Trastuzumab and paclitaxel in patients with EGFR mutated NSCLC that express HER2 after progression on EGFR TKI treatment.

BACKGROUND: HER2 expression and amplification are observed in ~15% of tumour biopsies from patients with a sensitising EGFR mutation who develop EGFR TKI resistance. It is unknown whether HER2 targeting in this setting can result in tumour responses. METHODS: A single arm phase II study was performed to study the safety and efficacy of trastuzumab and paclitaxel treatment in patients with a sensitising EGFR mutation who show HER2 expression in a tumour biopsy (IHC ≥ 1) after progression on EGFR TKI treatment. Trastuzumab (first dose 4 mg/kg, thereafter 2 mg/kg) and paclitaxel (60 mg/m2) were dosed weekly until disease progression or unacceptable toxicity. The primary end-point was tumour response rate according to RECIST v1.1. RESULTS: Twenty-four patients were enrolled. Nine patients were exon 21 L858R positive and fifteen exon 19 del positive. Median HER2 IHC was 2+ (range 1-3). For 21 patients, gene copy number by in situ hybridisation could be calculated: 5 copies/nucleus (n = 9), 5-10 copies (n = 8), and >10 copies (n = 4). An objective response was observed in 11/24 (46%) patients. Highest response rates were seen for patients with 3+ HER2 IHC (12 patients, ORR 67%) or HER2 copy number ≥10 (4 patients, ORR 100%). Median tumour change in size was 42% decrease (range -100% to +53%). Median duration of response was 5.6 (95% confidence interval [CI], 3.8 to 7.3) months. Treatment toxicity was mild with four patients experiencing grade ≥3 toxicity, including fatigue, neuropathy, neutropaenia, urinary tract infection, and pneumonitis. CONCLUSIONS: Trastuzumab-paclitaxel induces objective tumour responses in 46% of EGFR TKI pretreated patients with an activating EGFR mutation and HER2 expression. The treatment was well tolerated. The relation between response rate and HER2 expression level and copy number suggests effective HER2 targeting by trastuzumab, although the combination with paclitaxel does not allow to determine the relative contribution of the individual drugs in terms of treatment efficacy.

Rearranged EML4-ALK fusion transcripts sequester in circulating blood platelets and enable blood-based crizotinib response monitoring in non-small-cell lung cancer.

PURPOSE: Non-small-cell lung cancers harboring EML4-ALK rearrangements are sensitive to crizotinib. However, despite initial response, most patients will eventually relapse, and monitoring EML4-ALK rearrangements over the course of treatment may help identify these patients. However, challenges associated with serial tumor biopsies have highlighted the need for blood-based assays for the monitoring of biomarkers. Platelets can sequester RNA released by tumor cells and are thus an attractive source for the non-invasive assessment of biomarkers. METHODS: EML4-ALK rearrangements were analyzed by RT-PCR in platelets and plasma isolated from blood obtained from 77 patients with non-small-cell lung cancer, 38 of whom had EML4-ALK-rearranged tumors. In a subset of 29 patients with EML4-ALK-rearranged tumors who were treated with crizotinib, EML4-ALK rearrangements in platelets were correlated with progression-free and overall survival. RESULTS: RT-PCR demonstrated 65% sensitivity and 100% specificity for the detection of EML4-ALK rearrangements in platelets. In the subset of 29 patients treated with crizotinib, progression-free survival was 3.7 months for patients with EML4-ALK+ platelets and 16 months for those with EML4-ALK- platelets (hazard ratio, 3.5; P = 0.02). Monitoring of EML4-ALK rearrangements in the platelets of one patient over a period of 30 months revealed crizotinib resistance two months prior to radiographic disease progression. CONCLUSIONS: Platelets are a valuable source for the non-invasive detection of EML4-ALK rearrangements and may prove useful for predicting and monitoring outcome to crizotinib, thereby improving clinical decisions based on radiographic imaging alone.

Treatment and survival of patients with EGFR-mutated non-small cell lung cancer and leptomeningeal metastasis: A retrospective cohort analysis.

