Anti-PD-1 therapy plus chemotherapy versus anti-PD-1 therapy alone in patients with high-risk chemorefractory or relapsed gestational trophoblastic neoplasia: a multicenter, retrospective study

Immunotherapy in gestational trophoblastic neoplasia: advances and future directions

Gestational trophoblastic neoplasia (GTN) is a rare but aggressive malignancy that follows normal or aberrant pregnancies. Until the advent of immunotherapy in 2017, surgery and chemotherapy were the standard treatment modalities, with chemotherapy remaining the cornerstone. However, chemoresistance and high-risk disease present significant challenges in managing GTN. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors (ICIs), have offered new hope for managing these difficult cases. This review provides the comprehensive overview of the mechanisms underlying ICIs in GTN, and explores the potential synergy of combining ICIs with targeted therapies, such as vascular endothelial growth factor and epidermal growth factor receptor inhibitors. We also provide an overview of the latest evidence on the use of ICIs in treating GTN, focusing on their effectiveness in both low- and high-risk cases, as well as in chemorefractory settings. In addition, we discuss ongoing clinical trials, immune-related adverse events associated with ICIs, biomarker-driven approaches, immunosuppressive tumor microenvironments, and the challenges posed with ICIs resistance. The review also explores future directions, including the integration of ICIs into standard regimens, the potential for personalized treatment based on tumor biology, and the importance of fertility preservation in young patients with GTN. In conclusion, while challenges remain, immunotherapy represents a promising frontier in GTN treatment, with the potential to improve outcomes and provide a more personalized approach to care.

Pembrolizumab in gestational trophoblastic neoplasia: Systematic review and meta-analysis with sub-group analysis of potential prognostic factors

OBJECTIVE

To assess the performance of pembrolizumab for the treatment of Gestational Trophoblastic Neoplasia (GTN).

METHODS

The Medical Subject Headings related to immunotherapy/pembrolizumab and GTN were used alone or in combination to retrieve relevant articles. The authors searched in EMBASE, MEDLINE/PubMed, Elsevier's Scopus, and Web of Science until November/2024. The authors included any randomized controlled trials, cohort studies, case series, and case reports focusing on pembrolizumab treatment in GTN. Meta-analysis of proportions was carried out employing a random-effects model. The meta-analysis employed the inverse variance method, with the arcsine link function for the analysis of proportional data. All analyses were performed using Stata 18. For all analyses, a p-value < 0.05 indicated statistical significance. This study was registered on PROSPERO (CRD42023493329).

RESULTS

A total of 550 studies were identified after a literature search among which 15 original studies were included in the systematic review and in the meta-analysis. Pembrolizumab induced complete sustained remission in 71.59% (95% CI 53.27‒84.78%; I2 = 0.00%, H2 = 1.00, p = 0.90) of cases. The subgroups meta-analysis showed pembrolizumab had similar performance, regardless of age (< 40 vs. ≥ 40-years-old, p = 0.38), GTN histopathology (Placental Site Trophoblastic Tumor [PSTT], Epithelioid Trophoblastic Tumor [ETT]/noninvasive mole/others versus invasive mole/choriocarcinoma, p = 0.48), time from diagnosis to the beginning of immunotherapy (< 4 vs. ≥ 4-years, p = 0.84), pembrolizumab combined with chemotherapy (yes vs. no, p = 0.66).

CONCLUSIONS

Pembrolizumab seems an effective treatment for patients with high-risk GTN with chemoresistant or relapsed disease, including cases of PSTT/ETT, notwithstanding patient age, time to initiate immunotherapy and whether or not it was associated with chemotherapy.

Future Directions for Gestational Trophoblastic Disease

Gestational trophoblastic disease encompasses a spectrum of premalignant and malignant conditions. While centralized care models significantly improve survival rates, many countries still lack such specialized centers, leading to preventable deaths. Current research focuses on refining diagnostic and treatment methods, aiming to better predict the risk of malignancy and reduce the need for aggressive therapies. Immunotherapy has emerged as a promising treatment modality, offering high cure rates with fewer side effects compared to traditional chemotherapy. Global efforts must continue to expand access to specialized care and integrate new therapies to improve outcomes and reduce treatment-related harm.

Placental Site Trophoblastic Tumors and Epithelioid Trophoblastic Tumors

Placental site trophoblastic disease (PSTT) and epithelioid trophoblastic tumor (ETT) are the rarest forms of gestational trophoblastic neoplasia (GTN) with unique clinical features and treatment considerations. Unlike other GTN, human chorionic gonadotropin (hCG) is minimally, if at all, elevated. Additionally, unlike other GTN, WHO risk scores are not applied to PSTT/ETT. Management of PSTT/ETT is predominately surgical with hysterectomy and possible lymphadenectomy. There are case reports of fertility sparing surgery for uterine confined disease. Multi-agent chemotherapy ± pembrolizumab is added for those with high risk features defined as advanced stage disease and those diagnosed ≥48 months from the antecedent pregnancy. Survival for early stage, low risk disease remains quite good but the prognosis for high-risk disease is poor and an scenario for which novel treatments are needed.

