The Disease Landscape and Molecular Subtypes Driving Drug Development
Endometrial cancer is the most common gynecologic malignancy in the United States, with an estimated 61,380 new diagnoses annually and a significant unmet need in advanced, recurrent, and metastatic settings. The molecular heterogeneity of the disease — spanning two broad histological and biological subtypes — directly shapes which therapeutic modalities are being prioritized in the patent and clinical literature.
A 2014 academic paper from the University of Iowa Carver College of Medicine describes Type 1 tumors as predominantly low-grade endometrioid carcinomas that are estrogen receptor/progesterone receptor (ER/PR)-positive and frequently EGFR-expressing. Type 2 tumors are more aggressive, ER/PR-negative, and carry a substantially worse prognosis. PI3K/AKT/mTOR and MAPK pathway alterations are identified as frequent molecular drivers across both subtypes — a finding reinforced by multiple patent filings targeting those pathways.
A 2017 WO patent from the British Columbia Cancer Agency describes a classification scheme stratifying endometrial cancers into four subtypes: MMR protein deficiency (dMMR/MSI-H), POLE exonuclease domain mutations, p53 wild-type, and p53-aberrant. This framework directly informs immunotherapy eligibility and companion diagnostic development, and is referenced in AstraZeneca’s clinical-stage filings as the basis for patient stratification.
PTEN is identified in older literature as the most frequently mutated gene in endometrioid adenocarcinoma, with PTEN protein loss serving as a biomarker for premalignant disease. While not directly coupled to a therapeutic in the retrieved patent results, PTEN loss connects to PI3K pathway activation targeted by small molecules across this dataset. CDK2 pathway dysregulation emerges in a 2025 Blueprint Medicines filing as a predictive biomarker context, with PI3K/MAPK co-activation named explicitly in filings from Onconova Therapeutics as the biological rationale for CDK inhibitor deployment.
Endometrial cancer is the most common gynecologic malignancy in the United States, with an estimated 61,380 new diagnoses annually. The disease is molecularly heterogeneous, with Type 1 tumors being low-grade endometrioid carcinomas that are ER/PR-positive, and Type 2 tumors being more aggressive, ER/PR-negative, and carrying a substantially worse prognosis.
ADC Pipeline: HER2, Tissue Factor, and Folate Receptor Alpha Targeting
Antibody-drug conjugates represent the most endometrial cancer-specific innovation signal in the retrieved patent dataset, with three distinct molecular targets — HER2, tissue factor (TF), and folate receptor alpha (FRα) — each attracting dedicated patent families from different assignees with differentiated payload chemistries.
HER2-Targeted Duocarmycin ADCs for Uterine Serous Carcinoma
The most endometrial cancer-specific ADC signal originates from Synthon Biopharmaceuticals / Byondis B.V., with multiple active and inactive filings covering duocarmycin-containing ADCs targeting HER2-expressing solid tumors, specifically uterine serous carcinoma (USC). These patents explicitly address low-level HER2 expression — IHC 2+ or 1+, FISH-negative — a patient population historically excluded from trastuzumab-based therapies. This positions duocarmycin ADCs as a potential mechanism for delivering cytotoxic benefit to tumors with sub-amplified HER2 expression.
“Synthon/Byondis’ duocarmycin ADC patents cover HER2 IHC 2+ and 1+ FISH-negative tumors — a population historically excluded from trastuzumab-based therapies — positioning these ADCs as a potential mechanism for delivering cytotoxic benefit to sub-amplified HER2-expressing uterine serous carcinoma.”
A separate ADC strategy filed by RemeGen describes anti-HER2 ADC in combination with PD-1/PD-L1 checkpoint inhibitors in urothelial cancer, documenting efficacy even in HER2 IHC 1+ patients — a cross-tumor precedent that signals potential relevance to the endometrial HER2-low combination space.
Tissue Factor ADCs: Genmab’s Three-Jurisdiction Patent Family
Genmab has filed multiple patents across CA, AU, and US jurisdictions covering anti-TF ADCs for endometrial cancer alongside a broad multi-tumor indication. Tissue factor is identified as overexpressed in endometrial cancer, and the retrieved text explicitly names endometrial cancer as one of the primary indications. The mechanism involves antibody-mediated targeted delivery of cytotoxic payloads to TF-expressing tumor cells via tissue factor-mediated internalization.
Genmab A/S holds a three-jurisdiction (CA, AU, US) anti-tissue factor antibody-drug conjugate patent family explicitly listing endometrial cancer as a primary indication. Tissue factor overexpression in endometrial tumors is cited as the therapeutic rationale, with the ADC mechanism involving targeted cytotoxic delivery via tissue factor-mediated internalization.
Folate Receptor Alpha: Payload Diversification Signal
Eisai R&D Management has filed patents on eribulin-based ADCs targeting folate receptor alpha (FRα), including the MORAb-003-eribulin conjugate (MORAb-202), evaluated in FRα-expressing tumors. Eribulin’s anti-tubulin mechanism is distinct from duocarmycin’s DNA alkylating payload, signalling payload diversification in the ADC space for gynecologic malignancies.
