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<journal-id journal-id-type="publisher-id">Front. Immunol.</journal-id>
<journal-title-group>
<journal-title>Frontiers in Immunology</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Immunol.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1664-3224</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.3389/fimmu.2026.1771548</article-id>
<article-version article-version-type="Version of Record" vocab="NISO-RP-8-2008"/>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Review</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Dual PD-1 and CTLA-4 targeting in endometrial carcinoma: integrating efficacy, toxicity, and biomarkers into clinical practice</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name><surname>Zhong</surname><given-names>Lan</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="methodology" vocab-term-identifier="https://credit.niso.org/contributor-roles/methodology/">Methodology</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; original draft" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-original-draft/">Writing &#x2013; original draft</role>
</contrib>
<contrib contrib-type="author" corresp="yes">
<name><surname>Song</surname><given-names>Liang</given-names></name>
<xref ref-type="aff" rid="aff1"><sup>1</sup></xref>
<xref ref-type="aff" rid="aff2"><sup>2</sup></xref>
<xref ref-type="corresp" rid="c001"><sup>*</sup></xref>
<uri xlink:href="https://loop.frontiersin.org/people/3260769/overview"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="conceptualization" vocab-term-identifier="https://credit.niso.org/contributor-roles/conceptualization/">Conceptualization</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Data curation" vocab-term-identifier="https://credit.niso.org/contributor-roles/data-curation/">Data curation</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Funding acquisition" vocab-term-identifier="https://credit.niso.org/contributor-roles/funding-acquisition/">Funding acquisition</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="supervision" vocab-term-identifier="https://credit.niso.org/contributor-roles/supervision/">Supervision</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &amp; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-review-editing/">Writing &#x2013; review &amp; editing</role>
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<aff id="aff1"><label>1</label><institution>Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University</institution>, <city>Chengdu</city>, <state>Sichuan</state>,&#xa0;<country country="cn">China</country></aff>
<aff id="aff2"><label>2</label><institution>Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education</institution>, <city>Chengdu</city>, <country country="cn">China</country></aff>
<author-notes>
<corresp id="c001"><label>*</label>Correspondence: Liang Song, <email xlink:href="mailto:drsongliang@163.com">drsongliang@163.com</email></corresp>
</author-notes>
<pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-02-27">
<day>27</day>
<month>02</month>
<year>2026</year>
</pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2026</year>
</pub-date>
<volume>17</volume>
<elocation-id>1771548</elocation-id>
<history>
<date date-type="received">
<day>19</day>
<month>12</month>
<year>2025</year>
</date>
<date date-type="accepted">
<day>16</day>
<month>02</month>
<year>2026</year>
</date>
<date date-type="rev-recd">
<day>03</day>
<month>02</month>
<year>2026</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2026 Zhong and Song.</copyright-statement>
<copyright-year>2026</copyright-year>
<copyright-holder>Zhong and Song</copyright-holder>
<license>
<ali:license_ref start_date="2026-02-27">https://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open-access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License (CC BY)</ext-link>. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</license-p>
</license>
</permissions>
<abstract>
<p>The management of advanced endometrial cancer (EC) has been transformed by immunotherapy, raising a pivotal clinical challenge: selecting patients with mismatch repair&#x2013;deficient (dMMR) disease for intensive dual PD-1/CTLA-4 blockade versus standard PD-1 monotherapy. We conducted a narrative review of phase II/III clinical trials and key translational studies published up to 2023 to critically appraise current evidence. In dMMR EC, the conventional ipilimumab-nivolumab combination yields higher objective response rates (ORR &#x2248; 63%) than PD-1 monotherapy (ORR &#x2248; 48%) but is associated with a substantially increased incidence of grade &#x2265; 3 immune-related adverse events (&#x2248; 23% vs. &#x2248; 12%). The development of bispecific antibodies like cadonilimab, which demonstrates robust efficacy with a lower incidence of high-grade toxicity (grade &#x2265; 3 treatment-related adverse events: 8.3%), presents a promising strategy to improve the therapeutic index. For clinicians, the current decision-making process must be highly individualized, weighing factors such as tumor burden, pace of disease, and patient tolerance for toxicity in the absence of validated biomarkers to guide treatment intensity beyond dMMR status. We also addressed the critical importance of accurate MMR/MSI testing and the clinical implications of a well-documented methodological discordance rate. In contrast, for patients with mismatch repair&#x2013;proficient (pMMR) tumors, the evidence firmly supports alternative regimens, such as lenvatinib plus pembrolizumab, over dual PD-1/CTLA-4 blockade. Navigating the evolving landscape of immunotherapy in EC requires a nuanced, patient-centric approach. The integration of novel bispecific antibodies may soon simplify the balance between efficacy and toxicity, but until then, treatment selection remains a deliberate process, underscoring the gynecologic oncologist&#x2019;s pivotal role in personalizing care.</p>
</abstract>
<kwd-group>
<kwd>biomarkers</kwd>
<kwd>endometrial carcinoma</kwd>
<kwd>immune checkpoint inhibitors</kwd>
<kwd>immunotherapy</kwd>
<kwd>treatment-related adverse events</kwd>
</kwd-group>
<funding-group>
