Fatal myositis and spontaneous haematoma induced by combined immune checkpoint inhibitor treatment in a patient with pancreatic adenocarcinoma.

BACKGROUND

Immune checkpoint inhibitors (ICIs) have achieved unprecedented success in cancer treatment over the past decade. The application of ICIs hasled to the discovery of various types of immune-related adverse events (irAEs). Here, we report a case of fatal myositis and spontaneous haematoma following concurrent treatment of nivolumab and ipilimumab for pancreatic adenocarcinoma.

CASE PRESENTATION: A 71-year-old gentleman with pancreatic adenocarcinoma underwent the Whipple procedure in September 2014. The patient received 8 cycles of adjuvant chemotherapy with gemcitabineand achieved a complete responsein April 2015. Treatment with the PD-1 inhibitor nivolumab was started due to suspected tumour recurrence in November 2015. In August 2016, the CTLA-4 inhibitor ipilimumab was added to nivolumab for 2 cycles. Eight weeks after the last dose, the patient developed severe myositis complicated with spontaneous haematomain skeletalmuscle. Pathology of the skeletal muscle autopsy revealed lymphocytic infiltration. Intense immunosuppressive therapy, including high-dose corticosteroids and methotrexate, resulted in clinical success in the treatment of myositis. However, the patient died of cancer recurrence.

CONCLUSION

Myositis due to immunotherapy can be a fatal adverse event of ICIs, which requires close monitoring and cautious management.