The KRAS mutation landscape in PDAC and CRC

KRAS mutations occur in up to 95% of pancreatic ductal adenocarcinoma (PDAC) cases and approximately 40–50% of colorectal cancer (CRC) cases, establishing the KRAS GTPase as the dominant oncogenic driver across both indications. The RAS/MAPK signalling cascade — encompassing RAF, MEK, and ERK effectors — is the primary proliferative and survival axis downstream of mutant KRAS, and its hyperactivation underpins resistance to a broad range of therapeutic agents.

The specific mutation landscape differs markedly between the two indications. G12D predominates in both PDAC and CRC; G12V and G13D are represented across both; G12R is noted primarily in PDAC; and G12C — while pharmacologically privileged — has a frequency of only approximately 1% in pancreatic cancers and a similarly low share in CRC. KRAS G12C mutations are cited as present in approximately 1–2% of malignant solid tumours overall, according to patent filings from Amgen Inc. and Novartis AG. This allele distribution has profound consequences for therapeutic strategy: the tractability of G12C for covalent inhibition has concentrated early IP activity on a relatively rare allele, while the dominant G12D variant — most prevalent in the indication with the worst prognosis — remains a substantially harder biochemical problem.

Academic literature in this dataset describes EGF receptor (EGFR) and its ligands — TGF-α, epiregulin, and amphiregulin — as strongly upregulated in PDAC and as upstream activators of KRAS-dependent signalling. Preclinical pancreatic cancer models demonstrate that TGFA overexpression drives fibrosis and epithelial morphogenesis associated with PDAC formation, providing mechanistic grounding for EGFR-targeting strategies even in KRAS-mutant disease. Genetically engineered mouse models co-harbouring KRAS activating mutations at codons G12, G13, and Q61 alongside tumour suppressor losses (p53, Ink4a/Arf, Smad4) — documented in University of Pennsylvania filings — have established the molecular context for therapeutic target validation across the field.

Covalent G12C inhibitors: from first approval to combination filings

Covalent KRAS G12C inhibitors exploit the unique reactive cysteine substitution at position 12 to form irreversible adducts with the GDP-bound (inactive) form of the protein, locking KRAS in an off-state. This mechanism — inaccessible for other KRAS alleles — has produced the field’s first regulatory approval: sotorasib (AMG 510), developed by Amgen Inc., received FDA accelerated approval for KRAS G12C-mutant non-small-cell lung cancer (NSCLC), representing the most advanced clinical signal in this dataset.

Amgen is the highest-volume assignee for direct KRAS G12C small-molecule inhibitor filings in this dataset, covering multiple structural scaffolds — benzisothiazole, isothiazolopyridine, quinazoline, phthalazine, and pyrido-pyrimidine — across at least five jurisdictions (CA, MX, SG, BR, JP, EP) between 2019 and 2024. Array Biopharma Inc. (a subsidiary of Pfizer) filed piperazinyl-acrylamide compounds in the same structural class. These patents are in active or pending legal status across multiple jurisdictions, indicating sustained and broadening IP prosecution. According to WIPO, multi-jurisdictional patent prosecution of this breadth is characteristic of assets with commercial launch ambitions across major pharmaceutical markets.

“Resistance mechanisms — including secondary KRAS mutations and MAPK/mTOR feedback reactivation — are explicitly noted in Kura Oncology and Novartis filings, signalling that combination strategies are not optional but necessary.”

Adagrasib (MRTX849) is the second covalent G12C inhibitor referenced in this dataset. Clinical resistance data cited in a Novartis US filing (2024) reference a Tanaka 2021 study identifying a specific double KRAS mutation mediating adagrasib resistance in clinical trials. Foundation Medicine, Inc.’s liquid biopsy patent further documents acquired KRAS Q61H mutations and EGFR amplification/mutations (V441G, G465R) in CRC patients previously treated with adagrasib ± cetuximab — constituting a clinical resistance portrait derived from patient samples. A Sun Yat-sen University patent describes the generation of a KRAS G12C inhibitor-resistant pancreatic cancer cell line (MIA PaCa/KIR, deposited at CCTCC NO: C2024358), directly enabling resistance mechanism research at the preclinical level.

KRAS G12D — the dominant allele and the highest unmet need

KRAS G12D is the dominant allele in PDAC and is also present in CRC and NSCLC, yet it lacks the reactive cysteine that makes G12C amenable to covalent inhibition, making it a substantially harder biochemical problem. Only a small number of early-stage patent families in this dataset are specifically directed at G12D, representing what the dataset characterises as the highest-unmet-need opportunity in the KRAS inhibitor space.