<funding-statement>The author(s) declared that financial support was received for this work and/or its publication. This work was supported by the China Foundation for Youth Entrepreneurship and Employment (25H0209) and the Sichuan Cancer Society (25H0764).</funding-statement>
</funding-group>
<counts>
<fig-count count="0"/>
<table-count count="2"/>
<equation-count count="0"/>
<ref-count count="32"/>
<page-count count="8"/>
<word-count count="4299"/>
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<custom-meta-group>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>Cancer Immunity and Immunotherapy</meta-value>
</custom-meta>
</custom-meta-group>
</article-meta>
</front>
<body>
<sec id="s1">
<title>Highlights</title>
<list list-type="bullet">
<list-item>
<p>dMMR EC: Dual PD-1/CTLA-4 blockade improves response rates but increases toxicity versus PD-1 monotherapy.</p></list-item>
<list-item>
<p>Bispecific antibodies (e.g., cadonilimab) show improved efficacy-toxicity profiles, simplifying treatment choice.</p></list-item>
<list-item>
<p>Individualized decisions integrating tumor burden &amp; progression kinetics are needed without predictive biomarkers.</p></list-item>
<list-item>
<p>MMR/MSI testing discordance necessitates confirmatory strategies for accurate patient identification.</p></list-item>
<list-item>
<p>In pMMR EC, dual checkpoint blockade has limited efficacy;lenvatinib/pembrolizumab remains standard.</p></list-item>
</list>
</sec>
<sec id="s2" sec-type="intro">
<label>1</label>
<title>Introduction</title>
<p>Endometrial carcinoma remains the most prevalent gynecologic malignancy in developed regions. Its increasing incidence rates underscore the urgent need for advanced therapeutic strategies tailored to improve patient outcomes (<xref ref-type="bibr" rid="B1">1</xref>). The molecular classification system established by The Cancer Genome Atlas has evolved from a prognostic framework to a clear guide for treatment selection (<xref ref-type="bibr" rid="B2">2</xref>). The mismatch repair&#x2013;deficient (dMMR) or microsatellite instability&#x2013;high (MSI-H) molecular subgroup comprises approximately 30% of endometrial cancer cases. This subgroup exhibits a high tumor mutational burden and an immunologically active microenvironment, making it particularly susceptible to immune checkpoint inhibition (<xref ref-type="bibr" rid="B3">3</xref>).</p>
<p>Regulatory approval of anti&#x2013;PD-1 antibodies, including pembrolizumab and dostarlimab, has established a new therapeutic paradigm for advanced mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) endometrial cancer (EC), demonstrating durable responses and manageable toxicity profiles (<xref ref-type="bibr" rid="B4">4</xref>, <xref ref-type="bibr" rid="B5">5</xref>). This success prompted investigations of more intensive immunotherapy regimens. The combination of PD-1 and CTLA-4 blockade has emerged as a highly effective strategy for advanced endometrial cancer, yet it introduces a fundamental and unresolved clinical dilemma: determining which patients will derive sufficient benefit from this approach to justify the substantial increase in toxicity risks. Although PD-L1 inhibitors such as durvalumab and atezolizumab have shown activity in other solid tumors and are under investigation in EC, the most robust clinical evidence currently supports PD-1/CTLA-4 targeting strategies in EC. This preference is based on the non-redundant biological roles of the PD-1 and CTLA-4 pathways and the demonstrated clinical synergy of their combined inhibition in dMMR/MSI-H tumors across multiple cancer types. Direct comparisons between PD-1/CTLA-4 combinations and PD-L1 inhibitors in EC are lacking, but the PD-1/CTLA-4 combination approach has generated more extensive efficacy data specifically in endometrial carcinoma. This review critically evaluates the current evidence for traditional combinations and emerging bispecific antibodies, to address this pivotal question, while underscoring the essential role of the gynecologic oncologist in navigating these complex therapeutic decisions in the absence of definitive predictive biomarkers.</p>
</sec>
<sec id="s3">
<label>2</label>
<title>Biological rationale for combination therapy</title>
<p>The therapeutic synergy between inhibition of PD-1 and CTLA-4 stems from their complementary roles in T-cell regulation. CTLA-4 primarily functions in lymphoid organs during early T-cell activation, modulating the magnitude of initial immune responses. Inhibition of CTLA-4 promotes T-cell repertoire diversification and expansion, thereby potentially recruiting novel anti-tumor clones (<xref ref-type="bibr" rid="B6">6</xref>). Conversely, the PD-1 pathway operates predominantly in peripheral tissues where it attenuates effector functions of tumor-infiltrating lymphocytes, resulting in a state of functional exhaustion. PD-1 blockade serves to reinvigorate these pre-existing antitumor T-cell populations within the tumor microenvironment (<xref ref-type="bibr" rid="B7">7</xref>).</p>
<p>This immunobiological framework aligns with the observed heterogeneity of the endometrial cancer tumor microenvironment. dMMR/MSI-H tumors typically display an immune-inflamed phenotype, characterized by abundant cytotoxic T-cell infiltration and PD-L1 expression, thereby providing the necessary immune context for effective PD-1 blockade therapy (<xref ref-type="bibr" rid="B3">3</xref>, <xref ref-type="bibr" rid="B8">8</xref>). In contrast, many mismatch repair&#x2013;proficient/microsatellite stable (pMMR/MSS) tumors exhibit immune-excluded or immune-desert phenotypes, suggesting deficiencies in initial T-cell priming and trafficking. These processes can potentially be modulated through CTLA-4 inhibition (<xref ref-type="bibr" rid="B9">9</xref>). This spectrum of &#x2018;immune-hot&#x2019; to &#x2018;immune-cold&#x2019; phenotypes, as conceptualized in the cancer-immunity cycle (<xref ref-type="bibr" rid="B10">10</xref>), provides a strategic framework for rational combination immunotherapy. Thus, the combination strategy concurrently targets both the initiation and effector phases of the cancer-immunity cycle, a principle supported by the efficacy of the nivolumab and ipilimumab combination therapy in tumors with a high mutational burden across cancer types (<xref ref-type="bibr" rid="B11">11</xref>).</p>
