Real-World Experience with Pembrolizumab Treatment in Patients with Heavily Treated Recurrent Gynecologic Malignancies

Real-world efficacy and safety of low-dose pembrolizumab in patients with advanced and refractory gynecologic cancers

OBJECTIVE

The approved standard dose of pembrolizumab (200 mg administrated every 3 weeks) for cancer treatment imposes a significant financial burden on patients. However, no study has analyzed the clinical outcomes of low-dose pembrolizumab among individuals diagnosed with gynecologic cancer. The primary objective of this study was to assess the effectiveness and safety of a low-dose pembrolizumab regimen in real-world clinical practice.

METHODS

We retrospectively assessed the efficacy and safety data of patients with gynecologic malignancies who received pembrolizumab between 2017 and 2022 at Kaohsiung Chang Gung Memorial Hospital. Furthermore, we conducted a comparative analysis of the objective response rate (ORR) and progression-free survival (PFS) between patients with deficient mismatch repair (dMMR) and proficient MMR (pMMR).

RESULTS

A total of thirty-nine patients were included and received pembrolizumab at fixed dosages of 50 mg (5.1%), 100 mg (84.6%) and 200 mg (10.3%) per cycle. Compared to the pMMR group, the dMMR group exhibited a tendency toward improved ORR (45.5% vs. 13.0%, p = 0.074), and notably, the median duration of response remained unreached. There was no significant difference in PFS between the dMMR and pMMR groups; however, the patients with dMMR in tumor tissue had a trend of better survival (p = 0.079). Incidence of immune-related adverse events (irAEs) of any grade was observed in 13 patients (33.3%), with 3 individuals (7.7%) experiencing grade 3 or 4 events.

CONCLUSION

Low-dose pembrolizumab may be a cost-effective and safe treatment option without compromising clinical outcomes in patients with refractory gynecologic cancers.

Rechallenge with Anti-PD-1 Inhibitors in Patients with Recurrent Gynecologic Malignancies

PURPOSE

We investigated the treatment outcomes of immune checkpoint inhibitor (ICI) rechallenge in patients with recurrent gynecologic cancers.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 20 patients who underwent rechallenge with PD-1 inhibitors for recurrent gynecologic cancers at two tertiary centers between January 2018 and September 2022.

RESULTS

The median age of the patients was 56 years (range, 35-79). Seven (35%), 1 (5%), 11 (55%), and 1 (5%) patients presented with cervical, vulvar, ovarian, and endometrial cancers, respectively. Sixteen (80%) patients received pembrolizumab and 4 (20%) received nivolumab at first treatment. Eight (40%) and 12 (60%) patients received pembrolizumab and nivolumab, respectively, at second treatment. At initial ICI treatment, 1 (5%) and 4 (20%) cases of a complete response (CR) and a partial response (PR) were observed, respectively, with a median progression-free survival (PFS) of 2.8 months (range, 1.4-49.6). Reasons for first ICI discontinuation were disease progression (n=16), severe adverse events (AEs) (n=2), and treatment withdrawal (n=2). During second ICI treatment, 1 (5%) patient achieved CR, 2 (10%) showed PR, and 5 (25%) experienced stable disease. The median PFS to second ICI was 1.8 months (range, 0.4-10.4). The median overall survival was 21.3 months (range, 10.1-52.7). Neither patient who discontinued ICI treatment due to AEs experienced AE relapse during second ICI treatment.

CONCLUSION

These results suggest that responses to ICI rechallenge are not as intolerable as responses to previous ICI. Clinicians should carefully consider rechallenge with PD-1 inhibitors outside of clinical trials until there are sufficient data to routinely support this practice.

Immune Checkpoint Inhibitors Targeting the PD-1/PD-L1 Pathway in Advanced, Recurrent Endometrial Cancer: A Scoping Review with SWOT Analysis

Results of recent clinical trials using the immune check point inhibitors (ICI) pembrolizumab or dostarlimab with/without lenvatinib has led to their approval for specific molecular subgroups of advanced recurrent endometrial cancer (EC). Herein, we summarise the clinical data leading to this first tissue-agnostic approval. As this novel therapy is not yet available in the United Kingdom standard care setting, we explore the strengths, weaknesses, opportunities, and threats (SWOT) of ICI treatment in EC. Major databases were searched focusing on clinical trials using programmed cell death protein 1 (PD-1) and its ligand (PD-L1) ICI which ultimately contributed to anti-PD-1 approval in EC. We performed a data quality assessment, reviewing survival and safety analysis. We included 15 studies involving 1609 EC patients: 458 with mismatch repair deficiency (MMRd)/microsatellite instability-high (MSI-H) status and 1084 with mismatch repair proficiency/microsatellite stable (MMRp/MSS) status. Pembrolizumab/dostarlimab have been approved for MMRd ECs, with the addition of lenvatinib for MMRp cases in the recurrent setting. Future efforts will focus on the pathological assessment of biomarkers to determine molecular phenotypes that correlate with response or resistance to ICI in order to identify patients most likely to benefit from this treatment.

