WRN PARP Synthetic Lethality MSI-H CRC — PatSnap Eureka
WRN and PARP Synthetic Lethality in MSI-High Colorectal Cancer
Microsatellite instability-high colorectal cancer harbors unique DNA repair vulnerabilities. Explore the patent landscape, molecular targets, and IP strategy around WRN helicase dependency and PARP inhibitor sensitivity in MMR-deficient tumors.
MMR Deficiency as the Foundation of MSI-H CRC Vulnerability
Microsatellite instability-high (MSI-H) colorectal cancer arises from defective mismatch repair (MMR) — involving gene products including MLH1, MSH2, and MSH3 — resulting in the accumulation of mutations at microsatellite repeat loci. This genetic instability creates a distinct therapeutic landscape compared to microsatellite-stable CRC.
Frameshift mutations within the MSH3 gene's poly-[A]8 repeat are frequent in MSI CRC, occurring in 20–50% of cases, leading to loss or reduction of MSH3 protein expression. This MSH3 deficiency is posited as a determinant of sensitivity to both PARP inhibitors and platinum-based genotoxic agents, based on the role of MSH3 in DNA double-strand break (DSB) repair.
MSH3-negative cancer cell populations also exhibit elevated microsatellite alterations at tetranucleotide repeats — the EMAST phenotype — a marker co-occurring with low-level MSI. A patent from VIB VZW further frames MMR-deficient tumor cells as sensitive to synthetic lethality via inhibition of the DNA base excision repair (BER) pathway, noting that "MSI positive tumors are often resistant to standard chemotherapies."
The Francis Crick Institute filing extends the PARP synthetic lethality concept to homologous recombination (HR)-deficient cells, identifying that DNPH1 catalytic inhibition sensitizes HR-deficient cells to PARP inhibition — mechanistically relevant to the broader paradigm of exploiting DNA repair deficiency for selective tumor killing in oncology drug discovery.
Assignee Activity & Synthetic Lethality Modalities
Patent-driven commercial activity in the MSI-H CRC synthetic lethality space is concentrated among a small number of institutions, with distinct IP positions across therapeutic and diagnostic modalities.
Patent Assignee Jurisdiction Coverage
Baylor Research Institute leads with 7+ jurisdictions for the MSH3/PARPi axis; VIB VZW holds the most current active EP patent on BER synthetic lethality.
Therapeutic Modalities by Development Stage
All retrieved modalities are at preclinical stage; no clinical trial data or patient cohort outcomes are present in the dataset for any WRN-targeted or PARPi therapy in MSI-H CRC.
DNA Repair Targets Driving Synthetic Lethality in MMR-Deficient CRC
Four molecular target classes emerge from the retrieved dataset, each representing a distinct mechanism of exploiting DNA repair deficiency for selective tumor killing in life sciences drug discovery.
MSH3 — Mismatch Repair / DSB Repair
The most frequently appearing DNA repair target in this dataset. MSH3 deficiency in MSI CRC — arising from frameshift mutations in the poly-[A]8 repeat occurring in 20–50% of cases — impairs double-strand break (DSB) repair, increasing reliance on PARP-mediated single-strand break repair. Baylor Research Institute patent families across at least 7 jurisdictions (US, AU, CA, CN, JP, MX, BR) converge on MSH3 expression status as the predictive biomarker for PARPi and platinum sensitivity. Experimental evidence includes isogenic CRC cell lines with tet-off shRNA-regulated MSH3 expression tested against cisplatin, oxaliplatin, and PARP inhibitors.
20–50% MSI CRC frequency · Baylor RI, 7 jurisdictionsBER Pathway Enzymes — Base Excision Repair
The VIB VZW patent (2021, active EP) identifies MMR-deficient cells — detected via novel microsatellite mutation markers — as sensitive to BER enzyme inhibition as a class. The synthetic lethal logic is that MMR-deficient cells accumulate replication errors processed via BER; BER inhibition therefore creates lethal DNA damage specifically in MMR-deficient cells. This modality is conceptually distinct from direct PARP inhibition, targeting BER pathway components including PARP1/2, APE1, and POLB. Standard chemotherapy resistance in MSI-positive tumors motivates this alternative approach.