</sec>
<sec id="s4">
<label>3</label>
<title>Clinical evidence and therapeutic applications</title>
<sec id="s4_1">
<label>3.1</label>
<title>dMMR/MSI-H population: weighing intensity against toxicity</title>
<p>The clinical efficacy of the ipilimumab-nivolumab combination in dMMR/MSI-H endometrial cancer is primarily supported by a recent basket trial reported by Carlino et&#xa0;al. (<xref ref-type="bibr" rid="B12">12</xref>), which represents the only dedicated phase II study evaluating this specific combination in dMMR/MSI-H EC. In the prespecified endometrial cancer subgroup of this trial (n=26), the regimen demonstrated an objective response rate (ORR) of 58% (95% CI, 39&#x2013;74) and a disease control rate (DCR) of 77% (95% CI, 58&#x2013;89). While other basket trials (e.g., CheckMate 142) have included small EC cohorts, they were not powered for subtype-specific analysis (<xref ref-type="bibr" rid="B13">13</xref>). The observed efficacy is consistent with the established, potent activity of dual PD-1/CTLA-4 blockade in other dMMR/MSI-H solid tumors, such as metastatic colorectal cancer (<xref ref-type="bibr" rid="B13">13</xref>).</p>
<p>This ORR is numerically higher than the 48.5% (95% CI, 36.2&#x2013;61.0) reported for pembrolizumab monotherapy in the KEYNOTE-158 endometrial cancer cohort (<xref ref-type="bibr" rid="B4">4</xref>). However, such cross-trial comparisons must be interpreted with caution. Notably, the current standard first-line therapy for advanced EC, regardless of MMR status, is increasingly shifting toward chemo-immunotherapy combinations. The phase III NRG-GY018 trial established that adding pembrolizumab to carboplatin and paclitaxel significantly improved progression-free survival in both dMMR and pMMR cohorts (<xref ref-type="bibr" rid="B21">21</xref>). In the dMMR subgroup, the hazard ratio for progression-free survival was 0.30 (95% CI, 0.19&#x2013;0.48), demonstrating exceptional efficacy of this combination. However, there are currently no direct head-to-head trials comparing the ipilimumab-nivolumab regimen with chemo-immunotherapy in dMMR EC. Therefore, the current decision to employ this intensive regimen must carefully weigh a substantial and well-documented increase in toxicity against an incremental benefit over standard PD-1 monotherapy whose magnitude remains unquantified, while acknowledging the emerging role of first-line chemo-immunotherapy. It is also important to note that, while molecular classification guides therapy, prospective data on dual checkpoint blockade specifically stratified by TCGA molecular subgroups are limited in availability, with current evidence primarily based on MMR status. Definitive evidence establishing the superiority of the combination over PD-1 inhibitor monotherapy in endometrial cancer is awaited from the ongoing phase III NRG-GY025 trial.</p>
</sec>
<sec id="s4_2">
<label>3.2</label>
<title>Bispecific antibodies: an engineered approach to dual blockade</title>
<p>The logistical and toxicity challenges associated with co-administering two separate monoclonal antibodies have spurred the development of innovative, engineered molecules designed for coordinated dual targeting, aiming to improve the therapeutic index.</p>
<p>Cadonilimab (AK104) is a tetravalent bispecific antibody that targets both PD-1 and CTLA-4 with a single molecular entity. Its design, featuring a higher affinity for PD-1, aims to achieve preferential dual immune checkpoint blockade within the tumor microenvironment (TME). While CTLA-4 primarily functions in secondary lymphoid organs during early T-cell priming, the bispecific design of cadonilimab is theorized to concentrate dual blockade of PD-1 and CTLA-4 within the tumor microenvironment (TME). This approach potentially reduces systemic CTLA-4&#x2013;mediated toxicities while still allowing for CTLA-4 inhibition on tumor-infiltrating lymphocytes and antigen-presenting cells that have migrated to the tumor site (<xref ref-type="bibr" rid="B14">14</xref>). This localized activity may mitigate the systemic CTLA-4&#x2013;related toxicities often seen with conventional combination therapy by sparing excessive peripheral T-cell activation (<xref ref-type="bibr" rid="B14">14</xref>). Early-phase clinical trials of cadonilimab have demonstrated antitumor activity and a manageable safety profile across a spectrum of advanced solid tumors (<xref ref-type="bibr" rid="B15">15</xref>). A recent systematic review and meta-analysis reported a pooled incidence of grade &#x2265;3 treatment-related adverse events of 11.3% (95% CI, 9.5&#x2013;13.3) (<xref ref-type="bibr" rid="B16">16</xref>). The consistency of this favorable safety data across studies, characterized by a lower rate of high-grade toxicities than typically associated with conventional CTLA-4&#x2013;containing combinations, supports the premise that cadonilimab may offer an improved therapeutic index.</p>
<p>Recent phase II evidence has further solidified the potential of cadonilimab in endometrial carcinoma. A multicenter, single-arm trial evaluated cadonilimab in combination with lenvatinib as a second- or later-line therapy for patients with advanced endometrial cancer who progressed after platinum-based chemotherapy (<xref ref-type="bibr" rid="B17">17</xref>). Among 32 enrolled patients, the objective response rate was 37.5% (12/32) in the full analysis set and 42.9% (12/28) in the efficacy-evaluable set, with a compelling disease control rate of 81.3% and 92.9%, respectively. Notably, the median progression-free survival was not reached after a median follow-up of 7.6 months. The combination exhibited a manageable safety profile, with grade 3 or higher treatment-related adverse events occurring in 21.9% of patients; the most common were intestinal obstruction (6.3%), increased alanine aminotransferase (6.3%), and hypertension (3.1%). This study provides preliminary but encouraging clinical evidence for the cadonilimab-lenvatinib combination in a dedicated endometrial cancer cohort. However, these findings should be interpreted considering the current evidence base, which is derived primarily from single-arm studies. The absence of randomized comparative data necessitates cautious interpretation.</p>
