ADC TOXICITY ATLAS
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Aprutumab ixadotin

Discontinued
BAY 1187982
Sponsor
Bayer
Indication
FGFR2+ solid tumors
Target family
Receptor tyrosine kinase
RP2D dose
0.2 mg/kg (Q3W MTD; trial terminated, no formal RP2D)
Q3WRP2D
01
Multi-organ toxicity

Fingerprint & organ drill-down

Also reported
0%severity100%
0
Assessed · clear
true 0%
No data
never assessed
5 adverse-event terms

Ocular

Any-grade
40%
G3+
5%
RP2D
sagittal schematic · Reversible

Tissues shaded by reported adverse-event rate.

Cornea
AE
20%
Express.
58.38%
Limbus
AE
-
Express.
77.56%
Conjunctiva
AE
-
Express.
74.29%
Lens
AE
-
Express.
-
Retina / RPE
AE
-
Express.
-
0.7 nTPM
Off-target signature

20% corneal toxicity, yet the FGFR2 target is detected in only 58.38% of central cornea - toxicity is not explained by target expression.

Dominant tissue
Cornea
Surface subtype
Corneal (off-target)
Reversibility
Reversible
Reported ocular events
Corneal deposits20%
G3+ 0%n=20
Corneal epithelial microcysts15%
G3+ 5%n=20
Vision blurred5%
n=20
Retinal haemorrhage-
Ocular discomfort-
Per-trial detail

Adverse events by trial

NCT02368951Phase 10.1-1.3 mg/kg (pooled across 5 escalation cohorts) IV day 1 of every 21-day cycle (Q3W)n=20CTCAE 4.03PooledBto verify
Kim 2019 Target Oncol PMID:31502117
36 adverse-event terms · 3 systems · expand a system below
Other31
Aspartate aminotransferase increased
60%G3+ 15%
12/20
Thrombocytopenia
50%G3+ 25%
10/20
Anaemia
30%G3+ 10%
6/20
Fatigue
30%G3+ 0%
6/20
Nausea
25%G3+ 0%
5/20
Pyrexia
25%G3+ 0%
5/20
Alanine aminotransferase increased
25%G3+ 5%
5/20
Blood alkaline phosphatase increased
25%G3+ 15%
5/20
Decreased appetite
25%G3+ 5%
5/20
Abdominal pain
20%G3+ 0%
4/20
Corneal deposits
20%G3+ 0%
4/20
Corneal epithelial microcysts
15%G3+ 5%
3/20
Dyspepsia
15%G3+ 0%
3/20
Vomiting
15%G3+ 5%
3/20
Urinary tract infection
15%G3+ 5%
3/20
Hypoalbuminaemia
15%G3+ 0%
3/20
Cough
15%G3+ 0%
3/20
Abdominal distension
10%G3+ 0%
2/20
Ascites
10%G3+ 5%
2/20
Blood cholesterol increased
10%G3+ 0%
2/20
Blood creatinine increased
10%G3+ 0%
2/20
Blood fibrinogen increased
10%G3+ 0%
2/20
Brain natriuretic peptide increased
10%G3+ 0%
2/20
Fibrin D-dimer increased
10%G3+ 0%
2/20
Lipase increased
10%G3+ 0%
2/20
White blood cell count decreased
10%G3+ 0%
2/20
Dehydration
10%G3+ 5%
2/20
Hypercalcaemia
10%G3+ 0%
2/20
Proteinuria
10%G3+ 10%
2/20
Epistaxis
10%G3+ 0%
2/20
Productive cough
10%G3+ 0%
2/20
Overall/Summary4
Ocular1
Any ocular event
40%
8/20
02
Construct

Molecular anatomy

Antibody
IgG1
Human
Linker
Non-cleavable
4.1
DAR
Payload
Tubulin inhibitor
Linker structureC6H12O2
CCCCCC(=O)O
Payload structureC45H73N7O8
CC[C@H](C)[C@@H]([C@@H](CC(=O)N1CCC[C@H]1[C@@H]([C@@H](C)C(=O)N[C@@H](CC2=CNC3=CC=CC=C32)C(=O)N4CCCCO4)OC)OC)N(C)C(=O)[C@H](C(C)C)NC(=O)[C@H](C(C)C)NC
03
Antibody

Antibody & Fc engineering

Antibody
anti-FGFR2 (aprutumab)
Isotype
IgG1
Origin
Human
Fc modifications
None
Glycoengineering
Standard
Effector silencing
None
FcγR binding
Retained
C1q binding
Retained
Dev code
BAY 1179470
Epitope / domain
N-terminal extracellular epitope of FGFR2
04
Linker & conjugation