Astellas Pharma Inc. has concentrated recent filings (2024) on heterocyclic compounds with both inhibitory and degradation-inducing activity against the G12D protein — a mechanism potentially involving targeted protein degradation (PROTAC-like) or allosteric degrader chemistry, though the precise mechanism is not fully elaborated in the retrieved patent text. Astellas’s companion combination patents describe pairing these G12D-active compounds with taxanes, fluoropyrimidines, platinum agents, camptothecin analogues, CDK4/6 inhibitors, SHP2 inhibitors, EGFR inhibitors, mTOR inhibitors, PI3K inhibitors, SOS1 inhibitors, and Aurora kinase inhibitors — a broad combination claim landscape that anticipates multiple resistance bypass routes. Theras Inc. has filed pan-KRAS inhibitor patents with activity against G12D, G12V, G12C, G12S, G12A, G12R, G13D, and Q61H alleles, offering a profile relevant across both PDAC and CRC.

The most biologically anchored combination finding for a non-direct KRAS inhibitor strategy in this dataset involves GREM1 (Gremlin-1). UCB Biopharma SRL filed patents combining anti-GREM1 antagonists with MEK/ERK inhibitors for KRAS-mutant PDAC. Retrieved data from a LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx1-Cre (KPC) mouse model — the standard genetically engineered model for PDAC — demonstrate that GREM1 blockade induces Ras-RAF-MEK-ERK pathway upregulation, providing mechanistic rationale for co-administration of MEK inhibitors to prevent compensatory MAPK activation. Significantly increased survival and tumour shrinkage were observed in this model, representing one of the strongest in vivo preclinical signals in the dataset.

Kura Oncology has filed farnesyltransferase inhibitor (FTI) patents specifically for KRAS-dependent cancers, noting that feedback reactivation of MAPK/mTOR pathways limits the efficacy of covalent G12C inhibitors. MEK inhibitor clinical trial failures in pancreatic cancer patients — cited explicitly in Kura Oncology and UCB Biopharma filings with reference to Brauswetter et al. (2017, PLoS ONE) — motivate the development of combination strategies to overcome adaptive pathway reactivation, a lesson directly applicable to G12D-targeting programmes now entering the clinic.

Anti-EGFR antibodies and the biomarker stratification imperative

Anti-EGFR antibodies — cetuximab, panitumumab, and nimotuzumab — remain clinically relevant in KRAS-stratified patient populations, but their utility depends entirely on accurate molecular selection. KRAS mutations at codons 12 and 13 confer resistance to anti-EGFR antibody therapies, establishing KRAS wild-type status as a companion diagnostic criterion in CRC; this relationship is extensively documented across multiple Merck Patent GmbH patent families spanning ES, EP, IL, CA, AU, MX, CN, and HK jurisdictions between 2010 and 2018.

Even within the KRAS wild-type CRC population, approximately 40% of patients do not respond to anti-EGFR agents, according to academic literature from the University of California, San Francisco. This non-response rate implicates additional resistance biomarkers: Merck Patent GmbH’s biomarker patent family identifies epiregulin (EREG), amphiregulin (AREG), and RasGRP1 as positive predictors of anti-EGFR response, while BRAF co-mutations are noted as additional resistance determinants. Oregon Health & Science University and EPFL filings provide molecular subtype classifiers — “Stem-like,” “Inflammatory,” “Transit-amplifying” — that further refine anti-EGFR response prediction in CRC, moving beyond single-gene mutation testing toward expression-based patient stratification.

The anti-EGFR biomarker IP landscape, dominated by Merck Patent GmbH and Innocimab, defines a molecularly stratified subpopulation — KRAS wild-type — that remains therapeutically addressable even as direct KRAS targeting matures. Standards bodies including the European Medicines Agency have incorporated KRAS mutation testing into cetuximab and panitumumab prescribing guidance, reflecting the clinical entrenchment of this biomarker strategy. The continuing active prosecution of nimotuzumab PDAC patents into 2025 signals commercial intent in a niche but well-defined patient population.

Combination strategies and the resistance IP race

The most recent patent filings (2023–2025) in this dataset consistently converge on multi-agent strategies designed to address adaptive resistance to KRAS inhibition — a resistance pattern that is mechanistically predictable and clinically documented. According to the National Cancer Institute, adaptive resistance through pathway reactivation is a central challenge for targeted oncology agents, and the KRAS inhibitor field is following a trajectory well-established with EGFR and BRAF inhibitors in other tumour types.

EGFR and upstream receptor bypass

Genentech, Inc. has filed patents specifically combining KRAS G12C inhibitors with EGFR inhibitors for CRC and PDAC, addressing the known adaptive reactivation of EGFR signalling following KRAS G12C blockade. This combination mirrors the clinical rationale for adagrasib plus cetuximab, for which Foundation Medicine’s resistance data provide a post-treatment molecular portrait. Biocarta Therapeutics has filed patents (CN, 2025) combining KRAS inhibitors with dual EGFR/TGFβ-targeting agents, addressing both upstream receptor reactivation and immunosuppressive TGFβ in the tumour microenvironment, with explicit claims for use in KRAS inhibitor-resistant settings.

