Purpose: Programmed death-1/programmed death-ligand 1 (PD-L1) inhibitors have shown efficacy in metastatic esophageal squamous cell carcinoma (ESCC) therapy. However, data is still limited regarding neoadjuvant immunotherapy for operable ESCC. Materials and Methods: Patients with clinical stage T2 or T3 and N0 ESCC received three cycles of nivolumab therapy every two weeks before surgical resection. The primary endpoint is major pathologic responses (MPR) rate (≤ 10% of residual viable tumor [RVT]). Results: Total 20 patients completed the planned nivolumab therapy. Among them, 17 patients underwent surgery as protocol, showing MPR in two patients (MPR rate, 11.8%), including one pathologic complete response, on conventional pathologic response evaluation. Pathologic response was re-evaluated using the immune-related pathologic response criteria based on immune-related RVT (irRVT). Three patients were classified as immunologic major pathologic response (iMPR; ≤ 10% irRVT, iMPR rate: 17.6%), five as pathologic partial response (> 10% and < 90% irRVT), and nine as pathologic nonresponse (≥ 90% irRVT). The combined positive score (CPS) for PD-L1 in the baseline samples was predictable for iMPR, with the probability as 37.5% in CPS ≥ 10 (3/8) and 0% in CPS < 10 (0/9). Conclusion Although the efficacy of neoadjuvant nivolumab therapy was modest in unselected ESCC patients, further researches on neoadjuvant immunotherapy are necessary in patients with PD-L1 expressed ESCC.

Purpose: Alectinib and brigatinib are second-generation anaplastic lymphoma receptor tyrosine kinases (ALKs) that are widely used as first-line therapy for treating ALK-positive advanced non–small cell lung cancer (NSCLC). Given the lack of a head-to-head comparison of these drugs as first-line therapies, this retrospective observational study aimed to compare the real-world efficacy and safety of alectinib and brigatinib. Materials and Methods: Patients who received alectinib or brigatinib as the first-line treatment for ALK-positive advanced NSCLC were evaluated for clinical outcomes of objective response rate (ORR), intracranial ORR, time to next treatment (TTNT), progression-free survival (PFS), overall survival (OS), and safety profiles. Results: Of 208 patients who received either alectinib or brigatinib as a first-line treatment, 176 received alectinib and 32 received brigatinib. At the data cutoff point, the median follow-up duration was 16.5 months (95% confidence interval [CI], 14.7 to 18.3) in the brigatinib group and 27.5 months (95% CI, 24.6 to 30.4) in the alectinib group. The ORR was 92.5% with alectinib and 93.8% for brigatinib. The intracranial ORR rates were 92.7% (38/41) and 100% (10/10), respectively. The rate of PFS at 12 months was comparable between the alectinib group and the brigatinib groups (84.4% vs. 84.1%, p=0.64), and the median TTNT, PFS, and OS were not reached in either group. Treatment-related adverse events were usually mild, and treatment discontinuation due to adverse events was rare (alectinib 4.5% vs. brigatinib 6.25%). Conclusion Alectinib and brigatinib had similar clinical benefits when used as the first-line treatment of NSCLC patients with ALK rearrangement in the real world.

