I'll assess freedom-to-operate for your proposed anti-CLDN18.2 ADC. Let me start by orienting myself in the corpus and searching for relevant patents.
{
"n_families": 14,
"targets": {
"CLDN18.2": {
"modalities": [
"Antibody-drug conjugate",
"Naked monoclonal antibody"
],
"n_families": 6
},
"HER2": {
"modalities": [
"Antibody-drug conjugate",
"Naked monoclonal antibody"
],
"n_families": 4
},
"DLL3": {
"modalities": [
"Antibody-drug conjugate",
"T-cell engager (bispecific)"
],
"n_families": 4
}
},
"assignees": [
"AbbVie / Stemcentrx",
"Amgen",
"Astellas Pharma",
"Boehringer Ingelheim",
"Byondis",
"Daiichi Sankyo",
"Ganymed Pharmaceuticals",
"Ganymed Pharmaceuticals / Astellas",
"Genentech",
"Harbour BioMed",
"ImmunoGen",
"Keymed Biosciences",
"LaNova Medicines",
"Sotio Biotech"
],
"jurisdictions": [
"CN",
"US",
"WO"
]
}{
"count": 6,
"families": [
{
"publication_number": "US9051370B2",
"jurisdiction": "US",
"assignee": "Ganymed Pharmaceuticals / Astellas",
"title": "Antibodies binding to CLDN18.2 and uses thereof",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2008-01-03",
"expiry": "2029-01-03",
"legal_status": "GRANTED",
"claim_types": [
"composition",
"method"
],
"keywords": [
"CLDN18.2",
"claudin",
"zolbetuximab",
"naked antibody",
"gastric",
"composition of matter",
"extracellular loop"
]
},
{
"publication_number": "WO2016166122A1",
"jurisdiction": "WO",
"assignee": "Astellas Pharma",
"title": "Combination therapy of a CLDN18.2 antibody with chemotherapy",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2015-04-13",
"expiry": "2036-04-13",
"legal_status": "PENDING",
"claim_types": [
"method"
],
"keywords": [
"CLDN18.2",
"combination",
"chemotherapy",
"gastric",
"GEJ",
"method of treatment",
"first line"
]
},
{
"publication_number": "CN103509118A",
"jurisdiction": "CN",
"assignee": "Ganymed Pharmaceuticals",
"title": "Antibodies for the diagnosis and treatment of claudin-18.2 expressing tumours",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2009-11-24",
"expiry": "2018-11-24",
"legal_status": "EXPIRED",
"claim_types": [
"composition"
],
"keywords": [
"CLDN18.2",
"diagnostic",
"imaging",
"expired",
"early filing"
]
},
{
"publication_number": "WO2019173420A1",
"jurisdiction": "WO",
"assignee": "LaNova Medicines",
"title": "Anti-CLDN18.2 antibody-drug conjugates with a cleavable linker",
"target": "CLDN18.2",
"modality": "Antibody-drug conjugate",
"priority_date": "2018-03-08",
"expiry": "2039-03-08",
"legal_status": "GRANTED",
"claim_types": [
"composition",
"method"
],
"keywords": [
"CLDN18.2",
"ADC",
"MMAE",
"auristatin",
"cleavable linker",
"DAR",
"composition of matter",
"payload genus"
]
},
{
"publication_number": "CN114106192A",
"jurisdiction": "CN",
"assignee": "Keymed Biosciences",
"title": "Anti-claudin18.2 antibody conjugated to a topoisomerase-I inhibitor payload",
"target": "CLDN18.2",
"modality": "Antibody-drug conjugate",
"priority_date": "2020-09-30",
"expiry": "2040-09-30",
"legal_status": "PENDING",
"claim_types": [
"composition"
],
"keywords": [
"CLDN18.2",
"ADC",
"topoisomerase",
"exatecan",
"DXd",
"cleavable linker",
"pending",
"China"
]
},
{
"publication_number": "US11078291B2",
"jurisdiction": "US",
"assignee": "Sotio Biotech",
"title": "Maytansinoid antibody-drug conjugates targeting CLDN18.2",
"target": "CLDN18.2",
"modality": "Antibody-drug conjugate",
"priority_date": "2017-06-15",
"expiry": "2038-06-15",
"legal_status": "GRANTED",
"claim_types": [
"composition"
],
"keywords": [
"CLDN18.2",
"ADC",
"maytansinoid",
"DM1",
"DM4",
"non-cleavable linker",
"composition of matter"
]
}
]
}Let me read the full claims of the most relevant families — the granted US patents and the ADC-specific filings.
