Immune checkpoint inhibitors-associated risk of immune-related hypothyroidism in older patients with advanced melanoma: a real-world analysis of US SEER-Medicare data

ABSTRACT

Background: The risk of immune-related(ir)-hypothyroidism in older patients with advanced melanoma treated with anti-CTLA4 or anti-PD1 therapies is poorly understood, especially in the real-world setting.

Research design and methods: We identified older patients (≥65 years) diagnosed with advanced melanoma between 2011-2015 and treated with anti-CTLA4 or anti-PD1 agents in the SEER-Medicare database. Applying probability-of-treatment-weighting for confounder adjustment and proportional hazards models, we estimated the risk of ir-hypothyroidism between treatment initiation and up to 90 days from last dose between anti-PD1 and anti-CTLA4 users.

Results: Of 210 older patients with advanced melanoma identified, 164 received anti-CTLA4 (ipilimumab) and 46 anti-PD1 agents (11 nivolumab, 35 pembrolizumab). There was no statistically significant difference in ir-hypothyroidism risk between anti-PD1 and anti-CTLA4 users (HR=2.15, 95%CI=0.83-5.53). Pairwise medication comparisons showed a lower risk among ipilimumab versus nivolumab (HR=0.15, 95%CI=0.06-0.40) and pembrolizumab versus nivolumab users (HR=0.13, 95%CI=0.03-0.55). Sensitivity analyses using an all-stages melanoma cohort did not show a difference in ir-hypothyroidism risk between medication classes and individual medications.

Conclusions:This retrospective claims data analysis revealed no statistically significant difference in ir-hypothyroidism risk between anti-CTLA4 or anti-PD1 users. However, patients with advanced melanoma treated with ipilimumab or pembrolizumab may have a lower ir-hypothyroidism risk compared to nivolumab users.

KEYWORDS:

• Immune checkpoint inhibitors
• anti-CTLA4
• anti-PD1
• ipilimumab
• nivolumab
• pembrolizumab
• risk
• hypothyroidism
• melanoma

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Supplementary material

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Additional information

Funding

This paper was not funded.