Purpose: Optimal treatment for stage IIIA/N2 non–small cell lung cancer (NSCLC) is controversial. We aimed to assess the efficacy and safety of adjuvant pembrolizumab for stage IIIA/N2 NSCLC completely resected after neoadjuvant concurrent chemoradiation therapy (CCRT). Materials and Methods: In this open-label, single-center, single-arm phase 2 trial, patients with stage IIIA/N2 NSCLC received adjuvant pembrolizumab for up to 2 years after complete resection following neoadjuvant CCRT. The primary endpoint was disease-free survival (DFS). Secondary endpoints included overall survival (OS) and safety. As an exploratory biomarker analysis, we evaluated the proliferative response of blood CD39+PD-1+CD8+ T cells using fold changes in the percentage of proliferating Ki-67+ cells from days 1 to 7 of cycle 1 (Ki-67D7/D1). Results: Between October 2017 and October 2018, 37 patients were enrolled. Twelve (32%) and three (8%) patients harbored EGFR and ALK alterations, respectively. Of 34 patients with programmed cell death ligand 1 assessment, 21 (62%), nine (26%), and four (12%) had a tumor proportion score of < 1%, 1%-50%, and ≥ 50%, respectively. The median follow-up was 71 months. The median DFS was 22.4 months in the overall population, with a 5-year DFS rate of 29%. The OS rate was 86% at 2 years and 76% at 5 years. Patients with tumor recurrence within 6 months had a significantly lower Ki-67D7/D1 among CD39+PD-1+CD8+ T cells than those without (p=0.036). No new safety signals were identified. Conclusion Adjuvant pembrolizumab may offer durable disease control in a subset of stage IIIA/N2 NSCLC patients after neoadjuvant CCRT and surgery.

Background: The cutaneous adverse effects (AEs) of amivantamab, a novel monoclonal bispecific antibody against the epidermal growth factor receptor and mesenchymal-epithelial transcription factor, have not been investigated. Objective: To analyze the type and prevalence of cutaneous AEs in patients with non-small cell lung cancer (NSCLC) treated with amivantamab. Methods: A single-institution retrospective medical record review was conducted on patients with NSCLC who were treated with amivantamab between January 1, 2021, and June 30, 2023. A total of 37 patients receiving amivantamab monotherapy for NSCLC were included in this study. Demographic data (age, sex, body mass index, age at cancer diagnosis, age at amivantamab therapy initiation, and duration of amivantamab use) and the types and severity of cutaneous AEs were evaluated. Results: Cutaneous AEs occurred in 59.5% of the patients. The most common AEs were maculopapular eruptions (37.8%), paronychia (24.3%), pruritus/xerosis (16.2%), acneiform eruptions (13.5%), pustulosis (5.4%), and scalp rashes (5.4%). No Grade 3 cutaneous AE, which led to the discontinuation of amivantamab therapy, was observed. Conclusion Our data describes an extensive review of cutaneous AEs caused by amivantamab. Further research with a larger patient population is necessary to reliably predict and manage cutaneous AEs associated with amivantamab.

Objectives: The coronavirus disease 2019 (COVID-19) pandemic has continued since its first detection in the Republic of Korea on January 20, 2020. This study describes the early countermeasures used to minimize the risk of COVID-19 outbreaks during cohort quarantine and compares the epidemiological characteristics of 2 outbreaks in long-term care facilities (LTCFs) in Gwangju Metropolitan City in summer 2020. Methods: An epidemiological investigation was conducted via direct visits. We investigated epidemiological characteristics, including incidence, morbidity, and mortality rates, for all residents and staff members. Demographic characteristics were analyzed using a statistical program. Additionally, the method of managing infection in LTCFs is described. Results: Residents and caregivers had high incidence rates in LTCF-A and LTCF-B, respectively. LTCF-B had a longer quarantine period than LTCF-A. The attack rate was 20.02% in LTCF-A and 27.9% in LTCF- B. The mortality rate was 2.3% (1/43) in LTCF-B, the only facility in which a COVID-19 death occurred. Conclusion Extensive management requires contact minimization, which involves testing all contacts to mitigate further transmission in the early stages of LTCF outbreaks. The findings of this study can help inform and prepare public health authorities for COVID-19 outbreaks, particularly for early control in vulnerable facilities.

