Rational design, biophysical and biological characterization of site-specific antibody-tubulysin conjugates with improved stability, efficacy and pharmacokinetics.
Antibody-drug conjugates (ADCs) are among the most promising empowered biologics for cancer treatment. ADCs are commonly prepared by chemical conjugation of small molecule cytotoxic anti-cancer drugs to antibodies through either lysine side chains or cysteine thiols generated by the reduction of interchain disulfide bonds. Both methods yield heterogeneous conjugates with complex biophysical properties and suboptimal serum stability, efficacy, and pharmacokinetics. To limit the complexity of cysteine-based ADCs, we have engineered and characterized in vitro and in vivo antibody cysteine variants that allow precise control of both site of conjugation and drug load per antibody molecule. We demonstrate that the chemically-defined cysteine-engineered antibody-tubulysin conjugates have improved ex vivo and in vivo stability, efficacy, and pharmacokinetics when compared to conventional cysteine-based ADCs with similar drug-to-antibody ratios. In addition, to limit the non-target FcγRs mediated uptake of the ADCs by cells of the innate immune system, which may result in off-target toxicities, the ADCs have been engineered to lack Fc-receptor binding. The strategies described herein are broadly applicable to any full-length IgG or Fc-based ADC and have been incorporated into an ADC that is in phase I clinical development.
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA.
Pamela
P
Thompson
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA.
Ryan
R
Fleming
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA.
Binyam
B
Bezabeh
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA.
Fengying
F
Huang
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Shenlan
S
Mao
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Cui
C
Chen
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Jay
J
Harper
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Haihong
H
Zhong
Clinical Pharmacology and DMPK, MedImmune, Gaithersburg, MD, USA.
Xizhe
X
Gao
Clinical Pharmacology and DMPK, MedImmune, Gaithersburg, MD, USA.
Xiang-Qing
XQ
Yu
Biologics Safety Assessment, MedImmune, Gaithersburg, MD, USA.
Mary Jane
MJ
Hinrichs
Biologics Safety Assessment, MedImmune, Gaithersburg, MD, USA.
Molly
M
Reed
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Adeela
A
Kamal
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Patrick
P
Strout
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Song
S
Cho
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA.
Rob
R
Woods
Oncology Research, MedImmune, Gaithersburg, MD, USA.
Robert E
RE
Hollingsworth
Biologics Safety Assessment, MedImmune, Gaithersburg, MD, USA.
Rakesh
R
Dixit
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA.
Herren
H
Wu
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA. Electronic address: gaoc@medimmune.com.
Changshou
C
Gao
Antibody Discovery and Protein Engineering, MedImmune, Gaithersburg, MD, USA. Electronic address: dimasin@medimmune.com.
Nazzareno
N
Dimasi
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000493:pharmacokinetics; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D045744:Cell Line, Tumor; D002470:Cell Survival; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine / Q000737:chemistry; D015195:Drug Design; D005260:Female; D006801:Humans; D018796:Immunoconjugates / Q000008:administration & dosage / Q000737:chemistry* / Q000493:pharmacokinetics; D008819:Mice, Nude; D058990:Molecular Targeted Therapy; D055550:Protein Stability; D011961:Receptors, Fc / Q000737:chemistry
D000911:Antibodies, Monoclonal; D000970:Antineoplastic Agents; D018796:Immunoconjugates; D011961:Receptors, Fc; D003545:Cysteine
Antibody-drug conjugates; Cysteine-engineered antibodies; Fc-gamma receptors; In vivo efficacy; Site-specific conjugation; Tubulysin