Amivantamab (JNJ-61186372) induces clinical, biochemical, molecular, and radiographic response in a treatment-refractory NSCLC patient harboring amplified triple EGFR mutations (L858R/ T790M/G796S) in cis

Liquid biopsy is a minimally-invasive diagnostic method that may improve access to molecular profiling for non-small cell lung cancer (NSCLC) patients. Although cell-free DNA (cf-DNA) isolation from plasma is the standard liquid biopsy method for detecting DNA mutations in cancer patients, the sensitivity can be highly variable. Vn96 is a peptide with an affinity for both extracellular vesicles (EVs) and circulating cf-DNA. In this study, we evaluated whether peptide-affinity (PA) precipitation of EVs and cf-DNA from NSCLC patient plasma improves the sensitivity of single nucleotide variants (SNVs) detection and compared observed SNVs with those reported in the matched tissue biopsy. NSCLC patient plasma was subjected to either PA precipitation or cell-free methods and total nucleic acid (TNA) was extracted; SNVs were then detected by next-generation sequencing (NGS). PA led to increased recovery of DNA as well as an improvement in NGS sequencing parameters when compared to cf-TNA. Reduced concordance with tissue was observed in PA-TNA (62%) compared to cf-TNA (81%), mainly due to identification of SNVs in PA-TNA that were not observed in tissue. EGFR mutations were detected in PA-TNA with 83% sensitivity and 100% specificity. In conclusion, PA-TNA may improve the detection limits of low-abundance alleles using NGS.

Although there has been significant progress in immune-checkpoint inhibitor (ICI) treatment, it remains controversial whether they should be used in the treatment of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). We herein report the case of an NSCLC patient with uncommon complex EGFR mutations (G719S and L861Q) who was refractory to afatinib treatment but who showed a good response to pembrolizumab treatment. A 65-year-old female ex-smoker was diagnosed with right upper lobe NSCLC (clinical stage IVB; cT2bN3M1c). She had received afatinib for two months, but her disease showed rapid progression. Pembrolizumab treatment was initiated because more than 75% of her tumor cells expressed PD-L1. Her tumor responded well to pembrolizumab treatment and it remained effective for more than 1 year. Our case suggests that pembrolizumab treatment is a treatment option for NSCLC patients with uncommon EGFR mutations and high PD-L1 expression levels who are refractory to EGFR-TKI treatment.

Abstract Leptomeningeal metastasis (LM) is a rare but lethal complication of advanced non-small cell lung cancer (NSCLC) that has a devastating impact on patient survival and quality of life. Osimertinib, an irreversible tyrosine kinase inhibitor, is approved as a therapy for advanced NSCLC with epidermal growth factor receptor (EGFR) mutation. However, the efficacy and optimal dosage of osimertinib in the treatment of NSCLC patients with LM who harbor uncommon EGFR mutations have yet to be fully investigated. Herein, we report a case of an advanced NSCLC patient with LM carrying EGFR G719S and L861Q, who was successfully treated by osimertinib at 160 mg. The patient initially presented with clear cell renal carcinoma and renal metastatic adenocarcinoma, and underwent right nephrectomy. At 2 months after nephrectomy, He developed a disturbance of consciousness and was subsequently diagnosed with NSCLC with LM by meningeal biopsy pathology and cerebrospinal fluid (CSF) cytology. Next-generation sequencing detected the rare EGFR mutations G719S and L861R in the meningeal biopsy tissues. The patient was then administered osimertinib at 80 mg quaque die (QD); after 1 month of treatment, his symptoms were alleviated. However, two months later, he experienced epileptic episode. Subsequently, the osimertinib dosage was doubled to 160 mg QD. After 1 month of treatment, the patient achieved central nervous system (CNS) response, and at the time of this manuscript’s submission, he had maintained stable disease (SD) for more than 1 year. To our knowledge, this study provides the first clinical evidence that the administration of osimertinib at 160 mg once daily can achieve an encouraging, durable response in an NSCLC patients with LM carrying EGFR G719S and L861Q. Aslo, it is recommended to consider performing leptomeningeal biopsy for precision treatment in NSCLC paiernts with leptomeningeal metastasis.

7682 Background: Activating epidermal growth factor receptor (EGFR) mutations identified in NSCLC patient tumors are often associated with rapid and profound response to EGFR tyrosine kinase inhibitors (TKIs). Conventional detection methods are cumbersome and may underestimate mutations frequencies due to limited sensitivity. We and others have shown that tumor-specific mutations such as KRAS can be detected in tumor DNA shed into patient plasma (Kimura, Ann N Y Acad Sci, 2004). Here we describe the performance of an allele- specific real-time PCR system utilizing Scorpion primers (kindly provided by DxS, UK) to detect EGFR mutations in plasma. Methods: DNA was extracted from archival tumor blocks, slides and plasma obtained from consenting patients. In order to determine the sensitivity of this technique both in terms of the ratio of mutant-to-wild-type genomic DNA as well as the minimum amount of DNA required for detection, a dilution experiment was conducted. Genomic DNA from cell lines containing either the exon 21 L858R point mutation or the exon 21 E746–750 deletion was diluted with wild-type genomic DNA at ratios ranging from 1:2 to 1:10,000. Clinical specimens including plasma and/or tissue from 35 advanced stage NSCLC patients treated with EGFR-TKIs were examined. Results: Mutant DNA was successfully detected when it comprised as little as 0.1% of the total sample or as low as 25 pg of mutant-positive genomic DNA in a pool of 2.5 μg of total DNA. EGFR mutations were identified by this approach in both plasma and tissue of 2 patients who were complete responders to EGFR-TKI therapy, only one of which was detectable by direct sequencing. For the 7 patients where only tissue was available, two were positive both with the Scorpion primers and direct sequencing while the rest were wild-type. Of 21 patients where only plasma was available, 6 mutations were detected using the Scorpion primers. Conclusions: Allele-specific Scorpion technology is 1) highly specific and sensitive for EGFR mutation analysis, 2) able to detect mutations that were not observable by direct sequencing in plasma and tissue, 3) capable of detecting mutations in shed tumor DNA in plasma of advanced NSCLC patients and 4) may be suitable for monitoring response or detecting recurrence. No significant financial relationships to disclose.