DP303c Clinical ADC

Antibody Information

Entry ID	567
INN	None
Status	Clinical
Drug code(s)	DP303c
Brand name	None
mAb sequence source	mAb humanized
General Molecular Category	ADC
Format, general category	Full length Ab conjugate
Format details	None
Isotype (Fc)	IgG1
Light chain isotype	kappa
Linker	Cleavable linker
Ave. DAR	2 (Site-specific)
Conjugated/fused moiety	Tubulin inhibitor, Monomethyl auristatin E (MMAE)
Discovery method/technology	None

Therapeutic information

Target(s)	HER2
Indications of clinical studies	HER2-positive Breast Cancer, gastric cancer with HER2 expression, advanced solid tumors
Primary therapeutic area	Cancer

Development stage information

Phase lengths*

*The graph represents early-stage clinical development phase lengths. For molecules approved or under evaluation for marketing authorization in the US is provided a complete overview of all clinical development phase lengths. Phase lengths are calculated from the start of the first in human (FIH) study (Start of clinical phase). “Start of Phase 2” bar represents Phase 1 length (Start of clinical phase to start of Phase 2); “Start of Phase 3” bar represents Phase 1+2 length (Start of clinical phase to start of Phase 3); “Date BLA/NDA submitted” bar represents Phase 1+2+3 length (Start of clinical phase to Date BLA/NDA submitted); and “Date of first US approval” bar represents Phase 1 to first US approval length (Start of clinical phase to Date of first US approval).

Most advanced stage of development (global)	Phase 3
Status	Active
Start of clinical phase (IND filing or first Phase 1)	November 15, 2019
Start of Phase 2	June 15, 2021
Start of Phase 3	November 08, 2023
Date BLA/NDA submitted to FDA
Year of first approval (global)	None
Date of first US approval
INN, US product name	None
US or EU approved indications	None

Company information

Company	CSPC Pharmaceutical Group Limited
Licensee/Partner	None
Comments about company or candidate	NCT06313086 Phase 3 due to start in Mar 2024. Aug 2023: Launch in breast cancer anticipated in 2025 (https://www.cspc.com.hk/en/ir/presentations/20231H.pdf) NCT05901935/CTR20231487 Phase 3 in breast cancer started in Nov 2023. Listed as Phase 2/3 pivotal on CSPC Pharmaceutical group Limited 2023 1Q Results presentation (May 2023) https://www.cspc.com.hk/en/ir/presentations/20231Q.pdf CTR20230784 not yet recruiting NCT05334810 Phase 2 in breast cancer due to start May 1 2022. NCT04828616 Phase 2 in ovarian cancer due to start in July 2021. CTR20210829 Phase 2 in gastric cancer, first subject enrolled in June 2021; NCT04826107 Phase 2 in gastric cancer due to start in August 2021. Phase 2 NCT04146610 Phase 1 in solid tumors not yet recruiting when posted on Oct 31, 2019. US orphan drug designation for treating stomach cancer, including gastroesophageal junction tumor.
Full address of company	No.226 Huanghe Street, Shijiazhuang, Hebei Province, PRC 050035 Asia China https://www.cspc.com.hk/en/contacts/contactus.php

Description/comment

DP303c consists of an antibody that selectively binds to HER2 and a cytotoxic agent, representing a new type of targeted drug for the treatment of HER2 positive gastric cancer. DP303c has shown potent anti-tumor effects in a mouse NCI-N87 model for HER2 positive human gastric cancer and in an in-vitro assay with HER2 positive SK-BR-3 cell line.
We developed DP303c, a novel HER2-targeting ADC made up of a humanized anti-HER2 antibody (DP001), an enzyme-based cleavable peptide-linker, and two tubulin polymerization inhibitors (MMAE), using our original conjugation and linker-payload technique. The materials used for DP303c production included anti-HER2 mAb (DP001), linker-MMAE (LND1002) and mTgase. DP001 was manufactured using a stable Chinese Hamster Ovary (CHO) cell line by ourselves. The amino acid sequence of DP001 was the same with that of Herceptin. Onco Targets Ther. 2022; 15: 331–343. doi: 10.2147/OTT.S357326

Additional information

Anticipated events	None
Factor(s) contributing to discontinuation	None