A Phase I First-in-Human Study of ABBV-011, a Seizure-Related Homolog Protein 6–Targeting Antibody–Drug Conjugate, in Patients with Small Cell Lung Cancer
AbstractPurpose:. Seizure-related homolog protein 6 (SEZ6) is a novel target expressed in small cell lung cancer (SCLC). ABBV-011, a SEZ6-targeted antibody conjugated to calicheamicin, was evaluated in a phase I study (NCT03639194) in patients with relapsed/refractory SCLC. We report initial outcomes of ABBV-011 monotherapy.Patients and Methods:. ABBV-011 was administered intravenously once every 3 weeks during dose escalation (0.3–2 mg/kg) and expansion. Patients with SEZ6-positive tumors (≥25% of tumor cells with ≥1+ staining intensity by IHC) were preselected for expansion. Safety, tolerability, antitumor activity, and pharmacokinetics were evaluated.Results:. As of August 2022, 99 patients received ABBV-011 monotherapy [dose escalation, n = 36; Japanese dose evaluation, n = 3; dose expansion, n = 60 (1 mg/kg, n = 40)]; the median age was 63 years (range, 41–79 years). Also, 32%, 41%, and 26% of patients received 1, 2, and ≥3 prior therapies, respectively. The maximum tolerated dose