Map the full endometrial cancer ADC patent landscape — by target, assignee, and jurisdiction — in PatSnap Eureka.
Explore ADC Patent Data in PatSnap Eureka →Checkpoint Immunotherapy and Cellular Approaches: From Clinical Data to Post-Failure Niches
PD-1/PD-L1 checkpoint inhibition is the most frequently addressed therapeutic axis across the retrieved patent results, with AstraZeneca, Chia Tai Tianqing, Bioatla, and Iovance Biotherapeutics each staking out distinct positions — from clinical-data-backed combination filings to adoptive cell therapy for checkpoint-refractory disease.
AstraZeneca’s Clinical-Stage Anti-PD-L1 Filings
AstraZeneca is the most prominently represented assignee in checkpoint immunotherapy for endometrial cancer in this dataset. Two patent families (filed in AU and WO) claim methods of treating endometrial cancer with anti-PD-L1 antibodies in combination with chemotherapy and optional PARP inhibitors. The patent text explicitly references ITT (intention-to-treat) population PFS and OS data, along with dMMR/pMMR subgroup analyses and PD-L1-positive/negative exploratory analyses — language consistent with a Phase III clinical data package. According to WHO and major oncology bodies, dMMR/MSI-H status is now a standard biomarker for immunotherapy eligibility across multiple tumor types.
AstraZeneca’s anti-PD-L1 filings (2025–2026) reference figures describing pre-specified exploratory and primary analyses typical of a Phase III clinical study protocol, including subgroup analyses for dMMR vs. pMMR and PD-L1-positive vs. -negative populations. This language signals that these method-of-treatment claims are backed by clinical-stage evidence, creating a strong freedom-to-operate challenge for follow-on entrants.
Chinese Biopharmaceutical Entrants: Chia Tai Tianqing and Bioatla
A Chinese filing from Chia Tai Tianqing Pharmaceutical Group covers anti-PD-L1 antibody use in endometrial cancer, specifically in MSI-H/dMMR tumors, with an optional combination with anlotinib — a multi-target receptor tyrosine kinase inhibitor targeting VEGFR, FGFR, PDGFR, and c-Kit. A 2025 Chia Tai Tianqing filing extends this to pharmacological combinations for malignant uterine tumors combining anti-PD-L1 antibody, chemotherapy, and anlotinib. This parallels lenvatinib-pembrolizumab combinations observed in the broader gynecologic oncology space, as documented by the FDA in approved combination regimens.
A separate Chinese filing from Bioatla covers anti-PD-1 antibody combined with taxane and/or platinum chemotherapy, explicitly including endometrial cancer alongside cervical cancer, with optional bevacizumab addition — indicating that Chinese companies are building regimen-specific IP for local and potentially global markets.
TIL Therapy: Positioning for Post-Checkpoint-Failure Disease
Iovance Biotherapeutics filed a 2025 WO patent specifically claiming tumor-infiltrating lymphocyte (TIL) therapy methods for endometrial cancer, including in patients who are refractory to or have progressed following prior PD-1/PD-L1 inhibitor treatment or chemotherapy. This represents a distinct adoptive cell therapy approach for checkpoint-refractory disease, and there is currently limited competitive overlap in the retrieved results — suggesting first-mover IP advantage may be achievable in this niche. Research published by Nature has documented TIL therapy efficacy in solid tumors, supporting the scientific rationale for this approach.
Iovance Biotherapeutics filed a 2025 WO patent claiming tumor-infiltrating lymphocyte (TIL) therapy specifically for endometrial cancer patients who are refractory to or have progressed following prior PD-1/PD-L1 inhibitor treatment or chemotherapy. This is the only TIL therapy-specific endometrial cancer patent in the retrieved dataset, indicating limited competitive overlap and potential first-mover IP positioning.
Combination Regimens and Emerging Precision Strategies: CDK, PARP, and Biomarker-Guided Approaches
Beyond single-agent ADC and checkpoint strategies, the retrieved patent landscape reveals several convergent combination approaches that reflect growing awareness of resistance mechanisms and the need to co-target multiple oncogenic dependencies in endometrial cancer.
CDK Inhibitors Paired with Hormone Therapy
Onconova Therapeutics has filed in four jurisdictions (WO×2, AU, BR) for a pyrido[2,3-d]pyrimidine CDK inhibitor compound in combination with an aromatase inhibitor (letrozole) specifically for hormone receptor-positive endometrial cancer, including low-grade endometrioid subtypes. PI3K/MAPK co-activation is explicitly named in Onconova’s filings as the biological rationale for CDK inhibitor deployment. This CDK inhibitor plus letrozole approach is consistent with strategies established in HR+ breast cancer, as documented in standards from ASCO.
Blueprint Medicines’ 2025 WO filing introduces CDK2 as a predictive biomarker and therapeutic target in endometrial cancer, with combination biomarker panels proposed to identify CDK2 inhibitor responders. This represents an emerging precision medicine framework distinct from MSI-H/POLE-based stratification.