<p>A distinct technological approach is embodied by QL1706, a fixed-ratio combination of two monoclonal antibodies produced using the MabPair<sup>&#xae;</sup> platform. This technology enables the co-expression of both antibodies from a single cell line, ensuring a consistent product ratio and quality (<xref ref-type="bibr" rid="B18">18</xref>). A key pharmacokinetic feature is the engineered shorter elimination half-life of the anti&#x2013;CTLA-4 component, designed to reduce its systemic exposure and potentially lower the risk of immune-related adverse events. This unique profile, which maintains sustained PD-1 blockade while limiting CTLA-4 exposure, aims to improve tolerability and facilitate longer treatment durations (<xref ref-type="bibr" rid="B18">18</xref>).</p>
<p>Together, bispecific and combination antibodies represent a shift toward the rational design of integrated dual-targeting agents. The goal of this approach is to enhance antitumor efficacy by concurrently engaging complementary immune pathways while aiming to improve the safety profile through optimized pharmacokinetics and tumor-targeted activity.</p>
</sec>
<sec id="s4_3">
<label>3.3</label>
<title>pMMR/MSS population: current therapeutic limitations and future directions</title>
<p>The efficacy of PD-1 inhibitor monotherapy is markedly limited in advanced pMMR/MSS endometrial cancer, with objective response rates consistently below 15%. In the KEYNOTE-158 endometrial cancer cohort, the ORR was 6.5% (95% CI, 2.2&#x2013;14.5) in pMMR patients (<xref ref-type="bibr" rid="B4">4</xref>), while in the GARNET study, dostarlimab monotherapy achieved an ORR of 14.1% in the pMMR/MSS population (<xref ref-type="bibr" rid="B5">5</xref>). This finding reflects the immunologically quiescent tumor microenvironment characteristic of this molecular subgroup (<xref ref-type="bibr" rid="B19">19</xref>). Similar challenges in overcoming the immunosuppressive milieu of pMMR tumors are noted across other cancer types, highlighting a common therapeutic hurdle (<xref ref-type="bibr" rid="B23">23</xref>). This fundamental limitation has redirected therapeutic strategies toward rational combinations capable of inducing inflammatory changes within the tumor immune landscape (<xref ref-type="bibr" rid="B20">20</xref>).</p>
<p>The clinical success of this paradigm is robustly supported by two landmark regimens. In the first-line setting, the phase III NRG-GY018 trial established that adding pembrolizumab to carboplatin and paclitaxel significantly improved progression-free survival (PFS) in the pMMR cohort. The hazard ratio (HR) for PFS was 0.64 (95% CI, 0.49&#x2013;0.85), confirming a substantial reduction in the risk of disease progression or death with the combination therapy (<xref ref-type="bibr" rid="B21">21</xref>). Similarly, in the later-line setting, the combination of lenvatinib with pembrolizumab demonstrated superior efficacy over chemotherapy (<xref ref-type="bibr" rid="B22">22</xref>).</p>
<p>The limited clinical efficacy observed to date with dual PD-1/CTLA-4 blockade in pMMR/MSS endometrial cancer underscores the profound immunosuppression characteristic of this molecular subgroup and indicates that this specific immunotherapeutic strategy may be insufficient to overcome the associated resistance mechanisms. Despite these results, the compelling biological rationale&#x2014;founded on the non-redundant roles of CTLA-4 and PD-1 inhibition (<xref ref-type="bibr" rid="B11">11</xref>)&#x2014;continues to motivate the investigation of this approach. Future studies in pMMR/MSS endometrial cancer should prioritize the integration of predictive biomarkers to identify patient subsets that may derive benefit from this intensive immunotherapy approach.</p>
</sec>
<sec id="s4_4">
<label>3.4</label>
<title>Emerging evidence in specific histologic subtypes</title>
<p>The therapeutic landscape of dual immune checkpoint blockade continues to evolve. Research is expanding to explore activity in rare histologic subtypes. Clear cell carcinoma of the endometrium, which is predominantly mismatch repair proficient/microsatellite stable (pMMR/MSS) and portends a poor prognosis (<xref ref-type="bibr" rid="B24">24</xref>), represents one such rare histologic subtype of interest. A recent nonrandomized clinical trial evaluated the activity of nivolumab plus ipilimumab in a cohort of patients with advanced clear cell carcinomas, which included both ovarian and endometrial primaries (<xref ref-type="bibr" rid="B25">25</xref>). In the overall population (N = 28), the objective response rate (ORR) was 54% (95% CI, 35&#x2013;71). Treatment efficacy appeared consistent across primary sites, with an ORR of 50% (95% CI, 9&#x2013;91) in the smaller endometrial clear cell carcinoma subgroup. These findings are supported by preliminary data from other studies: the BrUOG 354 trial (presented at ASCO 2024) evaluated nivolumab plus ipilimumab in recurrent gynecologic clear cell carcinomas and reported encouraging activity, while the biomarker-driven MoST-CIRCUIT trial (presented at ESMO 2024) demonstrated preliminary evidence of efficacy for dual checkpoint blockade in rare tumors, including clear cell histology (<xref ref-type="bibr" rid="B26">26</xref>, <xref ref-type="bibr" rid="B27">27</xref>). However, the small number of patients with endometrial primaries in these studies precludes definitive conclusions. This underscores the necessity for future studies with larger, histology-specific cohorts.</p>
</sec>
</sec>
<sec id="s5">
<label>4</label>
<title>Clinical implementation challenges</title>
<sec id="s5_1">
<label>4.1</label>
<title>The unresolved quest for predictive biomarkers</title>