VIB VZW · Active EP 2021 · MSI-positive screeningDNPH1 — Next-Generation Synthetic Lethal Agent
Identified in The Francis Crick Institute patent (2024, pending BR) as a novel synthetic lethal target: catalytic inhibition of DNPH1 (2'-deoxynucleoside 5'-phosphate N-hydrolase 1) sensitizes HR-deficient cells to PARP inhibition. Combined DNPH1 ablation plus substrate (5-hydroxymethyl-deoxyuridine) administration can itself produce synthetic lethality in HR-deficient cells, even without PARP inhibitors. This target is presented as distinct from, and potentially synergistic with, direct PARPi — relevant given that a subset of MSI-H CRC may harbor HR deficiency features.
Francis Crick Institute · 2024 pending · HR-deficient cellsHRD Genomic Signatures — LOH, TAI, LST, BRCA
Myriad Genetics (multiple active and pending JP patents, 2023–2025) describes in vitro methods for assessing homologous recombination deficiency (HRD) via genomic instability markers: loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), and large-scale state transitions (LST). The University of Tokyo patent additionally describes BRCA mutation signature analysis relative to Age signature as an HRD indicator. These companion diagnostic frameworks are applicable to the subset of MSI-H CRC with overlapping HRD features, and are essential for patient stratification in PARPi clinical programs.
Myriad Genetics · LOH + TAI + LST + BRCA signatureKey Patent Holders and IP Status in MSI-H CRC Synthetic Lethality
| Assignee | Focus Area | Jurisdictions / Patents | Filing Year | IP Status |
|---|---|---|---|---|
| Baylor Research Institute | MSH3/PARPi + platinum synthetic lethality; MSH3 as predictive biomarker in CRC | US, AU, CA, CN, JP, MX, BR (7+) | 2012 | Largely Inactive |
| VIB VZW | BER inhibitor synthetic lethality in MMR-deficient tumors; novel MSI marker detection | EP (active) | 2021 | Active EP |
| Myriad Genetics, Inc. | HRD assessment via LOH, TAI, LST for PARPi response prediction (companion Dx) | JP (multiple) | 2023–2025 | Active / Pending |
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IP Strategy & Drug Development Signals for MSI-H CRC
Retrieved patent and literature signals point to actionable opportunities for biotech and pharma teams developing synthetic lethality programs in MMR-deficient colorectal cancer, including companion diagnostic co-development.
Biomarker Stratification is Essential
Retrieved results converge on MSH3 expression and HRD genomic signatures (LOH, TAI, LST, BRCA mutational signature) as the most actionable biomarkers for predicting PARPi sensitivity in CRC. Drug developers should consider companion diagnostic co-development as integral to clinical programs in this space.
MSH3/PARP IP Landscape is Aged & Largely Lapsed
Baylor Research Institute's multi-jurisdiction patent family on MSH3-guided PARPi therapy appears to have entered inactive status across most jurisdictions (AU, CA, CN, JP, MX, BR), with the US patent also inactive. This creates potential freedom-to-operate for new entrants developing MSH3-stratified PARPi programs.
Five Emerging Strategies in MSI-H CRC Synthetic Lethality
1. MSH3 status-guided dual-agent therapy (PARPi + platinum): Baylor Research Institute patents claim methods covering the combined use of PARP inhibitors and platinum drugs in MSH3-deficient CRC, with MSH3 expression as the stratification biomarker. This combination is rationalized by complementary DSB induction (platinum) and repair suppression (PARPi), both exploiting MSH3 deficiency.