{
"publication_number": "US9051370B2",
"title": "Antibodies binding to CLDN18.2 and uses thereof",
"legal_status": "GRANTED",
"independent_claims": [
{
"claim_no": 1,
"claim_type": "composition",
"text": "A monoclonal antibody that binds to the extracellular loop of human Claudin-18 splice variant 2 (CLDN18.2) but does not bind CLDN18.1, covering the antibody and antigen-binding fragments thereof."
},
{
"claim_no": 14,
"claim_type": "method",
"text": "A method of treating a CLDN18.2-positive cancer comprising administering the antibody of claim 1."
}
]
}{
"publication_number": "WO2019173420A1",
"title": "Anti-CLDN18.2 antibody-drug conjugates with a cleavable linker",
"legal_status": "GRANTED",
"independent_claims": [
{
"claim_no": 1,
"claim_type": "composition",
"text": "An antibody-drug conjugate of formula Ab-(L-D)n wherein Ab is an antibody that specifically binds human CLDN18.2, L is a protease-cleavable peptide linker, and D is an auristatin payload, including MMAE, with a drug-to-antibody ratio of 2 to 8."
},
{
"claim_no": 9,
"claim_type": "method",
"text": "A method of treating a CLDN18.2-positive solid tumour comprising administering the antibody-drug conjugate of claim 1."
}
]
}{
"publication_number": "US11078291B2",
"title": "Maytansinoid antibody-drug conjugates targeting CLDN18.2",
"legal_status": "GRANTED",
"independent_claims": [
{
"claim_no": 1,
"claim_type": "composition",
"text": "An antibody-drug conjugate comprising an anti-CLDN18.2 antibody, a non-cleavable thioether linker, and a maytansinoid (DM1/DM4) payload."
}
]
}The two most concerning patents are US9051370B2 (Ganymed/Astellas) and WO2019173420A1 (LaNova). Let me get full records to check jurisdiction reach, priority, expiry, and whether the LaNova WO has a US counterpart, plus check the broader corpus for any genus auristatin/linker claims that could read on this.
{
"publication_number": "US9051370B2",
"jurisdiction": "US",
"assignee": "Ganymed Pharmaceuticals / Astellas",
"priority_date": "2008-01-03",
"expiry": "2029-01-03",
"legal_status": "GRANTED",
"title": "Antibodies binding to CLDN18.2 and uses thereof",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"independent_claims": [
{
"claim_no": 1,
"claim_type": "composition",
"text": "A monoclonal antibody that binds to the extracellular loop of human Claudin-18 splice variant 2 (CLDN18.2) but does not bind CLDN18.1, covering the antibody and antigen-binding fragments thereof."
},
{
"claim_no": 14,
"claim_type": "method",
"text": "A method of treating a CLDN18.2-positive cancer comprising administering the antibody of claim 1."
}
],
"keywords": [
"CLDN18.2",
"claudin",
"zolbetuximab",
"naked antibody",
"gastric",
"composition of matter",
"extracellular loop"
]
}{
"publication_number": "WO2019173420A1",
"jurisdiction": "WO",
"assignee": "LaNova Medicines",
"priority_date": "2018-03-08",
"expiry": "2039-03-08",
"legal_status": "GRANTED",
"title": "Anti-CLDN18.2 antibody-drug conjugates with a cleavable linker",
"target": "CLDN18.2",
"modality": "Antibody-drug conjugate",
"independent_claims": [
{
"claim_no": 1,
"claim_type": "composition",
"text": "An antibody-drug conjugate of formula Ab-(L-D)n wherein Ab is an antibody that specifically binds human CLDN18.2, L is a protease-cleavable peptide linker, and D is an auristatin payload, including MMAE, with a drug-to-antibody ratio of 2 to 8."
},
{
"claim_no": 9,
"claim_type": "method",
"text": "A method of treating a CLDN18.2-positive solid tumour comprising administering the antibody-drug conjugate of claim 1."
}
],
"keywords": [
"CLDN18.2",
"ADC",
"MMAE",
"auristatin",
"cleavable linker",
"DAR",
"composition of matter",
"payload genus"
]
}{
"count": 1,
"families": [
{
"publication_number": "WO2019173420A1",
"jurisdiction": "WO",
"assignee": "LaNova Medicines",
"title": "Anti-CLDN18.2 antibody-drug conjugates with a cleavable linker",
"target": "CLDN18.2",
"modality": "Antibody-drug conjugate",
"priority_date": "2018-03-08",
"expiry": "2039-03-08",
"legal_status": "GRANTED",
"claim_types": [
"composition",
"method"
],
"keywords": [
"CLDN18.2",
"ADC",
"MMAE",
"auristatin",
"cleavable linker",
"DAR",
"composition of matter",
"payload genus"
]
}
]
}{
"count": 0,
"families": []
}Let me verify the CLDN18.2 antibody landscape for design-around options (other naked antibody claims that might define usable binders) and confirm there's no separate US Astellas combination/method patent I'm missing.
