Combination of immune check inhibitor and immunomodulatory arabinomannan extracted from mycobacterium tuberculosis: A case report

Abstract

The present study selected two patients with lung cancer and epidermal growth factor receptor (EGFR) mutations who were treated with a programmed cell death protein 1 (PD-1) antibody and an immunomodulatory arabi-nomannan extracted from Mycobacterium tuberculosis. In the first case, a 67-year-old female was diagnosed with lung adenocarcinoma with an EGFR mutation (exon 19 deletion) and Stage IVB disease. Initial treatment with an EGFR mutation-targeted tyrosine kinase inhibitor (TKI), erlotinib, demonstrated a partial response. After disease progression this was followed by carboplatin and pemetrexed with beva-cizumab, and re-challenged by erlotinib plus bevacizumab; however, the tumor eventually progressed. Subsequently, the patient was treated with immunomodulatory arabinomannan for 3 months. Immediately after, she was treated with nivolumab and showed a partial response. In the second case, a 57-year-old male with a history of smoking was diagnosed with stage IVB pulmonary adenocarcinoma with an EGFR mutation (exon 19 deletion). He was treated with afatinib, followed by osimertinib when a T790M mutation was identified later. After disease progressed with TKIs, cisplatin plus pemetrexed and re-challenge with erlotinib plus bevacizumab were administered subsequently. Nivolumab was administered for recurrent disease. Although he experienced tumor remis-sion, regrowth of the tumors was observed. Under continuing nivolumab, he was treated by palliative irradiation treatments to the right pelvic bone metastasis and left adrenal metastasis with immunomodulatory arabinomannan. A chest computed tomography scan showed a reduction in the sizes of the primary site and pulmonary metastases, with a decreasing trend of carcinoma embryonic antigen. Overall, these cases may indi-cate that the immune adjuvant actions of immunomodulatory arabinomannan extracted from Mycobacterium tuberculosis improves the effect of PD-1 antibody treatments.