First-in-Human Randomized Trial to Assess Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of the KDM1A Inhibitor Vafidemstat.

BACKGROUND: Vafidemstat, an inhibitor of the histone lysine-specific demethylase KDM1A, corrects cognition deficits and behavior alterations in rodent models. Here, we report the results from the first-in-human trial of vafidemstat in healthy young and older adult volunteers. A total of 110 volunteers participated: 87 were treated with vafidemstat and 23 with placebo. OBJECTIVES: The study aimed to determine the safety and tolerability of vafidemstat, to characterize its pharmacokinetic and pharmacodynamic profiles, to assess its central nervous system (CNS) exposure, and to acquire the necessary data to select the appropriate doses for long-term treatment of patients with CNS disease in phase II trials. METHODS: This single-center, randomized, double-blind, placebo-controlled phase I trial included a single and 5-day repeated dose-escalation and open-label CNS penetration substudy. Primary outcomes were safety and tolerability; secondary outcomes included analysis of the pharmacokinetics and pharmacodynamics, including chemoprobe-based immune analysis of KDM1A target engagement (TE) in peripheral blood mononuclear cells (PBMCs) and platelet monoamine oxidase B (MAOB) inhibition. CNS and cognitive function were also evaluated. RESULTS: No severe adverse events (AEs) were reported in the dose-escalation stage. AEs were reported at all dose levels; none were dose dependent, and no significant differences were observed between active treatment and placebo. Biochemistry, urinalysis, vital signs, electrocardiogram, and hematology did not change significantly with dose escalation, with the exception of a transient reduction of platelet counts in an extra dose level incorporated for that purpose. Vafidemstat exhibits rapid oral absorption, approximate dose-proportional exposures, and moderate systemic accumulation after 5 days of treatment. The cerebrospinal fluid-to-plasma unbound ratio demonstrated CNS penetration. Vafidemstat bound KDM1A in PBMCs in a dose-dependent manner. No MAOB inhibition was detected. Vafidemstat did not affect the CNS or cognitive function. CONCLUSIONS: Vafidemstat displayed good safety and tolerability. This phase I trial confirmed KDM1A TE and CNS penetration and permitted characterization of platelet dynamics and selection of phase IIa doses. TRIAL REGISTRATION: EUDRACT No. 2015-003721-33, filed 30 October 2015.

First-in-Human Phase I Study of Iadademstat (ORY-1001): A First-in-Class Lysine-Specific Histone Demethylase 1A Inhibitor, in Relapsed or Refractory Acute Myeloid Leukemia.

PURPOSE: Iadademstat is a novel, highly potent, and selective inhibitor of LSD1 (KDM1A), with preclinical in vitro and in vivo antileukemic activity. This study aimed to determine safety and tolerability of iadademstat as monotherapy in patients with relapsed/refractory acute myeloid leukemia (R/R AML). METHODS: This phase I, nonrandomized, open-label, dose-escalation (DE), and extension-cohort (EC) trial included patients with R/R AML and evaluated the safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary antileukemic activity of this orally bioavailable first-in-class lysine-specific demethylase 1 inhibitor. RESULTS: Twenty-seven patients were treated with iadademstat on days 1 to 5 (5-220 µg/m2/d) of each week in 28-day cycles in a DE phase that resulted in a recommended dose of 140 µg/m2/d of iadademstat as a single agent. This dose was chosen to treat all patients (n = 14) in an EC enriched with patients with MLL/KMT2A-rearranged AML. Most adverse events (AEs) were as expected in R/R AML and included myelosuppression and nonhematologic AEs, such as infections, asthenia, mucositis, and diarrhea. PK data demonstrated a dose-dependent increase in plasma exposure, and PD data confirmed a potent time- and exposure-dependent induction of differentiation biomarkers. Reductions in blood and bone marrow blast percentages were observed, together with induction of blast cell differentiation, in particular, in patients with MLL translocations. One complete remission with incomplete count recovery was observed in the DE arm. CONCLUSION: Iadademstat exhibits a good safety profile together with signs of clinical and biologic activity as a single agent in patients with R/R AML. A phase II trial of iadademstat in combination with azacitidine is ongoing (EudraCT No.: 2018-000482-36).