NSCLC and HER2: between lights and shadows

Lung Cancer Biomarkers

The molecular characterization of lung cancer has changed the classification and treatment of these tumors, becoming an essential component of pathologic diagnosis and oncologic therapy decisions. Through the recognition of novel biomarkers, such as epidermal growth factor receptor mutations and anaplastic lymphoma kinase translocations, it is possible to identify subsets of patients who benefit from targeted molecular therapies. The success of targeted anticancer therapies and new immunotherapy approaches has created a new paradigm of personalized therapy and has led to accelerated development of new drugs for lung cancer treatment. This article focuses on clinically relevant cancer biomarkers as targets for therapy and potential new targets for drug development.

HER2 overexpression reverses the relative resistance of EGFR-mutant H1975 cell line to gefitinib

Gefitinib is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) that has been demonstrated to be clinically useful for the treatment of patients with non-small cell lung cancer (NSCLC). However, ~50% of patients do not respond to EGFR TKI treatment through the emergence of mutations, such as T790M. Therefore, it is important to determine which patients are eligible for treatment with gefitinib. As a preferred dimerization partner for EGFR, the role of EGFR 2 (HER2) in mediating sensitivity to gefitinib is poorly understood. In the present study, full-length human HER2 cDNA was introduced to the NSCLC cell lines H1975 and H1299, which have a low endogenous expression level of HER2. In addition, it was observed in the present study that the H1975 cell line harbored the L858R and T790M mutations in the EGFR kinase domain. Western blot analysis and MTT assay were used to evaluate the TKI sensitivity of HER2 expression status, and the activation of HER3 and HER2 downstream effectors. The results indicated that the sensitivity of H1975 cells to gefitinib was restored by the overexpression of HER2, which stimulated HER2-driven signaling cascades accompanied by the activation of protein kinase B. By contrast, ectopic HER2 overexpression in H1299 cells did not significantly alter the sensitivity to gefitinib treatment. In conclusion, the current study results suggested that the relatively resistance of the H1975 cell line to gefitinib could be reversed by the overexpression of HER2. Therefore, the expression of HER2 could also be considered when evaluate the patients' potential response to gefitinib, particularly in the subgroup of lung cancer patients who harbor an EGFR mutation.

Long time response with chemotherapy in ROS1 NSCLC patient with unusual metastatic site

During the last decade the therapeutic landscape of Non Small Cell Lung Cancer (NSCLC) has profoundly changed with the identification of actionable genetic alterations that defined molecularly selected subgroups of patients with specific clinic-pathological characteristics and increased sensitivity to specific targeted agents. The presence of ROS1 rearrangements defines a small subgroup of lung adenocarcinomas (∼1-2%) with peculiar clinic-pathological characteristics and increased sensitivity to Crizotinib. It has been reported that ROS1-tranlslocated NSCLCs may also respond well to Pemetrexed-based chemotherapy. Moreover, patients with oncogene-addicted NSCLC may present peculiar pattern of metastatization and, in some instances, are associated with unusual site of metastases. Herein, we present a case of a young woman with bilateral ovarian metastases from a ROS1-positive adenocarcinoma of the lung with a lengthy progression-free survival on Pemetrexed-containing chemotherapy.

A decade of EGFR inhibition in EGFR-mutated non small cell lung cancer (NSCLC): Old successes and future perspectives

The discovery of Epidermal Growth Factor Receptor (EGFR) mutations in Non Small Cell Lung Cancer (NSCLC) launched the era of personalized medicine in advanced NSCLC, leading to a dramatic shift in the therapeutic landscape of this disease. After ten years from the individuation of activating mutations in the tyrosine kinase domain of the EGFR in NSCLC patients responding to the EGFR tyrosine kinase inhibitor (TKI) Gefitinib, several progresses have been done and first line treatment with EGFR TKIs is a firmly established option in advanced EGFR-mutated NSCLC patients. During the last decade, different EGFR TKIs have been developed and three inhibitors have been approved so far in these selected patients. However, despite great breakthroughs have been made, treatment of these molecularly selected patients poses novel therapeutic challenges, such as emerging of acquired resistance, brain metastases development or the need to translate these treatments in earlier clinical settings, such as adjuvant therapy.

