ICHNO-ECHNO 2022 - Abstract Book

S88

ICHNO-ECHNO 2022

Poster: Immuno-oncology

PO-0140 Real world experience of Pembrolizumab in advanced Head and Neck SCC during the COVID-19 pandemic

D. Pritchard 1 , J. Wong 2 , H.L. Goh 3 , I.S. Boon 1

1 Leeds Cancer Centre, St James's Institute of Oncology, Department of Clinical Oncology, Leeds, United Kingdom; 2 Leeds Cancer Centre, St James's Institute of Oncology, Department of Pharmacy, Leeds, United Kingdom; 3 Guy's and St Thomas' NHS Foundation Trust, Department of Clinical Oncology, London, United Kingdom Purpose or Objective Significant disruption and modification were recommended during the onset of COVID-19 pandemic affecting oncology care of head and neck patients. Initial clinical concerns were immunotherapy could worsen outcome if patients were to contract COVID-19 due to fatal hyper-inflammatory sequela of COVID-19 pneumonia. Materials and Methods Real world data on advanced head and neck squamous cell carcinoma patients started and maintained on checkpoint inhibitor pembrolizumab during the COVID-19 pandemic were retrospectively assessed and followed up prospectively. Subsequent patients were included since 1st January 2020 in a large cancer centre in the United Kingdom. Survival data, treatment response, toxicities and COVID-19 infection were recorded. Survival data were analysed from start of first pembrolizumab administration to date of death or last follow up. Pembrolizumab was given 3 weekly or 6 weekly as allowed by local institutional protocol. Results A total of 22 patients were included with median age of 69 (range 54-82). There were 77% (n=17) male and 23% (n=11) female patients. Median WHO performance status is 1. Smoking status were 64% current or former smokers, 23% never smokers and 13% unknown. Head and neck primary sites distributions were oral cavity, oropharynx, larynx, hypopharynx and others/ unknown primary were 6, 8, 1, 5, and 2 cases respectively. All patients had PD-L1 status assessed and median PD-L1 expression was 2% ( range 1%-70%). Median follow up was 9 months (range 1-15 months). Median number of pembrolizumab administered is 4 cycles (range 1- 11 cycles) of equivalent 3 weekly pembrolizumab. Median overall survival was 5.8 months on Kaplan-Meier estimate. At time of analysis, 9 patients were still alive with 4 patients still on maintenance pembrolizumab and 3 patients on further lines of systemic chemotherapy and 2 patients for best supportive care.13 patients had since passed away. Best treatment response were 27% (n=6 ) partial response, 13% (n=3)stable disease and progressive disease 59% (n=13). Grade 3 toxicities in this cohort is 0%. No patients contracted COVID-19 during treatment. None of our patients had COVID-19 diagnosed during the entire duration of follow up until date of death or last follow up. No patient died of COVID-19 related symptoms or cause of death attributed to COVID-19. Conclusion Single centre real world data suggest pembrolizumab could be delivered safely during the COVID-19 pandemic with risk mitigation, robust national vaccination strategy and good infection control practices. Immunotherapy treatment for advanced head and neck SCC patients did not result in increased toxicities during the COVID-19 pandemic and no recorded additional COVID-19 related side effects or deaths. 1 Hacettepe University Faculty of Medicine, Radiation Oncology, Ankara, Turkey; 2 Afyonkarahisar State Hospital, Medical Oncology, Afyonkarahisar, Turkey; 3 Hacettepe University Faculty of Medicine, Medical Oncology, Ankara, Turkey Purpose or Objective Median survival in metastatic/recurrent HNC (M/R HN-SCC) is less than 1 year, and locoregional recurrence (LRR) is the main cause of cancer-related death. Combined local and systemic therapies are required in order to achieve better results. Stereotactic body radiotherapy (SBRT), which can work synergistically with immune checkpoint inhibitors (ICI), can be a promising treatment option with more satisfactory response rates. We frequently apply 3x8 Gy SBRT concurrently with ICI in patients with M/R HN-SCC, and this study aims to share the clinical results and toxicity profile of these patients. Materials and Methods Fifteen patients diagnosed with M/R HN-SCC were evaluated retrospectively. All patients received SBRT to all metastatic and recurrent foci with concurrent ICI. Toxicity was evaluated according to the Radiation Therapy Oncology Group (RTOG) and the European Organization for Research and Treatment of Cancer (EORTC) criteria. Results The median age at the time of diagnosis was 57 years (range: 19-80 years). Four patients were female, and 11 were male. A total of 25 lesions were irradiated in 15 patients between January 2019 and July 2020. Sixteen of these lesions were re- irradiation, and three of them received the 3 rd course of RT. At the last control, four patients were dead; one was due to disease progression. Eight patients had complete responses, one had a partial response, four had stable diseases, and two had progressive diseases. None of the lesions irradiated via SBRT with concurrent ICI progressed during the follow-up except for one. Therefore, the SBRT-C rate was 96%. The 6-, 12-, and 24-month OS rate was 93%, 76%, and 57%; the PFS rate was PO-0141 Results of Concurrent SBRT and Immunotherapy in Recurrent and Metastatic Head and Neck Cancer M.T. Yilmaz 1 , S. Yuce Sari 1 , B.Y. Aktas 2 , S. Aksoy 3 , I. Gullu 3 , M. Cengiz 1 , G. Ozyigit 1 , G. Yazici 1