title: Site-Specific Conjugation of Monomethyl Auristatin E to Anti-CD30 Antibodies Improves Their Pharmacokinetics and Therapeutic Index in Rodent Models.
abstract: Antibody-drug conjugates (ADCs) have demonstrated clinical benefits that have led to the recent FDA approval of KADCYLA and ADCETRIS. Most ADCs that are currently in clinical use or development, including ADCETRIS, are produced by chemical conjugation of a toxin via either lysine or cysteine residues, inevitably leading to heterogeneous products with variable drug-to-antibody ratios (DARs). Here, we describe the in vitro and in vivo characterization of four novel ADCs that are based on the anti-CD30 antibody cAC10, which has the same polypeptide backbone as ADCETRIS, and compare the results with the latter. Bacterial transglutaminase (BTG) was exploited to site-specifically conjugate derivatives of monomethyl auristatin E (all comprising a cleavable linker) to the glutamine at positions 295 and 297 of cAC10, thereby yielding homogeneous ADCs with a DAR of 4. In vitro cell toxicity experiments using two different CD30-positive cell lines (Karpas 299 and Raji-CD30(+)) revealed comparable EC50 values for ADCETRIS (1.8 ± 0.4 and 3.6 ± 0.6 ng/mL, respectively) and the four cAC10-based ADCs (2.0 ± 0.4 to 4.9 ± 1.0 ng/mL). Quantitative time-dependent in vivo biodistribution studies (3-96 h p.i.) in normal and xenografted (Karpas 299 cells) SCID mice were performed with a selected (125)I-radioiodinated cAC10 ADC and compared with that of (125)I-ADCETRIS. The chemo-enzymatically conjugated, radioiodinated ADC showed higher tumor uptake (17.84 ± 2.2% ID/g 24 h p.i.) than (125)I-ADCETRIS (10.5 ± 1.8% ID/g 24 h p.i.). Moreover, (125)I-ADCETRIS exhibited higher nontargeted liver and spleen uptake. In line with these results, the maximum tolerated dose of the BTG-coupled ADC (>60 mg/kg) was significantly higher than that of ADCETRIS (18 mg/kg) in rats. These results suggest that homogeneous ADCs display improved pharmacokinetics and better therapeutic indexes compared to those of chemically modified ADCs with variable DARs.
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: F
authors.initials: F
authors.lastname: Lhospice
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: D
authors.initials: D
authors.lastname: Brégeon
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: C
authors.initials: C
authors.lastname: Belmant
authors.affiliation: ‡Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Dennler
authors.affiliation: §Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Chiotellis
authors.affiliation: ‡Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Fischer
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: L
authors.initials: L
authors.lastname: Gauthier
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: A
authors.initials: A
authors.lastname: Boëdec
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: H
authors.initials: H
authors.lastname: Rispaud
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: S
authors.initials: S
authors.lastname: Savard-Chambard
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: A
authors.initials: A
authors.lastname: Represa
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: N
authors.initials: N
authors.lastname: Schneider
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: C
authors.initials: C
authors.lastname: Paturel
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: M
authors.initials: M
authors.lastname: Sapet
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: C
authors.initials: C
authors.lastname: Delcambre
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: S
authors.initials: S
authors.lastname: Ingoure
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: N
authors.initials: N
authors.lastname: Viaud
authors.affiliation: †Innate Pharma SA, F13276 Marseille, France.
authors.forename: C
authors.initials: C
authors.lastname: Bonnafous
authors.affiliation: ‡Center for Radiopharmaceutical Sciences, ETH-PSI-USZ, Paul Scherrer Institute, 5232 Villigen, Switzerland.|§Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Schibli
authors.affiliation: ∥MI-mAbs (C/0 CIML), Parc Scientifique et Technologique de Luminy, Avenue de Luminy case 906, F13288 Marseille Cedex 9, France.
authors.forename: F
authors.initials: F
authors.lastname: Romagné
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D000079963:Brentuximab Vedotin; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D018796:Immunoconjugates / Q000009:adverse effects / Q000737:chemistry / Q000493:pharmacokinetics*; D008297:Male; D051379:Mice; D016513:Mice, SCID; D009842:Oligopeptides / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000911:Antibodies, Monoclonal; D018796:Immunoconjugates; D009842:Oligopeptides; D000079963:Brentuximab Vedotin; C495575:monomethyl auristatin E
keywords: ADCETRIS; CD30; antibody−drug conjugate; monomethyl auristatin E; site-specific modification; transglutaminase