Evaluation of the effect of systemic corticosteroids for the treatment of immune-related adverse events (irAEs) on the development or maintenance of ipilimumab clinical activity

Abstract

9037 Background: Ipilimumab, a fully human monoclonal antibody that inhibits cytotoxic T-lymphocyte antigen-4, has clinical activity at 10 mg/kg in patients (pts) with advanced melanoma. Most grade 3/4 immune-related adverse events (irAEs) associated with ipilimumab can be managed with systemic corticosteroids following established treatment guidelines. However, little has been reported about the effects of corticosteroids used to treat irAEs on ipilimumab antitumor responses. Methods: Across 3 phase II studies with 10 mg/kg ipilimumab monotherapy in advanced melanoma (CA184008, 022, and 007; N=283), 83 pts (29.3%) achieved disease control [complete/partial responses (CR/PR), or stable disease (SD) ≥12 weeks] and 43/83 (52%) received steroids for treatment of irAEs. The pts' ability to develop and maintain disease control in the presence and absence of steroids was analyzed. Disease control was assessed by modified World Health Organization (mWHO) criteria and novel immune-related response criteria (irRC) (Hodi FS, et al. J Clin Oncol 26: 2008 [May 20 suppl; abstr 3008]). The range of follow-up was 5.7–6.3 months. Results: Of 117 pts who received steroids prior to response assessment, 26 pts achieved CR or PR, or maintained SD without disease progression by mWHO, and the remaining 91 pts had PD. Of 166 pts who either never received steroids or received them after response assessment, 31 achieved a CR, PR, or SD (by mWHO). Further, of 26 pts with CR/PR by mWHO, 14 received subsequent steroids and 11 maintained a response, while of 12 pts who received no subsequent steroids, 9 maintained a response. Similar results were obtained if irRC were used (see table ). Conclusions: Systemic corticosteroids for treatment of irAEs do not appear to impact the development or maintenance of ipilimumab clinical activity in advanced melanoma. [Table: see text] [Table: see text]