Plasma-Based Longitudinal Evaluation of ESR1 Epigenetic Status in Hormone Receptor-Positive HER2-Negative Metastatic Breast Cancer

Background: Endocrine therapy (ET) is the mainstay of treatment for hormone receptor-positive human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer; however, adaptive mechanisms emerge in about 25\u201330% of cases through alterations in the estrogen receptor ligand-binding domain, with a consequent ligand-independent estrogen receptor activity. Epigenetic-mediated events are less known and potentially involved in alternative mechanisms of resistance. The aim of this study was to test the feasibility of estrogen receptor 1 (ESR1) epigenetic characterization through liquid biopsy and to show its potential longitudinal application for an early ET sensitivity assessment. Methods: A cohort of 49 women with hormone receptor-positive HER2-negative MBC was prospectively enrolled and characterized through circulating tumor DNA using methylation-specific droplet digital PCR (MS-ddPCR) before treatment start (BL) and after 3 months concomitantly with computed tomography (CT) scan restaging (EV1). ESR1 epigenetic status was defined by assessing the methylation of its main promoters (promA and promB). The most established cell-free tumor DNA (ctDNA) factors associated with ET resistance [ESR1 and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutations] were assessed through next-generation sequencing. Associations were tested through Mann\u2013Whitney U test, matched pairs variations through Wilcoxon signed rank test, and survival was analyzed by log-rank test. Results: The ET backbone was mainly based on aromatase inhibitors (AIs) (70.83%) in association with CDK4/6 inhibitors (93.75%). Significantly lower promA levels at baseline were observed in patients with liver metastases (P = 0.0212) and in patients with ESR1 mutations (P = 0.0091). No significant impact on PFS was observed for promA (P = 0.3777) and promB (P = 0.7455) dichotomized at the median while a 652-fold increase in promB or in either promA or promB at EV1 resulted in a significantly worse prognosis (respectively P = 0.0189, P = 0.0294). A significant increase at EV1 was observed for promB among patients with PIK3CA mutation (P = 0.0173). A trend was observed for promB in ESR1 wild-type patients and for promA in the ESR1 mutant subgroup. Conclusion: The study proofed the concept of an epigenetic characterization strategy based on ctDNA and is capable of being integrated in the current clinical workflow to give useful insights on treatment sensitivity

Baseline BMI and BMI variation during first line pembrolizumab in NSCLC patients with a PD-L1 expression >= 50%: a multicenter study with external validation

Background The association between obesity and outcomes in patients receiving programmed death-1/ programmed death ligand-1 (PD-L1) checkpoint inhibitors has already been confirmed in pre-treated non-small cell lung cancer (NSCLC) patients, regardless of PD-L1 tumor expression. Methods We present the outcomes analysis according to baseline body mass index (BMI) and BMI variation in a large cohort of metastatic NSCLC patients with a PD-L1 expression ≥50%, receiving first line pembrolizumab. We also evaluated a control cohort of metastatic NSCLC patients treated with first line platinum-based chemotherapy. Normal weight was set as control group. Results 962 patients and 426 patients were included in the pembrolizumab and chemotherapy cohorts, respectively. Obese patients had a significantly higher objective response rate (ORR) (OR=1.61 (95% CI: 1.04– 2.50)) in the pembrolizumab cohort, while overweight patients had a significantly lower ORR (OR=0.59 (95% CI: 0.37–0.92)) within the chemotherapy cohort. Obese patients had a significantly longer progression-free survival (PFS) (HR=0.61 (95% CI: 0.45–0.82)) in the pembrolizumab cohort. Conversely, they had a significantly shorter PFS in the chemotherapy cohort (HR=1.27 (95% CI: 1.01–1.60)). Obese patients had a significantly longer overall survival (OS) within the pembrolizumab cohort (HR=0.70 (95% CI: 0.49–0.99)), while no significant differences according to baseline BMI were found in the chemotherapy cohort. BMI variation significantly affected ORR, PFS and OS in both the pembrolizumab and the chemotherapy cohorts. Conclusions Baseline obesity is associated to significantly improved ORR, PFS and OS in metastatic NSCLC patients with a PD-L1 expression of ≥50%, receiving first line pembrolizumab, but not among patients treated with chemotherapy. BMI variation is also significantly related to clinical outcomes

Post-progression outcomes of NSCLC patients with PD-L1 expression ≥ 50% receiving first-line single-agent pembrolizumab in a large multicentre real-world study

