PURPOSE Standard first-line therapy for EGFR-mutant advanced non–small-cell lung cancer (NSCLC) is an epidermal growth factor receptor (EGFR)–directed oral tyrosine kinase inhibitor. Adding pemetrexed and carboplatin chemotherapy to an oral tyrosine kinase inhibitor may improve outcomes. PATIENTS AND METHODS This was a phase III randomized trial in patients with advanced NSCLC harboring an EGFR-sensitizing mutation and a performance status of 0 to 2 who were planned to receive first-line palliative therapy. Random assignment was 1:1 to gefitinib 250 mg orally per day (Gef) or gefitinib 250 mg orally per day plus pemetrexed 500 mg/m2 and carboplatin area under curve 5 intravenously every 3 weeks for four cycles, followed by maintenance pemetrexed (gefitinib plus chemotherapy [Gef+C]). The primary end point was progression-free survival (PFS); secondary end points included overall survival (OS), response rate, and toxicity. RESULTS Between 2016 and 2018, 350 patients were randomly assigned to Gef (n = 176) and Gef+C (n = 174). Twenty-one percent of patients had a performance status of 2, and 18% of patients had brain metastases. Median follow-up time was 17 months (range, 7 to 30 months). Radiologic response rates were 75% and 63% in the Gef+C and Gef arms, respectively ( P = .01). Estimated median PFS was significantly longer with Gef+C than Gef (16 months [95% CI, 13.5 to 18.5 months] v 8 months [95% CI, 7.0 to 9.0 months], respectively; hazard ratio for disease progression or death, 0.51 [95% CI, 0.39 to 0.66]; P < .001). Estimated median OS was significantly longer with Gef+C than Gef (not reached v 17 months [95% CI, 13.5 to 20.5 months]; hazard ratio for death, 0.45 [95% CI, 0.31 to 0.65]; P < .001). Clinically relevant grade 3 or greater toxicities occurred in 51% and 25% of patients in the Gef+C and Gef arms, respectively ( P < .001). CONCLUSION Adding pemetrexed and carboplatin chemotherapy to gefitinib significantly prolonged PFS and OS but increased toxicity in patients with NSCLC.

Summary Deregulated HER2 is a target of many approved cancer drugs. We analyzed 111,176 patient tumors and identified recurrent HER2 transmembrane domain (TMD) and juxtamembrane domain (JMD) mutations, including G660D, R678Q, E693K and Q709L. Using a saturation mutagenesis screen and testing of patient-derived mutations we found several activating TMD and JMD mutations. Structural modeling and analysis showed that the TMD/JMD mutations function by improving the active dimer interface or stabilizing an activating conformation. Further, we found that HER2 G660D employed asymmetric kinase dimerization for activation and signaling. Importantly, anti-HER2 antibodies and small molecule kinase inhibitors blocked the activity of TMD/JMD mutants. Consistent with this, a G660D germline mutant lung cancer patient showed remarkable clinical response to HER2 blockade.

BackgroundThe significance of uncommon EGFR mutations in newly diagnosed advanced non-small-cell lung cancer (NSCLC) patients is incompletely known. We aimed to analyze the demographic profile, outcome, and treatment attributes of these patients.Patients and methodsWe retrospectively surveyed 5,738 advanced NSCLC patients who underwent EGFR testing in our center from 2013 to 2017 by in-house primer probes on real time PCR platform. Descriptive data were accumulated from electronic medical records. Survival plot was calculated using Kaplan–Meier method and compared between groups using log-rank test.ResultsOut of 1,260 EGFR mutation-positive patients, 83 (6.58%) had uncommon mutations in isolation or in various combinations. Uncommon mutations were more frequent in men, never-smokers, and adenocarcinomas. Overall, exon 18 G719X, exon 20 insertion, exon 20 T790M, exon 20 S768I, and exon 21 (L858R/L861Q) were present in 9.6%, 19.3%, 12%, 3.6%, and 3.6% patients, respectively. Dual mutation positivity was found in 50.6% patients. On classifying patients as per tyrosine kinase inhibitor (TKI) sensitivity, it was found that majority of the patients had a combination TKI sensitive and insensitive mutations. The median duration of follow-up was 13 months. Five patients were lost to follow-up. Median progression-free survival on first line therapy was 6.7 months (95% CI: 4.8–8.5). Median overall survival (OS) of patients who received TKI during the course of their disease was 20.2 months (95% CI: 11.4–28.9). Median overall survival (mOS) of the entire cohort was 15.8 months (95% CI: 10.1–21.5). Among all uncommon mutations, patients with dual mutations did better, with an mOS time of 22.6 months (95% CI: 8.2–37.0, P=0.005). It was observed that TKI sensitive/TKI insensitive dual mutations had a superior OS of 28.2 months (95% CI: 15.2–41.2, P=0.039) as compared to TKI sensitive and TKI insensitive EGFR mutations.ConclusionUncommon EGFR mutations constitute a heterogeneous group, hence, it is imperative to understand each subgroup more to define optimal treatment.

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