The study is an open-label extension study, offering patients who participated and completed previous studies 901 and 910 (an extension to 901) to continue treatment with DiaPep277 and clinical follow-up, for up to 2 additional years.The aim of the study is to collect safety and efficacy data of long term treatment effect of Diapep277.Only patients who completed studies 901 or 910 and still have stimulated C-peptide level equal to or above 0.2 nmol/L will be eligible for this extension study. The optimal dose and dosing regimen for this study will be the same as applied in the phase 3 study (901) and its extension study protocol (910), namely 1.0 mg DiaPep277® administered every 3 months. These conditions were determined as optimal based on the outcome of the phase 2 studies. For patients who just completed the 2-year 901 study, a 3-year extended treatment will be offered with 13 administrations; patients who completed the 2-year 910 extension study will be offered a 3rd year of treatment with 5 additional administrations.