Journal Article

ASCT2-Targeting Antibody-Drug Conjugate MEDI7247 in Adult Patients with Relapsed/Refractory Hematological Malignancies: A First-in-Human, Phase 1 Study

Ribrag, Vincent, Rebelatto, Marlon C, Cull, Elizabeth, Batlevi, Connie, Schiller, Gary, Maris, Michael, Salles, Gilles, Kim, Tae Min, Abboud, Camille N, Kim, Won Seog, Kirby, Lyndon C, Bothos, John, Lyons, Roger M, Townsley, Danielle M, Lee, Young, Kagiampakis, Ioannis, Fathi, Amir T, Karmali, Reem, Wang, Fujun, Arellano, Martha

2024

Overview

BackgroundMEDI7247 is a first-in-class antibody-drug conjugate (ADC) consisting of an anti-sodium-dependent alanine-serine-cysteine transporter 2 antibody-conjugated to a pyrrolobenzodiazepine dimer.ObjectiveThis first-in-human phase 1 trial evaluated MEDI7247 in patients with hematological malignancies.Patients and methodsAdults with acute myeloid leukemia (AML), multiple myeloma (MM), or diffuse large B-cell lymphoma (DLBCL) relapsed or refractory (R/R) to standard therapies, or for whom no standard therapy exists, were eligible. Primary endpoints were safety and determination of the maximum tolerated dose (MTD). Secondary endpoints included assessments of antitumor activity, pharmacokinetics (PK), and immunogenicity.ResultsAs of 26 March 2020, 67 patients were treated (AML: n = 27; MM: n = 18; DLBCL: n = 22). The most common MEDI7247-related adverse events (AEs) were thrombocytopenia (41.8%), neutropenia (35.8%), and anemia (28.4%). The most common treatment-related grade 3/4 AEs were thrombocytopenia (38.8%), neutropenia (34.3%), and anemia (22.4%). Anticancer activity (number of responders/total patients evaluated) was observed in 11/67 (16.4%) patients. No correlation was observed between ASCT2 expression and clinical response. Between-patient variability of systemic exposure of MEDI7247 ADC and total antibody were high (AUCinf geometric CV%: 62.3–134.2, and 74.8–126.1, respectively). SG3199 (PBD dimer) plasma concentrations were below the limit of quantification for all patients after Study Day 8. Anti-drug antibody (ADA) prevalence was 7.7%, ADA incidence was 1.9%, and persistent-positive ADA was 5.8%.ConclusionsThrombocytopenia and neutropenia limited repeat dosing. Although limited clinical activity was detected, the dose-escalation phase was stopped early without establishing an MTD.The study was registered with ClinicalTrials.gov (NCT03106428).

• Publisher: Springer Nature B.V
• Subject: Anemia / Antibodies / Drug dosages / Hematology / Neutropenia / Thrombocytopenia