continue with the 100 mg single-dose study extension of Relday. We believe the data from all three dosage strengths will allow us to accelerate both the 505(b)(2) development timeline and the potential identification of an appropriate partner prior to starting the multi-dose clinical trial."