Efficacy of icotinib in advanced lung squamous cell carcinoma

[Advances of Molecular Targeted Therapy in EGFR-mutated Squamous Cell Lung Cancer]

Non-small cell lung cancer (NSCLC) is a prevalent tumour type in our country, with lung squamous carcinoma being a commonly observed NSCLC subtype besides lung adenocarcinoma. Epidermal growth factor receptor (EGFR) is a significant driver gene in lung cancer, and EGFR mutation frequency is considerably lower in lung squamous carcinoma in comparison to lung adenocarcinoma. Although targeted therapy against EGFR has demonstrated significant advancements in lung adenocarcinoma, while progress in lung squamous carcinoma has been relatively sluggish. This paper reviews recent studies on molecular targeted therapy for EGFR-mutated lung squamous carcinoma and summarises the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) in treating squamous carcinoma of the lung, in order to provide a reference for treating patients with EGFR-mutated squamous carcinoma of the lung.
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Signaling pathways and targeted therapies in lung squamous cell carcinoma: mechanisms and clinical trials

Lung cancer is the leading cause of cancer-related death across the world. Unlike lung adenocarcinoma, patients with lung squamous cell carcinoma (LSCC) have not benefitted from targeted therapies. Although immunotherapy has significantly improved cancer patients' outcomes, the relatively low response rate and severe adverse events hinder the clinical application of this promising treatment in LSCC. Therefore, it is of vital importance to have a better understanding of the mechanisms underlying the pathogenesis of LSCC as well as the inner connection among different signaling pathways, which will surely provide opportunities for more effective therapeutic interventions for LSCC. In this review, new insights were given about classical signaling pathways which have been proved in other cancer types but not in LSCC, including PI3K signaling pathway, VEGF/VEGFR signaling, and CDK4/6 pathway. Other signaling pathways which may have therapeutic potentials in LSCC were also discussed, including the FGFR1 pathway, EGFR pathway, and KEAP1/NRF2 pathway. Next, chromosome 3q, which harbors two key squamous differentiation markers SOX2 and TP63 is discussed as well as its related potential therapeutic targets. We also provided some progress of LSCC in epigenetic therapies and immune checkpoints blockade (ICB) therapies. Subsequently, we outlined some combination strategies of ICB therapies and other targeted therapies. Finally, prospects and challenges were given related to the exploration and application of novel therapeutic strategies for LSCC.

Tissue Rigidity Increased during Carcinogenesis of NTCU-Induced Lung Squamous Cell Carcinoma In Vivo

Increased tissue rigidity is an emerging hallmark of cancer as it plays a critical role in promoting cancer growth. However, the field lacks a defined characterization of tissue rigidity in dual-stage carcinogenesis of lung squamous cell carcinoma (SCC) in vivo. Pre-malignant and malignant lung SCC was developed in BALB/c mice using N-nitroso-tris-chloroethylurea (NTCU). Picro sirius red staining and atomic force microscopy were performed to measure collagen content and collagen (diameter and rigidity), respectively. Then, the expression of tenascin C (TNC) protein was determined using immunohistochemistry staining. Briefly, all tissue rigidity parameters were found to be increased in the Cancer group as compared with the Vehicle group. Importantly, collagen content (33.63 ± 2.39%) and TNC expression (7.97 ± 2.04%) were found to be significantly higher (p < 0.05) in the Malignant Cancer group, as compared with the collagen content (18.08 ± 1.75%) and TNC expression (0.45 ± 0.53%) in the Pre-malignant Cancer group, indicating increased tissue rigidity during carcinogenesis of lung SCC. Overall, tissue rigidity of lung SCC was suggested to be increased during carcinogenesis as indicated by the overexpression of collagen and TNC protein, which may warrant further research as novel therapeutic targets to treat lung SCC effectively.

NTCU induced pre-malignant and malignant stages of lung squamous cell carcinoma in mice model

Mice have served as an excellent model to understand the etiology of lung cancer for years. However, data regarding dual-stage carcinogenesis of lung squamous cell carcinoma (SCC) remain elusive. Therefore, we aim to develop pre-malignant (PM) and malignant (M) lung SCC in vivo using N-nitroso-tris-chloroethylurea (NTCU). BALB/C mice were allotted into two main groups; PM and M groups which received treatment for 15 and 30 weeks, respectively. Then, the mice in each main group were allotted into three groups; control, vehicle, and cancer (n = 6), which received normal saline, 70% acetone, and 0.04 M NTCU by skin painting, respectively. Histopathologically, we discovered a mix of hyperplasia, metaplasia, and dysplasia lesions in the PM group and intracellular bridge; an SCC feature in the M group. The M group was positive for cytokeratin 5/6 protein which confirmed the lung SCC subtype. We also found significantly higher (P < 0.05) epithelium thickness in the cancer groups as compared to the vehicle and control groups at both the PM and M. Overall, this study discovered that NTCU is capable of developing PM and M lung SCC in mice model at appropriate weeks and the vehicle group was suggested to be adequate as control group for future research.