Use of a PD-1 checkpoint inhibitor in a patient with ultra-high-risk gestational trophoblastic neoplasia and gastrointestinal metastases

Gestational trophoblastic neoplasia (GTN) are rare diseases that are typically chemo-responsive. While the majority of patients are cured with chemotherapy alone, a small portion of cases are fatal due to chemotherapy resistance. Risk factors for treatment failure are liver and brain metastases, extensive disease, and chemo-refractory disease. Gastrointestinal (GI) metastases are extremely rare and indicate a poor prognosis. Treatment with immunotherapy has been studied and included in treatment guidelines for high-risk and chemotherapy-resistant GTN. This case reports on the early use of programmed cell death protein 1 (PD-1) inhibitor in combination with systemic chemotherapy in a patient with ultra-high risk GTN with GI metastases.

Prognosticating gestational trophoblastic neoplasia: from FIGO 2000 to future models

The FIGO 2000 Prognostic Scoring System is a global standard for prognostication in patients with gestational trophoblastic neoplasia (GTN). However, the system has not been updated in over 20 years, and in clinical practice it has several critical limitations, including inadequate assessment of single-agent chemotherapy resistance and overuse in unsuitable clinical scenarios. This review critically examines these shortcomings and summarizes recent efforts to refine the system. After identifying its limitations, we propose novel refinements: instead of relying on a single system to address multiple clinical objectives, we advocate for specialized scoring models, each tailored to a specific clinical goal. This approach simplifies and enhances the effectiveness of prognostic assessments. Additionally, biological and genetic markers must be integrated into these models to improve accuracy. Looking ahead, we emphasize the need for advanced technologies and multicentre collaboration to build more personalized and adaptive GTN management frameworks, ultimately improving clinical practice and outcomes.

Funding

This work was supported by the National Key R&D Program of China (2023YFC2705802) and National High Level Hospital Clinical Research Funding (2022-PUMCH-C-058).

Evolution of Treatment Strategies for Gestational Trophoblastic Neoplasia: Chemotherapy, Immunotherapy, and Molecular Targeted Therapy

OPINION STATEMENT

In addressing Gestational Trophoblastic Neoplasia (GTN), it is imperative to acknowledge the evolving landscape of treatment options, especially in light of the challenges posed by traditional methods. While historically, surgical interventions, radiation therapy, and chemotherapeutic agents have been the mainstays, the emergence of resistance and high-risk scenarios necessitates a reevaluation of our therapeutic approaches. Our review highlights the promising advancements in immunotherapy and molecular targeted therapy as viable alternatives for GTN management. The introduction of immune checkpoint inhibitors and kinase inhibitors offers a paradigm shift, particularly for patients resistant to conventional chemotherapy regimens. These novel therapies not only exhibit efficacy but also demonstrate manageable toxicity profiles, particularly in high-risk cases. However, integrating these innovative treatments into established international guidelines presents a formidable task. As we move forward, it is imperative that future research not only prioritizes fertility preservation but also rigorously evaluates long-term toxicity implications. International collaboration becomes pivotal in addressing the nuances of this rare and complex disease. In conclusion, our review underscores the need for a nuanced approach to GTN treatment, one that prioritizes reduced toxicity and improved quality of life. By embracing the advancements in immunotherapy and molecular targeted therapy, we can pave the way for more effective and patient-centered care in the management of GTN.

Assessing Additive Interactions between Protective Factors Using Relative Risk Reduction Due to Interaction

Background and Objectives: In the context of disease prevention, interaction on an additive scale is commonly assessed to determine synergistic effects between exposures. While the "Relative Excess Risk due to Interaction" represents the main measure of additive interaction between risk factors, in this study we aimed to extend this approach to assess additive interaction between factors known to prevent the event's occurrence, such as medical interventions and drugs. Materials and Methods: We introduced and described the "Relative Risk Reduction due to Interaction" (RRRI) as a key measure to assess additive interactions between preventive factors, such as therapeutic interventions and drug combinations. For RRRI values closer to 1, the combination of exposures has a greater impact on reducing the event risk due to their interaction. As a purely illustrative example, we re-evaluated a previous investigation of the synergistic effect between statins and blood pressure-lowering drugs in preventing major adverse cardiovascular events (MACE). Moreover, simulation studies were used to empirically evaluate the performance of a robust Poisson regression model to estimate RRRI across different scenarios. Results: In our example, the drug combination revealed a positive additive interaction in further reducing MACE risk (RRRI > 0), even if not statistically significant. This result is more straightforward to interpret as compared to the original one based on the RERI. Additionally, our simulations highlighted the importance of large sample sizes for detecting significant interaction effects. Conclusion: We recommend RRRI as the main measure to be considered when exploring additive interaction effects between protective exposures, such as the investigation of synergistic effects between drug combinations or preventive treatments.

