Genomic alterations profiling by liquid biopsy and their association to immune checkpoints inhibitors (ICI) response in a cohort of non-small cell lung cancer (NSCLC) patients

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Background: In metastatic NSCLC, identification of biomarkers of response to immune checkpoint inhibitors (ICI) is still an unmet need. Liquid biopsy, including the detection of circulating tumor DNA (ctDNA) in patients’ bloodstream, is an emerging tool for detecting and monitoring genetic alterations. Mutations in specific genes as KRAS or STK11, in combination with PDL1, have been suggested as potential biomarkers to select responders to ICI. Methods: Digital NGS of ctDNA was analyzed by Guardant360 in samples from 89 patients with advanced NSCLC treated with ICI between 2017 to 2019. Plasma samples after progression to ICI were obteined from 40 patients and we focus in this subgroup to explore mutations of genes commonly alterated in lung cancer and correlate them with clinical outcomes. Results: Forty patients were included in the analysis with a median age of 64.5 years and 62.5% were diagnosed with adenocarcinoma. Fourteen patients were treated with single agent ICI as first line, 19 patients as second line and 7 in third line. A median of 4 mutations per patient were detected (range 0-13). Mutations (mut) in TP53 were found in 85% of the patients, KRAS in 34%, STK11 in 22% and both genes KRAS and STK11 were alterated in 12.5% of the patients. Globally, median PFS (mPFS) of the patients treated with ICI was 7.5 months. mPFS in patients harboring KRAS mutations was 4.9 m ( vs 10.1 m in patients without KRASmut, logrank test p-value = 0.031) and 4.1 m in those patients with STK11 mutations (vs 9.5 m in patients without STK11mut, logrank test p-value = 0.034). Additionally, mutations in both genes were also associated to statistically significant shorter mPFS 3.9 m vs 9.5 m (logrank test p-value < 0.01). Conclusions: Our results support the idea that tumor alterations identified by liquid biopsy panels can potentially contribute as biomarkers of response to ICI in NSCLC. When analyzing the mutational panorama after ICI treatment, we find that those patients exhibiting KRAS and/or STK11 mutations in their ctDNA have a shorter PFS.

Immune checkpoint inhibitors (ICI) response in metastatic non-small cell lung cancer (NSCLC) patients with WNT pathway mutations (APC/CTNNB1)

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Background: APC and CTNNB1 mutations (mut) lead to an aberrant activation of the WNT pathway which has been linked to lack of benefit of immunotherapy in patients (pts) with lung cancer. Our aim is to describe the pts’ characteristics of a NSCLC cohort with APC or CTNNB1 mut and their association with outcomes (Overall survival [OS] and Progression-Free-Survival [PFS]) when treated with ICI. Methods: We selected NSCLC pts with mut in APC or CTNNB1 by targeted NGS (tissue), whole exome sequencing (tissue) or Guardant 360(plasma) between January 2014 and October 2019. Functionality of mut and β-catenin protein expression by immunohistochemistry (IHC) were correlated with outcome. Results: We identified a total of 37 patients with 44 mutually-exclusive mutations in APC (31) or CTNNB1 (6), 25 adenocarcinomas (68%). Of APC mut cohort, 16 had pathogenic mut (52%) and 15 of unknown significance (48%). All 6 CTN NB1 mut were known pathogenic. Median OS (mOS) in metastatic setting was 21.6 months (m) (CI95% 14.9-NR), without differences between APC and CTNNB1 groups (HR 1.5, p = 0.4) or when stratified by mut functionality (HR 1.1, p = 0.8). Globally, 21 pts received treatment with ICI (57%, 19 APC, 2 CTNNB1), median PFS (mPFS) was 5.43m (1.8-21.7), with trend for shorter mPFS in CTNNB1 mut (mPFS 1.7m) vs. APC mut (mPFS 6.6m, HR 1.5, p = 0.1). Among patients treated with ICI, 8 (38%) had coexisting driver targetable alterations ( EGFR, ERBB2 or MET) and 13 (62%) other functional mut were found ( TP53, KRAS, STK11, BRCA2, ATM). mPFS was 3.9m (1.8-NR) in the subgroup with driver mut vs. 6.6m (1.4-NR) for remaining pts (HR 1.36, p = 0.5). In 15 pts β-catenin IHC was performed, being positive in 7 cases (47%), 4 of them received ICI with a mPFS 12.1m. Conclusions: In our experience, benefit with ICI is not influenced by the presence of APC mut, and small numbers of CTNNB1 cohort limit conclusive statements. Additional studies are required to assess WNT pathway activation on top of genomics and correlate with the ICI efficacy.