{
"count": 3,
"families": [
{
"publication_number": "US9051370B2",
"jurisdiction": "US",
"assignee": "Ganymed Pharmaceuticals / Astellas",
"title": "Antibodies binding to CLDN18.2 and uses thereof",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2008-01-03",
"expiry": "2029-01-03",
"legal_status": "GRANTED",
"claim_types": [
"composition",
"method"
],
"keywords": [
"CLDN18.2",
"claudin",
"zolbetuximab",
"naked antibody",
"gastric",
"composition of matter",
"extracellular loop"
]
},
{
"publication_number": "WO2016166122A1",
"jurisdiction": "WO",
"assignee": "Astellas Pharma",
"title": "Combination therapy of a CLDN18.2 antibody with chemotherapy",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2015-04-13",
"expiry": "2036-04-13",
"legal_status": "PENDING",
"claim_types": [
"method"
],
"keywords": [
"CLDN18.2",
"combination",
"chemotherapy",
"gastric",
"GEJ",
"method of treatment",
"first line"
]
},
{
"publication_number": "CN103509118A",
"jurisdiction": "CN",
"assignee": "Ganymed Pharmaceuticals",
"title": "Antibodies for the diagnosis and treatment of claudin-18.2 expressing tumours",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2009-11-24",
"expiry": "2018-11-24",
"legal_status": "EXPIRED",
"claim_types": [
"composition"
],
"keywords": [
"CLDN18.2",
"diagnostic",
"imaging",
"expired",
"early filing"
]
}
]
}{
"count": 1,
"families": [
{
"publication_number": "US9051370B2",
"jurisdiction": "US",
"assignee": "Ganymed Pharmaceuticals / Astellas",
"title": "Antibodies binding to CLDN18.2 and uses thereof",
"target": "CLDN18.2",
"modality": "Naked monoclonal antibody",
"priority_date": "2008-01-03",
"expiry": "2029-01-03",
"legal_status": "GRANTED",
"claim_types": [
"composition",
"method"
],
"keywords": [
"CLDN18.2",
"claudin",
"zolbetuximab",
"naked antibody",
"gastric",
"composition of matter",
"extracellular loop"
]
}
]
}I now have a complete picture of the US-relevant landscape. Here is the FTO assessment.
Your proposed product faces two material blocking risks in the US: one genus composition-of-matter patent on the anti-CLDN18.2 antibody itself (Ganymed/Astellas), and one WO ADC patent whose claim language reads almost verbatim on your product (LaNova). The LaNova WO is not itself a US right, so its US enforceability depends on whether a US national-phase member issued — that must be confirmed outside this corpus. The Sotio ADC patent does not block you (different linker/payload chemistry).
| Risk | Design-around | Viability |
|---|---|---|
| US9051370B2 (antibody genus) | Use an antibody that does not bind the extracellular loop / or that also binds CLDN18.1, etc. | Poor. Sparing CLDN18.1 is required for safety; binding the extracellular loop is required for surface targeting. The claim is functionally drawn around exactly the antibody you need. Design-around is essentially infeasible without undermining the product. |
| US9051370B2 | License from Astellas/Ganymed (likely the only clean path). | Recommended primary strategy. |
| US9051370B2 | Wait for expiry (Jan 2029) then launch. | Viable if timeline tolerates it; also check for any later Astellas continuations/method patents (e.g., WO2016166122A1 family) extending coverage. |
| LaNova ADC claim | Switch payload class: topoisomerase-I inhibitor (DXd/exatecan) or maytansinoid instead of auristatin. | Strong technically — but note DXd implicates Keymed (China only here) and DM1/DM4 implicates Sotio (US, granted). Auristatin→maytansinoid would walk you into US11078291B2. |
| LaNova ADC claim | Use a non-peptide / non-protease-cleavable linker (e.g., acid-labile, glucuronide-cleavable, or non-cleavable) while keeping MMAE. | Moderate — moves outside "protease-cleavable peptide linker" element. Glucuronidase-cleavable linkers are enzyme-cleavable but not "peptide"; assess claim construction carefully. |
| LaNova ADC claim | Operate at DAR outside 2–8 (e.g., site-specific DAR exactly 2 is within range; very high DAR is impractical). | Weak — 2–8 covers essentially all practical DARs. |
| LaNova ADC claim | Confirm no US family member exists; if abandoned/never filed, no design-around needed in US. | First and cheapest step. |
Caveats: This analysis is limited to the 14-family corpus provided and to US scope; it is not legal advice. The LaNova WO→US determination and any Astellas continuations/PTE require off-corpus public-register confirmation. Doctrine-of-equivalents and validity opinions require full prosecution-history and prior-art review.
