Previously treated recurrent or advanced endometrial cancer in England: A real-world observational analysis

Real-world treatment patterns and clinical outcomes from a retrospective chart review study of patients with recurrent or advanced endometrial cancer who progressed following prior systemic therapy in Europe

OBJECTIVE

To evaluate real-world treatment patterns and clinical outcomes in recurrent/advanced endometrial cancer patients who progressed following prior systemic therapy in clinical practice in Europe.

DESIGN

Endometrial Cancer Health Outcomes-Europe (ECHO-EU) is a retrospective patient chart review study.

SETTING

ECHO-EU is a multicentre study conducted in the UK, Germany, Italy, France and Spain.

PARTICIPANTS

Patients with recurrent/advanced endometrial cancer who progressed between 1 July 2016 and 30 June 2019 following prior first-line systemic therapy were eligible and data were collected until last available follow-up through November 2021.

PRIMARY AND SECONDARY OUTCOME MEASURES

Data collected included patient demographics, clinical and treatment characteristics, and clinical outcomes. Kaplan-Meier analyses were performed since initiation of second-line therapy to estimate time to treatment discontinuation, real-world progression-free survival (rwPFS) and overall survival (OS).

RESULTS

A total of 475 patients were included from EU5 countries. Median age was 69 years at advanced endometrial cancer diagnosis, 78.7% had stage IIIB-IV disease, 45.9% had Eastern Cooperative Oncology Group status ≥2 at second-line therapy initiation. In second line, a majority of patients initiated either non-platinum-based chemotherapy (55.6%) or endocrine therapy (16.2%). Physician-reported real-world overall response rate (classified as complete or partial response) to second-line therapy was 34.5%, median rwPFS was 7.4 months (95% CI 6.2 to 8.0) and median OS was 11.0 months (95% CI 9.9 to 12.3).

CONCLUSIONS

Patients had poor clinical outcomes with a median OS of <1 year and rwPFS of approximately 7 months, highlighting the significant unmet medical need in pretreated recurrent/advanced endometrial cancer patients. Novel therapies with potential to improve PFS and OS over conventional therapies could provide significant clinical benefit.

Cost effectiveness of pembrolizumab plus lenvatinib compared with chemotherapy for treating previously treated advanced endometrial cancer in Sweden

OBJECTIVE

Pembrolizumab plus lenvatinib was recently approved for the treatment of advanced or recurrent endometrial carcinoma in women with disease progression on or following prior treatment with a platinum‑containing therapy in any setting, and who are not candidates for curative surgery or radiation (KEYNOTE-775/Study-309; NCT03517449). The objective was to assess the cost effectiveness of pembrolizumab plus lenvatinib compared with chemotherapy from a Swedish healthcare perspective.

MATERIALS AND METHODS

A lifetime partitioned-survival model with three health states (progression free, progressed disease, death) was constructed. Chemotherapy was represented by paclitaxel or doxorubicin. Overall survival, progression-free survival, time on treatment, and utility data were obtained from KEYNOTE-775 (database lock: March 1, 2022). Costs (in 2020 Swedish Krona [SEK]) included drug acquisition and administration, health state, end of life, adverse event management, subsequent treatment, and societal (scenario analysis). Outcomes were calculated as quality-adjusted life-years (QALY) and life-years. Model results were presented as incremental cost-effectiveness ratios for all-comers, patients with proficient mismatch repair tumors, and deficient mismatch repair tumors. Deterministic and probabilistic sensitivity analyses were conducted.

RESULTS

Pembrolizumab plus lenvatinib is a cost-effective treatment when compared with chemotherapy, with estimated deterministic and probabilistic incremental cost-effectiveness ratios of SEK 795,712 and 819,757 per QALY gained. Pembrolizumab plus lenvatinib was associated with a large incremental QALY and life-year gain per person versus chemotherapy over the model time horizon (1.49 and 1.76).

LIMITATIONS

Time-to-event data were incomplete and semiparametric and parametric curves were utilized for lifetime extrapolation. Willingness-to-pay thresholds, costs, and utility weights vary by country, which would vary the treatment's cost effectiveness in different countries.

CONCLUSIONS

This partitioned survival analysis suggests that pembrolizumab plus lenvatinib is cost effective compared with chemotherapy in Sweden for women with advanced or recurrent endometrial carcinoma following previous systemic therapy. Results were robust to mismatch repair status and to changes in parameters/assumptions.

