Immunotherapy as a treatment strategy in advanced stage and recurrent endometrial cancer: review of current phase III immunotherapy clinical trials

The treatment of advanced stage, metastatic or recurrent endometrial cancer remains a clinically difficult scenario. Although combination carboplatin and paclitaxel is an effective standard-of-care regimen, alternate strategies have shown promise, particularly in biomarker select populations. In an effort to improve oncologic outcomes, investigators are exploring novel immunotherapy combinations. In this review, we discuss the clinical rationale and design of current phase III immuno-oncology clinical trials in patients with advanced stage or recurrent endometrial cancer.

Augmenting Anticancer Immunity Through Combined Targeting of Angiogenic and PD-1/PD-L1 Pathways: Challenges and Opportunities

Cancer immunotherapy (CIT) with antibodies targeting the programmed cell death 1 protein (PD-1)/programmed cell death 1 ligand 1 (PD-L1) axis have changed the standard of care in multiple cancers. However, durable antitumor responses have been observed in only a minority of patients, indicating the presence of other inhibitory mechanisms that act to restrain anticancer immunity. Therefore, new therapeutic strategies targeted against other immune suppressive mechanisms are needed to enhance anticancer immunity and maximize the clinical benefit of CIT in patients who are resistant to immune checkpoint inhibition. Preclinical and clinical studies have identified abnormalities in the tumor microenvironment (TME) that can negatively impact the efficacy of PD-1/PD-L1 blockade. Angiogenic factors such as vascular endothelial growth factor (VEGF) drive immunosuppression in the TME by inducing vascular abnormalities, suppressing antigen presentation and immune effector cells, or augmenting the immune suppressive activity of regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. In turn, immunosuppressive cells can drive angiogenesis, thereby creating a vicious cycle of suppressed antitumor immunity. VEGF-mediated immune suppression in the TME and its negative impact on the efficacy of CIT provide a therapeutic rationale to combine PD-1/PD-L1 antibodies with anti-VEGF drugs in order to normalize the TME. A multitude of clinical trials have been initiated to evaluate combinations of a PD-1/PD-L1 antibody with an anti-VEGF in a variety of cancers. Recently, the positive results from five Phase III studies in non-small cell lung cancer (adenocarcinoma), renal cell carcinoma, and hepatocellular carcinoma have shown that combinations of PD-1/PD-L1 antibodies and anti-VEGF agents significantly improved clinical outcomes compared with respective standards of care. Such combinations have been approved by health authorities and are now standard treatment options for renal cell carcinoma, non-small cell lung cancer, and hepatocellular carcinoma. A plethora of other randomized studies of similar combinations are currently ongoing. Here, we discuss the principle mechanisms of VEGF-mediated immunosuppression studied in preclinical models or as part of translational clinical studies. We also discuss data from recently reported randomized clinical trials. Finally, we discuss how these concepts and approaches can be further incorporated into clinical practice to improve immunotherapy outcomes for patients with cancer.

Second-line lenvatinib in patients with recurrent endometrial cancer

OBJECTIVE

This study assessed the efficacy of lenvatinib, a multitargeted tyrosine kinase inhibitor, as second-line therapy in patients with unresectable endometrial cancer. The primary end point was the objective response rate (ORR) as assessed by independent radiologic review (IRR). Secondary end points included median progression-free survival (PFS), overall survival (OS), and clinical benefit rate. Exploratory end points examined the association of baseline levels of plasma biomarkers (50 circulating cytokine and/or angiogenic factors measured by immunoassays) with efficacy outcomes.

METHODS

An international, open-label, single-arm, multicenter, phase 2 trial was conducted. Eligible patients had histologically confirmed unresectable endometrial cancer that relapsed after 1 prior systemic platinum-based chemotherapy. Patients received once-daily oral lenvatinib 24 mg in a 28-day dosing cycle.

RESULTS

There were 133 patients in the study. By IRR, 19 patients had a confirmed objective response for an ORR of 14.3% (95% CI: 8.8-21.4). Durable stable disease (≥23 weeks) was observed in 31 patients (23.3%) and the clinical benefit rate was 37.6% (95% CI: 29.3-46.4). Median PFS was 5.6 months (95% CI: 3.7-6.3), and median OS was 10.6 months (95% CI: 8.9-14.9). The most common (any grade) treatment-related adverse events were fatigue/asthenia (48%), hypertension (49%), nausea/vomiting (32%), decreased appetite (32%), and diarrhea (31%). Lower baseline levels of angiopoietin-2 were associated with longer PFS, OS, and a higher ORR.

CONCLUSIONS

Patients with recurrent endometrial cancer treated with second-line lenvatinib experienced modest antitumor activity and treatment was generally well tolerated, with a safety profile consistent with previous studies.

European society of medical oncology (ESMO) 2019 meeting report features practice changing data in gynecologic malignancies

Multiple practice changing studies were presented at the 2019 ESMO Congress in Barcelona, Spain. The ovarian cancer studies presented at the Presidential session will likely refine and redefine the initial treatment of ovarian cancer. Other compelling trial data in ovarian, uterine and cervical cancer were also unveiled. The key oral abstracts from this meeting are summarized in this meeting report.