Genocea Biosciences, Inc. announced the dosing of the first patients in its Phase 1/2a clinical trial testing the safety, immunogenicity, and clinical efficacy of its neoantigen cancer vaccine candidate GEN-009. The company also announced that enrollment of patients in the first part of the clinical trial has been completed. This Phase 1/2a GEN-009 clinical trial consists of three parts. Part A is studying the safety and immunogenicity of GEN-009 as monotherapy in cancer patients with no evidence of disease, but at high risk of relapse. This part of the program has accrued nine patients previously treated for melanoma, non-small cell lung cancer, head and neck cancer, or urothelial carcinoma. Following proof of immunogenicity, the company expects to study GEN-009 in combination with checkpoint inhibitors in patients with advanced or metastatic solid tumors and in patients who have progressed despite checkpoint inhibitor therapy.