Early Metabolic Response by PET Predicts Sensitivity to Next-Line Targeted Therapy in EGFR-Mutated Lung Cancer with Unknown Mechanism of Acquired Resistance.

Targeted therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has established the precision oncology paradigm in lung cancer. Most patients with EGFR-mutated lung cancer respond but eventually acquire resistance. Methods: Patients exhibiting the EGFR p.T790M resistance biomarker benefit from sequenced targeted therapy with osimertinib. We hypothesized that metabolic response as detected by 18F-FDG PET after short-course osimertinib identifies additional patients susceptible to sequenced therapy. Results: Fourteen patients with EGFR-mutated lung cancer and resistance to first- or second-generation EGFR TKI testing negatively for EGFR p.T790M were enrolled in a phase II study. Five patients (36%) achieved a metabolic 18F-FDG PET response and continued osimertinib. In those, the median duration of treatment was not reached (95% CI, 24 mo to not estimable), median progression-free survival was 18.7 mo (95% CI, 14.6 mo to not estimable), and median overall survival was 41.5 mo. Conclusion: Connecting theranostic osimertinib treatment with early metabolic response assessment by PET enables early identification of patients with unknown mechanisms of TKI resistance who derive dramatic clinical benefit from sequenced osimertinib. This defines a novel paradigm for personalization of targeted therapies in patients with lung cancer dependent on a tractable driver oncogene.

Favorable survival outcomes in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer sequentially treated with a tyrosine kinase inhibitor and osimertinib in a real-world setting.

PURPOSE: EGFR tyrosine kinase inhibitor (TKI) therapy in EGFR-mutated lung cancer is limited by acquired resistance. In half of the patients treated with first/second-generation (1st/2nd gen) TKI, resistance is associated with EGFR p.T790M mutation. Sequential treatment with osimertinib is highly active in such patients. Currently, there is no approved targeted second-line option for patients receiving first-line osimertinib, which thus may not be the best choice for all patients. The present study aimed to evaluate the feasibility and efficacy of a sequential TKI treatment with 1st/2nd gen TKI, followed by osimertinib in a real-world setting. METHODS: Patients with EGFR-mutated lung cancer treated at two major comprehensive cancer centers were retrospectively analyzed by the Kaplan-Meier method and log rank test. RESULTS: A cohort of 150 patients, of which 133 received first-line treatment with a first/second gen EGFR TKI, and 17 received first-line osimertinib, was included. Median age was 63.9 years, 55% had ECOG performance score of ≥ 1. First-line osimertinib was associated with prolonged progression-free survival (P = 0.038). Since the approval of osimertinib (February 2016), 91 patients were under treatment with a 1st/2nd gen TKI. Median overall survival (OS) of this cohort was 39.3 months. At data cutoff, 87% had progressed. Of those, 92% underwent new biomarker analyses, revealing EGFR p.T790M in 51%. Overall, 91% of progressing patients received second-line therapy, which was osimertinib in 46%. Median OS with sequenced osimertinib was 50 months. Median OS of patients with p.T790M-negative progression was 23.4 months. CONCLUSION: Real-world survival outcomes of patients with EGFR-mutated lung cancer may be superior with a sequenced TKI strategy. Predictors of p.T790M-associated resistance are needed to personalize first-line treatment decisions.

Clinical Outcome and Treatment Sequences of Patients with Advanced Pancreatic Cancer Treated with Contemporary Chemotherapy Protocols.

INTRODUCTION: Systemic therapy is firmly established in patients with advanced or metastatic pancreatic ductal adenocarcinoma (PDAC). Clinical efficacy is still modest and options are limited. Combination therapy protocols such as FOLFIRINOX and gemcitabine/nab-paclitaxel (Gem/NP) define standard-of-care. Patients may receive a sequence of both regimens as first- and second-line palliative treatment. However, there is no guidance regarding a preferred order. METHODS: This is a retrospective analysis of clinical characteristics, treatment trajectories, and outcomes of patients with advanced PDAC treated at the West German Cancer Center Essen from 2014 to 2020 to inform treatment decisions with respect to predictive factors, impact of chemotherapy regimen sequence, and maintenance treatment. RESULTS: We identified 170 patients with available follow-up. Of those, 160 (94.1%) patients received palliative CTX for primary metastatic, locally advanced, or recurrent PDAC. Median progression-free survival (PFS) upon first palliative chemotherapy was 4.1 (3.1-5.9) months. First-line FOLFIRINOX was associated with superior PFS (median 6.3 months) and OS (9.7 months, HR 0.7, p = 0.03) as compared to Gem/NP or other regimens (PFS 3.0, OS 6.9 months). However, OS benefit of first-line FOLFIRINOX was lost in patients who received at least two treatment lines (median OS 12.1 vs. 13.1 months, p = 0.43). A landmark analysis of patients with clinical benefit (defined as CR/PR/SD for at least 20 weeks) upon first-line therapy revealed improved OS (HR 0.53, p = 0.02) for patients receiving continued deescalated maintenance therapy. Second-line regimens resulted in similar PFS (overall log-rank p = 0.92, median PFS upon second-line therapy 2.3 [1.8-2.9], per-regimen median between 1.8 and 3.9 months). A previously established systemic inflammation score proved to be strongly prognostic and allowed identification of a patient subgroup with dismal prognosis (OS 2.9 vs. 11.4 months, HR 5.23, p < 0.001), independent of other prognostic factors and with no relevant interaction with the choice of first-line regimen. CONCLUSION: In this real-world population of PDAC patients treated with contemporary combination chemotherapies, a positive impact of first-line FOLFIRINOX was only observed when no second or further line treatment was administered. Intensity-reduced maintenance therapy may lead to superior survival.