Purpose: Rearranged during transfection (RET) gene rearrangement is a well-known driver event in non–small cell lung cancer (NSCLC). Pralsetinib is a selective inhibitor of RET kinase and has shown efficacy in oncogenic RET-altered tumors. This study evaluated the efficacy and safety of expanded access program (EAP) use of pralsetinib in pretreated, advanced NSCLC patients with RET rearrangement. Materials and Methods: Patients who received pralsetinib as part of the EAP at Samsung Medical Center were evaluated through a retrospective chart review. The primary endpoint was overall response rate (ORR) per the Response Evaluation Criteria in Solid Tumors (RECIST) ver. 1.1 guidelines. Secondary endpoints were duration of response, progression-free survival (PFS), overall survival (OS), and safety profiles. Results: Between April 2020 and September 2021, 23 of 27 patients were enrolled in the EAP study. Two patients who were not analyzed due to brain metastasis and two patients whose expected survival was within 1 month were excluded from the analysis. After a median follow-up period of 15.6 months (95% confidence interval [CI], 10.0 to 21.2), ORR was 56.5%, the median PFS was 12.1 months (95% CI, 3.3 to 20.9), and the 12-month OS rate was 69.6%. The most frequent treatment-related adverse events (TRAEs) were edema (43.5%) and pneumonitis (39.1%). A total of 8.7% of patients experienced extra-pulmonary tuberculosis. TRAEs with a common grade of three or worse were neutropenia (43.5%) and anemia (34.8%). Dose reduction was required in nine patients (39.1%). Conclusion Pralsetinib presents a clinical benefit when used in patients with RET-rearranged NSCLC, consistent with a pivotal study.

Purpose: Brain metastasis is common in patients with epidermal growth factor receptor (EGFR)–mutant non–small cell lung cancer (NSCLC) at initial presentation. A previous study showed that brain radiotherapy (RT) before first-generation (first-G) EGFR–tyrosine kinase inhibitor (TKI) therapy is associated with longer overall survival than TKI therapy alone. However, there is no data regarding the role of additional brain RT before afatinib therapy. Materials and Methods: Between October 2014 and June 2019, EGFR-mutant NSCLC patients with brain metastases who started first-G EGFR-TKIs (gefitinib or erlotinib) or afatinib as first-line therapy were retrospectively analyzed. This study compared overall survival and intracranial progression-free survival (PFS) between patients who received EGFR-TKIs alone and EGFR-TKIs with brain RT and either a first-G EGFR-TKI or afatinib, respectively. Results: The median follow-up duration was 29.6 months (range, 1.5 to 116.9 months). In the first-G EGFR-TKI group (n=155), 94 patients (60.6%) received the first-G EGFR-TKI alone and 61 patients (39.4%) received brain RT prior to their first-G EGFR-TKI. In the afatinib group (n=204), 126 patients (61.8%) received afatinib alone and 78 patients (38.2%) received brain RT prior to afatinib. There was no difference in overall survival rates between the groups with RT (35.6 months: 95% confidence interval [CI], 27.9 to 43.3) and without RT (31.4 months: 95% CI, 23.9 to 38.9) in the afatinib group (p=0.58), but there was a significant difference in overall survival in the first-G EGFR-TKI group in a manner favoring additional brain RT (41.1 months: 95% CI, 30.5 to 51.7 vs. 25.8 months: 95% CI, 20.1 to 31.5; p=0.02). Meanwhile, median intracranial PFS was not different between patients who received EGFR-TKI therapy alone vs. EGFR-TKI therapy with brain RT in both the first-G EGFR-TKI (p=0.39) and afatinib (p=0.24) groups. Conclusion Afatinib therapy alone showed comparable survival outcomes to those of afatinib with brain RT. The current study suggests that brain RT could be an optional, not mandatory, treatment modality when afatinib therapy is considered in patients with EGFR-mutant NSCLC.