Case report: Multidrug resistant gestational trophoblastic neoplasia: focus on failure of immunotherapy and success of high-dose chemotherapy

Gestational trophoblastic neoplasia (GTN) is extremely rare, but has a very good prognosis, with a cure rate close to 100%, for low-risk diseases. This article describes the case of a healthy 28-year-old nulliparous patient with GTN resistant to multiple lines of treatment. The era of immunotherapy is revolutionizing oncology, having already proved its worth in the treatment of many cancers. This article will have a specific focus on the emerging role of immunotherapy in the treatment of GTN. Unfortunately, the use of an immune checkpoint inhibitor (ICI) failed in our case, emphasizing on the necessity to clearly define the future role of immune therapy in GTN. Finally, given the rapid progression of the disease after hysterectomy, induction with Paclitaxel- Ifosfamide and then intensification with high-dose Carboplatin and Etoposide with peripheral blood stem cell support was given as a rescue therapy with still curative intent.

Role of immune checkpoint inhibitors combined with chemotherapy in recurrent drug-resistant gestational trophoblastic neoplasia: Four case reports and literature review

BACKGROUND

Multiple studies have confirmed that programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) is widely expressed in gestational trophoblastic neoplasia (GTN) tissues. Therefore, immune checkpoint inhibitors may be an option for the treatment of recurrent and drug-resistant GTN.

CASE

Four patients with recurrent or drug-resistant GTN who were treated with PD-1/PD-L1 checkpoint inhibitor agents combined with chemotherapy were reported. The mean age of recurrence was 45.8 years (35-56 years), including three cases of choriocarcinoma (CC) and one case of invasive mole (IM). International Federation of Gynecology and Obstetrics (FIGO) prognosis score: ≤6 (low risk) in one case, 7-12 (high risk) in one case, ≥13 (very high risk) in two cases. There were two cases of lung metastasis and one case of vulvar and inguinal lymph node metastasis. One of the four patients underwent total hysterectomy and one patient underwent resection of lung metastases. All the four patients received comprehensive treatment of immunotherapy combined with chemotherapy after relapse, among which one patient achieved complete response (CR), two patients achieved partial response (PR), and one patient developed progressive disease (PD). Three patients who achieved PR or CR were maintained by single agent immunotherapy after combination therapy, and there was no disease recurrence during follow-up. One patient with PD also achieved CR after using salvage chemotherapy after recurrence, and there was no disease recurrence during follow-up. During the treatment, four patients had different degrees of immune-related adverse reactions, all of which were grade I-II, and no severe adverse reactions were found.

CONCLUSION

Immune checkpoint inhibitors combined with chemotherapy has an impressive therapeutic effect on recurrent or drug-resistant GTN with mild adverse reactions, which can be used as a treatment option for such patients. However, due to the lack of large sample data support, the specific time and treatment course of its use, long-term use of adverse reactions and whether it affects fertility function remain to be solved.

Intracardiac metastasis of gestational choriocarcinoma: a case report and literature review

INTRODUCTION

Gestational trophoblastic neoplasia (GTN) with intracardiac metastasis is rare, and here we reported a patient with intracardiac metastasis of high-risk and refractory gestational choriocarcinoma and reviewed relevant literatures.

CASE PRESENTATION

A 37-year-old woman presented with vaginal bleeding and high level of β-human chorionic gonadotropin (β-hCG) at 199,060 (mIU/mL). It was clinically diagnosed with gestational choriocarcinoma. The patient initially received eight cycles of chemotherapy but unsatisfactory response was observed, and the level of β-hCG still ranged between 5000 and 10,000. Then there was found intracardiac masses in the right atrium (2.6*1.7 cm), anterior chordae tendineae of the tricuspid valve (1.4*0.7 cm) and the right ventricle (4.1*2.9 cm) by ultrasonic cardiogram (UCG). PET/CT highly suspected the intracardiac metastasis of choriocarcinoma (SUVmax = 9.3) and no disease was found in the lung and pelvis. The patient undertook complete intracardiac masses resection. The pathology confirmed the intracardiac metastasis of disease. After a week of operation, the UCG found a 5.4*4.2 cm mass in the right atrium again. Considering the poor prognosis, the patient received palliative care and eventually died of disease progression.

