Outcomes of Australian patients receiving non-funded anti-PD-1 immune checkpoint inhibitors for non-melanoma cancers

Abstract

Aim: To characterize the outcomes of patients with nonmelanoma solid tumors receiving anti-PD-1 immunotherapy not funded by the Australian Pharmaceutical Benefits Scheme.

Methods: Medical records of patients with metastatic nonmelanoma tumor diagnoses treated with anti-PD-1 (self-funded pembrolizumab or nivolumab through an access program) from January 1, 2014, to December 31, 2016, at Peter MacCallum Cancer Centre, were retrospectively reviewed. Events after December 31, 2016, were censored.

Results: Of 47 patients identified, 27 (57%) had lung cancer. Twenty-six had compassionate access to nivolumab (24 lung, one renal, one gastroesophageal with possible new lung primary). Median overall survival was 5.7 months. Eleven (23%) achieved a partial response; none had complete response. Twenty (43%) had disease progression on first imaging; 16 (48%) of these continued treatment beyond radiological progression, with three achieving subsequent partial responses. Ten (21%) were not re-staged mostly due to rapid deterioration or death. At 6 and 12 months, nine (20%) and two (4%) remained on treatment, respectively. Five (12%) discontinued treatment due to immune-related toxicities. Of 34 patients who died, 71% received treatment within the last month of life; 38% died in an acute hospital. None of 25 patients with poor Eastern Cooperative Oncology Group performance scores of 2-4 responded.

Conclusion: The response rates and overall survival of patients with NSCLC, renal carcinoma and triple negative breast cancer of good performance status receiving anti-PD-1 therapy outside of a clinical trial are consistent with clinical trial data. However, patients with poor ECOG performance status are unlikely to respond. Careful patient selection and counseling about the potential outcomes of self-funding treatment in this setting is needed.

Keywords: PD-1; nivolumab; patient selection; pembrolizumab; performance status.