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This prospective pharmacokinetic (PK) ancillary study of the TEXCAN phase II GERCOR trial of patients with chemorefractory metastatic colorectal cancer and treated with regorafenib (REGO) investigated correlations between overall survival (OS) and concentrations (C) of REGO and its active metabolites, M-2 and M-5. 55 patients received REGO 160 mg/day for 21 days of a 28-day cycle (NCT02699073). REGO, M-2, M-5 were measured by liquid chromatography-mass spectrometry assay on day 15 of cycle 1 (C1) and 2 (C2). We studied the association between OS and Cmin of REGO, M-2 and M-5 at C1 and their accumulations between C1 and C2. Medians of C2/C1 M-2 and M-5 ratios were 0.82 (interquartile range 0.50–1.78) and 0.75 (interquartile range 0.41–1.93), respectively. Patients with C2/C1 M-2 ratio ≥ median had improved survival compared to those < median (12.6 versus 4.0 months, P = 0.023), corresponding to a 66% mortality risk reduction in multivariate analysis. The C2/C1 M-2 ratio correlated with C1 REGO+M-2+M-5 (Csum; P = 0.006). Restricted cubic spline analysis showed an increased OS benefit as the C2/C1 M-2 ratio raises and when C1 Csum ranged between 2.5 and 5.5 mg/L. Patients within the Csum range had a reduced incidence of serious adverse events and improved OS. We identified PK parameters associated with a survival benefit in patients with metastatic colorectal cancer treated by REGO. OS and safety were favourable when C1 REGO+M-2+M-5 Csum ranged between 2.5 and 5.5 mg/L. These results pave the way for individual REGO dose modification strategies based on PK monitoring. NCT02699073 - Therapeutic monitoring of regorafenib in metastatic colorectal cancer is feasible. - We define a safe range of residual concentration regorafenib + M-2+M-5. - This range translates into a survival benefit and decreased serious adverse events. - Only one-third of the patients are within range at C1 D14. - Therapeutic monitoring of regorafenib may help to optimise its dose. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal carcinoma (CRC) is one of the most prevalent malignomas worldwide and a leading cause of cancer associated mobidity and mortality. While screening and therapeutic developments have improved long-term survival and cure rates, a considerable fraction of patients suffers disease progression and death. Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR) are amongst the cornerstones of therapy in advanced-stage CRC. However, while prospective clinical trials have confirmed the benefit of including those agents into the regimes for advanced CRC, disease progression or therapy-related toxicities might require physicians to switch from anti-EGFR-based therapies to alternative treatments. With limiting options in later treatment lines however, re-exposure to anti-EGFR-based therapy regimes is a valuable option and evidence for this approach is limited. This real-world study from a large oncology center in germany includes data from more than 500 patients to underscore the benefit of anti-EGFR re-exposure in patients with advanced CRC. Background and Aims: In patients with Rat sarcoma proto-oncogene (RAS) wild-type metastatic colorectal cancer (mCRC), anti-epidermal growth factor receptor (EGFR) antibodies have been established in first- and further therapy lines. Due to limited treatment options upon disease progression, anti-EGFR re-exposure is increasingly employed in real-world oncology. The aim of this study was to assess clinical implementation and utility of anti-EGFR retreatment strategies in real-world mCRC patients. Methods: In this monocentric retrospective study, we included 524 patients with CRC and identified patients who received an anti-EGFR-based treatment as well as anti-EGFR rechallenge (progression on first-line anti-EGFR therapy) or reintroduction (discontinuation due to intolerance/toxicity/other). Results: In total, 143 patients received an anti-EGFR-based first- or second-line treatment, showing a similar overall survival (OS) compared to the non-anti-EGFR treatment group (38.3 vs. 39.6 months, p = 0.88). Thirty-three patients met the inclusion criteria for anti-EGFR re-exposure and were either assigned to rechallenge (n = 21) or reintroduction (n = 12) subgroups. The median FU after re-exposure was 45.8 months. Cetuximab and Panitumumab were used in 21 and 12 patients, respectively, and the main chemotherapy at re-exposure was FOLFIRI in 39.4%. Anti-EGFR re-exposure was associated with a distinct trend towards a better outcome (median OS 56.0 vs. 35.4 months, p = 0.06). In a subgroup comparison, reintroduction was associated with a higher OS and PFS in trend compared to the rechallenge (mOS 66 vs. 52.4, n.s., mPFS 7.33 vs. 3.68 months, n.s.). Conclusions: This retrospective study provides real-world evidence underscoring that anti-EGFR re-exposure strategies might benefit patients independently of the reason for prior discontinuation. [ABSTRACT FROM AUTHOR]

The review deals with research of new multikinase inhibitor regorafenib used for treatment of chemorefractory metastatic colorectal cancer. Regorafenib inhibits various protein kinases implicated in oncogenesis, angiogenesis, and the tumour microenvironment. In two placebo- controlled, randomized, phase III trials (CORRECT and CONCUR) treatment with regorafenib has demonstrated statistically significant improvements in terms of overall survival, progression-free urvival and disease control rates when compared with placebo in pretreated patients. Correlative analyses suggest a clinical benefit favouring regorafenib across various patient subgroups including subgroups defined by KRAS mutational status and other biomarkers. The most common grade ≥3 adverse events were hand-foot syndrome, fatigue, diarrhea, hypertension and rash/desquamation. The benefit provided by regorafenib was observed in two open-label, single-arm studies (REBECCA and CONSIGN) performed in the real-world setting.