Linker chemistry

Linker profile
Linker
Lys non-cleavable (auristatin W)
Class
Non-cleavable
Cleavage
Non-cleavable
Attachment
Lysine
Conjugation
Conventional Lys (non-cleavable)
Symmetry
Asymmetric
DAR (mean)
4.1
DAR homogeneity
Heterogeneous
Plasma t½
-
Cleavage trigger
Non-cleavable
Release control
Unconditional
Hydrophilicity mask
-
Cell line
CHO
Formula
C6H12O2
Linker MW
116.16 Da
Linker TPSA
37.3 Ų
Linker xLogP
1.6513
ADCdb linker
LIN0IUSXC
In-vitro stability
-
Stability note
Lys-NHS non-cleavable to auristatin W; Phase 1 terminated at MTD 0.2 mg/kg below therapeutic threshold (Kim Target Oncol 2019 N=20); Sommer MCT 2016 reports off-target toxicity from circulating linker-payload metabolite in cyno but no clinical t½ in d in either source
05
Payload

Payload & physicochemistry

Payload profile
Payload
Auristatin W
Class
Auristatin
Mechanism
Tubulin inhibitor
Released catabolite
BAY 1159184 (auristatin W-derived toxophore metabolite)
Mechanistic subtype
Tubulin-auristatin
Stereochem / salt
-
Bystander
No
PAMPA rank
-
MW
746 Da
XLogP3
2.6
logD₇.₄
1.5
TPSA
158 Ų
pKa
3.5 pKa
Charge pH 7.4
Zwitterion
H-bond donors
4
H-bond acceptors
9
IC50 (HCEC)
-
Formula
C45H73N7O8
PubChem CID
86678408
ADCdb payload
PAY0PBONE
Hydrophobicity · logD₇.₄
hydrophilic −2+1.5+4 lipophilic
Bioactivity note
Auristatin W is a microtubule-inhibiting auristatin (dolastatin-10 analog); ADCdb lists payload mechanism as 'Microtubule (MT)' disruption. No discrete payload IC50 reported on ADCdb/PubChem. Clinically (first-in-human phase I, PMID 31502117) the ADC was terminated for poor toler
06
Dosing & regimen

Dosing

RP2D dose
0.2 mg/kg (Q3W MTD; trial terminated, no formal RP2D)
Schedule
Q3W
Route
IV
Fractionated
No
n at RP2D
20
Dose basis
TBW
Trial phase
Phase 1
Dose-OAE available
No
Tox summary basis
RP2D
08
Ocular & expression

Ocular profile & eye-tissue target expression

Target profile
OAE any-grade
40 %
OAE grade 3+
5 %
OAE data status
reported
Severity (weighted)
15.5
Keratopathy
20 %
Conjunctival
-
Dry eye
-
Blurred vision
5 %
Dominant tissue
Cornea
Surface subtype
Corneal (off-target)
Grading scale
CTCAE v4.03
Reversibility
Reversible
Target expression in eye tissues (HCA detection · HPA bulk)
Cornea (central)
58.38 %
Cornea (limbal)
77.56 %
Conjunctiva
74.29 %
RPE
-
Retina (HPA)
0.7 nTPM
Cross-trial comparability · source-verified
Ascertainment: Systematic eye examsScale: CTCAE v4Denominator: RP2D
Dose & schedule → ocular toxicity · keratopathy (any-grade) by cohort
0.1-1.3 mg/kg (pooled across 5 escalation cohorts)
IV day 1 of every 21-day cycle (Q3W)
40%
n=20 · NCT02368951
0.1-1.3 mg/kg (pooled; events only at 0.8 and 1.3 mg/kg)
IV Q3W (day 1 of 21-day cycle)
20%
n=20 · BAY 1187982 FIH
0.1-1.3 mg/kg (pooled across 5 escalation cohorts)
IV day 1 of every 21-day cycle (Q3W)
5%
n=20 · NCT02368951
Per-cohort rates from the per-trial extraction, sorted by dose. Cross-trial comparison is subject to ascertainment / scale differences (see comparability above) — e.g. an early symptom-driven trial can read lower than a later systematic-exam trial at a higher dose.
Ocular AE grading reference — interspecialty consensus · 6 scales + dose modification
09
Identity & registry

Identifiers, registry & notes

ADC id
aprutumab-ixadotin
Approval status
Discontinued
Approval year
-
UniProt
P21802
ADCdb ADC
DRG0JJEUT
ADCdb antibody
ANI0KNFWI
ADCdb target
TAR0OXEAL
Primary source
Kim Target Oncol 2019
Aliases & development codes
BAY 1187982
Notes
Trial terminated early due to off-target coagulation toxicity. V3.1: RP2D corrected 0.7→0.2 mg/kg Q3W per Kim Target Oncol 2019 (0.7 not among tested cohorts 0.1/0.2/0.4/0.8/1.3). Corneal events: 15% microcysts + 20% deposits (distinct events).