Long-term response of metastatic renal clear cell carcinoma following a subcutaneous injection of mixed bacterial vaccine: a case report

In this study, we present the case of a 56-year-old patient with renal clear cell carcinoma who developed lung metastases 13 months after nephrectomy and subsequently received tyrosine kinase inhibitor (sunitinib) and PD-1 antibody (nivolumab) immunotherapy, which failed to control the progression of the disease. The patient further developed metastases to the left pleura, bilateral hilar lymph nodes, liver, right lower kidney, scapula, left sixth rib, right tonsil, and other organs. There was severe anemia, requiring weekly blood transfusions. Karnofsky score was 30. After receiving mixed bacterial vaccine (MBV) consisting of 6 kinds of heat-inactivated bacteria plus Poly I:C, the patient’s condition rapidly improved, systemic metastases gradually reduced in size or disappeared, anemia was corrected, and the patient was able to resume normal life and work. MBV treatment in the setting of failure of previous immunotherapy treatment appears to have achieved objective response for this patient with metastatic renal clear cell carcinoma, which has lasted more than 20 months.