Australian Government subsidisation of ipilimumab for the treatment of patients with metastatic melanoma was conditional on the sponsor entering a 'managed entry scheme' to assess the 2-year overall survival rate in metastatic melanoma patients who received ipilimumab in the first year of Pharmaceutical Benefits Scheme listing.
All unresectable stage IIIc / IV metastatic melanoma patients treated with at least one dose of ipilimumab therapy in Australia from the PBS listing date to a time point 12 months later (i.e. from 1-Aug-2013 to 31-Jul-2014) were invited to participate. Overall survival at 2 years post treatment initiation was measured, with Cox regression analysis used to examine the relationship between survival and patient baseline characteristics.
The evaluable population (910 patients) was on average 63.3 years old, male (70.1%) and treated in a public hospital (64.4%) in an urban area (76.5%). The majority of patients were treatment naïve (63.3%), did not have brain metastases (71.1%), and were classified as ECOG performance status 0 or 1 (90.4%). The 2 year overall survival rate was conservatively calculated to be at least 23.9% and potentially as high as 34.2%. A significant difference in overall survival at 2 years was demonstrated across the categories of ECOG performance status (p < 0.0001), M-status (p = 0.0005) and treatment status (p = 0.0114). No statistical difference in survival rate was observed when examining brain metastases vs no brain metastases (p = 0.2622), treatment at private vs public hospitals (p = 0.7601) nor treatment in the urban vs rural setting (p = 0.5048).
The 2 year overall survival rate for all patients receiving PBS subsidised ipilimumab in Australia from the first year Pharmaceutical Benefits Scheme cohort is estimated to be between 23.9% and 34.2%, which is higher than the 23.5% observed in the key ipilimumab registrational trial. Results and learnings from the ipilimumab 'managed entry scheme' illustrate that early access with the promise of future evidence to confirm a medicine's cost-effectiveness can work, but needs to be carefully considered, constructed and managed.