<p>The central challenge in dMMR/MSI-H endometrial cancer management remains the absence of validated biomarkers to stratify patients according to treatment intensity. Although dMMR status generally predicts immunotherapy response reliably, it cannot consistently identify patients who require combination therapy versus those who achieve optimal outcomes with monotherapy. As emphasized by Cosgrove, exploratory analyses have not identified consistent genomic correlates&#x2014;such as JAK1/2 and B2M alterations&#x2014;that differentiate these patient subsets (<xref ref-type="bibr" rid="B28">28</xref>).</p>
<p>Tumor mutational burden (TMB) and PD-L1 expression have been extensively investigated as potential predictive biomarkers. In KEYNOTE-158, a TMB cutoff of &#x2265;10 mutations/megabase was associated with improved response to pembrolizumab across tumor types; however, this biomarker lacks standardization and validation specifically in endometrial cancer (<xref ref-type="bibr" rid="B29">29</xref>). Similarly, PD-L1 expression by combined positive score (CPS) shows variable association with response in endometrial cancer, with some studies suggesting predictive value, while others show responses in PD-L1-negative tumors (<xref ref-type="bibr" rid="B30">30</xref>). Furthermore, JAK1/2 mutations and B2M loss, which can lead to resistance to interferon signaling and antigen presentation, respectively, have been implicated in primary resistance to checkpoint blockade, but these alterations are not routinely assessed in clinical practice.</p>
<p>Therefore, the development and validation of robust predictive biomarkers&#x2014;potentially integrating genomic, transcriptomic, and microenvironmental features&#x2014;is not merely an academic pursuit but an urgent clinical necessity. Achieving true personalization of immunotherapy intensity depends on this advancement.</p>
</sec>
<sec id="s5_2">
<label>4.2</label>
<title>Navigating toxicity and aiding patient decision-making</title>
<sec id="s5_2_1">
<label>4.2.1</label>
<title>Spectrum and incidence of immune-related adverse events</title>
<p>The toxicity profile of conventional ipilimumab-nivolumab therapy represents its principal limitation. In the Carlino et&#xa0;al. trial (<xref ref-type="bibr" rid="B12">12</xref>), grade &#x2265;3 immune-related adverse events (irAEs) occurred in 23% of patients receiving ipilimumab-nivolumab (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>, Part B). This incidence is substantially higher than the 12.0% observed with pembrolizumab monotherapy in KEYNOTE-158 (<xref ref-type="bibr" rid="B4">4</xref>) (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>, Part B). Moreover, the spectrum of these severe toxicities differs qualitatively. The combination regimen is associated with higher incidences of colitis (7&#x2013;10%), hepatitis (5&#x2013;7%), rash (3&#x2013;5%), and endocrinopathies such as hypophysitis (2&#x2013;4%) and thyroiditis (2&#x2013;3%), typically emerging within 6&#x2013;12 weeks (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>, Part A). In contrast, PD-1 monotherapy exhibits a lower incidence of these events&#x2014;particularly colitis and hypophysitis&#x2014;which are more strongly linked to CTLA-4 inhibition (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>, Part A).</p>
<table-wrap id="T1" position="float">
<label>Table&#xa0;1</label>
<caption>
<p>Safety profile of PD-1/CTLA-4-targeted therapies in endometrial carcinoma.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" colspan="5" align="left">Part A: Incidence and management of common Grade &#x2265;3 Immune-Related Adverse Events (irAEs)</th>
</tr>
<tr>
<th valign="middle" align="left">Adverse event</th>
<th valign="middle" align="left">Ipilimumab-Nivolumab (Grade &#x2265;3)</th>
<th valign="middle" align="left">Pembrolizumab monotherapy (Grade &#x2265;3)</th>
<th valign="middle" align="left">Typical onset (weeks)</th>
<th valign="middle" align="left">Key management principles</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="left">Colitis</td>
<td valign="middle" align="left">7-10%</td>
<td valign="middle" align="left">1-2%</td>
<td valign="middle" align="left">6-8</td>
<td valign="middle" align="left">Corticosteroids, infliximab for steroid-refractory cases.</td>
</tr>
<tr>
<td valign="middle" align="left">Hepatitis</td>
<td valign="middle" align="left">5-7%</td>
<td valign="middle" align="left">1-3%</td>
<td valign="middle" align="left">6-12</td>
<td valign="middle" align="left">Corticosteroids, mycophenolate mofetil if severe.</td>
</tr>
<tr>
<td valign="middle" align="left">Rash</td>
<td valign="middle" align="left">3-5%</td>
<td valign="middle" align="left">1-2%</td>
<td valign="middle" align="left">2-4</td>
<td valign="middle" align="left">Topical/systemic corticosteroids, antihistamines.</td>
</tr>
<tr>
<td valign="middle" align="left">Hypophysitis</td>
<td valign="middle" align="left">2-4%</td>
<td valign="middle" align="left">&lt;1%</td>
<td valign="middle" align="left">8-12</td>
<td valign="middle" align="left">Hormone replacement, corticosteroids for acute inflammation.</td>
</tr>
<tr>
<td valign="middle" align="left">Thyroiditis</td>
<td valign="middle" align="left">2-3%</td>
<td valign="middle" align="left">1-2%</td>
<td valign="middle" align="left">6-12</td>
<td valign="middle" align="left">Thyroid hormone replacement, rarely corticosteroids.</td>
</tr>
<tr>
<td valign="middle" align="left">Pneumonitis</td>
<td valign="middle" align="left">1-2%</td>
<td valign="middle" align="left">1-2%</td>
<td valign="middle" align="left">Variable</td>
<td valign="middle" align="left">Corticosteroids, infliximab/cyclophosphamide if severe.</td>
</tr>
<tr>
<th valign="middle" colspan="5" align="left">Part B: Overall safety parameters</th>
</tr>
<tr>
<th valign="middle" colspan="2" align="left">Safety parameter</th>
<th valign="middle" colspan="2" align="left">Ipilimumab-Nivolumab combination</th>
<th valign="middle" align="left">Pembrolizumab monotherapy</th>
</tr>
<tr>
<td valign="middle" colspan="2" align="left">Study Population (Trial)</td>
<td valign="middle" colspan="2" align="left">52 patients (Carlino et&#xa0;al. <italic>JAMA Oncol</italic>.) (<xref ref-type="bibr" rid="B12">12</xref>)</td>
<td valign="middle" align="left">351 patients (KEYNOTE-158, Cohort K) (<xref ref-type="bibr" rid="B4">4</xref>)</td>
</tr>
<tr>
<td valign="middle" colspan="2" align="left">Incidence of Any-Grade irAEs</td>