Purpose: The impact of epidermal growth factor receptor (EGFR) mutation in locally advanced non–small cell lung cancer (NSCLC) remains controversial. This study was conducted to investigate the clinical outcomes and recurrence patterns after definitive chemoradiotherapy (CRT) in patients with unresectable stage III non-squamous-cell lung cancer according to EGFR mutation status. Materials and Methods: We retrospectively reviewed 604 patients with pathologically confirmed stage III NSCLC who were treated with definitive CRT and were examined for EGFR mutation at Samsung Medical Center, Korea, from January 2013 to December 2018. Among them, we identified 236 patients with stage III non-squamous-cell lung cancer who were treated with definitive CRT and were examined for EGFR mutation status. We analyzed the frequency of EGFR mutation, progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and recurrence pattern. Results: Among 236 patients, EGFR mutation was detected in 71 patients (30.1%) and the median follow-up duration was 41.7 months. There were no significant differences in PFS (9.9 vs. 10.9 months, p=0.236), and ORR to CRT (93.0% vs. 90.3%, p=0.623) according to EGFR mutation status. However, the EGFR mutant group showed significantly higher recurrence (88.7% vs. 75.2%, p=0.022), distant metastasis (76.1% vs. 61.2%, p=0.036) rates, especially brain (38.0% vs. 12.7%, p < 0.001), and better median OS (59.2 vs. 41.3 months, p=0.037) compared with patients without EGFR mutation. Conclusion Patients with EGFR mutation–positive unresectable stage III non-squamous lung cancer exhibited higher recurrence and distant metastasis rates, especially brain metastasis.

Background: Paxlovid is an oral antiviral drug that received emergency use authorization in South Korea for the treatment of patients with mild-to-moderate coronavirus disease 2019 (COVID-19) on January 14, 2022. Since the onset of the severe acute respiratory syndrome coronavirus 2 pandemic, the virus has continued to evolve. The emergence of new variants has raised concerns about possible reductions in the effectiveness of vaccines and drugs. The effectiveness of Paxlovid in patients infected with the omicron variant and subvariants has not yet been determined. This study assessed the effectiveness of Paxlovid at reducing the risk of severe/critical illness or death and death in patients with mild-to-moderate COVID-19 caused by omicron subvariant BA.5. Methods: In this nationwide retrospective cohort study, data on 8,902,726 patients were collected from four sources (the Drug Utilization Review database, COVID-19 Patient Information Management System, confirmed patient information, and basic epidemiological investigation data) between July 1 and November 30, 2022. Multivariable logistic regression analysis was conducted, with adjustment for age, sex, severe acute respiratory syndrome coronavirus 2 immunity (vaccination), and comorbidities. Results: A total of 1,936,925 patients with COVID-19 were included in the analysis, including 420,996 patients treated with Paxlovid, and 1,515,959 patients not treated with Paxlovid. Paxlovid treatment in patients aged ≥ 60 years of age was associated with significantly reduced risk of severe/critical illness or death (46.0%), and death rate (32.5%), and its effectiveness was high, regardless of vaccination status. Conclusion Paxlovid is effective at reducing the risk of death due to COVID-19 in patients with omicron BA.5 infection, especially in older patients, regardless of vaccination status. This suggests that older patients with COVID-19-related symptoms should be administered Paxlovid, regardless of their vaccination status, to reduce severity and risk of death.

Objectives: We evaluated the effectiveness of coronavirus disease 2019 vaccination in high-risk facilities in the Republic of Korea during the period when the highly transmissible Delta variant was prevalent. Additionally, we aimed to explore any disparities in vaccine effectiveness (VE) across various types of institutions, specifically distinguishing between non-medical and medical establishments. Methods: We examined 8 outbreak clusters covering 243 cases and 895 contacts from 8 highrisk facilities divided into 2 groups: group A (4 non-medical institutions) and group B (4 medical institutions). These clusters were observed from July 27, 2021 to October 16, 2021 for the attack rate (AR) and VE with respect to disease severity. A generalized linear model with a binomial distribution was used to determine the odds ratio (OR) for disease severity and death. Results: AR was notably lower in group B (medical institutions). Furthermore, VE analysis revealed that group A exhibited higher effectivity for disease severity and death than group B. The OR for disease severity was 0.24 (95% confidence interval [CI], 0.03–2.16) for group A and 0.27 (95% CI, 0.12–0.64) for group B, with the OR for death at 0.12 (95% CI, 0.01–1.32) in group A and 0.34 (95% CI, 0.14–0.87) in group B. Conclusion Although VE may vary across institutions, our findings underscore the importance of implementing vaccinations in high-risk facilities. Customized vaccination programs, tailored response plans, and competent management personnel are essential for effectively addressing and mitigating public health challenges.