Outcomes of dostarlimab versus chemotherapy in post-platinum patients with recurrent/advanced endometrial cancer: data from the GARNET trial and the National Cancer Registration Service in England

OBJECTIVES

Immune checkpoint inhibitors have emerged as novel treatment options in patients with endometrial cancer. In this study we aimed to compare the survival outcomes of patients with recurrent or advanced endometrial cancer. These patients had received dostarlimab after platinum-based chemotherapy in the single-arm, Phase I GARNET trial. We compared them with a matched indirect real-world cohort.

METHODS

The real-world cohort was established using National Cancer Registration and Analysis Service data, with five treatment-specific real-world sub-cohorts identified. To compare clinical outcomes between the GARNET trial and real-world cohorts, we performed matching-adjusted indirect comparisons. We used prognostic variables to create matching scenarios, including scenario 1 that incorporated grade, histology, and platinum-based chemotherapy number; scenario 2 that considered histology and platinum-based chemotherapy number; and scenario 3 that included race/ethnicity, stage at diagnosis, histology, and prior surgery. Overall survival was defined as the time between the first dostarlimab dose or second-line real-world treatment and death. Adjusted hazard ratios for matching-adjusted indirect comparisons were estimated via weighted Cox proportional-hazards models. Progression-free survival, using time-to-next treatment as a proxy for real-world cohorts, was summarized descriptively.

RESULTS

Distribution of baseline characteristics that were matched was similar between the GARNET cohort (n=153) and the real-world cohort (n=999). The most common International Federation of Gynecology and Obstetrics (FIGO) stage in both cohorts was stage III/IV (n=88; 57.5% and n=778; 77.9%, respectively), with endometroid histology predominating in the GARNET cohort (n=121; 79.1%) and non-endometrioid the predominant form in the real-world cohort (n=575; 57.6%). The median overall survival for dostarlimab was longer (range 27.1-40.5 months [95% confidence interval (CI) 6.4-non-estimable and 19.4-non-estimable]) both before and after matching for all scenarios compared with the real-world cohort (10.3 months). Across all matching scenarios, patients in the GARNET cohort had a decreased risk of death, with a HR for overall survival of 0.32 (p<0.0001) before matching, as compared with the overall real-world cohort and most treatment-specific real-world cohorts. For all three scenarios, progression-free survival rates at 12 and 18 months were higher for patients on dostarlimab compared with the real-world cohort (0.48 and 0.43 respectively before matching in the GARNET cohort vs 0.28 and 0.16 respectively in the real-world cohort; using time to next treatment as proxy). The effective sample size for scenario 1 was low when compared with the other scenarios (scenario 1: n=18; scenario 2: n=62; scenario 3: n=67).

CONCLUSION

In this adjusted indirect dataset, patients with recurrent/advanced mismatch repair deficient/microsatellite instability-high endometrial cancer post-platinum-based chemotherapy who received dostarlimab in the GARNET trial had significantly improved overall survival compared with patients receiving current second-line treatment in England.

Treatment Patterns and Outcomes Among Patients With Advanced or Recurrent Endometrial Cancer Initiating First-Line Therapy in the United States

Background: Patients with advanced or recurrent endometrial cancer (EC) typically have limited treatment options and poor long-term survival outcomes following first-line therapy. Real-world treatment patterns and survival outcomes data are limited for patients in this setting. Objectives: The objective of this retrospective study was to describe real-world demographics, clinical characteristics, treatment patterns, and overall survival among patients in the United States with primary advanced or recurrent EC who initiated at least 1 line of therapy (LOT). Methods: Patients with a diagnosis of primary advanced or recurrent EC in a real-world database from January 1, 2013, to July 31, 2021, were included. The date for inclusion was the date of EC diagnosis documentation; patients were indexed for treatment patterns and outcomes at the start of the first LOT and at the start of each subsequent LOT they initiated. Data were stratified by subgroups of patients who had mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) tumors. Results: A total of 1961 patients who received at least 1 LOT were included. Most patients in this cohort, and the dMMR/MSI-H subgroup, received a platinum combination as first-line treatment, with carboplatin-paclitaxel being the most common regimen. Only 53% of patients who received first-line treatment subsequently received second-line therapy. Of the patients who received at least 1 LOT, use of immunotherapy in the second-line setting was more common in the dMMR/MSI-H subgroup. Median overall survival ranged from 14.1 to 31.8 months across the 5 most frequently used first-line treatment regimens in the ≥1 LOT cohort and became shorter with each subsequent LOT. Discussion: The use of platinum-based chemotherapy for first-line treatment of advanced or recurrent EC predominates in the real-world setting, despite the poor long-term survival outcomes associated with most of these regimens. Conclusions: Patients with recurrent/advanced EC have a poor prognosis, highlighting the need for therapies with more durable benefits.