I now have a complete picture of the US-relevant landscape. Here is the FTO assessment.
Your proposed product faces two material blocking risks in the US: one genus composition-of-matter patent on the anti-CLDN18.2 antibody itself (Ganymed/Astellas), and one WO ADC patent whose claim language reads almost verbatim on your product (LaNova). The LaNova WO is not itself a US right, so its US enforceability depends on whether a US national-phase member issued — that must be confirmed outside this corpus. The Sotio ADC patent does not block you (different linker/payload chemistry).
| Risk | Design-around | Viability |
|---|---|---|
| US9051370B2 (antibody genus) | Use an antibody that does not bind the extracellular loop / or that also binds CLDN18.1, etc. | Poor. Sparing CLDN18.1 is required for safety; binding the extracellular loop is required for surface targeting. The claim is functionally drawn around exactly the antibody you need. Design-around is essentially infeasible without undermining the product. |
| US9051370B2 | License from Astellas/Ganymed (likely the only clean path). | Recommended primary strategy. |
| US9051370B2 | Wait for expiry (Jan 2029) then launch. | Viable if timeline tolerates it; also check for any later Astellas continuations/method patents (e.g., WO2016166122A1 family) extending coverage. |
| LaNova ADC claim | Switch payload class: topoisomerase-I inhibitor (DXd/exatecan) or maytansinoid instead of auristatin. | Strong technically — but note DXd implicates Keymed (China only here) and DM1/DM4 implicates Sotio (US, granted). Auristatin→maytansinoid would walk you into US11078291B2. |
| LaNova ADC claim | Use a non-peptide / non-protease-cleavable linker (e.g., acid-labile, glucuronide-cleavable, or non-cleavable) while keeping MMAE. | Moderate — moves outside "protease-cleavable peptide linker" element. Glucuronidase-cleavable linkers are enzyme-cleavable but not "peptide"; assess claim construction carefully. |
| LaNova ADC claim | Operate at DAR outside 2–8 (e.g., site-specific DAR exactly 2 is within range; very high DAR is impractical). | Weak — 2–8 covers essentially all practical DARs. |
| LaNova ADC claim | Confirm no US family member exists; if abandoned/never filed, no design-around needed in US. | First and cheapest step. |
Caveats: This analysis is limited to the 14-family corpus provided and to US scope; it is not legal advice. The LaNova WO→US determination and any Astellas continuations/PTE require off-corpus public-register confirmation. Doctrine-of-equivalents and validity opinions require full prosecution-history and prior-art review.
Heuristic reference over the curated corpus for target=CLDN18.2, modality=Antibody-drug conjugate. Families in scope: 6 ({'GRANTED': 3, 'PENDING': 2, 'EXPIRED': 1}). BLOCKING = granted composition-of-matter on the same target+modality and not expired; WATCH = pending or method-only; CLEARABLE = expired. This is illustrative reasoning over a teaching snapshot, NOT legal advice.
| Publication # | Assignee | Legal status | Expiry | Claim type(s) | FTO relevance |
|---|---|---|---|---|---|
| WO2019173420A1 | LaNova Medicines | GRANTED | 2039-03-08 | composition, method | BLOCKING (granted composition-of-matter) |
| CN114106192A | Keymed Biosciences | PENDING | 2040-09-30 | composition | WATCH (pending — claims not yet fixed) |
| US11078291B2 | Sotio Biotech | GRANTED | 2038-06-15 | composition | BLOCKING (granted composition-of-matter) |
| US9051370B2 | Ganymed Pharmaceuticals / Astellas | GRANTED | 2029-01-03 | composition, method | BLOCKING (granted composition-of-matter) |
| WO2016166122A1 | Astellas Pharma | PENDING | 2036-04-13 | method | WATCH (pending — claims not yet fixed) |
| CN103509118A | Ganymed Pharmaceuticals | EXPIRED | 2018-11-24 | composition | CLEARABLE (expired) |
| OVERALL FTO VERDICT (heuristic) | BLOCKED — 3 granted composition-of-matter family(ies) read on the proposed product; need a licence or a design-around. |