<td valign="middle" colspan="2" align="left">75% (39/52)</td>
<td valign="middle" align="left">19.7% (69/351)*</td>
</tr>
<tr>
<td valign="middle" colspan="2" align="left">Incidence of Grade &#x2265;3 irAEs</td>
<td valign="middle" colspan="2" align="left">23% (12/52)</td>
<td valign="middle" align="left">12.0% (42/351)</td>
</tr>
<tr>
<td valign="middle" colspan="2" align="left">Most Common Grade &#x2265;3 irAEs</td>
<td valign="middle" colspan="2" align="left">Hepatitis (6%), Enterocolitis (6%)</td>
<td valign="middle" align="left">Pneumonitis (0.9%), Colitis (0.3%)</td>
</tr>
<tr>
<td valign="middle" colspan="2" align="left">Treatment Discontinuation Due to irAEs</td>
<td valign="middle" colspan="2" align="left">9.6% (5/52)</td>
<td valign="middle" align="left">6.6% (23/351)</td>
</tr>
<tr>
<td valign="middle" colspan="2" align="left">Fatal irAEs</td>
<td valign="middle" colspan="2" align="left">Not reported</td>
<td valign="middle" align="left">0.9% (3/351)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>Data synthesized from Carlino et&#xa0;al. (2025) (<xref ref-type="bibr" rid="B12">12</xref>) and KEYNOTE-158 (O&#x2019;Malley et&#xa0;al., 2022) (<xref ref-type="bibr" rid="B4">4</xref>).</p></fn>
<fn>
<p>1. Ipilimumab-Nivolumab data are derived from the phase 2 MOST-CIRCUIT trial in advanced dMMR/MSI-H noncolorectal cancers, where endometrial carcinoma represented 50% of the cohort (<xref ref-type="bibr" rid="B12">12</xref>).</p></fn>
<fn>
<p>2. Pembrolizumab data are from the phase 2 KEYNOTE-158 study (Cohort K) in previously treated advanced MSI-H/dMMR noncolorectal cancers, which included 22.5% endometrial carcinoma (<xref ref-type="bibr" rid="B4">4</xref>).</p></fn>
<fn>
<p>3. *The reported 19.7% refers specifically to &#x201c;immune-mediated AEs&#x201d; in KEYNOTE-158; treatment-related AEs of any grade occurred in 64.7% of patients (<xref ref-type="bibr" rid="B4">4</xref>).</p></fn>
<fn>
<p>4. Typical Onset represents the median or most frequent range from treatment initiation.</p></fn>
<fn>
<p>5. Thyroiditis in the monotherapy cohort primarily encompassed hypothyroidism (8.8% any grade) and hyperthyroidism (4.3% any grade), with minimal Grade &#x2265;3 events (<xref ref-type="bibr" rid="B4">4</xref>).</p></fn>
<fn>
<p>Management principles are aligned with contemporary ESMO clinical practice guidelines.</p></fn>
</table-wrap-foot>
</table-wrap>
<p>In this context, a systematic review and meta-analysis specifically addressing the safety of cadonilimab reported a pooled incidence of grade &#x2265;3 irAEs of 11.3% (95% CI, 9.5&#x2013;13.3) (<xref ref-type="bibr" rid="B16">16</xref>). This well-characterized and manageable irAE profile, which appears favorable compared to conventional dual checkpoint inhibition, is a critical consideration for clinical decision-making. In the cadonilimab-lenvatinib combination study, the toxicity profile showed a lower incidence of severe irAEs typically associated with CTLA-4 inhibition and was instead dominated by adverse events commonly linked to lenvatinib (e.g., hypertension) or by complications related to the tumor burden itself (e.g., intestinal obstruction) (<xref ref-type="bibr" rid="B17">17</xref>).</p>
</sec>
<sec id="s5_2_2">
<label>4.2.2</label>
<title>Mechanisms and management principles</title>
<p>The pathophysiology of irAEs stems from the non-specific activation of autoreactive T-cells and subsequent inflammatory damage to normal tissues. CTLA-4 inhibition primarily affects early T-cell activation in lymphoid organs, leading to a broader repertoire of activated T-cells, which explains the higher incidence of multi-organ irAEs with dual checkpoint blockade compared to PD-1 monotherapy. PD-1 blockade, operating mainly in peripheral tissues, is associated with more frequent tissue-specific toxicities.</p>
<p>Management of irAEs follows established guidelines (<xref ref-type="bibr" rid="B31">31</xref>) and is based on prompt recognition, grading, and intervention with corticosteroids (grade 2-4), or other immunosuppressants for steroid-refractory cases. For high-grade colitis, early initiation of infliximab is recommended. Endocrinopathies typically require hormone replacement therapy. Proactive patient education, regular monitoring of laboratory parameters (including thyroid function, liver enzymes, and cortisol), and multidisciplinary collaboration are essential for the safe administration of dual checkpoint blockade.</p>
<p>Given these complexities, the gynecologic oncologist must facilitate a shared decision-making process. This process should incorporate critical considerations such as tumor burden and the rate of disease progression, patient performance status and comorbidities, and individual preferences regarding risks and benefits.</p>
</sec>
</sec>
<sec id="s5_3">
<label>4.3</label>
<title>Ensuring accurate biomarker testing</title>
<p>The effective implementation of precision oncology in endometrial cancer hinges on diagnostic accuracy. A critical challenge is the documented 3&#x2013;7% discordance rate between mismatch repair (MMR) immunohistochemistry (IHC) and microsatellite instability (MSI) testing methods. This discordance can lead to both under-treatment and over-treatment (<xref ref-type="bibr" rid="B24">24</xref>). To mitigate this risk, expert consensus recommends the adoption of reflex testing protocols, such as confirmatory next-generation sequencing, following an abnormal IHC result, to enable more reliable treatment personalization (<xref ref-type="bibr" rid="B32">32</xref>).</p>
</sec>
<sec id="s5_4">
<label>4.4</label>
<title>Synthesis of efficacy and safety: informing clinical trade-offs</title>
