Ipilimumab retreatment following induction therapy: The expanded access program (EAP) experience.

Abstract

9041 Background: Phase III study MDX010-020 for patients (pts) with advanced melanoma showed that retreatment (ReRx) with ipilimumab (Ipi) upon disease progression could result in further clinical benefit (Hodi et al. NJEM 2010). The Ipi EAP (CA184-045), conducted from 3/2010 to 3/2011, allowed ReRx with Ipi for a subset of pts with progression after benefit from their initial Ipi (SD for ≥3 months or objective response). Methods: Pts with unresectable stage III/IV melanoma who progressed on ≥1 systemic therapies or had no alternative treatment options were eligible for the EAP. Pts who received 3 mg/kg Ipi i.v. q 3 wks up to 4 doses on the EAP were eligible for ReRx using the same regimen if they had not experienced unacceptable toxicity requiring Ipi discontinuation (e.g., grade 4 any severe adverse events (AEs), grade 3/4 immune-related AEs (excluding endocrinopathies)), and had disease progression after clinical benefit defined as ≥3 months SD or objective response, or delayed response following progressive disease not requiring a different interval therapy. Endpoints of this retrospective analysis were clinical benefit defined by objective response or SD ≥3 months and toxicities measured by occurrence of serious adverse events (SAEs), irAEs, or death on study. Results: 108/2155 pts (5%) met the eligibility criteria for ReRx. Among these 108 pts, grade 3 drug-related SAEs during initial therapy were endocrinopathies only (4%). During ReRx, grade 3 drug-related SAEs, all <2%, were colitis, diarrhea, GI hemorrhage, fatigue and dehydration, similar to the toxicities of Ipi in the full EAP cohort of 2155 pts. Three pts (3%) of the 108 in this ReRx cohort had drug-related GI SAEs leading to discontinuation of Ipi. Among these pts who underwent ReRx, the median OS from the 1st initial therapy dose was 21.1 months. Conclusions: In this analysis of EAP pts who experienced benefit from initial Ipi therapy (including those with durable SD who subsequently progressed) and received ReRx with Ipi, no new safety signals were identified. The potential benefit of Ipi ReRx on OS will be prospectively evaluated in an ongoing phase II study in which pts who qualify are randomized to Ipi ReRx or physician’s choice alternative therapy. Clinical trial information: NCT00495066.