Patients harboring uncommon EGFR exon 19 deletion-insertion mutations respond well to first-generation EGFR inhibitors and osimeritinib upon acquisition of T790M

Successful therapy of a critically ill non-small cell lung cancer patient with compound mutations in EGFR G719X and S768I genes using furmonertinib: A case report

Background

Somatic mutations in epidermal growth factor receptor (EGFR) genes, such as G719X and S768I, and tyrosine kinase inhibitors (TKIs) have been confirmed to be promising for developing new targeted therapies against advanced non-small-cell lung cancer (NSCLC). The G719X and S768I mutations are uncommon and often occur in the form of compound mutations. However, the efficacy of furmonertinib in patients with these uncommon compound mutations has not yet been elucidated.

Case presentation

In this study, the G719X/S768I compound mutations were detected in a critically ill NSCLC patient. This patient received furmonertinib for 14 months and successfully responded to the treatment. The present case report highlights the ideal clinical response, with ongoing follow-up.

Conclusion

We report the successful treatment of a critically ill NSCLC patient carrying rare compound EGFR G719X and S768I mutations using furmonertinib. To the best of our knowledge, this is the first reported case of a successful furmonertinib treatment of compound EGFR G719X and S768I mutations. Furmonertinib, a third-generation EGFR-TKI, may be effective in controlling the EGFR G719X and S768I compound mutations in NSCLC.

Non-small cell lung cancer cells with uncommon EGFR exon 19delins variants respond poorly to third-generation EGFR inhibitors

BACKGROUND

This study compared the clinical efficacy of first-, second-, and third-generation tyrosine kinase inhibitors (TKIs) in previously untreated non-small cell lung cancer (NSCLC) patients harboring uncommon epidermal growth factor receptor (EGFR) exon 19delins variants.

METHODS

We retrospectively analyzed the clinical outcomes of NSCLC patients with EGFR exon 19delins mutations who were treated with third- and first-generation EGFR TKIs. In vitro and in vivo studies were conducted to verify the sensitivity of these mutations to distinct generations of TKIs. Molecular simulation was used to investigate the structural characteristics of the EGFR mutant molecules.

RESULTS

In a multicenter cohort of 1,526 patients, 37 (2.4 %) had uncommon EGFR 19delins mutations. Twenty-four patients were treated with first-generation EGFR TKIs, and third-generation TKIs were administered to ten patients as frontline therapy. Patients carrying EGFR exon 19delins mutations who were given third-generation TKIs exhibited comparatively shorter progression-free survival (PFS) and overall survival (OS) in relation to those who received first-generation EGFR inhibitors; median PFS: 6.9 months vs. 19.1 months (p < 0.001), Median OS: 19.1 months vs. 32.6 months (p < 0.001). In vivo and in vitro studies revealed that uncommon EGFR 19delins variants exhibit limited sensitivity to third-generation EGFR inhibitors in contrast to first- and second-generation EGFR inhibitors. The molecular binding affinity of third-generation EGFR TKIs toward uncommon EGFR 19delins mutations was less than that of first- and second-generation EGFR inhibitors.

CONCLUSIONS

Uncommon EGFR 19delins variants respond poorly to third-generation EGFR inhibitors in NSCLC. Uncommon EGFR 19delins mutations may serve as an unfavorable predictive factor for the efficacy of third-generation EGFR TKI therapy, offering potential guidance for future clinical decision-making.

Clinical outcomes of advanced NSCLC patients with different EGFR exon 19 deletion subtypes treated with first-line tyrosine kinase inhibitors: A single-center ambispective cohort study

BACKGROUND

Clinical significance of various subtypes of epidermal growth factor receptor (EGFR) exon 19 deletion (ex19del) mutation in non-small cell lung cancer (NSCLC) remains unclear.

METHODS

We analyzed EGFR ex19del subtypes in NSCLC patients receiving first-line tyrosine kinase inhibitor (TKI) therapy at our center (January 2018-June 2022) and correlated them with median progression-free survival (mPFS) and median overall survival (mOS).

RESULTS

We identified 17 different EGFR ex19del variants in 101 patients. Between the classic (E746_A750del, 64.4%) and nonclassic groups (the rest variants), no significant difference was observed in mPFS (13.5 vs. 19.3 months, p = 0.18) or mOS (44.1 vs. 77.0 months, p = 0.06). mPFS showed no significant difference between ex19del subgroups classified based on the presence of insertion (ex19delins), starting position or length of deletion. However, patients with ex19delins starting at E746 showed longer mPFS than the others (29.7 vs. 12.5 months, p = 0.04), and patients with ex19del of 15 nucleotides had shorter mOS than the others (44.1 vs. 77.0 months, p = 0.03). In multivariate analysis, ex19delins independently predicted a better PFS (HR = 0.311, p = 0.03); however, 15 nucleotide deletion was no longer associated with OS (HR = 0.181, p = 0.11). Secondary T790M mutation incidence was significantly higher in the ex19del subgroup starting at E746 than the others (64.7% vs. 30.8%, p = 0.04).

