Safety of sequential immune checkpoint inhibitors after prior immune therapy.

BACKGROUND: The use of immune checkpoint inhibitors (ICI) has transformed cancer treatment. Subsequent ICI use has become increasingly common following disease progression. We aim to evaluate the safety and tolerability of the sequential ICI treatment modality. METHODS: Retrospective review of confirmed carcinoma from January 2014 to December 2018. Patients were categorized into "initial ICI arm" and "sequential ICI arm" defined as patients receiving single, dual or chemo-immunotherapy ICI following an initial ICI regimen. Primary outcome was the development of a new or recurrent immune related adverse event (irAE) during sequential therapy. Secondary outcomes were the number of cycles prior to the development of irAE and grade of irAE. RESULTS: A total of 483 patients received ICI during the timeframe. Of those, 22 patients received sequential ICI. The diagnoses included ten lung cancer, seven melanoma, four renal cell carcinoma and one bladder cancer. 16 patients received single agent ICI following the initial ICI, three patients received dual ICI following the initial ICI, one patient received chemotherapy-immunotherapy following initial ICI, and two patients received chemo-immunotherapy after dual ICI. Four patients developed new irAE and one patient developed the same irAE on sequential treatment. A higher proportion of patients experienced grade 3 irAE in the sequential arm compared to the initial ICI arm (p = 0.03). No statistical difference was found between the development of irAE and the number of cycles prior to development of irAE in either treatment groups (p = 0.5). CONCLUSION: Our data shows overall safety of sequencing ICI when close monitoring was employed.

Acute Deep Vein Thrombosis in a Cyclist With Iliac Vein Compression From Psoas Muscle Hypertrophy.

A 22-year-old avid cyclist presented with 1 month of right lower extremity pain and associated swelling. Subsequent imaging demonstrated an extensive acute deep vein thrombosis (DVT) in the setting of right iliac vein compression from psoas muscle hypertrophy. We present an unusual risk factor for DVT among cyclists. (Level of Difficulty: Intermediate.).

Disseminated Histoplasmosis Mimicking Acute Liver Failure in a Patient Treated With a Tumor Necrosis Factor Inhibitor.

Disseminated histoplasmosis (DH) is typically seen in patients with organ transplantation or human immunodeficiency virus and rarely presents with acute liver failure. Tumor necrosis factor inhibitors may be immunosuppressive but unlikely to result in DH. A 70-year-old woman with a history of psoriatic arthritis on infliximab presented with altered mental status, fevers, and severe liver injury. She was found to have DH, which resolved on antifungal agents. Because the use of tumor necrosis factor inhibitors has increased, providers should consider this uncommon infection in patients who present with cryptogenic severe liver injury.