Outcome of EGFR mutant patirnts included in a clinical trial after progression on EGFR TKI

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Background: EGFR mutant(EGFRm) NSCLC patients develop adquired resistance after 12 months on EGFR TKI. Acquired T790mutation(T790M) is the most common mechanism of resistance in around 60% of patients, followed by MET amplification in 20% of cases. Inclusion in a clinical trials at progression may have an impact in patients’ outcome. Methods: We retrospectively assessed the overall survival in EGFRm patients according to post-progression treatment on 1st/2nd generation EGFR TKI: standard vs. experimental (clinical trial). Also, we assessed the survival in the cohort of acquired T790M NSCLC patients(p). X2 test and long rank test P values are described. OS was defined since progression 1st/2nd generation EGFR TKI to death or last follow up Results: 42p EGFRm were enrolled. According to EGFRm subtype (24 p EGFR del19, 14p EGFR L858R, 1p EGFR exon18, 1 EGFR exon20 ,2p unknown). Median age was 58 (33-83) and 27 (64%) females. First-line EGFR TKI was 30% gefitinib / 58 % erlotinib /10 % afatinib/2% dacotinib At PD, in 51 biopsies (b) were performed,11p were biopsy twice.Tumor tissue for molecular determinations was available in in 86% of cases. Druggable molecular alterations were detected in 57% of cases: 20 acquired T790M and 4 MET amplification. According to these results all 24 p were enrolled in a clinical trial (NCT02108964,NCT01802632,NCT02147990,NCT02335944, NCT02151981), and 18p were screening failure; 8p (45%) of them due to abscense of adquired resistance mechanisms. 10 received platinum-based chemotherapy and 6 only received best supportive care. OS metastatic disease was 51 months for patients included in a clinical trial vs 22 months for those on standard treatment (p < 0.001; 95%CI: 14.4-47). OS was: 34 months vs 10 months for those included in a clinical trial vs standard, respectively (p < 0.001; 95%CI: 8.88-25). For T790M tumours, OS post-progression was 25 months Conclusions: Enrolling patients in clinical trials may allow personalised treatment according to mechanisms of resistance improving survival after 1st/2nd generation EGFR TK progression disease.

Outcome of KRAS mutated (m) non-small cell lung cancer (NSCLC) patients (pts) treated with immune checkpoint inhibitors (immuneCI)

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Background: The most frequent genetic alteration in advanced NSCLC is KRASm in ~25% of tumors. This event associates with smoking pattern and high mutational burden, which correlate with the efficacy of CI in NSCLC. There is in silico evidence that coexisting KRASm and TP53m positively impact immuneCI benefit , but this association needs clinical validation. Methods: We retrospectively assess the efficacy of PD-1/PDL-1 CI (atezolizumab, pembrolizumab, nivolumab or durvalumab) in a cohort of NSCLC patients whose tumors were KRASm (with or without coexisting TP53m) as assessed by a next-generation sequencing test. Endpoints were clinical benefit rate (CBR), defined as partial response or stable disease > 4 months (m), and time to progression (TTP) on immuneCI. Fisher-exact test and log-rank test P values are described. Results: 25 pacients were identified, 68% female, median age 54 y (33-75), 95% former/current smoker; 95% adenocarcinoma; 59% with 2 or more metastatic sites; 36% immuneCI as third-line or beyond (median time from first-line to immuneCI of 7.5 m). 20 tumors had KRASm in codon 12, 3 codon 13 and 2 in codon 61. Overall, CBR was 36% (CI95% 19%-57%) and median TTP was 3.7 m (CI95% 2.2-NA). Coexisting KRASm/ TP53m (n = 11) did not associate with higher CB (27% vs 50%, p = 0.56). A trend for lower TTP in the KRASm/ TP53m vs TP53 wild-type was observed (2.1 vs 5.6 m, HR 0.3; p = 0.11). Conclusions: NSCLC patients whose tumors are KRASm can have substantial benefit with immuneCI. In our series, the population with KRASm/ TP53m tumors did not derive higher clinical benefit from this therapeutic intervention