PARP Inhibitors: From Foundational IP to Triplet Combinations
Bipar Sciences filed multiple patents (CA, AU, IL) covering PARP inhibitor monotherapy and combination therapy for endometrial and uterine cancer from 2009–2012, establishing foundational IP for PARP inhibitor use in the indication. AstraZeneca’s more recent checkpoint immunotherapy filings include PARP inhibitors as an optional combinatorial component alongside anti-PD-L1 and chemotherapy, signalling evolution toward triplet regimens that attempt to co-target DNA repair deficiency alongside immune evasion.
AstraZeneca’s 2025–2026 endometrial cancer patent filings claim triplet regimens combining anti-PD-L1 antibody, platinum-based or taxane chemotherapy, and optionally a PARP inhibitor. The patent text references ITT population PFS and OS data with dMMR/pMMR subgroup analyses, language consistent with a Phase III clinical data package.
Anti-PD-L1 Plus Anti-VEGF/Multi-Kinase Inhibition
Chia Tai Tianqing’s filings combining anti-PD-L1 with anlotinib — targeting VEGFR, FGFR, PDGFR, and c-Kit simultaneously — suggest a Chinese-market combination strategy with angiogenesis co-targeting. This parallels lenvatinib-pembrolizumab combinations that have demonstrated activity in the broader gynecologic oncology space, with the VEGF/VEGFR axis well-established as a therapeutic target in endometrial cancer as catalogued by ClinicalTrials.gov.
Identify white-space opportunities in CDK, PARP, and combination regimen IP for endometrial cancer using PatSnap Eureka.
Analyse Combination Strategies in PatSnap Eureka →Assignee Landscape and Strategic Implications for Drug Developers
The endometrial cancer patent landscape is dominated by Western biopharma and Chinese biopharmaceutical companies, with academic institutions contributing classification and biomarker IP that may enable companion diagnostic licensing opportunities.
Key Assignees and Their IP Positions
- AstraZeneca AB — Most active in endometrial cancer-specific immunotherapy; multiple filings in AU, WO, and CN covering anti-PD-L1 combinations with chemotherapy and optional PARP inhibitors, backed by what appears to be Phase III-level clinical data.
- Synthon Biopharmaceuticals B.V. / Byondis B.V. — Hold the most endometrial cancer-specific ADC IP in the dataset, with active MX and AU filings covering HER2-targeted duocarmycin ADCs specifically for uterine serous carcinoma.
- Genmab A/S — Holds a three-jurisdiction (CA, AU, US) anti-TF ADC patent family covering endometrial cancer among multiple solid tumor indications.
- Onconova Therapeutics, Inc. — Filed in four jurisdictions (WO×2, AU, BR) for CDK inhibitor plus aromatase inhibitor combinations in hormone receptor-positive endometrial cancer.
- Iovance Biotherapeutics, Inc. — Holds the only TIL therapy-specific endometrial cancer patent in the dataset (WO, 2025), with no apparent competitive overlap.
- Blueprint Medicines Corporation — Filed the most recent CDK2 inhibitor patent covering endometrial cancer (WO, 2025), introducing biomarker-guided patient selection.
- Chia Tai Tianqing Pharmaceutical Group — Represents Chinese industry activity with anti-PD-L1 plus anlotinib combination patents in CN, ID, and CA jurisdictions.
- British Columbia Cancer Agency Branch / Mayo Foundation / Brigham and Women’s Hospital — Academic institutions contributing classification and biomarker IP relevant to companion diagnostic development.
Strategic Implications
HER2-low targeting in uterine serous carcinoma is an active IP space with unmet clinical need. Developers entering this space will face existing duocarmycin payload IP from Synthon/Byondis and will need to differentiate by payload chemistry, linker design, or combination strategy. AstraZeneca’s clinical-data-backed checkpoint immunotherapy filings present a strong freedom-to-operate challenge: the combination of anti-PD-L1 plus chemotherapy, with or without a PARP inhibitor, is now backed by what appears to be Phase III-level data, creating method-of-treatment claims that are increasingly specific and defensible against follow-on entrants.
MMR and POLE classification IP from academic institutions — particularly the British Columbia Cancer Agency’s 2017 WO classification patent — may enable companion diagnostic licensing opportunities relevant to patient selection for immunotherapy, PARP inhibitor, and CDK inhibitor programs. Chinese biopharmaceutical entrants filing in CN, ID, and CA jurisdictions represent both a competitive and a licensing opportunity for Western developers seeking Asian market access.
“Iovance’s 2025 WO filing staking out TIL therapy for endometrial cancer after PD-1/PD-L1 failure indicates an early IP positioning strategy; there is currently limited competitive overlap in the retrieved results, suggesting first-mover IP advantage is achievable in this post-checkpoint-failure niche.”
This analysis is derived from a targeted set of patent and literature records retrieved across three therapeutic dimensions: ADCs, immune checkpoint inhibitors, and molecularly informed combinations. It represents a snapshot of innovation signals within this dataset only and should not be interpreted as a comprehensive view of the full clinical pipeline or regulatory landscape for endometrial cancer.