Phase 1 first-in-human study of ABBV-184 monotherapy in adult patients with previously treated acute myeloid leukemia or non-small cell lung cancer.

Abstract

TPS2674 Background: Survivin, a member of the inhibitor of apoptosis protein family, is an attractive therapeutic target in cancer, due to its broad expression in solid tumors and hematologic malignancies but limited expression in normal tissues. Elevated survivin expression is associated with an increased invasive phenotype and worse clinical outcomes. ABBV-184 is a first-in-class T-cell receptor (TCR)/anti-cluster of differentiation 3 (CD3) bispecific molecule. It is composed of a soluble TCR that binds to a survivin-derived peptide bound to the class I MHC allele HLA-A2:01 expressed on tumor cells and to the CD3 receptor on T cells. Preclinical data have demonstrated that treatment with ABBV-184 results in T-cell activation, proliferation, and redirected cytotoxicity of HLA-A2:01–positive target cell lines. This first-in-human trial evaluates ABBV-184 monotherapy in patients with previously treated acute myeloid leukemia (AML) or non-small cell lung cancer (NSCLC). Methods: Patients (≥18 years, Eastern Cooperative Oncology Group performance status ≤2, HLA-A2:01 restricted genotype) with relapsed or refractory AML or NSCLC are currently enrolling in this phase 1 multicenter, open-label trial (NCT04272203), which includes parallel dose-escalation and dose-expansion phases for both diseases. Primary objectives are to determine the recommended phase 2 dose (RP2D) of ABBV-184 (dose escalation) and to assess its preliminary efficacy (dose expansion). Secondary objectives include safety, tolerability, pharmacokinetics (PK), and immunogenicity assessments (dose escalation and dose expansion) and duration of response (dose expansion). Patients will receive intravenous infusion of ABBV-184 once weekly. Dose escalation of ABBV-184 is guided by a Bayesian optimal interval design and the RP2D will be determined on the basis of clinical safety, PK, and pharmacodynamic data. For patients with AML, disease assessment is performed according to modified European LeukemiaNet-International Working Group criteria. For patients with NSCLC, response will be assessed using Response Evaluation Criteria In Solid Tumors (RECIST) v1.1 and immune RECIST. Treatment can continue until disease progression or intolerable toxicity. Biomarker assessments will include longitudinal profiling of peripheral blood immune cells and cytokines, analysis of HLA-A2 and survivin levels on AML bone marrow blasts and NSCLC tumor biopsies, and retrospective correlations of biomarker data with antitumor activity. Enrollment initiated in Sep 2020, with 7 patients enrolled as of Jan 2021. Clinical trial information: NCT04272203.