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Simple Summary: According to the Society for Immunotherapy of Cancer, primary resistance to immune checkpoint inhibitor (ICI) treatment is defined as progression of disease within 6 months of ICI treatment with patients receiving at least 6 weeks of ICI monotherapy. We evaluated factors predictive of primary resistance to ICI monotherapy in 108 advanced non-small-cell lung cancer patients. The prevalence of primary resistance was 54.6%. The majority of patients were male, smokers, received pembrolizumab and had adenocarcinoma histology. We found that female gender, an elevated neutrophil-to-lymphocyte ratio of ≥3 at 6 weeks and a later line of immunotherapy treatment (≥2 lines) were key factors in predicting primary resistance to ICI monotherapy in advanced NSCLC. Introduction: Primary resistance to immune checkpoint inhibitors (ICI) is observed in routine clinical practice. We sought to determine factors predictive of primary resistance to ICI monotherapy, defined by the Society for Immunotherapy of Cancer (SITC) as progression within 6 months of ICI treatment with patients receiving at least 6 weeks of ICI monotherapy, in patients with advanced non-small-cell lung cancer (NSCLC). Method: Patients with stage IV NSCLC treated with at least 6 weeks of single-agent ICI at two tertiary hospitals in Singapore were included. A multivariate logistic regression model was utilised to elucidate factors predictive of primary resistance to ICI. Results: Of the 108 eligible patients, 59 (54.6%) experienced primary resistance. The majority were male (65.7%), smokers (66.3%), Chinese (79.6%), had adenocarcinoma (76.9%), received Pembrolizumab (55.6%) and received immunotherapy treatment in the later line setting (≥2 lines) (61.1%). Female gender (aOR = 3.16, p = 0.041), a sixth-week neutrophil-to-lymphocyte ratio (NLR) of ≥3) (aOR = 3.454, p = 0.037) and a later line of immunotherapy treatment (≥2 lines) (aOR = 2.676, p = 0.040) were factors predictive of primary resistance to ICI monotherapy in patients with advanced NSCLC. Conclusions: Using SITC criteria, an elevated NLR (≥3) at 6 weeks, female gender and a later line of immunotherapy treatment (≥2 lines) were predictive factors of developing primary resistance to ICI monotherapy in patients with advanced NSCLC. [ABSTRACT FROM AUTHOR]

The occurrence of neurotrophic tyrosine receptor kinase (NTRK) gene fusions in a wide range of tumor types presents an attractive opportunity for using a tropomyosin receptor kinase (TRK) inhibitor as cancer therapy. Recent clinical studies have demonstrated highly efficacious outcomes associated with the use of TRK inhibitors, such as larotrectinib and entrectinib in NTRK fusion‐bearing cancers, in both adult and pediatric populations. While NTRK gene fusions are commonly found in some uncommon adult and pediatric malignancies, they are also found, albeit rarely, in a wide range of more common malignancies. The potential value of testing for NTRK gene fusions in practically all advanced malignancies is underpinned by the remarkable therapeutic outcomes that TRK inhibitors offer. This requirement presents practical and financial challenges in real‐world oncological practice. Furthermore, different testing platforms exist to detect NTRK gene fusions, each with its advantages and disadvantages. It is, therefore, imperative to develop strategies for NTRK gene fusion testing in an attempt to optimize the use of limited tissue specimen and financial resources, and to minimize the turnaround time. A multidisciplinary task force of Singapore medical experts in both public and private sectors was convened in late 2020 to propose testing algorithms for adult colorectal tumors, sarcomas, non‐small cell lung cancer, and pediatric cancers, with particular adaptation to the Singapore oncological practice. The recommendations presented here highlight the heterogeneity of NTRK‐fusion positive cancers, and emphasize the need to customize the testing methods to each tumor type to optimize the workflow. [ABSTRACT FROM AUTHOR]