Triple combination: oncogene + upstream + checkpoint

Novartis AG’s triple-combination strategy — KRAS G12C inhibitor plus SHP2 inhibitor (TNO155) plus PD-1 checkpoint inhibitor (spartalizumab or tislelizumab) — reflects a three-pronged attack: direct oncogene inhibition, upstream reactivation suppression via SHP2 (a phosphatase mediating upstream RAS activation), and immune checkpoint restoration. Novartis holds multiple active or pending filings in IL, BR, CN, AU, and the US (2022–2024) for this combination, reflecting a clinical-stage partnership between its proprietary compound and combination immunotherapy.

Innate immune activation: CD47/SIRPα blockade

I-Mab Biopharma and TJ Biopharma (Shanghai) Co., Ltd. have filed patents (2023–2025) combining KRAS G12C or G12D inhibitors with CD47 “don’t eat me” signal blockers to stimulate macrophage-mediated phagocytosis of KRAS-mutant cancer cells. This approach integrates innate immune activation with direct oncogene targeting, representing a mechanistically distinct combination rationale from the receptor-level bypass strategies pursued by Genentech and Novartis.

Downstream MAPK node: ERK1/2 inhibition

D3 Bio (Wuxi) Co., Ltd. (WO, 2025) filed therapies combining ERK1/2 inhibitors with KRAS G12C inhibitors explicitly for acquired KRAS G12C inhibitor-resistant cancers including CRC and PDAC. This addresses downstream MAPK reactivation independently of upstream receptor-level bypass, providing an orthogonal resistance mechanism target. The FDA‘s accelerated approval pathway for sotorasib required confirmatory trials to validate clinical benefit, underscoring the regulatory urgency for combination data in this space.

MEI Pharma, Inc. presents CDK inhibitor (onvansertib, volasertib) combination data in KRAS-mutant CRC (SW48 G12C, G12D) and pancreatic cancer cell lines, showing synergy scores supporting continued development. Boehringer Ingelheim International GmbH has filed patents on dual Aurora kinase/MEK inhibitors applicable to CRC and PDAC contexts harbouring KRAS mutations at codons 12, 13, and 61 — a single-agent approach to dual-pathway suppression that avoids the pharmacokinetic complexity of combination dosing.

Strategic implications for drug developers and IP teams

The KRAS patent landscape in PDAC and CRC has shifted decisively from foundational structural claims toward combination and resistance-mechanism filings — a transition that carries concrete implications for freedom-to-operate analysis, partnering strategy, and clinical programme design.

The combination claim landscape is multi-assignee and multi-jurisdictional. Foundational structural patents from Amgen and Array Biopharma are being layered with combination patents from Amgen, Genentech, Novartis, I-Mab, and D3 Bio, spanning US, EU, IL, IN, SG, AU, MX, and CN jurisdictions. Any single KRAS G12C combination regimen will require navigation of this multi-assignee claim landscape. IP teams should conduct freedom-to-operate analysis that accounts for combination claims, not just compound patents.

KRAS G12D represents the highest-unmet-need opportunity in this dataset. Astellas Pharma and Theras Inc. hold the only early-stage patents specifically directed at G12D degradation or pan-KRAS inhibition, yet G12D is the dominant allele in PDAC — the indication with the greatest survival gap. Drug developers and investors should monitor whether these preclinical assets show differentiated in vivo activity versus the G12C-focused field. The National Institutes of Health has identified pancreatic cancer as a priority area for therapeutic development given its persistently low five-year survival rates.

Resistance mechanism IP is an active and growing area. Foundation Medicine’s liquid biopsy patent capturing KRAS Q61H and EGFR co-alterations as acquired resistance mechanisms post-adagrasib treatment signals that companion diagnostic and resistance-monitoring claims will become strategically important as first-generation KRAS inhibitors achieve broader clinical use. Organisations with liquid biopsy capabilities should assess whether their resistance-monitoring approaches intersect with existing IP.

Tumour microenvironment combination strategies represent an emerging differentiated IP space. UCB Biopharma’s GREM1 antagonist combination and Cambridge Enterprise’s CCR1 antagonist filings for PDAC address the immunosuppressive and pro-tumorigenic stroma that limits efficacy of all KRAS-targeting approaches in PDAC. This potentially provides IP white space for academic spinouts and partnering opportunities, particularly for organisations with antibody-based tumour microenvironment assets. Detailed patent analytics on this emerging space are accessible via PatSnap’s life sciences intelligence platform.

Arenavirus-based neoantigen immunotherapy is an outlier approach with early IP protection. Hookipa Biotech GmbH holds patents across CA, WO, AU, and US (2023–2025) for genetically modified arenavirus particles encoding antigenic fragments of mutant KRAS (G12D, G12V, G12C), treating the mutant KRAS peptide as a neoantigen rather than directly targeting the oncoprotein biochemically. This approach is at an early preclinical stage but occupies a distinct mechanistic space in an otherwise small-molecule-dominated competitive landscape.