Background Angiogenesis is critical to colorectal cancer (CRC) growth and metastasis. Phase I/II studies have demonstrated the efficacy of nintedanib, a triple angiokinase inhibitor, in patients with metastatic CRC. This global, randomized, phase III study investigated the efficacy and safety of nintedanib in patients with refractory CRC after failure of standard therapies. Patients and methods Eligible patients (Eastern Cooperative Oncology Group performance status 0–1, with histologically/cytologically confirmed metastatic/locally advanced CRC adenocarcinoma unamenable to surgery and/or radiotherapy) were randomized 1 : 1 to receive nintedanib (200 mg twice daily) or placebo (twice daily), until disease progression or undue toxicity. Patients were stratified by previous regorafenib, time from onset of metastatic disease to randomization, and region. Co-primary end points were overall survival (OS) and progression-free survival (PFS) by central review. Secondary end points included objective tumor response and disease control by central review. Results From October 2014 to January 2016, 768 patients were randomized; 765 were treated (nintedanib n  =   384; placebo n  =   381). Median follow-up was 13.4 months (interquartile range 11.1–15.7). OS was not improved [median OS 6.4 months with nintedanib versus 6.0 months with placebo; hazard ratio (HR), 1.01; 95% confidence interval (CI), 0.86–1.19; P =  0.8659]. There was a significant but modest increase in PFS with nintedanib versus placebo (median PFS 1.5 versus 1.4 months, respectively; HR 0.58; 95% CI 0.49–0.69; P  <   0.0001). There were no complete or partial responses. Adverse events (AEs) occurred in 97% of 384 nintedanib-treated patients and 93% of 381 placebo-treated patients. The most frequent grade ≥3 AEs were liver-related AEs (nintedanib 16%; placebo 8%) and fatigue (nintedanib 9%; placebo 6%). Conclusions The study failed to meet both co-primary end points. Nintedanib did not improve OS and was associated with a significant but modest increase in PFS versus placebo. Nintedanib was well tolerated. ClinicalTrials.gov number NCT02149108 (LUME-Colon 1). [ABSTRACT FROM AUTHOR]

Regorafenib, targeting a broad range of receptor tyrosine kinases (RTKs), is an oral multikinase inhibitor which improves the progression-free survival (PFS) and overall survival (OS) of patients diagnosed with chemorefractory metastatic colorectal cancer (mCRC), making an immunosuppressive tumour microenvironment. The correlation between PD-1/PD-L1 expression and RTKs inhibition has been studied in several tumour types but has not been analyzed extensively in mCRC in the era of regorafenib. In this study, using liquid biopsy, we evaluated the opportunity to reveal if PD-L1 expression on circulating tumour cells (CTCs) could serve as a predictive biomarker of response and clinical benefit in patients treated with regorafenib as the third line of treatment. We analyzed a cohort of forty chemorefractory metastatic colorectal cancer patients, of whom twenty-six KRAS mutated, treated with regorafenib, all as the third line of treatment. Blood samples were collected from patients prior to treatment and longitudinally four and eight weeks after initiation of therapy. CTCs were identified using multiparametric flow cytometry; therefore, PD-L1 expression was evaluated. Objective responses were defined following the RECIST criteria v.1.1. Moreover, focusing on peripheral blood biomarkers, we found that high platelet-to-lymphocyte ratio (PLR) was an independent prognostic indicator of poor OS. For the first time, our study showed the usefulness of sequential assessments of CTCs as a non-invasive real-time biopsy to evaluate PD-L1 expression in patients diagnosed with mCRC and treated with regorafenib. Our analysis suggests that by assessing PD-L1 expression on CTCs, we could predict who will benefit from regorafenib, offering highly individualized treatment plans. [ABSTRACT FROM AUTHOR]

Background: On the basis of retrospective analyses and phase 2 studies, metastatic colorectal cancer patients whose disease responded to a first-line regimen containing an anti-epidermal growth factor receptor (EGFR) agent may experience benefit from anti-EGFR readministration in later therapy lines. While the analysis of circulating tumor DNA seems a promising tool to select the best candidates for this strategy, identifying clinical predictors of anti-EGFR sensitivity would be useful to drive treatment choices in daily practice., Patients and Methods: A real-life database of 5530 patients treated at 6 institutions was queried. Included were patients who were retreated with anti-EGFRs, who had RAS/BRAF wild-type-status tissue samples, who had received a first-line anti-EGFR-based regimen with at least stable disease as best response, and who had received at least one further line of therapy before anti-EGFR retreatment. The association with overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) of variables potentially related to anti-EGFR sensitivity was investigated., Results: A total of 86 patients were identified. The ORR during anti-EGFR retreatment was 19.8%; median PFS and OS were 3.8 and 10.2 months, respectively. No significant association of clinical features of anti-EGFR sensitivity with ORR, PFS, and OS was observed. Among the 56 patients with a time from the last anti-EGFR administration to first-line progressive disease of < 3 months (rechallenge group), > 2 prior therapy lines and a longer anti-EGFR-free interval were associated with higher ORR, but not with longer PFS or OS., Conclusion: Clinical features we deemed surrogates of anti-EGFR sensitivity were not reliable predictors of benefit from anti-EGFR retreatment., (Copyright © 2020 Elsevier Inc. All rights reserved.)