Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2023

Real World Outcomes of Patients with Extensive Stage Small Cell Lung Cancer - a Multicenter Australian experience (#358)

Martin Hong 1 , Rebecca Nguyen 1 , Tamiem Adam 2 , Po Yee Yip 3 , Victoria Bray 1 , Ina Nordman 4 , Fiona Day 4 , Hiren Mandaliya 4 , Abhijit Pal 1
  1. Liverpool Hospital, Liverpool, NSW, Australia
  2. Department of Medical Oncology, Bankstown Hospital, Bankstown, NSW, Australia
  3. Campbelltown Hospital, Campbelltown, NSW, Australia
  4. Medical Oncology, Calvary Mater Newcastle, Waratah, NSW, Australia

Background

Extensive stage small cell lung cancer (ES-SCLC) has a poor prognosis with a median survival of 10 months with platinum and etoposide (EP) chemotherapy.1  IMpower133 showed the addition of atezolizumab to platinum and etoposide (EP + atezolizumab) chemotherapy led to modest improvements in both progression free survival (PFS) and overall survival (OS).2

It is recognised that clinical trials are not equal to real world practice due to heterogeneity of many factors in real world patients controlled in randomised clinical trials. Real world practice provides further information about an intervention’s efficacy and safety.3,4,5

This study aimed to investigate the outcomes seen in real world patients treated in 4 centres in Australia to assess the efficacy of the addition of atezolizumab.

Methods

We retrospectively reviewed patients with ES-SCLC who had systemic treatment between 2018 and 2021. The primary endpoint was OS, and the secondary endpoint was PFS. 

Baseline characteristics were analysed using descriptive statistics. OS and PFS were assessed using Kaplan-Meier method, and hazard ratios (HR) were calculated using Cox proportional hazards method.

Results

156 patients with ES-SCLC underwent treatment at our centres between 2018 and 2021. The median OS was 9.2 months for EP compared to 9.5 months with EP + atezolizumab (HR 1.52 [1.05 - 2.19], p=0.026). The 12 month OS was 31% vs 42% respectively.  The median PFS was 5.7 months vs 6.4 months respectively (HR 1.53 [1.06 - 2.22], p=0.023).  In univariate analysis, there were no associations between survival and known prognostic variables such as age, sex, and ECOG.

Conclusions

Our study shows that the modest survival benefits seen in IMpower133 are replicated in the real world patients treated in our Australian centres, but the improvement is insignificant.  This study highlights the discordance between trial-eligible and real world patients. This study again highlights the need to review our clinical trial practices to better emulate real world patients.

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  2. 2. Horn L, Mansfield AS, Szczęsna A, et al: First-Line Atezolizumab plus Chemotherapy in Extensive-Stage Small-Cell Lung Cancer. N Engl J Med 379:2220–2229, 2018
  3. 3. Unger JM, Cook E, Tai E, et al: The Role of Clinical Trial Participation in Cancer Research: Barriers, Evidence, and Strategies. Am Soc Clin Oncol Educ Book 185–198, 2016
  4. 4. Corrigan-Curay J, Sacks L, Woodcock J: Real-World Evidence and Real-World Data for Evaluating Drug Safety and Effectiveness. JAMA 320:867, 2018
  5. 5. Gyawali B, Parsad S, Feinberg BA, et al: Real-World Evidence and Randomized Studies in the Precision Oncology Era: The Right Balance. JCO Precis Oncol 1–5, 2017