Payload · Topoisomerase I inhibitor

KL610023 (also T030; belotecan-derived)

Topoisomerase I inhibitor (belotecan-derived camptothecin); arrests cell cycle at G2/S

CC[C@@]1(C2=C(COC1=O)C(=O)N3CC4=C(C5=CC=CC=C5N=C4C3=C2)CCN(C(C)C)S(=O)(=O)C)O

Physicochemistry

Properties

511.6 Da

XLogP3

1.3

logD₇.₄

TPSA

125 Å²

pKa

Charge pH 7.4

H-bond donors

H-bond acceptors

Bystander

Yes

PubChem CID

139294971

Bioactivity

ADCdb cell-line IC50 (ADC): Calu-3 1.28 nM, NCI-N87 2.24 nM, NCI-H23 3.41 nM, HCC1806 5.7 nM, BxPC-3 11.03 nM; in vivo tumor growth inhibition ~39-100% across PDX/xenografts depending on dose and TROP2 expression. Free payload KL610023 cytotoxic potency ~1.5x greater than SN-38 (

1 agent

ADCs built on this payload

Agent · target

Ocular

Hepatic

Neutrop.

Thrombo.

Anemia

ILD

Neuro.

Sacituzumab tirumotecanTACSTD2

2.3

0%severity100%

Assessed · clear

true 0%

No data

never assessed