Evaluation of EGFR protein expression by immunohistochemistry using H-score and the magnification rule: Re-analysis of the SATURN study

AbstractIntroductionThe phase III SATURN study demonstrated that first-line maintenance erlotinib extended progression-free survival (PFS) and overall survival (OS) versus placebo in patients with advanced non-small cell lung cancer (NSCLC). Analysis of epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) found no significant interaction between EGFR IHC status and PFS (p=0.63) or OS (p=0.52). The FLEX study of first-line cetuximab plus chemotherapy demonstrated that EGFR IHC expression was predictive of improved OS with cetuximab when assessed by H-score with a magnification rule. This novel method was used to reassess samples from SATURN.MethodsThe H-score method assigned a score of 0–300 to each patient, based on the percentage of cells stained at different intensities viewed at various magnifications. The discriminatory threshold was set at 200, per the FLEX study, and existing samples were re-read and classed as low (H-score<200) or high (≥200) EGFR expression. PFS and OS were re-analyzed based on these new classifications.ResultsIn the overall and EGFR wild-type populations, erlotinib provided a consistent survival benefit versus placebo. Hazard ratios (HRs) in the overall population were similar between EGFR IHC-positive and -negative patients for median PFS (HR 0.68 [95% confidence interval (CI) 0.53–0.86] and 0.76 [95% CI 0.62–0.93], respectively) and OS (HR 0.80 [95% CI 0.62–1.05] and 0.80 [95% CI 0.64–1.01] for IHC-positive and IHC-negative, respectively). In the EGFR wild-type population, HRs were again similar between EGFR IHC-positive and -negative subpopulations for PFS (HR 0.69 [95% CI 0.51–0.95] and 0.84 [95% CI 0.63–1.12], respectively) and OS (HR 0.78 [95% CI 0.55–1.10] and 0.76 [95% CI 0.55–1.05], respectively).ConclusionsThese data suggest that EGFR IHC does not have value as a marker to predict erlotinib benefit in the first-line maintenance setting for advanced NSCLC

Neoadjuvant Targeted Therapy in Resectable NSCLC: Current and Future Perspectives.

The standard of care (SoC) for medically operable patients with early-stage (stages I-IIIB) NSCLC is surgery combined with (neo)adjuvant systemic therapy for patients with stages II to IIIB disease and some stage IB or, rarely, chemoradiation (stage III disease with mediastinal lymph node metastases). Despite these treatments, metastatic recurrence is common and associated with poor survival, highlighting the need for systemic therapies that are more effective than the current SoC. After the success of targeted therapy (TT) in patients with advanced NSCLC harboring oncogenic drivers, these agents are being investigated for the perioperative (neoadjuvant and adjuvant) treatment of patients with early-stage NSCLC. Adjuvant osimertinib is the only TT approved for use in the early-stage setting, and there are no approved neoadjuvant TTs. We discuss the importance of comprehensive biomarker testing at diagnosis to identify individuals who may benefit from neoadjuvant targeted treatments and review emerging data from neoadjuvant TT trials. We also address the potential challenges for establishing neoadjuvant TTs as SoC in the early-stage setting, including the identification and validation of early response markers to guide care and accelerate drug development, and discuss safety considerations in the perioperative setting. Initial data indicate that neoadjuvant TTs are effective and well tolerated in patients with EGFR- or ALK-positive early-stage NSCLC. Data from ongoing trials will determine whether neoadjuvant targeted agents will become a new SoC for individuals with oncogene-addicted resectable NSCLC

IMpower150 Final Exploratory Analyses for Atezolizumab Plus Bevacizumab and Chemotherapy in Key NSCLC Patient Subgroups With EGFR Mutations or Metastases in the Liver or Brain

Introduction: Final overall survival (OS) analyses are presented for EGFR mutations and liver or brain metastases subgroups in the phase 3 IMpower150 study (NCT02366143) evaluating atezolizumab plus bevacizumab plus carboplatin and paclitaxel (ABCP) or atezolizumab plus carboplatin and paclitaxel (ACP) versus bevacizumab plus carboplatin and paclitaxel (BCP). Methods: Overall, 1202 patients (intention-to-treat population) with chemotherapy-naive, metastatic, nonsquamous NSCLC were randomized to ABCP, ACP, or BCP. Patients with treated, stable brain metastases were permitted. OS was evaluated in EGFR mutations and baseline liver metastases subgroups; rate and time to development of new brain metastases were evaluated in the intention-to-treat patients. Results: At data cutoff (September 13, 2019; median follow-up, 39.3 mo), OS improvements were sustained with ABCP versus BCP in sensitizing EGFR mutations (all: hazard ratio [HR] = 0.60; 95% confidence interval [CI]: 0.31–1.14; previous tyrosine kinase inhibitor [TKI]: HR = 0.74; 95% CI: 0.38–1.46) and baseline liver metastases (HR = 0.68; 95% CI: 0.45–1.02) subgroups. ACP did not have survival benefit versus BCP in sensitizing EGFR mutations (all: HR = 1.0; 95% CI: 0.57–1.74; previous TKI: HR = 1.22; 95% CI: 0.68–2.22) or liver metastases (HR = 1.01; 95% CI: 0.68–1.51) subgroups. Overall, 100 patients (8.3%) developed new brain metastases. Although not formally evaluated, an improvement toward delayed time to development was found with ABCP versus BCP (HR = 0.68; 95% CI: 0.39–1.19). Conclusions: This final exploratory analysis revealed OS benefits for ABCP versus BCP in patients with sensitizing EGFR mutations, including those with previous TKI failures, and with liver metastases, although these results should be interpreted with caution. The impact of ABCP on delaying the development of new brain lesions requires further investigation