Interview with Dr. Sandip Pravin Patel, Dr. Karen Yun and Dr. Karen Mccowen from the University of California San Diego

Volume 11, Issue 28 of Oncotarget features "Rapid onset type 1 diabetes with anti-PD-1 directed therapy", by Yun et al. and reported that Type 1 diabetes is a rare immune-related adverse event caused by checkpoint inhibitors with serious risk for diabetic ketoacidosis.

Of the patients who received immunotherapy, 5 patients were found to have type 1 diabetes, all of whom presented with DKA requiring insulin at 20 to 972 days from their first anti-PD- 1 dose.

Four patients had new-onset diabetes with mean Hb A1c of 9.1% on DKA presentation and persistent elevations over time.

Two patients who tested positive for glutamic acid decarboxylase antibodies presented with DKA at 20 and 106 days from first anti-PD-1 administration whereas patients who were autoantibody negative had DKA more than a year later.

The case series suggests that monitoring glycemia in patients on PD-1 inhibitors is not predictive for diabetes occurrence.

Dr. Sandip Pravin Patel from The Division of Hematology-Oncology in the Department of Medicine at The University of California San Diego said, "Cancer immunotherapy has broadened in clinical use over the last decade with FDA approval for treatment of various malignancies including melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma, urothelial carcinoma, head, and neck carcinomas, cutaneous squamous cell cancer, microsatellite unstable tumors, and Hodgkin's lymphoma."

Autoimmune type 1 diabetes is generally associated with positive autoantibodies to islet proteins including glutamic acid decarboxylase, insulin, insulinoma-associated antigen-2, zinc transporter 8, and islet cells.

However, only a subset of patients who acquire type 1 diabetes is found to have autoantibodies and specific HLA alleles, making these biomarkers poor predictors of diabetes incidence.

Given the rarity of type 1 diabetes as an ir AE, the authors sought to characterize the real-world diagnosis, management, and sequelae of patients who developed this ir AE in the context of their immune checkpoint blockade.

This Oncotarget paper highlights the rapid kinetics of type 1 diabetes in patients on checkpoint inhibitors.

"This Oncotarget paper highlights the rapid kinetics of type 1 diabetes in patients on checkpoint inhibitors"

Type 1 diabetes presented as DKA for all patients in this series and all but one patient had a new diagnosis of diabetes, without antecedent laboratory or imaging findings.

The Patel Research Team concluded in their Oncotarget Research Paper that their case series illustrates the rare incidence of immunotherapy-induced type 1 diabetes and describes the rapid course of this disease in patients.

Regardless of whether or not patients remain on checkpoint inhibitors, those with immunotherapy-induced diabetes are at risk for hyperglycemia and recurrent DKA. Surveillance of glycemia or Hb A1c does not predict diabetes but does have a role after type 1 diabetes arises as glycemia fluctuates and elevated Hb A1c levels persist.

Furthermore, GAD antibodies are present in about half of patients who develop type 1 diabetes after immunotherapy, warranting additional investigations into whether this is all association and a marker of immune attack.

Given the absence of prescient laboratory or imaging findings in patients who develop type 1 diabetes on anti-PD-1 therapy, patients should be counseled on the symptoms of hyperglycemia which include polyuria, polydipsia, abdominal pain, nausea and emesis and seek medical attention immediately.

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DOI - https://doi.org/10.18632/oncotarget.27665

Full text - https://www.oncotarget.com/article/27665/text/

Correspondence to - Sandip Pravin Patel - [email protected]

Keywords - type 1 diabetes, diabetic ketoacidosis (DKA), immune-related adverse event (irAE), immunotherapy, PD-1 inhibitors