EGFR-Mutated Squamous Cell Lung Cancer and Its Association With Outcomes

Background

The therapeutic efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in advanced EGFR-mutant lung squamous cell carcinoma (SCC) patients remains uncertain. Furthermore, the factors underlying the responsiveness have not been fully investigated. We therefore investigated the link between genomic profiles and EGFR-TKI efficacy.

Material and Methods

We consecutively enrolled stage IV, EGFR-mutant, and EGFR-TKI–treated patients with SCC. Patients with EGFR wild-type lung SCC and EGFR-mutant lung adenocarcinoma were consecutively enrolled as controls, and next-generation sequencing (NGS) was performed.

Results

In total, 28 EGFR-mutant lung SCC, 41 EGFR-mutant lung adenocarcinoma, and 40 EGFR wild-type lung SCC patients were included. Among the patients with EGFR mutations, shorter progression-free survival (PFS) was observed in SCC compared to adenocarcinoma (4.6 vs. 11.0 months, P<0.001). Comparison of the genomic profiles revealed that EGFR-mutant SCC patients had similar mutation characteristics to EGFR-mutant adenocarcinoma patients, but differed from those with EGFR wild-type SCC. Further exploration of EGFR-mutant SCC revealed that mutations in CREBBP (P = 0.005), ZNF217 (P = 0.016), and the Wnt (P = 0.027) pathway were negatively associated with PFS. Mutations in GRM8 (P = 0.025) were associated with improved PFS.

Conclusions

EGFR-mutant lung SCC has a worse prognosis than EGFR-mutant adenocarcinoma. Mutations in other genes, such as CREBBP, ZNF217, GRM8, or Wnt that had implications on PFS raise the possibility of understanding mechanisms of resistance to EGFR-TKI in lung SCC, which will aid identification of potential beneficial subgroups of patients with EGFR-mutant SCCs receiving EGFR-TKIs.

Discovery of Icotinib-1,2,3-Triazole Derivatives as IDO1 Inhibitors

Tumor immunotherapy is considered to be a highlight in cancer treatment in recent years. Indoleamine 2,3-dioxygenase 1 (IDO1) is closely related to the over expression of many cancers, and is therefore a promising target for tumor immunotherapy. To search for novel IDO1-targeting therapeutic agents, 22 icotinib-linked 1,2,3-triazole derivatives were prepared and evaluated for their inhibitory activity against IDO1. The structures of the prepared compounds were confirmed with¹H NMR, ¹³C NMR and HR MS. IDO1 inhibitory activity assay results indicated that 10 of those compounds showed remarkable inhibitory activity against IDO1, among which compound a17 was the most potent with IC₅₀value of 0.37 μM. The binding model between the prepared compounds and IDO1 was studied with molecular modeling study. The current study suggested that icotinib-1,2,3-triazole derivatives could be used as potential inhibitors that preferentially bind to the ferrous form of IDO1 through the formation of coordinate bond with the haem iron.

Icotinib: efficacy in different solid tumors and gene mutations

Icotinib is a first-generation inhibitor of epidermal growth factor receptor, which has been approved by the Chinese National Medical Products Administration, for the treatment of non-small cell lung cancer with epidermal growth factor receptor sensitive mutations. In addition, icotinib also shows moderate activity in other solid tumors driven by epidermal growth factor receptor, including non-small cell lung cancer with epidermal growth factor receptor rare non-resistant mutations, and esophageal cancer with epidermal growth factor receptor amplification or overexpression. This article reviews the efficacy of icotinib in different solid tumors with different epidermal growth factor receptor alterations.

Validated UPLC-MS/MS method for quantification of fruquintinib in rat plasma and its application to pharmacokinetic study

A new, simple, and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for quantification of fruquintinib was established to assess the pharmacokinetics of fruquintinib in the rat. The internal standard working solution was added to the plasma sample for extraction before analysis. The Acquity UPLC BEH C18 chromatography column (2.1 mm ×50 mm, 1.7 μm) was used to separated analytes under gradient elution using acetonitrile and 0.1% formic acid as the mobile phase. Positive multiple reaction monitoring modes were chosen to detect fruquintinib and diazepam (IS). The precursor-to-product ion transitions were 394.2 → 363.2 for fruquintinib and m/z 285 → 154 for IS. The current method was linear over the concentration range of 1.0-1000 ng/mL for fruquintinib with a correlation coefficient of 0.9992 or better. The matrix effect of fruquintinib and IS was acceptable under the current method. The intra- and interday precision (RSD%) and accuracy (RE%) were within 11.9% and ±13.7%, respectively. The recovery, stability, and sensitivity were validated according to the United States Food and Drug Administration (FDA) regulations for bioanalytical method validation. The analytical method had been validated and applied to a pharmacokinetic study of fruquintinib in rat.

Clinical characterization of icotinib-induced chemoresistance in erlotinib-treated lung adenocarcinoma patient with EGFR mutations: A case report

RATIONALE

Mounting evidences reveal that mutation of epidermal growth factor receptor (EGFR) may induce the resistance of tyrosine kinase inhibitors (TKIs). TKI-resistant lung cancer cells are sensitive to inhibition of the EGFR pathway. This case report aimed to characterize the therapeutic benefits of erlotinib, a targeted drug, on an advanced lung cancer patient with somatic EGFR mutation.