<p>The integrated evidence from <xref ref-type="table" rid="T1"><bold>Tables&#xa0;1</bold></xref>, <xref ref-type="table" rid="T2"><bold>2</bold></xref> establishes a clear efficacy-toxicity continuum for immunotherapy in dMMR/MSI-H EC. At one end, the conventional ipilimumab-nivolumab combination [as reported by Carlino et&#xa0;al. (<xref ref-type="bibr" rid="B12">12</xref>)] delivers the highest objective response rates (ORR 58%, <xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>) but imposes the greatest toxicity burden. This is characterized by nearly double the rate of grade &#x2265;3 irAEs compared to monotherapy (23% versus 12%; see <xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>, Part B) and a notably higher incidence of high-grade gastrointestinal and hepatic events (<xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>, Part A). At the other end, pembrolizumab monotherapy [KEYNOTE-158 (<xref ref-type="bibr" rid="B4">4</xref>)] offers a more manageable safety profile, with fewer severe CTLA-4&#x2013;associated toxicities, while maintaining clinically meaningful efficacy (ORR 48.5%, <xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>). Emerging agents such as the bispecific antibody cadonilimab, particularly in combination with lenvatinib, represent a potential intermediate option. Preliminary studies report encouraging activity (ORR 37.5&#x2013;42.9%, <xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>) and indicate a distinct toxicity pattern that differs from existing therapies (<xref ref-type="bibr" rid="B16">16</xref>, <xref ref-type="bibr" rid="B17">17</xref>). However, these findings require validation in randomized trials.</p>
<table-wrap id="T2" position="float">
<label>Table&#xa0;2</label>
<caption>
<p>Selected clinical trials of PD-1 and CTLA-4 targeting in advanced or recurrent endometrial carcinoma.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" align="left">Trial/Agent</th>
<th valign="middle" align="left">Phase</th>
<th valign="middle" align="left">Design</th>
<th valign="middle" align="left">Key inclusion criteria</th>
<th valign="middle" align="left">Population</th>
<th valign="middle" align="left">Key efficacy results (ORR)</th>
<th valign="middle" align="left">Median PFS</th>
<th valign="middle" align="left">Key safety results (Gr &#x2265;3)</th>
<th valign="middle" align="left">Reference/Status</th>
</tr>
</thead>
<tbody>
<tr>
<th valign="middle" colspan="9" align="left">dMMR/MSI-H Population</th>
</tr>
<tr>
<td valign="middle" align="left">Nivolumab + Ipilimumab</td>
<td valign="middle" align="left">II</td>
<td valign="middle" align="left">Basket, single-arm</td>
<td valign="middle" align="left">Advanced dMMR/MSI-H non-colorectal cancers</td>
<td valign="middle" align="left">EC subgroup: 26</td>
<td valign="middle" align="left">63% (95% CI, 49-76)</td>
<td valign="middle" align="left">NR</td>
<td valign="middle" align="left">23% (irAEs)</td>
<td valign="middle" align="left">Carlino et&#xa0;al. <italic>JAMA Oncol.</italic> 2025 (<xref ref-type="bibr" rid="B12">12</xref>)</td>
</tr>
<tr>
<td valign="middle" align="left">Pembrolizumab(KEYNOTE-158)</td>
<td valign="middle" align="left">II</td>
<td valign="middle" align="left">Cohort, single-arm</td>
<td valign="middle" align="left">Advanced MSI-H/dMMR tumors, &#x2265;1 prior therapy</td>
<td valign="middle" align="left">EC cohort: 79</td>
<td valign="middle" align="left">48% (95% CI, 37-60)</td>
<td valign="middle" align="left">13.1 months</td>
<td valign="middle" align="left">12% (irAEs)</td>
<td valign="middle" align="left">O&#x2019;Malley et&#xa0;al. <italic>J Clin Oncol.</italic> 2022 (<xref ref-type="bibr" rid="B4">4</xref>)</td>
</tr>
<tr>
<td valign="middle" align="left">Pembrolizumab + Chemotherapy (NRG-GY018)</td>
<td valign="middle" align="left">III</td>
<td valign="middle" align="left">Randomized, double-blind</td>
<td valign="middle" align="left">First-line advanced dMMR EC</td>
<td valign="middle" align="left">dMMR: 60</td>
<td valign="middle" align="left">82.1% (95%CI, 72.9%-89.2%)</td>
<td valign="middle" align="left">NR (HR 0.30)</td>
<td valign="middle" align="left">9.7%(irAEs)</td>
<td valign="middle" align="left">Eskander et&#xa0;al.<italic>Nat Med</italic>.2025 <italic>(</italic><xref ref-type="bibr" rid="B21">21</xref>)</td>
</tr>
<tr>
<th valign="middle" colspan="9" align="left">pMMR/MSS &amp; Other population</th>
</tr>
<tr>
<td valign="middle" align="left">Pembrolizumab + Chemotherapy (NRG-GY018)</td>
<td valign="middle" align="left">III</td>
<td valign="middle" align="left">Randomized, double-blind</td>
<td valign="middle" align="left">First-line advanced pMMR EC</td>
<td valign="middle" align="left">pMMR: 291</td>
<td valign="middle" align="left">72.3% (95%CI, 66.0%&#x2013;78.1%)</td>
<td valign="middle" align="left">11.1 months (HR 0.64)</td>
<td valign="middle" align="left">9.7%(irAEs)</td>
<td valign="middle" align="left">Eskander et&#xa0;al.<italic>Nat Med</italic>.2025 <italic>(</italic><xref ref-type="bibr" rid="B21">21</xref>)</td>
</tr>
<tr>
<td valign="middle" align="left">Lenvatinib+Pembrolizumab (KEYNOTE-775)</td>
<td valign="middle" align="left">III</td>
<td valign="middle" align="left">Randomized, open-label</td>
<td valign="middle" align="left">Advanced pMMR EC, post-chemotherapy</td>
<td valign="middle" align="left">pMMR: 411</td>
<td valign="middle" align="left">32.4% vs 15.1%*</td>
<td valign="middle" align="left">7.2 vs 3.8 months (HR 0.56)</td>
<td valign="middle" align="left">TRAEs:90.1% vs 73.7%&#x2020;</td>
<td valign="middle" align="left">Makker et&#xa0;al. <italic>J Clin Oncol</italic>. 2023 (<xref ref-type="bibr" rid="B17">17</xref>)</td>
</tr>
<tr>
<th valign="middle" colspan="9" align="left">Clear cell carcinoma</th>
</tr>
<tr>
<td valign="middle" align="left">Nivolumab + Ipilimumab</td>
<td valign="middle" align="left">II</td>
<td valign="middle" align="left">Nonrandomized, single-arm</td>
<td valign="middle" align="left">Advanced clear cell carcinoma (endometrial &amp; ovarian)</td>
<td valign="middle" align="left">Total: 28 (EC: 6)</td>
<td valign="middle" align="left">54% (95% CI, 35&#x2013;71)</td>
<td valign="middle" align="left">NR</td>
<td valign="middle" align="left">35%(irAEs)</td>
<td valign="middle" align="left">Gao et&#xa0;al. <italic>JAMA Oncol</italic>. 2025 (<xref ref-type="bibr" rid="B25">25</xref>)</td>
</tr>
<tr>
<th valign="middle" colspan="9" align="left">Bispecific &amp; Engineered antibodies</th>
</tr>
<tr>
<td valign="middle" align="left">Cadonilimab + Lenvatinib</td>
<td valign="middle" align="left">II</td>
<td valign="middle" align="left">Multicenter, single-arm</td>
