Case series: Outcomes of immunotherapy in locally advanced and metastatic cutaneous squamous cell carcinoma in Lakes and Waikato region.

Abstract

e21529 Background: Cutaneous squamous cell carcinomas (CSCC) have an incidence of 425 per 100,000 in New Zealand (1). 5% progress to locally advanced or metastatic disease. Immunotherapy is unfunded for this indication despite excellent response and safety profile (2). The objective was to evaluate real world outcomes of patients who managed to access immunotherapy. Methods: Review of referrals to medical oncology in the Lakes & Waikato region between 1 August 2017 to 31 August 2022 with unresectable locally advanced or metastatic CSCC who had immunotherapy. Patients who were not referred to medical oncology, could not afford immunotherapy and/or unsuitable for a clinical trial were excluded from analysis. Results: 13/15 (86.7%) reviewed were male. Mean age was 71. 7 were locally advanced and 8 were metastatic. 14 self-funded pembrolizumab (11 first line, 3 second line). 1 accessed immunotherapy via a trial. 12 (80%) had significant responses; 3 achieved a complete response and 9 achieved a partial response. Median duration of response was not reached, with a median number of 18 cycles delivered. Median follow up was 23.8 months. 9 (60%) remain alive with ongoing response. 6 died on treatment; 3 from non-malignancy and non-treatment related causes. No Grade IV toxicities were observed. Grade III transaminitis was seen in one patient. Grade I-II toxicities seen in 11 (73.3%), including arthralgia (26.7%), fatigue (20%), transaminitis (13.3%), rash (20%), hypothyroidism (6.7%), diarrhoea (6.7%) and dyspnoea (6.7%). Conclusions: Despite an elderly & comorbid cohort, immunotherapy resulted in durable responses and excellent safety profile, highlighting the unmet need for immunotherapy funding in New Zealand. More understanding is required around the different responses to anti-PD1 therapies for the same malignancy type. (1) Pondicherry A, et al. The burden of non-melanoma skin cancers in Auckland, New Zealand. Australas J Dermatol. 2018 Aug; 59(3):210-213 (2) Hughes B, et al. Pembrolizumab for locally advanced and recurrent/metastatic cutaneous squamous cell carcinoma (KEYNOTE-629 study): an open-label, nonrandomized, multicentre, phase II trial. Ann Oncol. 2021;32(10):1276-1285.