Phase II trial of pembrolizumab with cisplatin and gemcitabine in women with recurrent platinum-resistant ovarian cancer

Effectiveness and safety of PD-1/PD-L1 inhibitors in advanced or recurrent endometrial cancer: a systematic review and meta-analysis

Background: Studies in recent years have shown that PD-1/PD-L1 inhibitors may have better effectiveness in patients with advanced or recurrent endometrial cancer. The effectiveness of PD-1/PD-L1 inhibitors is thought to be related to mismatch repair-deficient (dMMR) and mismatch repair-proficient (pMMR) classification in advanced or recurrent endometrial cancer. This study aims to evaluate the effectiveness of PD-1/PD-L1 inhibitors in patients classified as dMMR and pMMR. Methods: Medical databases were searched to identify relevant publications up to 30 November 2022. The primary outcome was comparison of objective response rate (ORR) in patients with dMMR and pMMR following treatment with PD-1/PD-L1 inhibitors; secondary outcomes were single-group ORR in patients with dMMR and in patients with pMMR, respectively. Results: Eleven studies were eligible for analysis and patients with advanced or recurrent endometrial cancer with molecular classification of dMMR had a higher total ORR than those with pMMR [odds ratio (OR), 7.70; 95% confidence interval (CI), 3.22-18.38; p < 0.01], with low evidence of between-study heterogeneity (I2 = 0%). The total ORR of patients with advanced or recurrent endometrial cancer with molecular type dMMR was 51.9% (95% CI, 33.6%-69.9%). The overall ORR of patients with advanced or recurrent endometrial cancer with molecular type pMMR was 16.1% (95% CI, 5.5%-30.3%). Conclusion: In our including studies, the patients with advanced or recurrent endometrial cancer with molecular types of dMMR and pMMR, following treatment with PD-1/PD-L1 inhibitors, the total ORR of patients with dMMR was higher than that of patients with pMMR. Since the current number of studies is not very large, it is possible that more studies will be published in the future and more precise results will be discussed further.

Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer

Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.

Efficacy of PD-1/PD-L1 inhibitors in ovarian cancer: a single-arm meta-analysis

Several studies have evaluated the efficacy of PD-1/PD-L1 inhibitors in ovarian cancer; however, the response rate varies. This study aims to explore the efficacy of anti-PD-1/PD-L1 therapy in ovarian cancer. A quantitative meta-analysis was performed through a systematic search in PubMed, Web of Science, and the Cochrane Library. The pooled ORR was calculated and compared. Fifteen trials were included in this meta-analysis. Our analyses showed that the pooled ORR of all included studies was 19% (95% CI: 13%, 27%). Single PD-1/PD-L1 inhibitors had the lowest ORR of 9% (95% CI: 7%, 12%), while the combination of PD-1/PD-L1 inhibitors and chemotherapy had the highest ORR of 36% (95% CI: 24%, 51%). This study showed that PD-1/PD-L1 inhibitors alone have limited efficacy for ovarian cancer. The combination of PD-1/PD-L1 inhibitors and chemotherapy could be chosen as the recommended modality for further study.

Efficacy and Safety of Pembrolizumab in Combination With Bevacizumab and Oral Metronomic Cyclophosphamide in the Treatment of Recurrent Ovarian Cancer: A Phase 2 Nonrandomized Clinical Trial

Importance

Treatment options for recurrent ovarian cancer are of limited clinical benefit and adversely affect patient quality of life, representing an unmet need for tolerable effective therapies.

Objective

To assess the efficacy and safety of a combination of pembrolizumab with bevacizumab and oral metronomic cyclophosphamide in patients with recurrent platinum-sensitive, platinum-resistant, or refractory epithelial ovarian, fallopian tube, or primary peritoneal cancer.

Design, Setting, and Participants

This open-label, single-arm phase 2 cohort study enrolled patients from September 6, 2016, to June 27, 2018, at a single institution in the United States. Eligible patients had recurrent ovarian cancer, measurable disease per immune-related Response Evaluation Criteria In Solid Tumors (irRECIST), and Eastern Cooperative Oncology Group performance status of 0 to 1. Data were analyzed from September 6, 2016, to February 20, 2020.

Interventions

Patients received intravenous pembrolizumab, 200 mg, and bevacizumab, 15 mg/kg, every 3 weeks and oral cyclophosphamide, 50 mg, once daily during the treatment cycle until disease progression, unacceptable toxic effects, or withdrawal of consent.

Main Outcomes and Measures

Primary outcomes were objective response rate (ORR) and progression-free survival (PFS).

Results

Of the 40 women enrolled, 30 (75.0%) had platinum-resistant and 10 (25.0%) had platinum-sensitive ovarian cancer with a mean (SD) age of 62.2 (9.4) years. Three women (7.5%) had complete responses, 16 (40.0%) had partial responses, and 19 (47.5%) had stable disease in response to treatment based on irRECIST criteria, with an ORR of 47.5%, clinical benefit in 38 (95.0%), and durable response in 10 (25.0%). Median PFS was 10.0 (90% CI, 6.5-17.4) months. The most common grade 3 to 4 treatment-related adverse events were hypertension (6 [15.0%]) and lymphopenia (3 [7.5%]). The most frequently reported adverse events included fatigue (18 [45.0%]), diarrhea (13 [32.5%]), and hypertension (11 [27.5%]).

Conclusions and Relevance

In this phase 2 nonrandomized clinical trial, the combination of pembrolizumab with bevacizumab and oral cyclophosphamide was well tolerated and demonstrated clinical benefit in 95.0% and durable treatment responses (>12 months) in 25.0% of patients with recurrent ovarian cancer. This combination may represent a future treatment strategy for recurrent ovarian cancer.

Trial Registration

ClinicalTrials.gov Identifier: NCT02853318.