Immune‐related adverse events (IrAEs) of immune checkpoint inhibitors (ICIs) can be serious and unpredictable. We examine the incidence rate and risk factors for IrAEs in an Asian cohort of nonsmall cell lung cancer (NSCLC) patients treated with immunotherapy. Between June 2014 and August 2020, we retrospectively analysed IrAEs in NSCLC patients treated with anti‐PD‐1 or anti‐PD‐L1 inhibitors at the National University Cancer Institute, Singapore. A Poisson regression model was used to estimate the effect of risk factors on incidence rate of any grade IrAEs. One hundred and forty‐one patients were enrolled. Median age was 63. Majority were male (67%) with Eastern Cooperative Oncology Group (ECOG) PS 0‐1 (77%). More than half (56%) received pembrolizumab. Eleven percent harboured epidermal growth factor receptor (EGFR) mutation. Eighteen percent received concomitant chemotherapy. Median number of cycles was 4, and median duration of treatment was 2.1 months. IrAEs were seen in 71 (50.4%) patients, with an incidence rate of 99 events per 1000 person‐months. Fatigue (25%), rash (10.5%) and pneumonitis (7.9%) were the most common IrAEs. Twenty out of 152 IrAEs (13.2%) were Grade 3 or higher in severity: most common being pneumonitis (5.3%), fatigue (3.3%) and transaminitis (1.3%). Multivariable analysis demonstrated that concomitant chemotherapy use, higher BMI and presence of EGFR mutation are significant predictors for IrAEs (P <.0001; P =.016; P =.007). Our findings can help guide risk stratification and monitoring of IrAEs among NSCLC patients on immunotherapy. What's new? Immunotherapy is the mainstay of treatment for nonsmall cell lung cancers that lack oncogenic drivers. However, few studies have examined the risk factors for the potential immune‐related adverse events associated with immunotherapy. This retrospective study in an Asian cohort found that lung cancer patients who had concomitant chemotherapy use, a higher body mass index, and sensitising EGFR mutations were at higher risk of developing immune‐related adverse events with anti‐PD1 or anti‐PDL1 treatment. The findings can help guide risk stratification and the monitoring of immune‐related adverse events among patients receiving immunotherapy. [ABSTRACT FROM AUTHOR]

A dose of 200 mg 3‐weekly of pembrolizumab was approved by the Food and Drug Administration (FDA) as treatment for advanced non‐small cell lung cancer (NSCLC) without oncogenic drivers. This is despite evidence showing no difference in efficacy with 2 mg/kg. Our study aimed to assess the efficacy of a lower fixed dose of 100 mg, which is closer to 2 mg/kg weight‐based dose in an average‐sized Asian patient. All patients receiving pembrolizumab for advanced NSCLC from January 2016 to March 2020 in National University Hospital, Singapore, were included in this retrospective observational study. The effect of pembrolizumab 100 mg (Pem100) vs 200 mg (Pem200) upon survival outcomes, toxicity and cost were examined. One hundred fourteen patients received pembrolizumab. Sixty‐five (57%) and 49 (43%) received Pem100 and Pem200, respectively. There was no difference in progression‐free survival (PFS) and overall survival (OS) between Pem100 vs Pem200 as a single agent (PFS: 6.8 vs 4.2 months, hazard ratio [HR] 0.72, 95% confidence interval [CI] 0.36‐1.46, P =.36; 9 month OS: 58% vs 63%, HR 1.08, 95% CI 0.48‐2.41, P =.86) and when combined with chemotherapy (9‐month PFS: 60% vs 50%, HR0.84, 95% CI 0.34‐2.08, P =.71; 9‐month OS: 85% vs 58%, HR 0.27, 95% CI 0.062‐1.20, P =.09). No significant difference in response rate or ≥G3 immune‐related toxicities between Pem100 and Pem200 was observed. A cost minimisation analysis evaluating the degree of cost savings related to drug costs estimated a within study cost saving of SGD4,290,912 and cost saving per patient of SGD39,942 in the Pem100 group. A 100 mg of pembrolizumab appears to be effective with reduction in cost. A randomised trial should be done to investigate a lower dose of pembrolizumab. What's new? Pembrolizumab, a monoclonal antibody directed against the PD‐1 receptor, has received FDA approval for the treatment of lung cancer at a fixed dose of 200 mg every 3 weeks. However, doses above 2 mg/kg show a lack of benefit, calling for further evaluation in Asian populations. This retrospective observational study demonstrates the efficacy of a lower fixed dose of pembrolizumab (100 mg every 3 weeks) compared with standard‐dose pembrolizumab. The results also confirm the clinical activity of pembrolizumab at a lower dose than 2 mg/kg every 3 weeks, which could provide considerable cost savings to patients and the health system. [ABSTRACT FROM AUTHOR]

