BackgroundOsimertinib is efficacious in lung cancer patients with epidermal growth factor receptor (EGFR) mutations and acquired resistance (AR) to EGFR tyrosine kinase inhibitors due to EGFR-T790M mutation (T790M). We sought to describe T790M changes in serum/plasma during osimertinib therapy and correlate these changes with treatment outcomes.Material and methodsSerum/plasma from EGFR-mutant lung cancer patients with T790M-AR was collected before and during osimertinib treatment. Changes in T790M were evaluated using a peptide-nucleic acid-PCR assay, and correlated with clinical and radiographic response.ResultsThirteen patients were included. Median time on osimertinib treatment was 10.6 months with a median progression-free survival of 13.6 months. Best response to osimertinib was partial response (PR), stable disease (SD) or progression (PD) in 46.1%, 30.8% and 23.1% of patients, respectively.Most of the patients were paucisymptomatic at baseline. Symptom improvement was reported in 66.6% of responder patients; while symptoms remained stable in 75% of patients with SD, and 66% of patients with PD had clinical deterioration.Three patterns of T790M changes during osimertinib treatment were identified. T790 remained detectable with PD or a short-lasting SD in 15.4% of the patients. T790M disappeared in 69.2% of patients with PR or SD. T790M disappeared, despite clinical and/or radiographic progression in 15.4% of the patients.ConclusionChanges of T790M in serum/plasma in EGFR-mutant lung cancer patients with T790M-AR might be a useful marker of symptomatic and radiographic outcome to osimertinib. Longer follow-up is needed to establish if subsequent emergence of T790M could be a marker of resistance.

Background Anti-angiogenic agents are reported to exert clinical activity in patients with epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC). We evaluated the outcomes of the combination of docetaxel plus nintedanib in refractory NSCLC patients harboring EGFR mutations. Methods We retrospectively analyzed 19 patients with advanced EGFR-mutant NSCLC who had progressed to EGFR tyrosine kinase inhibitors (TKI) and platinum-based chemotherapy receiving docetaxel and nintedanib at 14 Spanish institutions from January 2013 to December 2019. Kaplan-Meier and log-rank tests were used to evaluate progression-free survival (PFS) and overall survival (OS). Results Median age was 58.9 years (range 42.8-81), 73.7% were female. All patients were Caucasian, and 73.7% were never or light smokers. The baseline Eastern Cooperative Oncology Group (ECOG) performance status (PS) was 0-1 in 94.7% of patients. All patients had adenocarcinoma. Brain and liver metastases were present in 47.4% and 31.6% of patients, respectively. The most common EGFR mutations were exon 19 deletion (52.6%) and exon 21 L858R mutation (36.8%); 47.4% patients presented the EGFR T790M. 94.8% of the patients had received 2-3 previous treatment lines. Docetaxel was administered at 75 mg/m 2 /3 weeks to 16 patients, at 60 mg/m 2 to 2 patients and at 45 mg/m 2 to one patient. Nintedanib was given until disease progression or unacceptable toxicity at 200 mg twice daily except in 2 patients who received 150 mg twice daily and one patient who received 100 mg/12 h. With a median follow-up of 11.4 months (1-38), the median PFS was 6.1 months [95% confidence interval (CI), 4.9-7.3] and the median OS 10.1 months (95% CI 5.9-14.3). The objective response rate (ORR) was 44.4% (23.7-66.8%) and the disease control rate (DCR) 72.2% (49.4-88.5%). Efficacy tended to be greater in patients with the acquired T790M who had received osimertinib, with a median PFS of 6.3 (95% CI 2.1-10.5) versus (vs.) 4.8 (95% CI 3.5-6.1) and a median OS of 12.3 months (95% CI 8.6-16.0) vs. 6.7 months (95% CI 3.9-9.4), although this tendency was not statistically significant (p = 0.468 and p = 0.159, respectively). Sixteen patients (84.2%) had a total of 34 adverse events (AEs), with a median of two (0-6) AEs per patient. The most frequent AEs were asthenia (20.6%) and diarrhea (20.6%). One treatment-related death due to portal thrombosis was reported. Conclusions Our data indicate that the combination of docetaxel and nintedanib can be considered to be an effective treatment for EGFR TKI-resistant EGFR-mutant NSCLC.

Figura 1. Corte coronal de cerebro con congestión leptomeníngea y leve edema.Figura 2. Corte transversal del tercio distal del tallo cerebral y sección medular C1, en el cual se observa congestión leptomeníngea y leve edema.Figura 3. Imagen del cuerno anterior del segmento cervical C1; en pequeño aumento, se observa proceso inflamatorio mononuclear, HE, 2,5X. Figura 4.Imagen del cuerno anterior de C1, en mayor aumento se observa un importante infiltrado inflamatorio linfomonocitario con daño neuronal. Mielitis importante de predominio motor, HE, 40X.

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