The aim of this paper is to provide a comprehensive review of the major progresses reported so far in the EGFR inhibition in this molecularly-selected subgroup of NSCLC patients, from the early successes with first generation EGFR TKIs, Erlotinib and Gefitinib, to the novel irreversible and mutant-selective inhibitors and ultimately the emerging challenges that we, in the next future, are called to deal with.

Clinicopathologic Characteristics of Patients with HER2 Insertions in Non-small Cell Lung Cancer

BACKGROUND

The human epidermal growth factor receptor-2 (HER2) genes have been described in a subset of non-small cell lung cancer (NSCLC). To help identify and treat these patients, we investigated the frequency, clinicopathologic characteristics, and clinical outcomes of patients who had NSCLC with or without HER2 insertions.

METHODS

The mutational status of the HER2 (exons 19-20) gene was assessed in a cohort of 1875 patients with NSCLC. All patients were also analyzed for mutations in EGFR, KRAS, BRAF, ALK, RET, and ROS1. Clinical characteristics, including age, sex, smoking status, stage, histology, tumor size, differentiation, overall survival, and relapse-free survival, were collected.

RESULTS

Among 1875 NSCLCs examined, 35 (1.9 %) were HER2 insertion. Compared with the HER2 insertion-negative group, patients with HER2 insertions were more likely to be never smokers (97.1 %, 34/35 patients, P < 0.001), significantly associated with female (91.4 %, 32/35 patients, P < 0.001), adenocarcinoma (91.4 %, 32/35 patients, P = 0.01), and with a tendency to be no more than 60 years of age (71.4 %, 25/35 patients, P = 0.051).

CONCLUSIONS

HER2 insertion could define a distinct subset of NSCLC, which had a higher prevalence among females, nonsmokers, and adenocarcinoma. HER2 should be in the clinical genotyping of lung cancer, so patients may benefit from HER2-targeted therapy.

Targeting HER2 aberrations as actionable drivers in lung cancers: phase II trial of the pan-HER tyrosine kinase inhibitor dacomitinib in patients with HER2-mutant or amplified tumors

BACKGROUND

HER2 mutations and amplifications have been identified as oncogenic drivers in lung cancers. Dacomitinib, an irreversible inhibitor of HER2, EGFR (HER1), and HER4 tyrosine kinases, has demonstrated activity in cell-line models with HER2 exon 20 insertions or amplifications. Here, we studied dacomitinib in patients with HER2-mutant or amplified lung cancers.

PATIENTS AND METHODS

As a prespecified cohort of a phase II study, we included patients with stage IIIB/IV lung cancers with HER2 mutations or amplification. We gave oral dacomitinib at 30-45 mg daily in 28-day cycles. End points included partial response rate, overall survival, and toxicity.

RESULTS

We enrolled 30 patients with HER2-mutant (n = 26, all in exon 20 including 25 insertions and 1 missense mutation) or HER2-amplified lung cancers (n = 4). Three of 26 patients with tumors harboring HER2 exon 20 mutations [12%; 95% confidence interval (CI) 2% to 30%] had partial responses lasting 3+, 11, and 14 months. No partial responses occurred in four patients with tumors with HER2 amplifications. The median overall survival was 9 months from the start of dacomitinib (95% CI 7-21 months) for patients with HER2 mutations and ranged from 5 to 22 months with amplifications. Treatment-related toxicities included diarrhea (90%; grade 3/4: 20%/3%), dermatitis (73%; grade 3/4: 3%/0%), and fatigue (57%; grade 3/4: 3%/0%). One patient died on study likely due to an interaction of dacomitinib with mirtazapine.

CONCLUSIONS

Dacomitinib produced objective responses in patients with lung cancers with specific HER2 exon 20 insertions. This observation validates HER2 exon 20 insertions as actionable targets and justifies further study of HER2-targeted agents in specific HER2-driven lung cancers.

CLINICALTRIALSGOV

NCT00818441.