ADC TOXICITY ATLAS
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BAT-8008

Investigational
BAT8008; BAT-8008
Sponsor
Bio-Thera Solutions, Ltd.
Indication
Advanced/metastatic solid tumors (NSCLC, HER2- breast, cervical, esophageal/ESCC, other GI)
Target family
TACSTD / EpCAM-TROP
RP2D dose
2.4 mg/kg
Q2W (14-day cycles; first cycle 21 days for safety observation)RP2D
01
Multi-organ toxicity

Fingerprint & organ drill-down

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

Ocular

Any-grade
0%
G3+
0%
RP2D
sagittal schematic · -
↳

Tissues shaded by reported adverse-event rate.

Cornea
AE
-
Express.
65.43%
Limbus
AE
-
Express.
73.31%
Conjunctiva
AE
-
Express.
86.39%
Lens
AE
-
Express.
-
Retina / RPE
AE
-
Express.
0%
0 nTPM
Dominant tissue
-
Surface subtype
None
Reversibility
-
Reported ocular events
Ocular toxicity (any ocular adverse event)0%
n=194
02
Construct

Molecular anatomy

Antibody
Humanized
Linker
Peptide
Cleavable
6
DAR
Payload
Exatecan
DNA topoisomerase 1 (TOP1) inhibitor
Linker structure
structure not applicable
Payload structureC24H22FN3O4
CC[C@@]1(C2=C(COC1=O)C(=O)N3CC4=C5[C@H](CCC6=C5C(=CC(=C6C)F)N=C4C3=C2)N)O
03
Antibody

Antibody & Fc engineering

Antibody
Fully-humanized anti-TROP2 monoclonal antibody (undisclosed)
Isotype
-
Origin
Humanized
Fc modifications
-
Glycoengineering
-
Effector silencing
-
FcγR binding
Retained
C1q binding
Retained
04
Linker & conjugation

Linker chemistry

Linker profile
Linker
Cleavable maleimide tetrapeptide-based linker
Class
Peptide
Cleavage
Cleavable
Attachment
Cysteine (interchain)
Conjugation
Cysteine (maleimide) conjugation
Symmetry
Symmetric
DAR (mean)
6
DAR homogeneity
-
Plasma t½
-
Cleavage trigger
Tetrapeptide cleavable linker (enzyme-cleavable; specific protease not disclosed)
Release control
Conditional
Hydrophilicity mask
Unknown
Formula
-
Linker MW
-
Linker TPSA
-
Linker xLogP
-
ADCdb linker
-
In-vitro stability
-
05
Payload

Payload & physicochemistry

Payload profile
Payload
Exatecan
Class
Topoisomerase I inhibitor
Mechanism
DNA topoisomerase 1 (TOP1) inhibitor
Released catabolite
Exatecan (TOP1 inhibitor payload)
Mechanistic subtype
TopoI
Stereochem / salt
-
Bystander
Yes
PAMPA rank
-
MW
435.46 Da
XLogP3
2.5
logD₇.₄
-
TPSA
107.44 Ų
pKa
9.5 pKa
Charge pH 7.4
+1
H-bond donors
2
H-bond acceptors
7
IC50 (HCEC)
-
Formula
C24H22FN3O4
PubChem CID
151115
ADCdb payload
PAY0LEIGJ
06
Dosing & regimen

Dosing

RP2D dose
2.4 mg/kg
Schedule
Q2W (14-day cycles; first cycle 21 days for safety observation)
Route
IV
Fractionated
No
n at RP2D
158
Dose basis
TBW
Trial phase
Phase 1
Dose-OAE available
Yes
Tox summary basis
RP2D
07
Ocular & expression

Ocular profile & eye-tissue target expression

Target profile
OAE any-grade
0 %
OAE grade 3+
0 %
OAE data status
documented-absent
Severity (weighted)
0
Keratopathy
-
Conjunctival
-
Dry eye
-
Blurred vision
-
Dominant tissue
-
Surface subtype
None
Grading scale
CTCAE (unversioned)
Reversibility
-
Target expression in eye tissues (HCA detection · HPA bulk)
Cornea (central)
65.43 %
Cornea (limbal)
73.31 %
Conjunctiva
86.39 %
RPE
0 %
Retina (HPA)
0 nTPM
Cross-trial comparability
Ascertainment: Symptom-driven reportingScale: CTCAE (unversioned)Denominator: RP2D⚠ OAE rate not directly comparable across trials
08
Identity & registry

Identifiers, registry & notes

ADC id
bat-8008
Approval status
Investigational
Approval year
-
UniProt
P09758
ADCdb ADC
DRG0AJCCS
ADCdb antibody
-
ADCdb target
TAR0MIBZW
Primary source
Zhao et al., BAT8008 TROP-2 ADC Phase 1, ASCO 2025 Abstract 3024; JCO 2025;43(16_suppl):3024; NCT05620017
Aliases & development codes
BAT8008; BAT-8008
Notes
BAT-8008 (BAT8008; Bio-Thera Solutions) is a fully-humanized anti-TROP-2 monoclonal antibody conjugated via a cleavable maleimide tetrapeptide-based linker to the topoisomerase-I inhibitor exatecan, DAR 6 (ADCdb DRG0AJCCS). First-in-human Phase 1 dose-escalation + expansion (NCT05620017; ASCO 2025 Abstract 3024, Zhao et al.; n=194; doses 0.8-2.7 mg/kg IV Q2W, first cycle 21d). 2 of 6 patients at 2.7 mg/kg had DLTs (G3 lipase increase; G4 thrombocytopenia + G4 febrile neutropenia); MTD = 2.4 mg/kg; expansion ongoing at 2.1 and 2.4 mg/kg. RP2D cohort = 2.4 mg/kg (n=158). OCULAR: triage-confirmed explicit-zero - poster safety section states 'No obvious ILD, ocular toxicity, or infusion reactions observed,' and the TRAEs>=20% table has no ocular term; oae_any_pct set to 0 (assessed-absent). Valuable negative/control case because TROP-2 is the Dato-DXd target, which carries notable ocular toxicity, yet this TROP2-exatecan ADC shows no ocular signal. Toxicity profile is hematologic (anemia, WBC/neutrophil/platelet/lymphocyte decreased) and GI/mucosal (stomatitis, nausea, vomiting) dominant. No FDA label; isotype, DAR homogeneity, Fc engineering, exact protease specificity, and linker physchem (no LIN id in ADCdb) not disclosed - left blank. Payload exatecan physchem: MW 435.46, XLogP3 ~2.5, TPSA 107.44 (ADCdb PAY0LEIGJ / PubChem CID 151115); logD7.4 not separately published (left blank); pKa/charge from aliphatic primary amine (cationic at pH 7.4); strong bystander effect reported preclinically (AACR 2023 P4-01-32). A combination study with BAT1308 (anti-PD-1) is underway.