<td valign="middle" align="left">Advanced EC, progressed after platinum-based chemotherapy</td>
<td valign="middle" align="left">32</td>
<td valign="middle" align="left">37.5% (FAS)</td>
<td valign="middle" align="left">NR (median FU 7.6 months)</td>
<td valign="middle" align="left">TRAEs: 21.9%&#x2021;</td>
<td valign="middle" align="left">Lan et&#xa0;al. SGO 2025 (<xref ref-type="bibr" rid="B17">17</xref>)</td>
</tr>
<tr>
<th valign="middle" colspan="9" align="left">Ongoing trials</th>
</tr>
<tr>
<td valign="middle" align="left">NRG-GY025</td>
<td valign="middle" align="left">III</td>
<td valign="middle" align="left">Randomized, open-label</td>
<td valign="middle" align="left">Recurrent dMMR/MSI-H EC</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">Primary Endpoints: PFS &amp; OS (<italic>Data Pending</italic>)</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">NCT05112601 (Ongoing)</td>
</tr>
<tr>
<td valign="middle" align="left">QLPPEC/GOG-003 (QL1706)</td>
<td valign="middle" align="left">II</td>
<td valign="middle" align="left">single-arm, open-label, multicenter</td>
<td valign="middle" align="left">Advanced EC, post&#x2013;PD-1/L1 therapy</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">ORR, PFS (<italic>Data Pending</italic>)</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">NCT06751277 (Ongoing)</td>
</tr>
<tr>
<td valign="middle" align="left">QL1706 + Chemotherapy</td>
<td valign="middle" align="left">II</td>
<td valign="middle" align="left">single-arm, multicenter</td>
<td valign="middle" align="left">1L Recurrent/Metastatic EC</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">PFS, ORR (<italic>Data Pending</italic>)</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">N/A</td>
<td valign="middle" align="left">NCT06917092 (Ongoing)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>CI, confidence interval; dMMR, mismatch repair-deficient; EC, endometrial carcinoma; FAS, full analysis set; FU, follow-up; HR, hazard ratio; irAEs, immune-related adverse events; MSI-H, microsatellite instability-high; NR, not reported; N/A, not applicable; ORR, objective response rate; OS, overall survival; PFS, progression-free survival; pMMR, mismatch repair-proficient; TRAEs, treatment-related adverse events.</p></fn>
<fn>
<p>*Compared to chemotherapy in KEYNOTE-775 trial.</p></fn>
<fn>
<p>&#x2020;Any grade treatment-related adverse events.</p></fn>
<fn>
<p>&#x2021;Grade 3 or higher treatment-related adverse events.</p></fn>
</table-wrap-foot>
</table-wrap>
<p>This spectrum underscores that contemporary treatment selection is an exercise in calibrated trade-offs. The clinician must weigh the magnitude of anticipated benefit&#x2014;considering factors such as tumor burden and disease kinetics, along with efficacy benchmarks from <xref ref-type="table" rid="T2"><bold>Table&#xa0;2</bold></xref>&#x2014;against the acceptable threshold for toxicity, which is informed by patient performance status, comorbidities, and preference, as well as risk profiles detailed in <xref ref-type="table" rid="T1"><bold>Table&#xa0;1</bold></xref>. In the absence of validated predictive biomarkers, this careful balancing, grounded in the comparative data presented here, serves as the cornerstone of personalized therapeutic decision-making in advanced dMMR/MSI-H endometrial cancer.</p>
</sec>
</sec>
<sec id="s6" sec-type="conclusions">
<label>5</label>
<title>Conclusions and future perspectives</title>
<p>The therapeutic landscape of dMMR/MSI-H endometrial carcinoma has been fundamentally reshaped by dual PD-1/CTLA-4 targeting, which now provides a multi-tiered strategy encompassing PD-1 monotherapy, conventional antibody combinations, and novel bispecific agents. Notwithstanding these advances, the integration of these regimens into a standardized treatment algorithm is hampered by the absence of head-to-head comparative trials and a dearth of predictive biomarkers beyond dMMR status.</p>
<p>Future progress hinges on addressing three pivotal challenges. First, the purported efficacy and safety advantages of novel constructs, particularly bispecific antibodies, must be rigorously evaluated in randomized controlled trials against the current standard of care. Second, a concerted translational effort is required to discover and validate biomarkers that can reliably stratify patients for treatment intensity. Third, the strategic expansion of combination immunotherapy into new clinical domains, notably in the first-line setting with chemotherapy, warrants careful exploration.</p>
<p>In this evolving and complex paradigm, the imperative for the clinical practitioner is to engage in a sophisticated decision-making process. This necessitates a critical appraisal of the available evidence, integration of comprehensive molecular profiling, and careful consideration of individual patient preferences and comorbidities to navigate the trade-offs between efficacy and toxicity, thereby personalizing therapy to optimize long-term outcomes.</p>
</sec>
</body>
<back>
<sec id="s7" sec-type="author-contributions">
<title>Author contributions</title>
<p>LZ: Methodology, Writing &#x2013; original draft. LS: Conceptualization, Data curation, Funding acquisition, Supervision, Writing &#x2013; review &amp; editing.</p></sec>
<sec id="s9" sec-type="COI-statement">
<title>Conflict of interest</title>
<p>The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p></sec>
<sec id="s10" sec-type="ai-statement">
<title>Generative AI statement</title>
<p>The author(s) declared that generative AI was not used in the creation of this manuscript.</p>
<p>Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.</p></sec>
<sec id="s11" sec-type="disclaimer">
<title>Publisher&#x2019;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p></sec>
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<p>Edited by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/236398">Subhayan Das</ext-link>, Brainware University, India</p></fn>
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<p><ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2682028">Alexandre Da Costa</ext-link>, A.C.Camargo Cancer Center, Brazil</p></fn>
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