Continuation of gefitinib beyond progression in patients with EGFR mutation-positive non-small-cell lung cancer: A phase II single-arm trial

T790M mutation sensitizes non-small cell lung cancer cells to radiation via suppressing SPOCK1

Background

Approximately 50% of patients harbor the T790M mutation after developing first-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance. Evidence has showed the major treatment failure is local relapses and limited metastases. Several studies have demonstrated the value of radiotherapy in metastatic non-small cell lung cancer (NSCLC) with the EGFR T790M mutation after the development of TKI resistance. The aim of this study was to explore the role of radiation in T790M-mutant NSCLC and the value of early radiotherapy for NSCLC with T790M-mediated EGFR-TKI resistance.

Methods

Gefitinib-resistant NSCLC cell lines were established via stepwise exposure to increasing concentrations of gefitinib (PC-9-GR). Droplet digital PCR was used to determine the relative T790M subclone abundance. In vitro and in vivo models were established using different mixtures of PC-9-GR and PC-9 cells. Differentially expressed genes were identified using RNA sequencing. Two research models were constructed (salvage and prophylactic radiotherapy) to determine the effects of early radiotherapy on gefitinib-resistant cells.

Results

PC-9-GR cells exhibited higher radiosensitivity than PC-9 cells (sensitivity enhancement ratio = 1.5). Salvage radiation reduced the number of T790M-mutant subclones, and the relative T790M abundance was significantly lower than that without radiation at 90 days (10.94% vs. 21.54%). Prophylactic radiation prevented the development of T790M subclones. These results were also confirmed in vivo. qRT-PCR revealed threefold elevation of miR-1243 in PC-9-GR cells, and the increased radiosensitivity of PC-9-GR cells was inhibited when miR-1243 was knocked down. RNA sequencing revealed that SPOCK1 was downregulated in PC-9-GR cells. Interestingly, bioinformatic analysis showed that SPOCK1 was a target gene of miR-1243. SPOCK1 knockdown markedly increased the radiosensitivity of PC-9 cells.

Conclusion

Gefitinib-resistant NSCLC with the T790M mutation had higher radiosensitivity than that without the mutation, possibly mediated by SPOCK1. Early radiotherapy can eliminate T790M subclones, providing evidence for the benefit of early local treatment in patients with TKI-resistant NSCLC.

Cetuximab Treatment beyond Progression in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: A Nationwide Population-Based Study (THNS-2021-08)

BACKGROUND

Little is known regarding the association of cetuximab treatment beyond progression (TBP) with survival among patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). Although immune checkpoint inhibitors (ICIs) are now considered as first-line treatment, not all patients are suitable for ICIs.

OBJECTIVE

We conducted a multicenter, retrospective study to evaluate the role of cetuximab TBP in patients with R/M HNSCC after failure of first-line cetuximab-containing chemotherapy.

PATIENTS AND METHODS

Patients with R/M HNSCC who had tumor progression after first-line cetuximab-containing chemotherapy were included into our study. Oncologic outcomes were estimated including time to cetuximab treatment discontinuation (TTD), progression-free survival 2 (PFS2), overall survival (OS), overall response rate (ORR), and disease control rate (DCR). Multivariate cox regression analysis with survival were conducted. Subgroup analysis with P16 and programmed death ligand 1 expression were performed.

RESULTS

A total of 498 patients were eligible with 259 patients in the TBP group and 239 patients in the non-TBP group. The most common first-line chemotherapy was the EXTREME regimen in both groups. As for second-line treatment, the most common regimen were TPEx in the TBP group and taxane-based chemotherapy in the non-TBP group. Median TTD was 8.7 months in TBP and 5.5 months in non-TBP (p < 0.001). In terms of survival, median OS1 was significant longer in the TBP group than in the non-TBP group [14.1 months versus 10.9 months (p = 0.016)]. Multivariate analysis demonstrated cetuximab TBP was a factor independently associated with OS.

CONCLUSIONS

Our retrospective study suggests cetuximab TBP to be effective and to provide better survival for patients with R/M HNSCC after failure of first-line cetuximab-containing chemotherapy. Further prospective studies are warranted to validate the role of cetuximab TBP in R/M HNSCC.

A randomized phase II study of docetaxel or pemetrexed with or without the continuation of gefitinib after disease progression in elderly patients with non-small cell lung cancer harboring EGFR mutations (JMTO LC12-01)

BACKGROUND

Gefitinib (G) is a recommended molecular-targeted agent for elderly patients with epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). Docetaxel (Doc) and pemetrexed (Pem) have similar efficacies, and either is often used as the sole agent during treatment. The efficacy of continuing G after progressive disease (PD) develops has been reported. It remains unclear whether the continuation of G in combination with a single cytotoxic agent beyond PD is beneficial for elderly patients. Here, we conducted a randomized phase II study to assess the efficacy and safety of cytotoxic chemotherapy with G for elderly patients with progressive EGFR-mutant NSCLC.

