Pembrolizumab induced type 1 diabetes mellitus in a patient with metastatic melanoma and literature review on steroids as a treatment option.

Objective: We report a case of a 77-year-old male with metastatic melanoma who developed immune-checkpoint-inhibitor (ICI) induced type 1 diabetes mellitus (T1DM) after seven months of pembrolizumab treatment and required life-long insulin use. This prompted a literature review of best practice guidelines for long-term management of checkpoint-inhibitor induced T1DM including oral steroids as a treatment option similar to other ICI adverse effects.

Data Sources And Summary: A literature search on PubMed was conducted to evaluate the efficacy of steroid treatment ICI-induced T1DM in any cancer type. Search terms consisted of "ipilimumab" OR "nivolumab" OR & "pembrolizumab" OR "immune checkpoint" AND "diabetes" OR "type 1 diabetes" AND "cancer" OR "melanoma" OR "carcinoma OR "sarcoma". Inclusion criteria were case reports published after 2015 in which the patient was diagnosed with ICI-induced T1DM or diabetic ketoacidosis where oral steroids were part of the treatment. Exclusion criteria included oral steroids not used as a treatment modality for T1DM, multiple endocrine comorbidities, no response recorded, and previous history of T1DM. 284 abstracts were found with these search terms of which 33 full-text articles were concluded to be eligible and screened and from which 8 records were included. From these 8 articles, there were 12 cases included.

Conclusion: This literature search suggests that ICI-induced T1DM cannot be reversed by steroids and that insulin must be used permanently for treatment management.