AstraZeneca Korea's '슬롯 머신 규칙': Korea’s only approved treatment for limited-stage small cell lung cancer

[by Yu, Suin] AstraZeneca Korea announced on April 7 that its immunotherapy drug '슬롯 머신 규칙 (durvalumab)' has received approval from the Ministry of Food and Drug Safety for the treatment of 'limited-stage small cell lung cancer (LS-SCLC).'

With this approval, 슬롯 머신 규칙 is now authorized for use as a monotherapy in patients with LS-SCLC whose disease has not progressed following platinum-based chemoradiotherapy (CRT). Accordingly, 슬롯 머신 규칙 has become the first and only immunotherapy drug approved in Korea for the treatment of LS-SCLC.

Small cell lung cancer (SCLC) represents approximately 15-25% of all diagnosed lung cancers and is characterized by its aggressive nature and poor prognosis, with only 15-30% of patients surviving beyond five years after diagnosis. The term 'limited-슬롯 머신 규칙' refers to diseases confined to one side of the lung, including the mediastinum, and approximately 30% of SCLC patients are diagnosed at this 슬롯 머신 규칙.

Above all, SCLC is often asymptomatic in its early stages and tends to metastasize rapidly, rendering surgical intervention challenging in most cases. While concurrent chemoradiotherapy remains the 'standard 슬롯 머신 규칙' approach, more than 50% of patients experience disease recurrence within two years. Additionally, the median overall survival (mOS) for these patients remains limited, from 16 to 24 months. Despite extensive research efforts, there have been few advances in the 슬롯 머신 규칙 paradigm for LS-SCLC, and no significant improvement in long-term patient survival outcomes has been achieved.

This indication approval was supported by data from the global phase 3 clinical trial (ADRIATIC) evaluating the efficacy of 슬롯 머신 규칙. The study’s co-primary endpoints were overall survival (OS) and progression-free survival (PFS) in patients receiving 슬롯 머신 규칙 monotherapy compared to those receiving placebo. The study results demonstrated that 슬롯 머신 규칙 monotherapy significantly improved both OS and PFS in the overall study population, including predefined subgroups stratified by age, gender, race, disease stage at diagnosis, and the number of prior lines of radiotherapy cycles at baseline.

According to the results of the ADRIATIC clinical trial, the mOS in the 슬롯 머신 규칙 monotherapy arm was 55.9 months (95% CI, 37.3-NR), representing an extension of 22.5 months compared to 33.4 months (95% CI, 25.5-39.9) in the placebo group. 슬롯 머신 규칙 also demonstrated a 27% reduction in the risk of death (HR 0.73; 98.321% CI 0.54-0.98; p=0.01). Additionally, the three-year survival rate was approximately 57% in the 슬롯 머신 규칙 monotherapy group, compared to 48% in the placebo group.

Furthermore, 슬롯 머신 규칙 demonstrated a 24% reduction in the risk of disease progression or death compared to placebo (HR 0.76; 97.195% CI 0.59-0.98; p=0.02). The mPFS was 16.6 months (95% CI, 10.2-28.2) in the 슬롯 머신 규칙 monotherapy group, compared to 9.2 months (95% CI, 7.4-12.9) in the placebo group. In addition, the proportion of patients who remained progression-free at two years post-treatment was higher in the 슬롯 머신 규칙 monotherapy group (approximately 46%) than in the placebo group (approximately 34%).

The safety profile of 슬롯 머신 규칙 observed in this study was consistent with that reported in previous clinical studies. The incidence of grade 3 or 4 adverse events was comparable at 24.4% in the 슬롯 머신 규칙 monotherapy group and 24.2% in the placebo group.

“The expansion of 슬롯 머신 규칙’s indications is particularly significant as it represents a groundbreaking advancement in the treatment of LS-SCLC for the first time in 30 years, offering patients access to immunotherapy in this setting for the first time,” stated Lee Hyun-ju, Oncology Business Unit Director at AstraZeneca Korea.

“슬롯 머신 규칙 previously offered new hope to patients by demonstrating a survival benefit in the treatment of stage III non-small cell lung cancer (NSCLC) through the previous PACIFIC clinical trial, and it is now driving a new treatment paradigm for LS-SCLC based on the results of the ADRIATIC clinical study,” Lee further commented. “AstraZeneca Korea will continue its efforts to innovate, aiming to improve treatment prognosis and offer the possibility of long-term survival for patients throughout all stages of lung cancer with 슬롯 머신 규칙.”

Conversely, the U.S. Food and Drug Administration (FDA) designated 슬롯 머신 규칙 as a ‘breakthrough therapy’ for this indication in August of last year and granted final approval in December 2024 through an accelerated review process. In November, the American Society of Clinical Oncology (ASCO) issued a revised rapid guideline for SCLC, incorporating the clinical benefits of 슬롯 머신 규칙 as demonstrated in the ADRIATIC trial.