Longitudinal extensive transverse myelitis after chemoradiation therapy with durvalumab, a rare complication: case report

Background: Longitudinal extensive transverse myelitis is a rare and potentially life-threatening complication of chemoradiation. Certain chemotherapy agents have been proposed to increased neurotoxicity with chemoradiation therapy. One such agent is durvalumab, a human IgG1 monoclonal antibody that blocks programmed death ligand 1, allowing T-cells to recognize and kill tumor cells. Durvalumab and other immune checkpoint inhibitors may also cause transverse myelitis without concomitant treatment with radiation. Durvalumab is a standard therapy for non-small cell lung carcinoma. Here we present a case of a 68-year-old male who presented after chemoradiation and durvalumab therapy with transverse myelitis extending outside the irradiation site.

Case presentation: A 68-year-old male presented to the emergency department with pain and weakness in his feet and hesitancy of urination. Medical history is significant for non-small cell lung cancer treated with chemoradiotherapy and consolidation therapy with durvalumab for one year. His last radiation treatment was 15 months prior, and his last infusion of durvalumab was 3 months prior. Exam revealed severe weakness of bilateral legs with absent vibration sensation. MRI showed central longitudinal extensive transverse myelitis extending from C4-T11. CSF studies showed 8 WBC with 63% lymphocyte predominance and a protein of 48. Oligoclonal bands and angiotensin-converting enzyme were negative. Serum Neuromyelitis Optica antibody (AQP4-IgG) and Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) were negative. Infectious workup came back negative. The patient was treated with steroids and plasma exchange with mild improvement. Etiology remained unknown, but longitudinal extensive transverse myelitis following durvalumab chemoradiotherapy was thought to be the likely cause. He was discharged on a high-dose prednisone taper with outpatient follow-up. His condition worsened near the end of the steroid taper. High-dose prednisone and cyclophosphamide infusions were started with mild improvement and stabilization of the patient's condition. He transitioned to methotrexate after completion of six cyclophosphamide infusions. The patient expired due to complications from his cancer.

Conclusion: Longitudinal extensive transverse myelitis is a rare and potentially life-threatening complication of durvalumab therapy. As durvalumab has become a standard treatment for non-small cell lung cancer, it is important to be able to identify and treat side effects.