Granulomatous and sarcoid-like immune related adverse events (irAEs) in melanoma patients following CTLA4 blockade adjuvant therapy: An analysis of 1670 high-risk patients

9582 Background: Granulomatous and sarcoid-like lesions (GSL) affecting the skin, lungs, thoracic lymph nodes, eyes and other organs following treatment with immune checkpoint inhibitors (ICIs) have been described in sporadic reports in the literature but the true incidence is unknown. Methods: We sought to estimate the incidence of GSL in the context of prospectively conducted ECOG-ACRIN E1609 phase III adjuvant trial in high-risk resected melanoma (N=1670 patients) testing ipilimumab 3 mg/kg (ipi3) and 10 mg/kg (ipi10) versus high-dose interferon-α (HDI). Descriptive statistics were used to calculate the incidence. Results: Among 1670 total patients treated with ICIs or with HDI in E1609, 1034 were treated with ipilimumab and 636 with HDI. Six GSL cases were reported among 1670 total patients treated with ipilimumab or with HDI as summarized in the table along with the corresponding CTCAE grades. More cases were observed with ipi10, followed by ipi3 and HDI, respectively. Organs involved included skin and subcutaneous tissue (granuloma annulare, granulomatous dermatitis), eye (ocular sarcoidosis), lymph nodes (noncaseating granulomatous lymphadenitis), lung and mediastinal lymph nodes (sarcoidosis, granulomatous inflammation). Conclusions: The incidence of granulomatous and sarcoid-like lesions (GSL) with adjuvant ipilimumab therapy in high-risk melanoma is rare. Reported cases ranged in grade from 1-3 and appeared manageable. Since most cases are asymptomatic, it is possible that GSLs are under-recognized and therefore, under-reported. A larger analysis including patients treated with anti-PD1 antibodies is currently underway. Clinical trial information: NCT01274338. [Table: see text]