Phase 2 study to assess the efficacy of INVAC-1 at a dose of 800 µg for 6 cycles 4 weeks apart on Minimal Residual Disease (MRD) eradication rate in the bone marrow, either as a single agent in a high risk "watch and wait" group (group 1 - 42 patients) or in combination with ibrutinib (group 2 - 42 patients), in patients with Chronic Lymphocytic Leukemia (CLL).