Treatments and outcomes of advanced/recurrent non-small cell lung cancer harboring the EGFR T790M mutation: a retrospective observational study of 141 patients in Japan.

BACKGROUND: The epidermal growth factor receptor (EGFR) T790M mutation is considered the major mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC) patients with EGFR-sensitizing mutations. Although chemotherapy is commonly used for those patients under the condition without T790M-targeted therapy, the clinical outcomes are poorly defined. Therefore, we aimed to reveal the treatment patterns and clinical outcomes in patients with T790M-positive NSCLC. METHODS: We conducted a retrospective observational study at 23 sites in Japan, and 141 patients with T790M-positive advanced/recurrent NSCLC were identified from January 2008 to December 2014. Their records were studied to understand treatment patterns after detection of a T790M mutation and to assess the objective response rate (ORR) and median survival time (MST) to specific treatment modalities. RESULTS: Of 141 patients, 24 had de novo T790M-positive tumors and 117 had acquired T790M-positive tumors, with MSTs (95% CI) of 21.4 (12.4-36.7) and 9.1 (6.4-13.9) months, respectively. The most common regimen was platinum-based doublet chemotherapy ± bevacizumab, which was associated with an ORR/MST of 25.0%/29.1 months, respectively, in patients with de novo T790M mutations, and 22.2%/15.3 months, respectively, in patients with acquired T790M mutations. CONCLUSIONS: This study reveals the treatment patterns and outcomes of NSCLC patients in Japan after detection of the T790M mutation. The most common treatment following detection of the T790M mutation was platinum-based doublet chemotherapy ± bevacizumab. Platinum-based doublet chemotherapy ± bevacizumab was moderately effective, indicating the need for targeted therapies for patients with T790M mutation-positive NSCLC.

Biomarker testing for personalized, first-line therapy in advanced nonsquamous non-small cell lung cancer patients in the real world setting in Japan: a retrospective, multicenter, observational study (the BRAVE study).

BACKGROUND: Molecular diagnostic testing is necessary to guide optimal first-line treatment. The number of patients who receive first-line treatment based on biomarker analysis in Japan is unknown. We aimed to determine the proportion of nonsquamous non-small cell lung cancer (NSCLC) patients for whom first-line treatment was selected based on biomarker testing. METHODS: This retrospective, multicenter, observational study registered patients aged ⩾20 years with locally advanced or metastatic nonsquamous NSCLC who started first-line treatment between August and December 2017 in Japan. Data were collected from medical records between January and May 2018. The primary endpoint was the proportion of patients with confirmed biomarker status for first-line treatment decision. RESULTS: Among 202 patients enrolled from 11 centers, 161 (79.7%; 95% confidence interval, 74.2-85.2%) had confirmed biomarker status. The testing rate was highest for epidermal growth factor receptor (EGFR; 97.5%), followed by anaplastic lymphoma kinase (ALK; 88.1%), programmed death ligand-1 (PD-L1; 87.1%), and ROS1 (67.3%). For first-line treatment, 70/75 patients with EGFR-positive tumors were administered an EGFR-TKI; 14/15 patients with ALK-positive tumors received an ALK inhibitor; 2/2 patients with ROS1-positive tumors received a ROS1 inhibitor; and 29/36 driver mutation-negative patients with a PD-L1 tumor proportion score ⩾50% were administered an anti-PD-1 monoclonal antibody. Median times from confirmed diagnosis date to first-line treatment initiation, and from first biomarker test order to last biomarker test result were 19 and 11 days, respectively. CONCLUSIONS: The proportion of nonsquamous NSCLC patients with confirmed biomarker status for first-line treatment was considered insufficient and in need of improvement.

Real-World Evaluation of Factors for Interstitial Lung Disease Incidence and Radiologic Characteristics in Patients With EGFR T790M-positive NSCLC Treated With Osimertinib in Japan.

INTRODUCTION: Using real-world Japanese postmarketing data, we characterized interstitial lung disease (ILD) development during the second- or later-line osimertinib treatment for EGFR mutation-positive NSCLC. Retrospective radiologic image evaluation of patients developing ILD was also performed. METHODS: Patients who had ILD events reported as an adverse drug reaction by their physicians and who were assessed as having developed ILD as assessed by an ILD expert committee in Japan were included. RESULTS: Among 3578 patients, 252 ILD events were reported in 245 patients (6.8%) by their attending physicians. The median (range) time to the first onset of ILD after osimertinib treatment initiation was 63.0 (5-410) days, and 29 patients with a fatal outcome were reported. The ILD expert committee assessed 231 of 3578 patients (6.5%) as having ILD. A previous history of nivolumab therapy (adjusted OR: 2.84; 95% confidence interval: 1.98-4.07) and a history or concurrence of ILD (3.51; 2.10-5.87) were identified as factors potentially associated with ILD onset during osimertinib treatment. In patients who had received a previous nivolumab treatment, the number and proportion of patients developing ILD were highest for patients who discontinued nivolumab treatment within the first month before initiating osimertinib; trends for decreasing incidence and proportion were observed, with an increasing duration between the end of nivolumab treatment and the initiation of osimertinib treatment. CONCLUSIONS: The frequency of ILD was consistent with the known osimertinib safety profile in the Japanese population. A history or concurrence of ILD and history of previous nivolumab therapy are factors potentially associated with ILD onset during osimertinib treatment.