CONCLUSIONS

Our study revealed potential differences in TKI efficacy, resistance mechanism, and prognosis of various EGFR ex19del subtypes in NSCLC, underscoring the need for precise selection of first-line therapy.

Rigid Scaffolds Are Promising for Designing Macrocyclic Kinase Inhibitors

Macrocyclic kinase inhibitors (MKIs) are gaining attention due to their favorable selectivity and potential to overcome drug resistance, yet they remain challenging to design because of their novel structures. To facilitate the design and discovery of MKIs, we investigate MKI rational design starting from initial acyclic compounds by performing microsecond-scale atomistic simulations for multiple MKIs, constructing an MKI database, and analyzing MKIs using hierarchical cluster analysis. Our studies demonstrate that the binding modes of MKIs are like those of their corresponding acyclic counterparts against the same kinase targets. Importantly, within the respective binding sites, the MKI scaffolds retain the same conformations as their corresponding acyclic counterparts, demonstrating the rigidity of scaffolds before and after molecular cyclization. The MKI database includes 641 nanomole-level MKIs from 56 human kinases elucidating the features of rigid scaffolds and the core structures of MKIs. Collectively these results and resources can facilitate MKI development.

Efficacy of Osimertinib in Patients with Lung Cancer Positive for Uncommon EGFR Exon 19 Deletion Mutations

PURPOSE

The uncommon EGFR exon 19 deletion (ex19del), L747_A750>P, demonstrates reduced sensitivity to osimertinib compared with the common ex19del, E746_A750del in preclinical models. The clinical efficacy of osimertinib in patients with non-small cell lung cancer harboring L747_A750>P and other uncommon ex19dels is not known.

EXPERIMENTAL DESIGN

The AACR GENIE database was interrogated to characterize the frequency of individual ex19dels relative to other variants, and a multicenter retrospective cohort was used to compare clinical outcomes for patients with tumors harboring E746_A750del, L747_A750>P, and other uncommon ex19dels who received osimertinib in the first line (1L) or in second or later lines of therapy and were T790M+ (≥2L).

RESULTS

ex19dels comprised 45% of EGFR mutations, with 72 distinct variants ranging in frequency from 28.1% (E746_A750del) to 0.03%, with L747_A750>P representing 1.8% of the EGFR mutant cohort. In our multi-institutional cohort (N = 200), E746_A750del was associated with significantly prolonged progression-free survival (PFS) with 1L osimertinib versus L747_A750>P [median 21.3 months (95% confidence interval, 17.0-31.7) vs. 11.7 months (10.8-29.4); adjusted HR 0.52 (0.28-0.98); P = 0.043]. Osimertinib efficacy in patients with other uncommon ex19dels varied on the basis of the specific mutation present.

CONCLUSIONS

The ex19del L747_A750>P is associated with inferior PFS compared with the common E746_A750del mutation in patients treated with 1L osimertinib. Understanding differences in osimertinib efficacy among EGFR ex19del subtypes could alter management of these patients in the future.

Osimertinib in NSCLC With Atypical EGFR-Activating Mutations: A Retrospective Multicenter Study

Introduction

EGFR mutations drive a subset of NSCLC. Patients harboring the common EGFR mutations, deletion of exon 19 and L858R, respond well to osimertinib, a third-generation tyrosine kinase inhibitor. Nevertheless, the effect of osimertinib on NSCLC with atypical EGFR mutations is not well described. This multicenter retrospective study evaluates the efficacy of osimertinib among patients with NSCLC harboring atypical EGFR mutations.

Methods

Patients with metastatic NSCLC treated with osimertinib, harboring at least one atypical EGFR mutation, excluding concurrent deletion of exon 19, L858R, or T790M mutations, from six U.S. academic cancer centers were included. Baseline clinical characteristics were collected. The primary end point was the time to treatment discontinuation (TTD) of osimertinib. Objective response rate by the Response Evaluation Criteria in Solid Tumors version 1.1 was also assessed.