2. BER inhibition as an orthogonal synthetic lethal strategy: The VIB VZW patent (2021, active EP) signals emerging interest in BER enzyme inhibitors as alternatives or complements to PARPi in MMR-deficient tumors. Standard chemotherapy resistance in MSI-positive tumors motivates this alternative approach, as noted in the patent itself.
3. DNPH1 inhibition as a PARPi sensitizer or standalone agent: The 2024 Francis Crick Institute filing represents a recent signal toward next-generation synthetic lethal combinations layerable onto MMR-deficient/HR-deficient CRC contexts. Track this emerging target class via PatSnap's IP analytics platform.
4. Mutation signature-based patient stratification: Retrieved patents from Myriad Genetics and the University of Tokyo signal ongoing efforts to refine HRD biomarker panels (combining LOH, TAI, LST, and BRCA mutational signatures) to identify CRC patients most likely to benefit from PARPi regimens.
5. MSI subtype differentiation as a treatment selection tool: Retrieved patents from Baylor Research Institute and a paper evaluating tumour mutational signatures in MMR germline variant carriers suggest that not all MSI-H CRC is equivalent; EMAST, MSI-M, and MSI-H subtypes carry different prognostic implications, which may translate to differential PARPi sensitivity. Explore the full customer use cases for oncology IP strategy at PatSnap.
HRD Biomarker Components for PARPi Response Prediction
Retrieved Myriad Genetics and University of Tokyo patents identify a multi-component HRD biomarker panel as the most actionable framework for identifying MSI-H CRC patients likely to benefit from PARPi regimens.
HRD Biomarker Panel Components
Four genomic instability markers combine to predict PARPi sensitivity; all are described in retrieved Myriad Genetics and University of Tokyo patent filings.
MSI Subtype Differentiation & Clinical Relevance
Not all MSI-H CRC is equivalent: EMAST, MSI-M, and MSI-H subtypes carry different prognostic implications and may translate to differential PARPi sensitivity, per retrieved Baylor RI findings.
WRN and PARP Synthetic Lethality in MSI-H CRC — key questions answered
Synthetic lethality in MSI-high CRC refers to the concept that MMR-deficient tumor cells, which already have impaired DNA repair, can be selectively killed by inhibiting a second DNA repair pathway. For example, MSH3 deficiency in MSI-H CRC compromises double-strand break repair, creating a reliance on PARP-mediated single-strand break repair — a classical synthetic lethal configuration exploitable with PARP inhibitors.
MSH3 deficiency is posited as a determinant of sensitivity to both PARP inhibitors and platinum-based genotoxic agents, based on the role of MSH3 in DNA double-strand break repair. Frameshift mutations within the MSH3 gene's poly-[A]8 repeat are frequent in MSI CRC, occurring in 20–50% of cases, leading to loss or reduction of MSH3 protein expression.
Baylor Research Institute is the dominant assignee for the MSH3/PARP synthetic lethality axis, with patent families filed across at least 7 jurisdictions (US, AU, CA, CN, JP, MX, BR). VIB VZW holds the most current active EP patent on BER synthetic lethality in MSI-H CRC. The Francis Crick Institute holds a 2024 pending BR patent on DNPH1-PARP synthetic lethality. Myriad Genetics holds multiple active and pending JP patents on HRD assessment methodology.
WRN helicase inhibition is not directly evidenced in the retrieved dataset. The absence of WRN-specific data in these results may reflect search limitations or genuine early-stage status of WRN inhibitor IP. This gap represents an opportunity for IP strategy — the WRN synthetic lethality concept in MSI-H CRC may be underpatented relative to its scientific novelty.
Baylor Research Institute's multi-jurisdiction patent family on MSH3-guided PARPi therapy appears to have entered inactive status across most jurisdictions (AU, CA, CN, JP, MX, BR), with the US patent also inactive. This creates potential freedom-to-operate for new entrants developing MSH3-stratified PARPi programs.
