A mouse-canine chimeric ADC using peptide linker technology (CCAP) killed podoplanin-expressing cancer cells in vitro and showed superior anti-tumor activity in vivo.
CCAP peptide linkerenabled a functional ADC with superior anti-tumor activity compared to antibody alone, validating this conjugation technology
What the researchers found
The antibody-drug conjugate P38B-DM1 was constructed using a mouse-canine chimeric antibody (P38B) that targets dog podoplanin, a peptide linker, and the cytotoxic payload emtansine (DM1). Construction used the chemical conjugation by affinity peptide (CCAP) method.
In cell culture, P38B-DM1 killed podoplanin-overexpressing cells in a dose-dependent manner. In a mouse xenograft model, P38B-DM1 showed significantly higher anti-tumor activity than the antibody alone (P38B).
The peptide linker and CCAP conjugation method allowed controlled attachment of the drug to the antibody, which is critical for consistent drug-to-antibody ratios.
Why it matters
Antibody-drug conjugates are one of the fastest-growing areas in cancer therapy. Using peptide linkers offers advantages in controlling how and when the drug is released from the antibody.
While this specific ADC targets canine cancers (melanoma and squamous cell carcinoma), the CCAP conjugation method and peptide linker technology could be applied to human cancer targets.
The numbers in context
Dose-dependent cytotoxicity in vitro; higher anti-tumor activity than antibody alone in vivo; CCAP peptide linker conjugation
How the study worked
This was a preclinical study. Researchers created the ADC using the CCAP method to conjugate emtansine to the P38B antibody via a peptide linker. Cytotoxicity was tested in vitro against CHO cells overexpressing dog podoplanin. Anti-tumor activity was tested in a mouse xenograft model.
Who was studied
CHO cells overexpressing dog podoplanin; mouse xenograft model
What this study cannot tell us
The xenograft model used artificially overexpressing cells rather than naturally occurring tumors. Results in natural canine cancers may differ.
The study focused on a veterinary target (dog podoplanin) and would need separate development for human applications. Safety data was not reported.
How to read the evidence
Preliminary evidence from a xenograft model using artificially overexpressing cells. Natural tumor activity not tested.
When this study was published
Published in 2020. ADC technology continues to advance with multiple new approvals annually.
The bigger picture
ADCs are one of the fastest-growing cancer drug classes. Peptide linker technology offers advantages in controlling where and how the drug is released from the antibody, potentially improving both efficacy and safety. This veterinary-focused study validates the CCAP conjugation approach.
Questions still open
- Can the CCAP method be applied to human-targeting ADCs?
- How does CCAP linker stability compare to conventional linker chemistries?
- Would this ADC work against natural canine tumors in veterinary oncology?
Common questions
What is CCAP technology?
Why develop this for dog cancer?
Read the original research
Antibody-Drug Conjugates Using Mouse-Canine Chimeric Anti-Dog Podoplanin Antibody Exerts Antitumor Activity in a Mouse Xenograft Model.
Monoclonal antibodies in immunodiagnosis and immunotherapy, 39(2), 37-44
Citation
Kato, Yukinari; Ito, Yuji; Ohishi, Tomokazu; Kawada, Manabu; Nakamura, Takuro; Sayama, Yusuke; Sano, Masato; Asano, Teizo; Yanaka, Miyuki; Okamoto, Saki; Handa, Saori; Komatsu, Yu; Takei, Junko; Kaneko, Mika K. (2020). Antibody-Drug Conjugates Using Mouse-Canine Chimeric Anti-Dog Podoplanin Antibody Exerts Antitumor Activity in a Mouse Xenograft Model.. Monoclonal antibodies in immunodiagnosis and immunotherapy, 39(2), 37-44. https://doi.org/10.1089/mab.2020.0001