OBJECTIVES: ICIs have led to significant improvement in survival for cancer patients. However, they are associated with considerable toxicity burden leading to additional costs for patients and payers alike. This study aimed to estimate AE management costs for each ICI-based regimen approved for patients with advanced or metastatic cancers in the US.

METHODS: AE management costs (2023 US$) for each ICI regimen were calculated by multiplying the frequency reported of each AE by its unit management cost and then aggregating across all the AEs. Only grade 3-4 AEs were considered in the analysis, as grade 1-2 AEs are not associated with significant cost.

The frequencies of grade 3–4 AEs were obtained from the publications of the registrational clinical trials for the ICI regimens in the respective indication. The analysis assumes that all grade 3-4 AEs require inpatient treatment. The unit costs of inpatient stay for each AE were obtained from the discharge-level data of National (Nationwide) Inpatient Sample of the HCUP databases.

RESULTS: AE management costs per patient ranged between $614-$6,777 for different ICI regimens in melanoma, $2,946-$12,899 in bladder cancer, $1,190-$9,720 in renal cell carcinoma, $689-$17,921 in gastric cancer, $1,935-$17,035 in head and neck squamous cell carcinoma, $463-$15,197 in lung cancer, $4,732-$13,225 in breast cancer, $2,848-$11,225 in cervical cancer, $1,582-$9,932 for hepatocellular carcinoma, $2,165-$9,990 for classic Hodgkin lymphoma, $2,068-$5,040 in cutaneous squamous cell cancer, and $1,951-$6,090 for colorectal cancer. For Merkel cell carcinoma and B-cell lymphoma, where only one ICI is approved, AE management costs were $2,947 and $2,214, respectively. Across different cancers, AE managements costs were lowest for ICI monotherapies.

CONCLUSIONS: ICIs are associated with substantial AE management costs, varying by the specific ICI regimen and type of cancer. These results underscore the pertinence of AE management costs when choosing between ICI regimens for treatment.