Background: Treatment sequencing with first-line immunotherapy, followed by second-line chemotherapy, is still a viable option for NSCLC patients with PD-L1 expression ≥50%. Methods: We evaluated post-progression treatment pathways in a large real-world cohort of metastatic NSCLC patients with PD-L1 expression ≥ 50% treated with first-line pembrolizumab monotherapy. Results: Overall, 974 patients were included. With a median follow-up of 22.7 months (95%CI: 21.6–38.2), the median overall survival (OS) of the entire population was 15.8 months (95%CI: 13.5–17.5; 548 events). At the data cutoff, among the 678 patients who experienced disease progression, 379 (55.9%) had not received any further treatment, and 359 patients (52.9%) had died. Patients who did not receive post-progression therapies were older (p = 0.0011), with a worse ECOG-PS (p < 0.0001) and were on corticosteroids prior to pembrolizumab (p = 0.0024). At disease progression, 198 patients (29.2%) received a switched approach and 101 (14.9%) received pembrolizumab ByPD either alone (64 [9.4%]) or in combination with local ablative treatments (37 [5.5%]) (LATs). After a random-case control matching according to ECOG-PS, CNS metastases, bone metastases, and (previous) best response to pembrolizumab, patients receiving pembrolizumab ByPD plus LATs were confirmed to have a significantly longer post-progression OS compared to patients receiving pembrolizumab ByPD alone 13.9 months versus 7.8 months (p = 0.0179) 241 patients (35.5%) among the 678 who had experienced PD, received a second-line systemic treatment (regardless of previous treatment beyond PD). As compared to first-line treatment commencement, patients’ features at the moment of second-line initiation showed a significantly higher proportion of patients aged under 70 years (p = 0.0244), with a poorer ECOG-PS (p < 0.0001) and having CNS (p = 0.0001), bone (p = 0.0266) and liver metastases (p = 0.0148). Conclusions: In the real-world scenario NSCLC patients with PD-L1 expression ≥50% treated with first-line single-agent pembrolizumab achieve worse outcomes as compared to the Keynote-024 trial. Poor post-progression outcomes are major determinants of the global results that should be considered when counselling patients for first-line treatment choices

Clinicopathologic correlates of first-line pembrolizumab effectiveness in patients with advanced NSCLC and a PD-L1 expression of 65 50%

Background: Single-agent pembrolizumab represents the standard first-line option for metastatic non-small-cell lung cancer (NSCLC) patients with a PD-L1 (programmed death-ligand 1) expression of 65 50%. Methods: We conducted a multicenter retrospective study aimed at evaluating the clinicopathologic correlates of pembrolizumab effectiveness in patients with treatment-na\uefve NSCLC and a PD-L1 expression of 65 50%. Results: One thousand and twenty-six consecutive patients were included. The objective response rate (ORR) was 44.5% (95% CI 40.2\u201349.1), while the median progression free survival (PFS) and overall survival (OS) were 7.9 months (95% CI 6.9\u20139.5; 599 events) and 17.2 months (95% CI 15.3\u201322.3; 598 censored patients), respectively. ECOG-PS 65 2 (p < 0.0001) and bone metastases (p = 0.0003) were confirmed to be independent predictors of a worse ORR. Former smokers (p = 0.0002), but not current smokers (p = 0.0532) were confirmed to have a significantly prolonged PFS compared to never smokers at multivariate analysis. ECOG-PS (p < 0.0001), bone metastases (p < 0.0001) and liver metastases (p < 0.0001) were also confirmed to be independent predictors of a worse PFS. Previous palliative RT was significantly related to a shortened OS (p = 0.0104), while previous non-palliative RT was significantly related to a prolonged OS (p = 0.0033). Former smokers (p = 0.0131), but not current smokers (p = 0.3433) were confirmed to have a significantly prolonged OS compared to never smokers. ECOG-PS (p < 0.0001), bone metastases (p < 0.0001) and liver metastases (p < 0.0001) were also confirmed to be independent predictors of a shortened OS. A PD-L1 expression of 65 90%, as assessed by recursive partitioning, was associated with significantly higher ORR (p = 0.0204), and longer and OS (p = 0.0346) at multivariable analysis. Conclusion: Pembrolizumab was effective in a large cohort of NSCLC patients treated outside of clinical trials. Questions regarding the effectiveness in clinical subgroups, such as patients with poorer PS and with liver/bone metastases, still remain to be addressed. We confirmed that the absence of tobacco exposure, and the presence of bone and liver metastasis are associated with worse clinical outcomes to pembrolizumab. Increasing levels of PD-L1 expression may help identifying a subset of patients who derive a greater benefit from pembrolizumab monotherapy