Real-world dostarlimab use in advanced/recurrent endometrial cancer in France

INTRODUCTION

In October 2020, the French Health Authority granted early access outside of the clinical trial setting for dostarlimab, a programmed death-1 inhibitor. Dostarlimab was approved by the European Medicines Agency (in April 2021) as monotherapy for patients with post-platinum mismatch repair deficient/microsatellite instability-high advanced/recurrent endometrial cancer, based on the results of the GARNET trial (NCT02715284).

METHODS

This was a real-world descriptive analysis of patients granted cohort temporary authorization of use to receive dostarlimab between November 2020 and June 2021. Physicians could complete follow-up forms at each treatment cycle to provide clinical information, safety, and efficacy data. Safety and disease progression data were also captured through pharmacovigilance reports.

RESULTS

Of 95 temporary authorization of use requests made by 80 oncologists in 59 French hospitals, 87 patients were eligible, and 80 received≥1 dose of dostarlimab. Based on treatment response assessments received (n=43), the mean (standard deviation) time from treatment initiation to response evaluation was 11 (6) weeks. The disease control rate (complete plus partial responses plus stable disease rates) was 56% (n=24/43), and the overall response rate was 35% (n=15/43); both consistent with those reported in the GARNET trial. No new safety signals were reported.

DISCUSSION

The enrolment of 80 patients in an 8-month period highlights the need for access to novel treatment regimens in France for these patients post-platinum. Prospective randomized studies are ongoing to assess the efficacy and safety of dostarlimab and other checkpoint inhibitors as first-line treatment in patients with endometrial cancer.

Association Between Intermediate End Points, Progression-free Survival, and Overall Survival in First-line Advanced or Recurrent Endometrial Cancer

PURPOSE

Advanced/recurrent endometrial cancer is associated with poor long-term outcomes. Clinical studies of novel regimens are ongoing, but given that data on overall survival (OS) take a long time to mature, surrogate end points are often used to support clinical-research interpretation. The aim of this study was to explore the correlation between progression-free survival (PFS)/time to progression (TTP) and OS across multiple time points in the first-line treatment of advanced/recurrent endometrial cancer.

METHODS

This study comprised meta-analyses of Phase 2/3 randomized, controlled trials of first-line treatments in patients with advanced primary or first-recurrent endometrial cancer identified via systematic literature review. The strength of the surrogacy relationship was assessed by correlation analyses (estimated with Spearman and Pearson correlation coefficients) and weighted linear regression.

FINDINGS

Data from 15 studies were included. PFS and TTP (TTP was reported in one study only) were highly correlated with future OS at multiple time points (Spearman values, 0.83-0.90; Pearson values, 0.86-0.93), suggesting that a change in PFS/TTP would likely be correlated with a change in OS in the same direction. On weighted linear regression, a 10% increase in PFS/TTP probability was significantly associated with a 9.3% to 13.3% increase in the probability of future OS. The strong positive association between PFS/TTP and OS was supported by findings from sensitivity analyses based on identified sources of interstudy heterogeneity.

IMPLICATIONS

PFS/TTP is a good potential candidate for predicting long-term OS outcomes in trials of first-line treatment in patients with advanced/recurrent endometrial cancer. The findings from this report may help to inform health-authority and clinical decision makers that PFS/TTP improvements are likely to translate into subsequent OS improvements once data mature.