Real-world utilization and outcomes of systemic therapy among patients with advanced or recurrent endometrial cancer in the United States

OBJECTIVE

Evaluate systemic therapy utilization patterns and outcomes by line of therapy among patients with advanced/recurrent endometrial cancer (EC) treated in the United States.

METHODS

This retrospective observational study used the Optum Clinformatics Extended Data Mart Date of Death database (1 January 2004-31 December 2019) and included de-identified data from adult patients with advanced/recurrent EC who were treated with first-line (1L) platinum-based chemotherapy and initiated second-line (2L) anti-neoplastic therapy. The index date was the date of 1L therapy initiation. The number and sequence of treatments received and the proportion of patients who received each type of treatment for each line of therapy were evaluated. To account for new drug approvals, patients first treated in 2018 or 2019 were also assessed separately.

RESULTS

Among the 1317 patients who met all eligibility criteria, 520 (39.5%) and 235 (17.8%) patients received 3 or 4+ lines of treatment, respectively, during a median total follow-up time of 25.2 months (range, 2.5-173.3 months) following the index date. Chemotherapy, including platinum- and non-platinum-based regimens, was the most common treatment across all lines of therapy: 2L, 80.0%; 3L, 66.2%; 4L+, 80.4%. Overall, 2.5%, 2.3%, and 8.9% of 2L, 3L, and 4L + patients, respectively, received anti-program death 1 (anti-PD-1) immunotherapies. In patients first treated in 2018 and 2019 (n = 163), 9.8% of patients received anti-PD-1 immunotherapy in the 2L. In the overall population, median time to next treatment (TTNT) was 19.3, 10.5, and 8.1 months for patients undergoing 2L, 3L, and 4L treatment, respectively.

CONCLUSIONS

Among patients with advanced/recurrent EC treated with 1L platinum-based therapy in clinical practice, chemotherapy was the most common treatment choice across all lines of therapy. Immunotherapy use was low overall but increased in patients who started treatment in 2018 or 2019. Overall, median TTNT decreased as lines of therapy increased.

Pembrolizumab in endometrial cancer: Where we stand now

Recently, immunotherapy has shown promising results in solid tumors. To the best of our knowledge, this is the first systematic review of published literature synthesizing all the available data and evaluating both the efficacy and safety of pembrolizumab in endometrial cancer. The present study was performed in accordance with the PRISMA guidelines. Eligible articles were identified by searching the MEDLINE and ClinicalTrials.gov databases, using a predefined combination of the terms 'endometrial cancer' and 'pembrolizumab'. Overall, nine articles incorporating data from 712 patients were eligible. Pembrolizumab was demonstrated to be an effective and safe therapeutic option for the management of advanced/metastatic endometrial cancer. Results of ongoing trials evaluating either pembrolizumab alone or in combination with other antineoplastic regimens are expected to confirm its efficacy in this setting of patients. Pembrolizumab appears to be both durable and robust in endometrial cancer. However, there is an emerging need for novel predictive biomarkers to guide clinical practice.

High-intensity focused ultrasound ablation in the treatment of recurrent ovary cancer and metastatic pelvic tumors: a feasibility study

OBJECTIVE

To explore the feasibility of high-intensity focused ultrasound (HIFU) ablation for treating metastatic pelvic tumors and recurrent ovary cancer.

MATERIALS AND METHODS

Eight patients with metastatic pelvic tumors or recurrent ovary cancer were enrolled in this study. Among them, 5 patients had ovarian cancer, 1 had cervical cancer, 1 had endometrial cancer, and 1 had rectal cancer. Six of them received abdominal surgical operation for their primary cancer, no one received radiotherapy. HIFU treatment was performed under conscious sedation. Vital signs were monitored during the procedure, and adverse effects were recorded. Postoperative follow-up was performed to observe pain relief and the improvement of the patient's quality of life.

RESULTS

The median age of the patients was 54 (range: 33-76) years, with a total of 12 lesions. The average volume of the lesions was 238.0 cm³. Six patients completed 12 months follow-up. Postoperative pain relief rate was 60% (3/5), and the quality of life improved in the short term. The main adverse effect of HIFU was pain in the treated area, with the pain score lower than 4, and all of which was self-relieved within 1 day after HIFU treatment. No serious complications such as skin burn, intestinal perforation, and nerve injury occurred.

CONCLUSION

HIFU is feasible for the treatment of metastatic pelvic tumors or recurrent ovary cancer without serious complications. Therefore, HIFU seems a promising treatment for recurrent ovary cancer, metastatic pelvic tumors from cervical cancer, endometrial cancer, and rectal cancer.