Molecular sequencing and gene fusion detection in non-small cell lung cancer (NSCLC) patients: Impact of co-existing alterations

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Background: There is a growing need for accurate molecular diagnostics for proper targeted therapeutics selection in NSCLC patients (pts). We assess whether next generation techniques increase the identification of alterations in a prospective cohort of NSCLC pts, and evaluate prognostic value of different molecular alterations. Methods: Next generation sequencing (Amplicon-seq, 60 genes) and NanoString Gene fusion (20 genes) testing were conducted in NSCLC pts treated in a single center from November 2014 to May 2016. Overall survival (OS) according to the molecular profile was analysed by Kaplan-Meier method and Cox models. Results: Molecular tests were performed in 73advanced NSCLC pts.Median age was 54 year, 50% were women. Histology: 73% adenocarcinoma; 7% squamous, 20% others (Neuroendocrine, NOS). Tests were performed in biopsies from metastatic sites in 55% of pts.These techniques identified molecular alterations in 89% of cases: TP53 mutation (mut) 37/73 (51%); KRASmut 21/73 (29%); EGFRmut 11/73 (15%) ; CDKN2mut 7/73 (9%); BRAFmut (pG469R), ERBB2mut and METexon14mut in (1/73) 1.3%, respectively; ALKfusion (fus) 2/73 (2.7%); ROS1fus 1/73 (1.3%) , and RET fus 3/73 (4%). Concomitant mutations were identified in 32% of pts mainly with TP53 (TP53/EGFR: (5/11) 45% and TP53/KRAS: (7/21) 33%). Matched targeted treatment was offered in 17/73 (23%), mostly tyrosine kinase inhibitors (TKI); anti-EGFR in 11/17 (65%) and ALK/ROS TKI in 3/17 (17.5%). Three pts (17.5%) received anti-MET or anti-HER2 TKI. OS in this whole population treated with target therapies (n = 17) was 45.7 months (m) (CI95% 26.8-NA). The KRASmut group had median OS of 10 m (CI95% 7.5-NA), while the remaining population with wild type (WT) for all driver alterations had median OS of 23 m (CI95% 20-NA), (HR 1.71 for KRASmut vs WT pts, p = 0.18). The presence of coexisting TP53mut did not negatively impact on OS in the cohorts with EGFRmut and KRASmut (p > 0.1) in a multivariate model. Conclusions: Combined next generation techniques for molecular profile in NSCLC pts identifies molecular alterations that have clinically relevant impact in survival. Coexisting TP53mut alteration shows no detrimental effect in OS.

Nanoparticle albumin-bound paclitaxel in a patient with locally advanced breast cancer and taxane-induced skin toxicity: a case report

INTRODUCTION

Taxanes have demonstrated effectiveness in the treatment of breast cancer, the most common type of cancer in women. The toxicity profile of taxanes (including skin toxicities) induces dose adjustment, delay, or discontinuation, which prevents a sufficient dose intensity to achieve a response. Nanoparticle albumin-bound paclitaxel, a solvent-free form of paclitaxel, prevents toxicities and reduces the pharmacokinetic interferences between paclitaxel and other drugs.

CASE PRESENTATION

We describe the case of a 55-year-old Caucasian woman with locally advanced breast cancer treated with neoadjuvant therapy who developed secondary skin toxicity due to delayed hypersensitivity to taxanes. She received Adriamycin® (doxorubicin), cyclophosphamide and docetaxel and developed toxicity that promoted treatment delay and a switch to weekly paclitaxel. After the third and fourth weeks of treatment, paclitaxel toxicities also induced treatment delay and paclitaxel was switched to nanoparticle albumin-bound paclitaxel. She completed the five planned nanoparticle albumin-bound paclitaxel cycles with acceptable tolerability (including persistent grade 2 neuropathy) and without dose delay or adjustments. Clinical response was achieved although pathological response was not good.

CONCLUSIONS

Nanoparticle albumin-bound paclitaxel treatment is a good option for patients with breast cancer with taxanes-related skin toxicity. This drug allows the treatment to be completed with acceptable tolerance in our case.