Recent advancements in tumour microenvironment landscaping for target selection and response prediction in immune checkpoint therapies achieved through spatial protein multiplexing analysis

Immune checkpoint therapies have significantly advanced cancer treatment. Nevertheless, the high costs and potential adverse effects associated with these therapies highlight the need for better predictive biomarkers to identify patients who are most likely to benefit from treatment. Unfortunately, the existing biomarkers are insufficient to identify such patients. New high-dimensional spatial technologies have emerged as a valuable tool for discovering novel biomarkers by analysing multiple protein markers at a single-cell resolution in tissue samples. These technologies provide a more comprehensive map of tissue composition, cell functionality, and interactions between different cell types in the tumour microenvironment. In this review, we provide an overview of how spatial protein-based multiplexing technologies have fuelled biomarker discovery and advanced the field of immunotherapy. In particular, we will focus on how these technologies contributed to (i) characterise the tumour microenvironment, (ii) understand the role of tumour heterogeneity, (iii) study the interplay of the immune microenvironment and tumour progression, (iv) discover biomarkers for immune checkpoint therapies (v) suggest novel therapeutic strategies.

Understanding Characteristics, Treatment Patterns, and Clinical Outcomes for Individuals with Advanced or Recurrent Endometrial Cancer in Alberta, Canada: A Retrospective, Population-Based Cohort Study

Endometrial cancer (EC) incidence has increased in recent decades. However, population-based outcomes data are limited. In this retrospective cohort study, we examined characteristics, treatment patterns, and clinical outcomes, including time to next treatment (TNNT) and overall survival (OS), among advanced/recurrent (A/R) EC patients between 2010 and 2018 in Alberta, Canada. Kaplan-Meier statistics evaluated TTNT and OS, stratified by patient (A/R) and treatment. A total of 1053 patients were included: 620 (58.9%) advanced and 433 (41.1%) recurrent. A total of 713 (67.7%) patients received first-line therapy: 466 (75.2%) advanced and 247 (57.0%) recurrent. Platinum-based chemotherapy (PBCT) was the most common first-line regimen (overall: 78.6%; advanced: 96.1%; recurrent: 45.3%). The median TTNT and OS from first-line therapy were 19.9 months (95% confidence interval [CI]: 17.5-23.5) and 35.9 months (95% CI: 31.5-53.5), respectively. Following first-line PBCT, the median OS from second-line chemotherapy (N = 187) was 10.4 months (95% CI: 8.9-13.3) and higher for those rechallenged with PBCT (N = 72; 38.5%) versus no rechallenge (N = 115; 61.5%) (13.3 months [95% CI: 11.2-20.9] vs. 6.4 months [95% CI: 4.6-10.4; p < 0.001]). The findings highlight poor outcomes in A/R EC, particularly following first-line therapy, and that additional tolerable therapeutic options are needed to improve patient outcomes.

An Indirect Comparison of the Efficacy and Safety of Dostarlimab and Doxorubicin for the Treatment of Advanced and Recurrent Endometrial Cancer

BACKGROUND

There is no clear standard of care for advanced/recurrent endometrial cancer (EC) following platinum-based therapy. Dostarlimab is approved for patients with mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) advanced/recurrent EC. This indirect treatment comparison (ITC) assessed dostarlimab efficacy and safety from the single-arm GARNET (NCT02715284) trial compared with doxorubicin from ZoptEC (NCT01767155).

PATIENTS AND METHODS

Patient-level data and study variables from GARNET Cohort A1 (dMMR/MSI-H EC) and the ZoptEC doxorubicin control arm were merged. Patients were matched based on eligibility criteria (main analysis population). Safety population included all patients who received treatment. The primary efficacy comparison outcome, overall survival (OS), was calculated using a Cox proportional hazards model, with adjusted stabilized inverse probability of treatment weighting. Modified assessment-scheduled matching Kaplan--Meier analysis was used for progression-free survival (PFS) and time to deterioration (TTD) in quality of life (QoL).

RESULTS

In the main analysis population, median (95% CI) OS was not reached (NR; 18.0 months--NR) for dostarlimab (n = 92) and was 11.2 (10.0-13.1) months for doxorubicin (n = 233; HR: 0.41 [95% CI: 0.28-0.61]); median PFS was 12.2 (3.3-NR) and 4.9 (4.1-6.6) months, respectively. Median TTD in QoL was NR (2.5-NR; n = 61) and 4.5 (4.1-5.4; n = 188) months, respectively. Similar rates of adverse events (AEs, 11.6% vs 15.3%) and serious AEs (34.1% vs 30.1%) were observed with dostarlimab (n = 129) and doxorubicin (n = 249). Grade ≥3 AEs occurred in 48.1% vs 78.3%, respectively.

CONCLUSION

This ITC suggests a favorable benefit:risk profile for dostarlimab in patients with dMMR/MSI-H advanced/recurrent EC.