Phase 3, randomized, open-label study of pembrolizumab plus lenvatinib versus chemotherapy for first-line treatment of advanced or recurrent endometrial cancer: ENGOT-en9/LEAP-001

BACKGROUND: Pembrolizumab plus lenvatinib is a novel combination with promising efficacy in patients with advanced and recurrent endometrial cancer. This combination demonstrated high objective response rates in a single-arm phase 1b/2 trial of lenvatinib plus pembrolizumab in patients with advanced endometrial cancer (KEYNOTE-146/Study 111) after ≤2 previous lines of therapy. In a randomized phase 3 trial of lenvatinib in combination with pembrolizumab versus treatment of physician's choice in patients with advanced endometrial cancer (KEYNOTE-775/Study 309), after 1‒2 previous lines of therapy (including neoadjuvant/adjuvant), this combination improved objective response rates, progression-free survival, and overall survival compared with chemotherapy. PRIMARY OBJECTIVE: To compare the efficacy and safety of first-line pembrolizumab plus lenvatinib versus paclitaxel plus carboplatin in patients with newly diagnosed stage III/IV or recurrent endometrial cancer, with measurable or radiographically apparent disease. STUDY HYPOTHESIS: Pembrolizumab plus lenvatinib is superior to chemotherapy with respect to progression-free survival and overall survival in patients with mismatch repair-proficient tumors and all patients (all-comers). TRIAL DESIGN: Phase 3, randomized (1:1), open-label, active-controlled trial. Patients will receive pembrolizumab intravenously every 3 weeks plus lenvatinib orally daily or paclitaxel plus carboplatin intravenously every 3 weeks, stratified by mismatch repair status (proficient vs deficient). Patients with mismatch repair-proficient tumors will be further stratified by Eastern Cooperative Oncology Group performance status (0/1), measurable disease (yes/no), and prior chemotherapy and/or chemoradiation (yes/no). MAJOR INCLUSION/EXCLUSION CRITERIA: Adults with stage III/IV/recurrent histologically confirmed endometrial cancer that is measurable or radiographically apparent per blinded independent central review. Patients may have received previous chemotherapy only as neoadjuvant/adjuvant therapy and/or concurrently with radiation. Patients with carcinosarcoma (malignant mixed Müllerian tumor), endometrial leiomyosarcoma, or other high grade sarcomas, or endometrial stromal sarcomas were excluded. PRIMARY ENDPOINTS: Progression-free and overall survival (dual primary endpoints). SAMPLE SIZE: About 875 patients. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Enrollment is expected to take approximately 24 months, with presentation of results in 2022. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03884101

Vessel co-option mediates resistance to anti-angiogenic therapy in liver metastases

The efficacy of angiogenesis inhibitors in cancer is limited by resistance mechanisms that are poorly understood. Notably, instead of through the induction of angiogenesis, tumor vascularization can occur through the nonangiogenic mechanism of vessel co-option. Here we show that vessel co-option is associated with a poor response to the anti-angiogenic agent bevacizumab in patients with colorectal cancer liver metastases. Moreover, we find that vessel co-option is also prevalent in human breast cancer liver metastases, a setting in which results with anti-angiogenic therapy have been disappointing. In preclinical mechanistic studies, we found that cancer cell motility mediated by the actin-related protein 2/3 complex (Arp2/3) is required for vessel co-option in liver metastases in vivo and that, in this setting, combined inhibition of angiogenesis and vessel co-option is more effective than the inhibition of angiogenesis alone. Vessel co-option is therefore a clinically relevant mechanism of resistance to anti-angiogenic therapy and combined inhibition of angiogenesis and vessel co-option might be a warranted therapeutic strategy

Preclinical Evidence That Trametinib Enhances the Response to Antiangiogenic Tyrosine Kinase Inhibitors in Renal Cell Carcinoma.

Sunitinib and pazopanib are antiangiogenic tyrosine kinase inhibitors (TKI) used to treat metastatic renal cell carcinoma (RCC). However, the ability of these drugs to extend progression-free and overall survival in this patient population is limited by drug resistance. It is possible that treatment outcomes in RCC patients could be improved by rationally combining TKIs with other agents. Here, we address whether inhibition of the Ras-Raf-MEK-ERK1/2 pathway is a rational means to improve the response to TKIs in RCC. Using a xenograft model of RCC, we found that tumors that are resistant to sunitinib have a significantly increased angiogenic response compared with tumors that are sensitive to sunitinib in vivo. We also observed significantly increased levels of phosphorylated ERK1/2 in the vasculature of resistant tumors, when compared with sensitive tumors. These data suggested that the Ras-Raf-MEK-ERK1/2 pathway, an important driver of angiogenesis in endothelial cells, remains active in the vasculature of TKI-resistant tumors. Using an in vitro angiogenesis assay, we identified that the MEK inhibitor (MEKI) trametinib has potent antiangiogenic activity. We then show that, when trametinib is combined with a TKI in vivo, more effective suppression of tumor growth and tumor angiogenesis is achieved than when either drug is utilized alone. In conclusion, we provide preclinical evidence that combining a TKI, such as sunitinib or pazopanib, with a MEKI, such as trametinib, is a rational and efficacious treatment regimen for RCC

Enrichment of the tumour immune microenvironment in patients with desmoplastic colorectal liver metastasis