PATIENT CONCERNS

A 52-year-old non-smoking Chinese woman was suffered from pneumonia-based chest pains, and the patient was diagnosed as advanced lung cancer through medical imaging, thoracoscopy, and pathological examination.

DIAGNOSES

Blood tests, pathological examination, thoracoscopy, computed tomography (CT)/positron emission computed tomography (PET) scans, next-generation sequencing (NGS) testing were subjected to the patient's samples before and after targeted drug treatments.

INTERVENTIONS

After icotinib-induced resistance, the chemoresistance mechanism was involved in EGFR mutations before being prescribed with erlotinib.

OUTCOMES

The therapeutic effectiveness of icotinib for 4-month showed undetected carcinomatous metastasis. The lung tumor sizes were reduced, and improved quality of life (QOL) was described by the patient. Followed by monotherapy with erlotinib for 1.5-year, the icotinib-resistant patient benefited from longer survival rate without tumor enlargement and neoplastic metastasis. In therapeutic duration of erlotinib, T790M mutation of EGFR, R248W mutation of tumor protein p53 (TP53), K844S mutation of retinoblastoma protein 1 (RB1) were identified through NGS test.

LESSONS

In conclusion, the anti-cancer benefits of icotinib and erlotinib against advanced lung cancer may contribute to suppress neoplastic growth and metastasis. Further, erlotinib exerts potent efficacy for extended survival rate of patient because detectable mutations may not or limitedly induce erlotinib-resistance. In addition, reduced circulating hormones by menopause may enhance the therapeutic effectiveness of erlotinib.

Larger tumors are associated with inferior progression-free survival of first-line EGFR-tyrosine kinase inhibitors and a lower abundance of EGFR mutation in patients with advanced non-small cell lung cancer

BACKGROUND

The impact of primary tumor size on the therapeutic outcomes of EGFR-tyrosine kinase inhibitors (TKIs) in advanced non-small cell lung cancer (NSCLC) with EGFR mutation remains unclear.

METHODS

A total of 291 consecutive patients with advanced EGFR-mutant NSCLC administered first-line EGFR-TKIs were enrolled. Computed tomography was used to assess primary tumor diameter. The amplification refractory mutation system plus was used to quantitatively evaluate the abundance of EGFR mutations. Associations between depth of response, abundance of EGFR mutations, and tumor size was investigated.

RESULTS

Patients were divided into three groups according to T classification: ≤ 3 cm (n = 109), 3-5 cm (n = 121), and > 5 cm (n = 61). Median progression-free survival (PFS) was significantly longer in the ≤ 3 cm and 3-5 cm groups compared to the > 5 cm group (10.8 vs. 10.5 vs. 7.1 months; P < 0.001). Subgroup analysis revealed a consistent result in patients with exon 19 deletion and 21 L858R mutation. Multivariate analysis revealed that tumor size was an independent predictive factor for PFS (hazard ratio 1.528, 95% confidence interval 1.104-2.115; P = 0.010). Larger tumors (> 5 cm) were marginally significantly less EGFR-mutant abundant than smaller tumors (≤ 5 cm) (mean ± standard deviation 30.5 ± 29.5% vs. 45.8 ± 43.1%; P = 0.08).

CONCLUSION

Larger tumors (> 5 cm) were associated with inferior PFS of first-line EGFR-TKI therapy in advanced NSCLC patients with activating EGFR mutations. A potential explaination might be that EGFR mutations are less abundant in larger tumors.

Efficacy of icotinib in advanced lung squamous cell carcinoma

BACKGROUND

There are controversial data supporting the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in patients with advanced lung squamous cell carcinoma (SCC). In this study, the efficacy of icotinib in unselected and EGFR-mutated patients with lung SCC was assessed.

METHODS

We retrospectively analyzed the survival time of unselected advanced lung SCC patients treated with icotinib for at least 5 months between June 2013 and June 2016, and selected appropriate EGFR-mutated advanced lung ADC patients to have 1:1 ratio of propensity score matching with EGFR-mutated advanced lung SCC patients, and matching factors were age, sex, clinical stage, Karnofsky performance status (KPS), smoking history, EGFR mutation type, and treatment lines.

RESULTS

A total of 487 unselected advanced lung SCC patients were available for analysis of icotinib treatment efficacy. The progression-free survival (PFS) was 13.0 months (95% CI 12.2-13.8), the overall survival (OS) was 16.0 months (95% CI 14.7-17.3), and the objective response rate (ORR) was 41.3%. After propensity score matching, 78 EGFR-mutated lung SCC and 78 EGFR-mutated lung ADC patients were selected and compared. Although no statistical difference was found, ADC patients were associated with a longer PFS (15.8 months vs 12.7 months, P = 0.275) and OS (24.2 months vs 18.5 months, P = 0.150), and a better ORR (59.0% vs 48.7%, P = 0.199) than compared with SCC patients when treated with icotinib.

CONCLUSION

Icotinib has a modest therapeutic effect in patients with advanced lung SCC, especially for the population with EGFR mutations.