CONCLUSION

Intracardiac metastasis of GTN is an aggressive sign of disease. Patients can benefit from chemotherapy and surgery. Future investigation of PD-1 immunotherapy combines with chemotherapy are expected to improve the prognosis in this group of patients.

Progress of immunotherapies in gestational trophoblastic neoplasms

BACKGROUND

Different from other malignant gynecologic tumors, gestational trophoblastic neoplasms (GTNs) exhibit an exceptionally high cure rate primarily through chemotherapeutic interventions. However, there exists a small subset of refractory GTNs that do not respond to conventional chemotherapies. In such cases, the emergence of immunotherapies has demonstrated significant benefits in managing various challenging GTNs.

PURPOSE

This article aims to provide a comprehensive and systematic review of the immune microenvironment and immunotherapeutic approaches for GTNs. The purpose is to identify potential biomarkers that could enhance disease management and summarize the available immunotherapies for ease of reference.

METHODS

We reviewed the relevant literatures toward immunotherapies of GTNs from PubMed.

CONCLUSION

Current immunotherapeutic strategies for GTNs mainly revolve around immune checkpoint inhibitors (ICIs) targeting programmed death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1). Prominent examples include avelumab, pembrolizumab, and camrelizumab. However, existing researches into the underlying mechanisms are still limited.

Immunotherapy for Gestational Trophoblastic Neoplasia: A New Paradigm

BACKGROUND

Immune checkpoint immunotherapy (CPI) targeting programmed cell death 1 (PD-1)/ligand (PD-L1) has been shown to be an effective treatment for gestational trophoblastic neoplasia (GTN). This includes those with multidrug resistance, ultra-high-risk disease, and epithelioid trophoblastic tumour/placental site trophoblastic tumour subtypes that are inherently chemotherapy resistant, but there is also emerging evidence in low-risk disease.

OBJECTIVES

We set out to generate an overview of the current data supporting the use of CPI for GTN in both high-risk and low-risk disease and to consider future research goals and directions in order to implement CPI in current treatment guidelines.

METHODS

We identified and reviewed the published data on the use of CPI agents in GTN.

OUTCOME

133 patients were identified who had been treated with CPI for GTN with pembrolizumab (23), avelumab (22), camrelizumab (57), toripalimab (15), or other anti-PD-1 agents (16), of whom 118 had high-risk diseases, relapse or multi-drug resistant disease, and 15 low-risk diseases. Overall 85 patients achieved complete remission, 77 (of 118) with high-risk disease, and 8 (of 15) with low-risk disease. 1 patient with complete remission in the high-risk group developed a relapse 22 months after anti-PD-1 treatment had been stopped. Treatment was generally well tolerated across studies.

CONCLUSIONS AND OUTLOOK

The majority of high-risk patients (77/118) treated with CPI are cured and this is particularly relevant amongst those with chemotherapy resistant disease who otherwise have very limited treatment options. Priorities for future research include determining whether these agents have a role earlier in the disease course, the utility of combination with chemotherapy, and effects on future fertility. Treatment availability remains a concern due to the high price of these agents.

Immunotherapy in the treatment of chemoresistant gestational trophoblastic neoplasia - systematic review with a presentation of the first 4 Brazilian cases

OBJECTIVE

To evaluate the efficacy of immunotherapy for GTN treatment after methotrexate-resistance or in cases of multiresistant disease, through a systematic review, as well as to present the first 4 Brazilian cases of immunotherapy for GTN treatment.

METHODS

Three independent researchers searched five electronic databases (EMBASE, LILACS, Medline, CENTRAL and Web of Science), for relevant articles up to February/2023 (PROSPERO CRD42023401453). The quality assessment was performed using the Newcastle Ottawa scale for case series and case reports. The primary outcome of this study was the occurrence of complete remission. The presentation of the case reports was approved by the Institutional Review Board.

RESULTS

Of the 4 cases presented, the first was a low-risk GTN with methotrexate resistance unsuccessfully treated with avelumab, which achieved remission with sequential multiagent chemotherapy. The remaining 3 cases were high-risk multiagent-resistant GTN that were successfully treated with pembrolizumab, among which there were two subsequent gestations, one of them with normal pregnancy and healthy conceptus. Regarding the systematic review, 12 studies were included, only one of them on avelumab, showing a 46.7% complete remission rate. The remaining 11 studies were on pembrolizumab, showing an 86.7% complete remission rate, regardless of tumor histology. Both immunotherapies showed good tolerability, with two healthy pregnancies being recorded: one after avelumb and another after pembrolizumab.

CONCLUSION

Immunotherapy showed effectiveness for GTN treatment and may be especially useful in cases of high-risk disease, where pembrolizumab achieves a high therapeutic response, regardless of the histological type, and despite prior chemoresistance to multiple lines of treatment.