Increased rates of immunosuppressive treatment and hospitalization after checkpoint inhibitor therapy in cancer patients with autoimmune disease.

Background Immune checkpoint inhibitors (ICIs) are important new therapeutic options for the treatment of malignancy. Existing data on the relative safety of ICI treatment in patients with pre-existing autoimmune disease (AID) are limited. Methods In this retrospective study utilizing an oncology medical claims database, we determined the rates of treatment with immunosuppressive agents and hospitalization within 180 days of treatment with ICIs (pembrolizumab, nivolumab, and ipilimumab) in patients both with and without AID. Patients had diagnoses of either malignant melanoma or lung cancer. Immunosuppressive agents evaluated included oral prednisone and intravenous methylprednisolone. Results 124 cancer patients with AID and 1896 cancer patients without AID met inclusion criteria for oral prednisone analysis, while 284 patients with AID and 3230 patients without AID met inclusion criteria for all other analyzes. Following treatment with PD-1 inhibitors, rates of treatment with both oral prednisone and intravenous methylprednisolone within 180 days of ICI treatment were significantly increased in the AID group relative to the control group (oral prednisone: 16.7% treatment in AID vs 8.3% in non-AID, p=0.0048; intravenous methylprednisolone: 8.4% treatment in AID vs 3.7% in non-AID, p=0.0012). Rates of hospitalization were significantly increased in melanoma patients with AID relative to melanoma patients without AID following treatment with PD-1 inhibitors (24.1% in AID vs 5.8% in non-AID, p<0.0001). Conclusion Cancer patients with AID have higher rates of hospitalization and treatment with immunosuppressive agents following treatment with ICI therapy compared with patients with no AID. This suggests that patients with AID may have increased toxicity risk while being treated with checkpoint inhibitor therapy. Further prospective clinical trials are needed to determine safety.