Follow Xiaobai Learning Medicine As of now, 17 ADC drugs have been approved worldwide, of which 5 ADCs are coupled with lysine.

Table 1 Summary of ADC Drugs Coupled with Lysine Approved

Product Name	Company	Target	DAR	Toxin	Linker	Antibody Type	Payload Type
Mylotarg	Pfizer	CD33	2~3	Calicheamicin	Hydrazone Link (Acid-labile)	IG4	DNA Damaging Agent
Kadcyla	Roche	Her2	3.5	DM1	SMCC (Non-cleavable)	IG1	Microtubule Inhibitor
Bseponsa	Pfizer	CD22	5~7	Calicheamicin	Hydrazone Link (Acid-labile)	IG4	DNA Damaging Agent
Akalux	Rakuten	EGFR	NA	IRDye700DX	Linear Alkyl/Aryloxy Linker (Non-cleavable)	IG1	Photoimmunotherapy
ELAHERE	ImmunoGen	FRa	3.4	DM4	Sulfo-SPDB (Reducible)	IG1	Microtubule Inhibitor

1. Introduction to Kadcyla

Kadcyla: An ADC drug using the non-cleavable linker SMCC

Linker: SMCC (N-succinimidyl-4-(maleimidomethyl) cyclohexane-1-carboxylate) is a classic non-cleavable linker

Payload: DM1 (effectively inhibits the polymerization of microtubules, thereby blocking the mitotic process of cells, ultimately leading to apoptosis)

Figure 1 Kadcyla Structural Diagram

Table 2 Summary of Kadcyla Drug Information

Product Name	Kadcyla
Generic Name	ado-trastuzumab emtansine
Manufacturer	Roche, Switzerland
Indication	HER2-positive breast cancer (for treatment of HER2-positive metastatic breast cancer patients who have previously received trastuzumab and taxane chemotherapy)
Target	HER2
Dosage Form	Lyophilized Powder
Specifications	100mg, 160mg/vial – 20mg/mL
Buffer Type	Buffer Salt: 10mM Succinic Acid Excipient: 60mg/mL Sucrose Surfactant: 0.2mg/mL Polysorbate 20, pH 5.0

2. Introduction to Mylotarg

Mylotarg：ADC drug using acid-labile linker hydrazone

Linker: Hydrazone (C=N-N) bond is acid-sensitive (butyric acid ester bond connects to the antibody part)

Payload: Calicheamicin (disulfide bond (S-S) linkage), when the drug is internalized by target cells, the hydrazone bond breaks in the low pH environment while the disulfide bond is reduced by cytoplasmic glutathione reductase, releasing calicheamicin (which breaks DNA double strands, thereby inducing apoptosis in tumor cells).

Figure 2 MylotargStructural Diagram

Table 3 Summary of Mylotarg Drug Information

Product Name	Mylotarg
Generic Name	gemtuzumab ozogamicin
Manufacturer	Pfizer, USA
Indication	CD33-positive acute myeloid leukemia
Target	CD33
Dosage Form	Lyophilized Powder
Specifications	4.5mg/vial – 1mg/mL
Buffer Type	Buffer Salt: 5mM Phosphate Excipient: 14mg/mL Sucrose, 8mg/mL Glucose 40 Surfactant: None, pH 7.4

3. BesponsaIntroduction

Besponsa: ADC drug using acid-labile linker hydrazone bond

Linker: Hydrazone (C=N-N) bond is acid-sensitive (butyric acid ester bond connects to the antibody part)

Payload: Calicheamicin (disulfide bond (S-S) linkage), when the drug is internalized by target cells, the hydrazone bond breaks in the low pH environment while the disulfide bond is reduced by cytoplasmic glutathione reductase, releasing calicheamicin (which breaks DNA double strands, thereby inducing apoptosis in tumor cells).

Figure 3 BesponsaStructural Diagram

Table 4 Summary of Besponsa Drug Information

Product Name	Besponsa
Generic Name	Inotuzumab ozogamicin
Manufacturer	Pfizer, USA (Wyeth Pharma, a subsidiary of Pfizer)
Indication	Besponsa is indicated for adults with relapsed or refractory B-cell acute lymphoblastic leukemia
Target	CD22
Dosage Form	Lyophilized Powder
Specifications	1mg/vial – 0.25mg/mL
Buffer Type	Buffer Salt: 18mM Ammonium Tris Excipient: 45mg/mL Sucrose, 5mg/mL Sodium Chloride Surfactant: 0.1mg/mL Polysorbate 80, pH 8.0

4.

Akalux Introduction

Akalux: A photoimmunotherapy ADC that needs to be used in conjunction with the BioBlade laser system during treatment.

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Linker-Payload: Photosensitive substance IRDye700DX (IR700), a water-soluble silicon phthalocyanine derivative, sensitive to red visible light.

Figure 4 AkaluxStructural Diagram

Table 5 Summary of Akalux Drug Information

Product Name	Akalux
Generic Name	Cetuximab sarotalocan
Manufacturer	Rakuten Medical, Japan
Indication	Colorectal cancer, head and neck cancer
Target	EGFR
Dosage Form	Lyophilized Powder
Specifications	250 mg/vial – 5mg/mL
Buffer Type	Buffer Salt: 10mM Phosphate Excipient: 90mg/mL Trehalose Surfactant: 0.2mg/mL Polysorbate 80, pH 7.1

5. Introduction to Elahere

Elahere: An antibody-drug conjugate targeting folate receptor (FRα) developed by ImmunoGen, consisting of the humanized anti-FRα monoclonal antibody M9346A of IgG1 subtype.

Linker: Sulfo-SPDB.Disulfide bond (S-S) linkageDM4, disulfide bond is reduced by cytoplasmic glutathione reductase, releasing calicheamicin

Payload: DM4, disulfide bond is reduced by cytoplasmic glutathione reductase, releasing active DM4, inhibiting microtubule polymerization and microtubule assembly, inducing effective anti-mitotic effects, leading to cell cycle arrest and apoptosis. Active metabolites may also diffuse to adjacent cells and induce further cell death.

Figure 5 ElahereStructural Diagram

Table 6 Summary of Elahere Drug Information

Product Name	Elahere 爱拉赫
Generic Name	mirvetuximab / soravtansine-gynx
Indication	Epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer
Target	Folate Receptor α (FRα)
Dosage Form	Injection
Specifications	100mg/vial – 5mg/mL
Buffer Type	Buffer Salt: Acetic Acid 0.22mg/mL, 0.53mg/mL Sodium Acetate Excipient: 90mg/mL Sucrose Surfactant: 0.1mg/mL Polysorbate 20, pH 5.0

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