Outcomes of patients with non-melanoma solid tumours receiving self-funded pembrolizumab at Chris O'Brien Lifehouse

Background: Immunotherapy agents show anti-cancer activity in several solid cancers. Efficacy in non-melanoma solid tumours for non-approved indications is unknown. Aim: To evaluate patient and disease characteristics, rate and duration of response, and toxicity of self-funded pembrolizumab in patients with non-melanoma solid cancers. Method: Retrospective review describing outcomes and toxicity of self-funded pembrolizumab in patients with non-melanoma solid cancers treated at Chris O'Brien Lifehouse. Results: From April 2015 to December 2015, 21 patients received or were planned to receive self-funded pembrolizumab. The median age was 50 years (16-76), 28 and 10% had an Eastern Cooperative Oncology Group performance status of 2, and 3-4 respectively. Sixty-two percent received at least two to four lines of prior drug treatment. Median follow-up was 3.0 months (range, 0.4-9.6). Fourteen (67%) patients requested pembrolizumab. Pembrolizumab was clinician offered for 7 (33%) patients. Patients who requested pembrolizumab had worse outcomes. Three patients died before receiving pembrolizumab. Of the 18 patients that received at least one dose, a partial response was observed in 3 (17%). Progressive disease occurred in 83%. Four patients received only one cycle of pembrolizumab and died after a median of 27 days (range 13-43). Immune-related adverse events of any grade occurred in 33%. No grade 3-4 events were observed. Conclusion: Pembrolizumab was well tolerated. Meaningful responses were observed in 17% of treated patients. Response continues after 5-6.5 months follow-up in 11% and >8 months of follow-up for the other responding patient. Financial impact to the patient can be substantial. Outcomes for 33% were poor with three patients dying prior to receiving therapy and four dying within weeks of receiving one dose. This highlights issues regarding the careful selection of patients, futility of anti-cancer therapy at the end-of-life and patients' perceived benefit of receiving this therapy.