The use of chemotherapy at the end of life is increasing. We characterized the use of targeted therapies in relation to the end of life in non–small cell lung cancer (NSCLC) patients who died in our institution. The frequency of systemic anticancer therapy usage at the end of life was consistent with that reported in other recent studies. The use of targeted therapies, especially epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), was strikingly more common than that of conventional chemotherapy. Targeted therapy was frequently initiated within the last 3 months of life. Targeted agents were also used in sequence, in combination, and in investigational protocols. We conclude that targeted agents, in particular EGFR TKIs, are now the drugs of choice in the systemic treatment of NSCLC at the end of life. [ABSTRACT FROM AUTHOR]

Importance: Standard of care for unresectable locally advanced non-small cell lung cancer (NSCLC) involves definitive chemoradiotherapy followed by maintenance therapy with durvalumab. However, the cost of durvalumab has been cited as a barrier to its use in various health systems., Objective: To evaluate the cost-effectiveness of durvalumab vs placebo as maintenance therapy in patients with unresectable stage III NSCLC from 4 international payer perspectives (US, Brazil, Singapore, and Spain)., Design, Setting, and Participants: In this economic evaluation, a Markov model was designed to compare the lifetime cost-effectiveness of maintenance durvalumab for unresectable stage III NSCLC with that of placebo, using 5-year outcomes data from the PACIFIC randomized placebo-controlled trial. Individual patient data were extracted from the PACIFIC, KEYNOTE-189, ADAURA, ALEX, and REVEL randomized clinical trials to develop a decision-analytic model to determine the cost-effectiveness of durvalumab compared with placebo maintenance therapy over a 10-year time horizon. Direct costs, adverse events, and patient characteristics were based on country-specific payer perspectives and demographic characteristics. The study was conducted from June 1, 2022, through December 27, 2023., Main Outcomes and Measures: Life-years, quality-adjusted life years (QALYs), lifetime costs, and incremental cost-effectiveness ratios (ICERs) were estimated at country-specific willingness-to-pay thresholds ([data reported in US$] US: $150 000 per QALY; Brazil: $22 251 per QALY; Singapore: $55 288 per QALY, and Spain: $107 069 per QALY). One-way and probabilistic sensitivity analyses were performed to account for parameters of uncertainty. A cost-threshold analysis was also performed., Results: The US base-case model found that treatment with durvalumab was associated with an increased cost of $114 394 and improved effectiveness of 0.50 QALYs compared with placebo, leading to an ICER of $228 788 per QALY. Incremental cost-effectiveness ratios, according to base-case models, were $141 146 for Brazil, $153 461 for Singapore, and $125 193 for Spain. Durvalumab price adjustments to the PACIFIC data improved cost-effectiveness in Singapore, with an ICER of $45 164. The model was most sensitive to the utility of durvalumab., Conclusions and Relevance: In this cost-effectiveness analysis of durvalumab as maintenance therapy for unresectable stage III NSCLC, the therapy was found to be cost-prohibitive from the perspective of various international payers according to country-specific willingness-to-pay thresholds per QALY. The findings of the study suggest that discounted durvalumab acquisition costs, as possible in Singapore, might improve cost-effectiveness globally.

Objective: Pharmacogenetics suggests variants of genes involved in gemcitabine pharmacology could be useful markers for predicting inter-ethnic and inter-patient outcomes from treatment with the agent. Here, we have characterized the distribution of variants of genes involved in gemcitabine pharmacology in ethnic Asian populations and their association with non-small cell lung cancer (NSCLC) patient outcome., Methods: All genes involved in gemcitabine transport, metabolism and activity were screened for suitable variants for analysis using publications and public databases. By pyrosequencing, the frequency of qualifying variants was characterized from germline DNA of 94 healthy Asian donors and 53 NSCLC patients receiving gemcitabine-based chemotherapy., Results: Significant differences in genotype distribution between Caucasians and Asians were seen at 10/25 (45%) variant loci. In NSCLC patients, CDA+435 C>T variants were associated with response (p=0.026) and time to progression (p=0.016) and SLC28A1+1561 G>A variants were associated with neutropenia (p=0.030) and thrombocytopenia nadir (p=0.037)., Conclusions: Many genotypes in gemcitabine pharmacology vary in their frequency between Caucasians and Asians. CDA+435, and SLC28A1+1561 are worthy of further investigation as potential indicators of patient outcome after gemcitabine treatment.