MYOSITIS AND RESPIRATORY FAILURE WITH PEMBROLIZUMAB

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: Pembrolizumab, an anti-programmed death 1 receptor monoclonal antibody, increases survival in non-small cell lung cancer (NSCLC). It causes less toxicity than traditional chemotherapy, however it can induce autoimmune adverse events including pneumonitis and colitis. There have been a limited number of case reports chronicling myositis with respiratory distress as effect pembrolizumab. We present patient NSCLC being treated pembrolizumab, which induced failure secondary to myositis. CASE PRESENTATION: A 77-year-old man metastatic status post right upper lobectomy on carboplatin/paclitaxel/pembrolizumab started 10/26/20, recent hepatitis diagnosed one week prior admission identified treatment prednisone (1 mg/kg), presented proximal weakness progressive exertional dyspnea over the last three weeks. Vital signs were remarkable for tachypnea tachycardia. Physical exam showed 2/5 muscle strength lower extremities, absent deep tendon reflexes, no skin rash. Labs revealed CK 1567, LDH 889, SARS-CoV2 PCR negative. CT pulmonary arteries was negative acute processes. The required noninvasive positive pressure ventilation (NIPPV) distress. Treatment initiated pyridostigmine (60mg QID PO) pulsed glucocorticoids (methylprednisolone g daily). He remained NIPPV dependent so increased 90mg PO IV immunoglobulin (IVIG) 85 QD added refractory weakness. Acetylcholine antibodies, ANA, anti SSA/SSB, anti-Jo1 Lumbar puncture performed normal opening pressure, CSF count, chemistry. clinical diagnosis attributed responded continued IVIG (30 5 more days) tapering steroids, improvement weaned off NIPPV. DISCUSSION: Pembrolizumab works immune checkpoint inhibitor, may cause effect. One study patients pembrolizumab Our patient, requiring NIPPV, two months after starting His not due disease. Autoimmune workup underwent lumbar ruled out Guillain-Barre syndrome. limitation our that biopsy never confirmed he steroids IVIG. In other cases, has by plasma exchange or immunosuppression. CONCLUSIONS: potentially fatal is crucial clinicians are aware this prompt be initiated. REFERENCE #1: Claus J, Van Den Bergh A, Verbeek S, Wauters E, Nackaerts K. Pembrolizumab-induced necrotizing non-small-cell cancer: report. Manag. 2019 May 8;8(2):LMT10. doi: 10.2217/lmt-2018-0017. PMID: 31645893; PMCID: PMC6802710. #2: Liewluck T, Kao JC, Mauermann ML. PD-1 Inhibitor-associated Myopathies: Emerging Immune-mediated Myopathies. J Immunother. 2018 May;41(4):208-211. 10.1097/CJI.0000000000000196. 29200081. #3: Robinson SD, Lai C, Hotton G, Anand G. Life threatening pembrolizumabinduced advanced adenocarcinoma lung. Acute Med. 2019;18(3):197-199. 31536059. DISCLOSURES: No relevant relationships Shlomo Greenberg, source=Web Response Daniel Kurbanov, Visala Natarajan,