Real-World EGFR T790M Testing in Advanced Non-Small-Cell Lung Cancer: A Prospective Observational Study in Japan.

INTRODUCTION: Approximately one-half of patients with epidermal growth factor receptor (EGFR) mutation-positive advanced/metastatic non-small-cell lung cancer (NSCLC) develop resistance to first- or second-generation EGFR tyrosine kinase inhibitors (TKIs) due to a secondary T790M mutation. This study investigated the pattern of T790M testing after EGFR TKI treatment in a real-world setting in Japan. METHOD: This prospective observational study enrolled patients with EGFR mutation-positive advanced/metastatic NSCLC who reported disease progression during treatment with first- or second-generation EGFR TKIs. Data regarding sampling methods for T790M mutation testing (plasma sample, cytology or tissue biopsy) and the treatment strategies after disease progression were recorded prospectively. RESULTS: A total of 236 patients were included in the study (female, 67.4%; median age, 73.0 years), and 205 patients (86.9%) underwent rebiopsy by any of the three possible methods: plasma sampling in 137 patients (58.1%) and tissue/cytology sampling in 68 patients (28.8%) during the first rebiopsy. Overall, 80.6% of the tissue/cytology samples contained tumor cells, and 40% of these samples were positive for the T790M mutation. T790M mutations were detected in only 19.7% of plasma samples. Of the 199 patients who underwent T790M testing, 61 (30%) tested positive, and 56 (91.8%) subsequently received osimertinib. CONCLUSION: Among the 87% of Japanese patients who underwent rebiopsy after progressing on treatment with a first- or second-generation EGFR TKI, approximately 30% tested positive for the T790M mutation and were eligible to receive osimertinib. Although plasma sampling is non-invasive, this rebiopsy method is less sensitive for T790M detection compared with tissue or cytology sampling (UMIN identifier: UMIN000024928). FUNDING: AstraZeneca Japan.

Identification of a glutamine residue essential for catalytic activity of aspergilloglutamic peptidase by site-directed mutagenesis.

Aspergilloglutamic peptidase (AGP, formerly called aspergillopepsin II) from Aspergillus niger var. macrosporus is a unique acid protease recently classified to the peptidase family G1. Our previous study using site-directed mutagenesis on the glutamic and aspartic acid residues of AGP conserved among the G1 family suggested that Glu219 and Asp123 (numbering in the preproform) are important for catalytic activity. However, the Asn mutant of Asp123 retained weak but significant activity and therefore it was unclear whether it is an active site residue. In this study, we performed site-directed mutagenesis on all the other hydrophilic residues including Gln, Asn, Ser, Thr, and Tyr, conserved in this family to screen other residues that might be essential for catalytic function, and found that mutations of only Gln133 resulted in almost complete loss of enzymatic activity without change in the native conformation of the enzyme. Meanwhile, the 3D structure of scytalidoglutamic peptidase, a homologue from Scytalidium lignicolum, has been reported, indicating that Glu136 and Gln53 (the counterparts of Glu219 and Gln133 in AGP) form a catalytic dyad. Therefore, the results obtained in this and our previous studies provide with complementary evidence for the definitive conclusion on the catalytic function of the Glu/Gln dyad in glutamic peptidases.

Activation profiles of the zymogen of aspergilloglutamic peptidase.

Aspergilloglutamic peptidase produced by Aspergillus niger var. macrosporus belongs to the novel glutamic peptidase family. Its zymogen is autocatalytically activated under acidic conditions to the mature enzyme with a two-chain structure. Analyses by SDS-PAGE and mass spectrometry of the activation products of the recombinant zymogen showed that the major pathway of activation includes initial fast cleavage at Glu12-Ala13, followed by stepwise cleavages in the N-terminal and intervening propeptide regions. Essentially the same activation profile was obtained with the recombinant zymogen lacking the N-terminal 12-aa sequence. The missing region includes the most prominent cluster of basic residues of the propeptide, indicating low importance of this cluster for activation and refolding of the zymogen.