OBJECTIVES: Development of leptomeningeal metastasis (LM) in non-small cell lung cancer (NSCLC)-patients is associated with a poor prognosis. It has been suggested that LM-patients with epidermal growth factor receptor mutated (EGFR+) NSCLC have a superior prognosis compared to EGFR-wild type NSCLC. Studies in EGFR+ NSCLC-patients with LM are scarce. We retrospectively evaluated a multi-institutional cohort of EGFR+ NSCLC-patients for LM to assess clinical outcome in relation to patient characteristics and treatment modalities. MATERIAL AND METHODS: Medical records of advanced-stage EGFR+ NSCLC-patients (diagnosed between August 2000 and June 2014) from 11 Dutch hospitals were evaluated for LM as diagnosed by MRI and/or cytopathological liquor analysis. Data on patient characteristics, treatment and outcome were collected. RESULTS: Thirty-two of 356 (9.0%) advanced-stage EGFR+ NSCLC-patients (median follow-up 21.0 months), were diagnosed with LM between 2006 and 2014. LM was diagnosed by MRI (59.4%), liquor analysis (9.4%) or by both MRI and liquor analysis (31.3%). Median survival after LM-diagnosis was 3.1 months (95% CI: 0.0-7.3). Six- and 12-month survival rates were 43.8% and 18.8%, respectively. Patients with performance status (PS) 0-1 at time of diagnosis of LM had a significantly higher chance to be alive after 6 months and had a significantly longer survival after diagnosis of LM compared to patients with PS≥2. Age, treatment with high-dose EGFR-TKI, radiotherapy and whether LM was the only site of progressive disease did not influence survival after LM-diagnosis. CONCLUSION: Although median survival after LM-diagnosis in EGFR-mutated NSCLC-patients was poor, a substantial part of the patients had a prolonged survival of more than 6 months. PS of 0-1 at time of diagnosis of LM was associated with prolonged survival. No other patient- or treatment-related characteristics were identified. Further research is warranted to identify treatment strategies that improve survival in EGFR+ NSCLC-patients with LM.

Detecting resistance in EGFR-mutated non-small-cell lung cancer after clonal selection through targeted therapy.

Tumor heterogeneity plays an important role in the development of treatment-resistance, especially in the current era of targeted therapies. Although tumor heterogeneity is a widely recognized phenomenon, it is at present unclear how this knowledge should be incorporated into daily clinical practice. In this report, we describe an innovative nuclear imaging method that may play a role in detecting tumor heterogeneity in the future.

Rationale and study design of the IRENE-trial (NVALT-16): a phase II trial to evaluate iressa rechallenge in advanced NSCLC patients with an activating EGFR mutation who responded to an EGFR-TKI used as first-line or previous treatment.

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown improved progression-free survival (PFS) and overall survival (OS) over chemotherapy in a molecularly defined subgroup of advanced non-small-cell lung cancer (NSCLC) patients (ie, patients with an activating mutation in the EGFR gene). Nevertheless, all EGFR-mutated NSCLC patients develop TKI resistance eventually and there is no registered treatment or therapeutic strategy available for these patients. Several retrospective or small cohort studies have described patients who re-responded to EGFR-TKI treatment after a TKI-free interval ('drug holiday'). To date, no large prospective evaluation of the clinical effects of EGFR-TKI rechallenge in EGFR-mutated NSCLC patients has been performed. PATIENTS AND METHODS: The IRENE (Iressa RE-challenge in advanced, EGFR-mutated NSCLC patients who responded to an EGFR-TKI used as first-line or previous treatment) (Dutch association for pulmonologists [NVALT]-16) trial is a multicenter, open-label, single-arm, single-stage, phase II study to evaluate gefitinib rechallenge in EGFR-mutated NSCLC patients who were previously treated with a TKI followed by a subsequent line of treatment (excluding EGFR-TKIs). The primary objective is disease control rate according to Response Evaluation Criteria in Solid Tumors criteria. Secondary objectives are objective response rate, PFS, OS, mutation characterization of sequential biopsies, VeriStrat correlation to PFS and OS, analysis of tumor-derived RNA in blood platelets and analysis of cell-free DNA in blood plasma. RESULTS: The IRENE (NVALT-16) trial will evaluate the safety, efficacy, and feasibility of readministration of gefitinib after an EGFR-TKI-free interval in EGFR-mutated NSCLC patients. CONCLUSION: The study will evaluate gefitinib re-challenge in EGFR-mutated NSCLC patients. The study will also provide more insight into the dynamic development of molecular characteristics of EGFR-mutated NSCLC along the course of the disease.

Challenges in the management of EGFR-mutated non-small cell lung cancer patients with acquired resistance to tyrosine kinase inhibitors.

Non-small cell lung cancer (NSCLC) patients with an epidermal growth factor receptor (EGFR) mutation have a median progression-free survival of 12 months on treatment with tyrosine kinase inhibitors (TKIs). Clearly, the introduction of these agents had major implications for the treatment of NSCLC, but new questions and challenges arise as well. Traditionally, response assessments of anti-cancer treatment are conducted according to the RECIST criteria. Progressive disease is usually indicative of a change of therapy. In the current era of targeted therapies, it has become clear that different patterns of progressive disease are observed with TKI treatment in EGFR-mutated NSCLC patients, with potential consequences for therapeutic decision-making. In this review, we will discuss whether the RECIST criteria are still optimal for response evaluation. Rebiopsy studies have provided more insight into different resistance mechanisms at the time of acquired resistance to TKIs. These mechanisms, as well as the role of rebiopsy in daily clinical practice, will subsequently be covered. Finally, treatment strategies for different types of progressive disease will be discussed.