METHODS

Elderly patients with EGFR-mutant NSCLC with PD previously treated with G were enrolled. Patients received Pem 500 mg/m or Doc 60 mg/m every 21 days and were randomly assigned to receive chemotherapy with 250 mg G (G+ Doc/Pem arm) or without G (Doc/Pem arm) until further disease progression or unacceptable toxicity.

RESULTS

This trial was terminated early owing to slow accrual. A group of 22 patients underwent analysis. The primary endpoint, progression-free survival (PFS), was significantly longer in the G + Doc/Pem arm (median: 1.6 months vs. 5.6 months, hazard ratio = 0.40, 95% CI: 0.16-0.99, p = 0.0391). Adverse events ≥ grade 3 were more frequent in the G + Doc/Pem arm (45.5% vs. 90.9%, p = 0.032).

CONCLUSIONS

Patients on G and Pem or Doc beyond PD showed a longer PFS than those on single-agent chemotherapy; however, it was associated with increased toxicity.

Treating disease progression with osimertinib in EGFR-mutated non-small-cell lung cancer: novel targeted agents and combination strategies

A precision medicine approach has been successfully applied in medical oncology for the treatment of non-small-cell lung cancer (NSCLC) through the identification of targetable driver molecular aberrations; activating mutations of epidermal growth factor receptor (EGFR) are the most common. Osimertinib, a third-generation, wild-type sparing, irreversible EGFR tyrosine kinase inhibitor (TKI), originally showed a striking activity after progression to first- and second-generation EGFR-TKIs when T790M resistance mutation was identified. Thereafter, upfront use of osimertinib became the standard of care based on overall survival benefit over first-generation TKIs erlotinib and gefitinib as reported in the FLAURA trial. For patients progressing on osimertinib, identification of resistance mechanisms is crucial to develop novel targeted therapeutic approaches. Moreover, innovative drugs or combination therapies are being developed for cases in which a specific resistance mechanism is not identifiable. In this review, the post-osimertinib treatment options for EGFR-mutated NSCLC are analyzed, with an outlook to ongoing clinical trials. An algorithm to guide clinicians in managing progression on osimertinib is proposed.

Reporting of Incidence and Outcome of Bone Metastases in Clinical Trials Enrolling Patients with Epidermal Growth Factor Receptor Mutated Lung Adenocarcinoma-A Systematic Review

Bone metastases, occurring in 30-60% of patients with non-small cell lung cancer (NSCLC), are associated with decreased survival, cancer-induced bone pain, and skeletal-related events (SREs). Those with an activating epidermal growth factor mutation (EGFR+) seem to be more prone to develop bone metastases. To gain more insight into bone metastases-related outcomes in EGFR+ NSCLC, we performed a systematic review on Pubmed (2006-2021). Main inclusion criteria: prospective, phase II/III trials evaluating EGFR-tyrosine kinase inhibitors, ≥10 EGFR+ patients included, data on bone metastases and/or bone-related outcomes available. Out of 663 articles, 21 (3176 EGFR+ patients) met the eligibility criteria; 4 phase III (one double blind), 17 phase II trials (three randomized) were included. In seven trials dedicated bone imaging was performed at baseline. Mean incidence of bone metastases at diagnosis was 42%; 3-33% had progression in the bone upon progression. Except for one trial, it was not specified whether the use of bone target agents was permitted, and in none of the trials, occurrence of SREs was reported. Despite the high incidence of bone metastases in EGFR+ adenocarcinoma, there is a lack of screening for, and reporting on bone metastases in clinical trials, as well as permitted bone-targeted agents and SREs.

Continued gefitinib retreatment beyond progression in patients with advanced non-small cell lung cancer harboring sensitive EGFR mutations

PURPOSE

To evaluate the effectiveness and safety of gefitinib retreatment beyond disease progression in patients with advanced non-small cell lung cancer (NSCLC) with sensitive epidermal growth factor receptor (EGFR) mutations.

METHODS

Data from patients with stage III/IV NSCLC were analyzed retrospectively. Patients with sensitive EGFR mutations received first-line treatment with gefitinib followed by retreatment with gefitinib after disease progression. Progression-free survival (PFS) after the first treatment (PFS-1) was defined as the time to progression or death using the Response Evaluation Criteria in Solid Tumors criteria (RECIST) v1.1 criteria. The second PFS (PFS-2) was defined as the interval between the first and second progressions, at the investigator's discretion. Toxicities were recorded in accordance with the National Cancer Institute (NCI)-Common Terminology Criteria (CTC) version 4.0.

