Swiss antibody–drug conjugate (ADC) drugs firm ADC Therapeutics (ADCT) has exercised its option to negotiate an exclusive license to Chiome Bioscience’s anti-delta-like 1 homolog (DLK-1) antibody candidate LIV-1205 for use in the development of an ADC comprising the antibody coupled with a proprietary ADCT payload.

Japan-based Chiome is leveraging its recombinant DNA-based ADLib® monoclonal antibody platform to develop antibody candidates for drug discovery partners. The firm said ADCT had been evaluating both LIV-1205 and an anti-trophoblast cell-surface antigen-2 (TROP-2) antibody LIV-2008b for potential use in ADCs, and has elected to license LIV-1205, but not the anti-TROP-2 antibody. Chiome retains rights to the humanized anti-DLK-1 monoclonal antibody (mAb) for non-ADC indications. The firm is also now looking to develop and outlicense the anti-TROP-2 antibody.

ADCT is developing ADC candidates against both solid and hematologic cancers, combining mAbs coupled to a novel class of potent pyrrolobenzodiazepine (PBD) dimer toxins. The firm’s early clinical-stage pipeline is headed by ADCT-301, which comprises HuMax®-TAC, licensed from Genmab, conjugated to a PBD dimer toxin, for the treatment of CD25-expressing lymphomas and leukemia. Earlier this month, ADCT reported what it termed “impressive” interim data from an ongoing Phase I study evaluating ADCT-301 in the treatment of relapsed or refractory Hodgkin's and non-Hodgkin's lymphoma. The data was presented at the 14th International Conference on Malignant Lymphoma (ICML) in Lugano, Switzerland.

ADCT’s ADC-402 is in development for the treatment of CD19-expressing non-Hodgkin's lymphoma and B-cell leukemia and combines a CD19-targeting humanized antibody conjugated to a PBD dimer toxin. ADCT-502 is in early clinical development for treating HER2-expressing solid tumors and comprises a humanized HER2-targeting antibody conjugated to the PBD dimer toxin tesirine. MEDI3726 (previously ADCT-401) is partnered with AstraZeneca’s MedImmune and is in early clinical development against prostate cancer.