Results

A total of 50 patients with NSCLC with uncommon EGFR mutations were identified. The most frequent EGFR mutations were L861Q (40%, n = 18), G719X (28%, n = 14), and exon 20 insertion (14%, n = 7). The median TTD of osimertinib was 9.7 months (95% confidence interval [CI]: 6.5-12.9 mo) overall and 10.7 months (95% CI: 3.2-18.1 mo) in the first-line setting (n = 20). The objective response rate was 31.7% (95% CI: 18.1%-48.1%) overall and 41.2% (95% CI: 18.4%-67.1%) in the first-line setting. The median TTD varied among patients with L861Q (17.2 mo), G719X (7.8 mo), and exon 20 insertion (1.5 mo) mutations.

Conclusions

Osimertinib has activity in patients with NSCLC harboring atypical EGFR mutations. Osimertinib activity differs by the type of atypical EGFR-activating mutation.

Alectinib versus crizotinib in ALK-positive advanced non-small cell lung cancer and comparison of next-generation TKIs after crizotinib failure: Real-world evidence

BACKGROUND

Anaplastic lymphoma kinase (ALK) fusion is a prognostic indicator for patients with non-small cell lung cancer (NSCLC) receiving tyrosine kinase inhibitors (TKIs). The real-world data of ALK TKIs remain a major concern.

METHODS

Patients with ALK-positive advanced NSCLC, who received crizotinib or alectinib treatment in first line, were retrospectively reviewed. ALK status was detected using immunohistochemistry (IHC) or next-generation sequencing (NGS). Clinical outcomes have been comprehensively analyzed between TKIs, ALK fusions, EML4-ALK variants, and next-generation TKIs after crizotinib failure.

RESULTS

One hundred sixty-eight patients were successively enrolled (crizotinib, n = 109; alctinib, n = 59). Alectinib showed consistent superiority in progressive-free survival (PFS) over crizotinib (hazard ratio [HR]: 0.43, 95% confidential interval [CI]: 0.24-0.77, p = 0.004). Multivariate Cox regression showed chemotherapy (CT) prior to TKIs or synchronous chemotherapy seemed not to improve PFS compared to ALK inhibitors alone (p > 0.05). And, alectinib was superior to crizotinib in prolonging intracranial PFS (HR 0.12, 95% CI: 0.03-0.49, p = 0.003). Patients in EML4 group had a better prognosis than those in non-EML4 group after alectinib administration (HR 0.13, 95% CI: 0.03-0.60, p = 0.009). TP53 co-mutations were relatively common (34.0%) and associated with adverse outcome in ALK-positive patients (adjusted HR 2.22, 95% CI: 1.00-4.92, p = 0.049). After crizotinib failure, 33 patients received a sequential application of next-generation ALK TKIs. Compared to ceritinib and brigatinib, alectinib might have better PFS (p = 0.043).

CONCLUSION

Our results revealed alectinib had better PFS and higher intracranial efficacy compared to crizotinib in ALK-positive NSCLC, and might improve PFS by comparison with ceritinib and brigatinib after crizotinib failure.

Observation on the clinical efficacy and side effects of EGFR-TKI ± chemotherapy in the treatment of EGFR mutation-positive advanced lung adenocarcinoma

Objective

To assess the clinical efficacy and side effects of EGFR-TKI with or without chemotherapy in the treatment of EGFR mutation-positive advanced lung adenocarcinoma.

Methods

A total of 103 IIIB or IV EGFR mutation-positive lung adenocarcinoma patients admitted to the oncology department of Fujian Provincial Hospital from January 2017 to October 2020 were selected. According to genetic mutation status, patients were divided into the following groups: 19del alone, 19del combined with TP53 or other co-mutations, L858R mutation alone, and L858R mutation combined with TP53 or other co-mutations. Targeted drugs or targeted drugs combined with chemotherapy were respectively administered in the four groups. In patients with simple 19 deletion, only targeted drugs with no combined therapy were applied, resulting in seven total groups. The difference between short-term treatment and long-term treatment effects and the occurrence of adverse reactions was calculated and compared.

Results

There was no statistical significance of difference in the incidence of adverse reactions in seven groups ( p > 0.05). The short-term disease control rate of the combination group was higher than the targeted drug group with the difference yielding statistical significance ( p < 0.001). The short-term objective response rate of the combination group was higher than the targeted drug group, also yielding statistical significance ( p < 0.001). By October 2020, the median progression-free survival (PFS) was 16 months in the EGFR-TKI-targeted combined with chemotherapy group and 10 months in the single-drug EGFR-TKI group, and the PFS time was longer in the combination group than in the single targeted drug group, the difference being statistically significant ( p = 0.001).

Conclusions

In the treatment of advanced lung adenocarcinoma patients with EGFR-gene sensitive mutations, compared with single EGFR-TKI-targeted therapy, EGFR-TKI-targeted drug combined chemotherapy can control the disease progression more effectively, and does not increase adverse reactions.