RESULTS

Sixteen patients aged 53 to 80 years (median 66 years) were included in the analysis. The median PFS-1 and PFS-2 were 10.0 months and 14.0 months, respectively. The median overall survival (OS) was 36.0 months. No toxicity of grade 3 or worse was observed.

CONCLUSIONS

Our findings suggest that gefitinib retreatment beyond disease progression may be an effective and tolerable approach for NSCLC patients with sensitive EGFR mutations.

Treatment of advanced non-small-cell lung cancer: The 2019 AIOM (Italian Association of Medical Oncology) clinical practice guidelines

The Italian Association of Medical Oncology (AIOM) has developed clinical practice guidelines for the treatment of patients with advanced non-small cell lung cancer (NSCLC). In the current paper a panel of AIOM experts in the field of thoracic malignancies discussed the available scientific evidences, with the final aim of providing a summary of clinical recommendations, which may guide physicians in their current practice.

Epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small cell lung cancer

Introduction: Epidermal growth factor receptor (EGFR) mutations are well-described drivers of non-small cell lung cancer (NSCLC) and EGFR tyrosine kinase inhibitors (TKIs) have become key components of the NSCLC front-line treatment landscape. Tumors inevitably develop resistance to these agents, and development efforts continue to focus on identifying mechanisms of resistance and drugs to target these mechanisms. Areas covered: With several EGFR TKIs approved for use in the first-line or in later-line settings, an understanding of the efficacy and safety of these inhibitors in various populations is warranted. Furthermore, given the frequent emergence of drug resistance in NSCLC, examination of tumor tissue throughout the disease course provides the opportunity to select treatments based on the tumor's mutation profile. Here, we discuss: key efficacy and safety findings for approved and investigational EGFR TKIs; known mechanisms of resistance, particularly the T790M acquired EGFR mutation; and recent advances in EGFR mutational testing that may facilitate less invasive tissue testing and guide treatment selection. Expert commentary: The expanding armamentarium of EGFR TKIs, improvements in the understanding of resistance mechanisms and technological developments in the molecular analysis of tumors may help render EGFR mutation-positive NSCLC a chronic disease in many patients by facilitating optimal sequential therapy.

Pan-Asian adapted Clinical Practice Guidelines for the management of patients with metastatic non-small-cell lung cancer: a CSCO-ESMO initiative endorsed by JSMO, KSMO, MOS, SSO and TOS

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of metastatic non-small-cell lung cancer (NSCLC) was published in 2016. At the ESMO Asia Meeting in November 2017 it was decided by both ESMO and the Chinese Society of Clinical Oncology (CSCO) to convene a special guidelines meeting immediately after the Chinese Thoracic Oncology Group Annual Meeting 2018, in Guangzhou, China. The aim was to adapt the ESMO 2016 guidelines to take into account the ethnic differences associated with the treatment of metastatic NSCLC cancer in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with metastatic NSCLC representing the oncological societies of China (CSCO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence, and was independent of both the current treatment practices and the drug availability and reimbursement situations in the six participating Asian countries. During the review process, the updated ESMO 2018 Clinical Practice Guidelines for metastatic NSCLC were released and were also considered, during the final stages of the development of the Pan-Asian adapted Clinical Practice Guidelines.

Impact on prognosis of rebiopsy in advanced non-small cell lung cancer patients after epidermal growth factor receptor-tyrosine kinase inhibitor treatment: a systematic review

Background

Osimertinib, the third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has become the standard treatment in cases where rebiopsy reveals T790M mutation after the first-line EGFR-TKI treatment. However, the prognosis of patients after rebiopsy, the most important outcome for cancer patients, has not been described sufficiently. This systematic review aimed to clarify whether rebiopsy contributes to improved prognosis in the first- or second-generation EGFR-TKI refractory patients.

Methods

Using free word and control terms related to “non-small cell lung cancer” and “rebiopsy,” we searched studies from Medical Literature Analysis and Retrieval System Online via PubMed, Embase, Cochrane Central Register of Controlled Trials, and World Health Organization International Clinical Trials Registry Platform. We included cohort studies and case reports written in English and judged whether each study answers our research questions.

Results

Of the 144 studies included, only one reported the prognosis of patients with/without rebiopsy showing that in EGFR-TKI refractory non-small cell lung cancer patients, the post-progression survival (PPS) was significantly longer in patients who received rebiopsy and treatment based on a resistant mechanism (median PPS 24.2 months) than those who received rebiopsy and salvage regimen (median PPS 15.2 months, p = 0.002) and who did not receive rebiopsy (median PPS 9.7 months, p < 0.001). Most of the other studies reported the detection rate of T790M mutation or rebiopsy procedure.

Conclusions

Only a few previous studies have investigated the effectiveness of rebiopsy. Hence, further study is needed to determine the prognosis or adverse events of rebiopsy.