Background Patients with resected colorectal liver metastasis (CRLM) who display only the desmoplastic histopathological growth pattern (dHGP) exhibit superior survival compared to patients with any non-desmoplastic growth (non-dHGP). The aim of this study was to compare the tumour microenvironment between dHGP and non-dHGP. Methods The tumour microenvironment was investigated in three cohorts of chemo-naive patients surgically treated for CRLM. In cohort A semi-quantitative immunohistochemistry was performed, in cohort B intratumoural and peritumoural T cells were counted using immunohistochemistry and digital image analysis, and in cohort C the relative proportions of individual T cell subsets were determined by flow cytometry. Results One hundred and seventeen, 34, and 79 patients were included in cohorts A, B, and C, with dHGP being observed in 27%, 29%, and 15% of patients, respectively. Cohorts A and B independently demonstrated peritumoural and intratumoural enrichment of cytotoxic CD8+ T cells in dHGP, as well as a higher CD8+/CD4+ ratio (cohort A). Flow cytometric analysis of fresh tumour tissues in cohort C confirmed these results; dHGP was associated with higher CD8+ and lower CD4+ T cell subsets, resulting in a higher CD8+/CD4+ ratio. Conclusion The tumour microenvironment of patients with dHGP is characterised by an increased and distinctly cytotoxic immune infiltrate, providing a potential explanation for their superior survival

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference

A study of the decision outcomes and financial costs of multidisciplinary team meetings (MDMs) in oncology

Background:The benefits of multidisciplinary working in oncology are now accepted as the norm and widely accepted as being pivotal to the delivery of optimal cancer care. Central to this are the multidisciplinary meetings (MDMs) and we have evaluated decision outcomes and financial costs of these.Methods:We reviewed the electronic patient records of 551 newly referred patients, discussed at 14 tumour site-specific MDMs for adult solid tumours and lymphoma (paediatric oncology and acute leukaemia were excluded) over a 1-month period, a total of 52 MDMs were studied. In addition, the records of a further 81 patients from 10 different MDMs were reviewed where the treating consultant had clearly recorded their opinion of how the patient should be managed and this was compared with the final MDM's consensus view. We also costed the MDMs utilising two different methodologies.Results:The mean age of the 551 patients in the study was 62 years. In all, 536 (97.3%) patients were treatment naive before MDM discussion and 15 (2.7%) had prior treatment. Median time to treatment after the MDM was 16 days. In 535 (97.1%) cases, the MDM discussions were clearly documented, 16 (2.9%) were not clearly documented. In total, 319 (57.9%) patients were discussed once, and 232 (42.1%) were re-discussed (one to six occasions). In 62 (12.7%) patients, there were delays in MDM discussion, 30 (48.4%) were related to radiology, 26 (41.9%) to histopathology and 6 (9.7%) a combination of both. Adherence to the MDM management plan decision occurred 503 times (91.3%) with 48 (8.7%) deviations. In the smaller cohort of 81 patients, the consultant management plan and MDM consensus was compatible 71 (87.6%) times. On four occasions, there were major alterations in management while six were minor. The cost per month of our MDMs ranged from £2192 to £10 050 (median £5136) with total cost of £80 850 per month and the cost per new patient discussed was £415.Conclusion:Adherence to MDM decisions by health-care professionals occurs in the majority of patients. MDMs are costly, which may have relevance in the currently challenged health-care financial environment. There is a need to improve MDM efficiency without losing the considerable benefits associated with regular MDMs

Final results of a pharmacokinetic (PK) and pharmacodynamic (PD) phase I trial of ARQ 197 incorporating dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) studies investigating the antiangiogenic activity of selective c-Met inhibition

ARQ 197 (ARQ) is a selective non-ATP competitive inhibitor of c-Met, a receptor tyrosine kinase implicated in tumor cell proliferation, invasion and angiogenesis. Preclinical data and declines in circulating endothelial cell (CEC) levels in patients (pts) receiving ARQ suggest antiangiogenic potential of c-Met inhibition. Methods: ARQ was administered orally twice daily (bid) to pts with advanced solid tumors. Pre and post-therapy tumor biopsies were mandated for c-Met and FAK immunohistochemical studies during dose escalation (n = 16). CEC enumeration was evaluated. 12 pts are being investigated in the maximum tolerated dose (MTD) expansion cohort with DCE and Diffusion Weighted (DW) MRI. Results: 29 pts (14 F/15 M; mean 54.4 yrs) received ARQ at doses of 100 (n = 3), 200 (n = 6), 300 (n = 16), and 400 (n = 4) mg bid. 3 pts experienced dose limiting toxicities of CTCAEv3 grade (G)3 fatigue (200 mg bid); G3 hand-foot syndrome, G3 mucositis and G3 febrile neutropenia (400 mg bid). This established the ARQ MTD/recommended phase II dose (RP2D) at 300 mg bid. Other toxicities were G1-2, such as fatigue (n = 5); diarrhea, nausea and vomiting (n = 3). Mean AUC0-12h and Cmax increased linearly through the MTD. Statistically significant post-ARQ inhibition of high baseline phosphorylated c-Met and FAK expression in tumor tissue was seen in all dose cohorts confirming target inhibition. Disease stabilization (SD) was seen in 11 pts for up to 23 weeks with tumor regressions up to 12.4%. 13 of 20 pts had post-ARQ CEC declines of up to 100%. In the DCE-MRI cohort to date, preliminary analyses of ktrans histograms from pelvic lesions were consistent with antiangiogenic effects, with a ktrans median reduction of 20.1% on day 7 of ARQ (intrapatient baseline variability: 2.8%). This effect was still present (ktrans median decline: 8.3%) on day 56 of ARQ. Conclusions: ARQ is well tolerated with MTD/RP2D of 300mg bid, linear PK and evidence of phosphorylated c-Met and FAK inhibition. CEC and preliminary DCE-MRI data support the antiangiogenic effects of c-Met inhibition with ARQ. Correlation with other DCE parameters and DW changes will be presented