In vitro and in vivo evaluation of cysteine and site specific conjugated herceptin antibody-drug conjugates.
Antibody drug conjugates (ADCs) are monoclonal antibodies designed to deliver a cytotoxic drug selectively to antigen expressing cells. Several components of an ADC including the selection of the antibody, the linker, the cytotoxic drug payload and the site of attachment used to attach the drug to the antibody are critical to the activity and development of the ADC. The cytotoxic drugs or payloads used to make ADCs are typically conjugated to the antibody through cysteine or lysine residues. This results in ADCs that have a heterogeneous number of drugs per antibody. The number of drugs per antibody commonly referred to as the drug to antibody ratio (DAR), can vary between 0 and 8 drugs for a IgG1 antibody. Antibodies with 0 drugs are ineffective and compete with the ADC for binding to the antigen expressing cells. Antibodies with 8 drugs per antibody have reduced in vivo stability, which may contribute to non target related toxicities. In these studies we incorporated a non-natural amino acid, para acetyl phenylalanine, at two unique sites within an antibody against Her2/neu. We covalently attached a cytotoxic drug to these sites to form an ADC which contains two drugs per antibody. We report the results from the first direct preclinical comparison of a site specific non-natural amino acid anti-Her2 ADC and a cysteine conjugated anti-Her2 ADC. We report that the site specific non-natural amino acid anti-Her2 ADCs have superior in vitro serum stability and preclinical toxicology profile in rats as compared to the cysteine conjugated anti-Her2 ADCs. We also demonstrate that the site specific non-natural amino acid anti-Her2 ADCs maintain their in vitro potency and in vivo efficacy against Her2 expressing human tumor cell lines. Our data suggests that site specific non-natural amino acid ADCs may have a superior therapeutic window than cysteine conjugated ADCs.
Agensys, Inc, Santa Monica, California, United States of America.
Dowdy
D
Jackson
Agensys, Inc, Santa Monica, California, United States of America.
John
J
Atkinson
Agensys, Inc, Santa Monica, California, United States of America.
Claudia I
CI
Guevara
Agensys, Inc, Santa Monica, California, United States of America.
Chunying
C
Zhang
Agensys, Inc, Santa Monica, California, United States of America.
Vladimir
V
Kery
Agensys, Inc, Santa Monica, California, United States of America.
Sung-Ju
SJ
Moon
Agensys, Inc, Santa Monica, California, United States of America.
Cyrus
C
Virata
Agensys, Inc, Santa Monica, California, United States of America.
Peng
P
Yang
Agensys, Inc, Santa Monica, California, United States of America.
Christine
C
Lowe
Ambrx Incorporated, La Jolla, California, United States of America.
Jason
J
Pinkstaff
Ambrx Incorporated, La Jolla, California, United States of America.
Ho
H
Cho
Ambrx Incorporated, La Jolla, California, United States of America.
Nick
N
Knudsen
Ambrx Incorporated, La Jolla, California, United States of America.
Anthony
A
Manibusan
Ambrx Incorporated, La Jolla, California, United States of America.
Feng
F
Tian
Ambrx Incorporated, La Jolla, California, United States of America.
Ying
Y
Sun
Ambrx Incorporated, La Jolla, California, United States of America.
Yingchun
Y
Lu
Ambrx Incorporated, La Jolla, California, United States of America.
Aaron
A
Sellers
Agensys, Inc, Santa Monica, California, United States of America.
Xiao-Chi
XC
Jia
Agensys, Inc, Santa Monica, California, United States of America.
Ingrid
I
Joseph
Agensys, Inc, Santa Monica, California, United States of America.
Banmeet
B
Anand
Agensys, Inc, Santa Monica, California, United States of America.
Kendall
K
Morrison
Agensys, Inc, Santa Monica, California, United States of America.
Daniel S
DS
Pereira
Agensys, Inc, Santa Monica, California, United States of America.
David
D
Stover
D000818:Animals; D061067:Antibodies, Monoclonal, Humanized / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000737:chemistry*; D001665:Binding Sites; D045744:Cell Line, Tumor; D003545:Cysteine / Q000737:chemistry*; D004355:Drug Stability; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D018796:Immunoconjugates / Q000097:blood / Q000737:chemistry* / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D051379:Mice; D051381:Rats; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012709:Serum Albumin / Q000378:metabolism; D013379:Substrate Specificity; D000068878:Trastuzumab; D023041:Xenograft Model Antitumor Assays
D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D003545:Cysteine; D018796:Immunoconjugates; D018719:Erb-b2 Receptor Tyrosine Kinases; D012709:Serum Albumin; D000068878:Trastuzumab; C508053:ERBB2 protein, human