(1) Background: Multi-year research into the synergistic effect of cyclophosphamide and complex composite double-stranded DNA preparation (DNAmix) has made it possible to develop the novel Karanahan technology for treating malignant tumors, which is based on the eradication of cancer stem cells; (2) Methods: Pilot clinical trials for Karanahan technology were conducted in 12 patients with advanced stage IV breast cancer; (3) Results: The findings indicate that the analyzed treatment regimen ensures a local positive therapeutic response, significantly increases patient survival time, and activates the adaptive antitumor immune response. Adjustment of the basic regimen of Karanahan technology has been developed, which consists of increasing the dose of the DNAmix complex composite double stranded DNA preparation and its lymphotropic administration to the main lymph depots simultaneously with intratumoral injection; (4) Conclusions: Karanahan technology has a promising therapeutic potential in the treatment of inoperable stage IV breast cancer.