Retrieved results converge on MSH3 expression and HRD genomic signatures — including loss of heterozygosity (LOH), telomeric allelic imbalance (TAI), large-scale state transitions (LST), and BRCA mutational signature — as the most actionable biomarkers for predicting PARPi sensitivity in CRC. Drug developers should consider companion diagnostic co-development as integral to clinical programs in this space.
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References
- MSH3 Expression Status Determines the Responsiveness of Cancer Cells to the Chemotherapeutic Treatment with PARP Inhibitors and Platinum Drugs — Takahashi, Masanobu / Baylor Research Institute, 2012, US [Patent]
- MSH3 expression status determines the responsiveness of cancer cells to the chemotherapeutic treatment with PARP inhibitors and platinum drugs — Baylor Research Institute, 2012, AU [Patent]
- MSH3 expression status determines the responsiveness of cancer cells to the chemotherapeutic treatment with PARP inhibitors and platinum drugs — Baylor Research Institute, 2012, CA [Patent]
- Determination of responsiveness of cancer cell to chemotherapeutic treatment with PARP inhibitor and platinum drug based on MSH3 expression status — Baylor Research Institute, 2012, JP [Patent]
- MSH3 expression status determines the responsiveness of cancer cells to the chemotherapeutic treatment with PARP inhibitors and platinum drugs — Baylor Research Institute, 2012, AU [Patent]
- MSH3 expression status determines the responsiveness of cancer cells to the chemotherapeutic treatment with PARP inhibitors and platinum drugs — Baylor Research Institute, 2013, AU [Patent]
- MSH3的表达状态决定癌细胞对使用PARP抑制剂和铂药物的化学疗法治疗的响应性 — Baylor Research Institute, 2012, CN [Patent]
- MSH3 Expression Status to Determine the Responsibility of Cancer Cells to Chemotherapy Treatment with PARP Inhibitors and Platinum Drugs — Baylor Research Institute, 2013, BR [Patent]
- MSH3 expression status determines the responsiveness of cancer cells to the chemotherapeutic treatment with PARP inhibitors and platinum drugs — Baylor Research Institute, 2012, MX [Patent]
- Novel markers for detecting microsatellite instability in cancer and determining synthetic lethality with inhibition of the DNA base excision repair pathway — VIB VZW, 2021, EP [Patent]
- Cancer treatment for people with HR deficiency — The Francis Crick Institute Limited, 2024, BR [Patent]
- Methods and materials for assessing homologous recombination deficiency — Myriad Genetics, Incorporated, 2023, JP [Patent]
- Method and material for evaluating homologous recombination deficiency — Myriad Genetics, Incorporated, 2025, JP [Patent]
- Methods for predicting cancer sensitivity to PARP inhibitors and detecting cancers with homologous recombination repair deficiency — National University Corporation the University of Tokyo, 2021, JP [Patent]
- Biomarkers for Predicting the Recurrence of Colorectal Cancer Metastasis — Boland, C. Richard, 2012, US [Patent]
- Biomarkers for predicting the recurrence of colorectal cancer metastasis — Boland, C. Richard, 2012, WO [Patent]
- Biomarkers for predicting the recurrence of colorectal cancer metastasis — Baylor Research Institute, 2014, EP [Patent]
- Evaluating the utility of tumour mutational signatures for identifying hereditary colorectal cancer and polyposis syndrome carriers — University of Melbourne, 2019 [Paper]
- Methods and materials for assessing homologous recombination deficiency — Myriad Genetics, Incorporated, 2023, JP [Patent]
- Lynch Syndrome (Hereditary Nonpolyposis Colorectal Cancer) — NCBI GeneReviews
- Colorectal Cancer — National Cancer Institute
- Colorectal Cancer Fact Sheet — World Health Organization
All data and statistics on this page are sourced from the references above and from PatSnap's proprietary innovation intelligence platform. Patent status information reflects the retrieved dataset only and may not represent a comprehensive view of the full IP landscape.
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