Targeted Therapies for Lung Cancer Patients With Oncogenic Driver Molecular Alterations

Lung cancer has traditionally been classified by histology. However, a greater understanding of disease biology and the identification of oncogenic driver alterations has dramatically altered the therapeutic landscape. Consequently, the new classification paradigm of non-small-cell lung cancer is further characterized by molecularly defined subsets actionable with targeted therapies and the treatment landscape is becoming increasingly complex. This review encompasses the current standards of care for targeted therapies in lung cancer with driver molecular alterations. Targeted therapies for EGFR exon 19 deletion and L858R mutations, and ALK and ROS1 rearrangements are well established. However, there is an expanding list of approved targeted therapies including for BRAF V600E, EGFR exon 20 insertion, and KRAS G12C mutations, MET exon 14 alterations, and NTRK and RET rearrangements. In addition, there are numerous other oncogenic drivers, such as HER2 exon 20 insertion mutations, for which there are emerging efficacy data for targeted therapies. The importance of diagnostic molecular testing, intracranial efficacy of novel therapies, the optimal sequencing of therapies, role for targeted therapies in early-stage disease, and future directions for precision oncology approaches to understand tumor evolution and therapeutic resistance are also discussed.

Icotinib versus chemotherapy as adjuvant treatment for stage II-IIIA EGFR-mutant non-small-cell lung cancer (EVIDENCE): a randomised, open-label, phase 3 trial

BACKGROUND

Icotinib has provided survival benefits for patients with advanced, epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC). We aimed to compare icotinib with chemotherapy in patients with EGFR-mutant stage II-IIIA NSCLC after complete tumour resection. Here, we report the results from the preplanned interim analysis of the study.

METHODS

In this multicentre, randomised, open-label, phase 3 trial done at 29 hospitals in China, eligible patients were aged 18-70 years, had histopathogically confirmed stage II-IIIA NSCLC, had complete resection up to 8 weeks before random assignment, were treatment-naive, and had confirmed activation mutation in exon 19 or exon 21 of the EGFR gene. Participants were randomly assigned (1:1) with an interactive web-based response system to receive either oral icotinib 125 mg thrice daily for 2 years or four 21-day cycles of intravenous chemotherapy (vinorelbine 25 mg/m² on days 1 and 8 of each cycle plus cisplatin 75 mg/m² on day 1 of each cycle for adenocarcinoma or squamous carcinoma; or pemetrexed 500 mg/m² plus cisplatin 75 mg/m² on day 1 every 3 weeks for non-squamous carcinoma). The primary endpoint was disease-free survival assessed in the full analysis set. Secondary endpoints were overall survival assessed in the full analysis set and safety assessed in all participants who received study drug. This trial is registered with ClinicalTrials.gov, NCT02448797.

FINDINGS

Between June 8, 2015, and August 2, 2019, 322 patients were randomly assigned to icotinib (n=161) or chemotherapy (n=161); the full analysis set included 151 patients in the icotinib group and 132 in the chemotherapy group. Median follow-up in the full analysis set was 24·9 months (IQR 16·6-36·4). 40 (26%) of 151 patients in the icotinib group and 58 (44%) of 132 patients in the chemotherapy group had disease relapse or death. Median disease-free survival was 47·0 months (95% CI 36·4-not reached) in the icotinib group and 22·1 months (16·8-30·4) in the chemotherapy group (stratified hazard ratio [HR] 0·36 [95% CI 0·24-0·55]; p<0·0001). 3-year disease-free survival was 63·9% (95% CI 51·8-73·7) in the icotinib group and 32·5% (21·3-44·2) in the chemotherapy group. Overall survival data are immature with 14 (9%) deaths in the icotinib group and 14 (11%) deaths in the chemotherapy. The HR for overall survival was 0·91 (95% CI 0·42-1·94) in the full analysis set. Treatment-related serious adverse events occurred in two (1%) of 156 patients in the icotinib group and 19 (14%) of 139 patients in the chemotherapy group. No interstitial pneumonia or treatment-related death was observed in either group.

INTERPRETATION

Our results suggest that compared with chemotherapy, icotinib significantly improves disease-free survival and has a better tolerability profile in patients with EGFR-mutant stage II-IIIA NSCLC after complete tumour resection.

FUNDING

Betta Pharmaceuticals TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Adjuvant Chemotherapy

Five-year survival rates for patients with early-stage non-small cell lung cancer have room for improvement. Adjuvant chemotherapy results in a small but significant increase in overall survival at 5 years. Efforts to improve outcomes by intensifying adjuvant treatment, utilizing cancer-specific vaccines or tyrosine kinase inhibitors in unselected patients, have been unsuccessful. In addition to research with immune checkpoint inhibitors that are addressed in a separate article, ongoing studies to personalize adjuvant therapy either by selecting only patients with evidence of minimal residual disease or targeting tumor driver mutations are promising.

Epidermal growth factor receptor tyrosine kinase inhibitors in early-stage nonsmall cell lung cancer

PURPOSE OF REVIEW

Targeted molecular therapy is playing an increasingly important role in the treatment of nonsmall cell lung cancer (NSCLC). Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated efficacy in the advanced disease setting. Preliminary findings suggest that EGFR-TKIs may also be beneficial as adjuvant therapy following complete resection in patients with EGFR-mutation-positive early-stage I-III NSCLC; however, many questions remain unanswered.

RECENT FINDINGS

Single-arm trials of adjuvant EGFR-TKI therapy in patients with tumors harboring activating EGFR mutations show impressive 2-year disease-free survival (DFS). Phase III randomized trial data do not support adjuvant EGFR-TKI therapy in unselected completely resected stage I-III NSCLC, but show improved DFS in patients with completely resected EGFR-mutated NSCLC. Adverse events leading to treatment withdrawal and dose reductions are frequent with adjuvant EGFR-TKI therapy, and relapse following treatment withdrawal is common. Adjuvant EGFR-TKIs have not yet been shown to improve the overall survival (OS) in patients with tumors harboring activating EGFR mutations.

SUMMARY

There are no data to support the use of adjuvant EGFR-TKIs in unselected early-stage NSCLC. Although EGFR-TKIs hold promise as adjuvant therapy in patients whose tumors harbor EGFR mutations, in the absence of definitive data confirming an OS benefit eligible patients should continue to receive adjuvant chemotherapy following complete resection.