Oral azacitidine plus venetoclax in patients with relapsed/refractory or newly diagnosed acute myeloid leukemia: The phase 1b OMNIVERSE trial.

TPS7068 Background: For patients (pts) with acute myeloid leukemia (AML) who cannot undergo intensive chemotherapy (IC), lower-intensity treatment (Tx) regimens, including low-dose cytarabine (LDAC) and hypomethylating agents (HMAs; azacitidine [AZA], decitabine), are generally well tolerated but are associated with lower response rates than IC [Vey 2020]. Similarly, the BCL2 inhibitor, venetoclax (VEN), has shown antileukemic activity, although only modest clinical benefit as monotherapy [Konopleva 2016]. VEN + AZA shows synergistic activity in preclinical models, enhancing leukemic cell apoptosis in vitro and anti-tumor activity in vivo [Jin 2020]. In IC-ineligible pts with ND AML, VEN + injectable AZA significantly increased complete remission (CR)/CR with incomplete hematologic recovery (CRi) rates ( P < 0.001) and prolonged overall survival (OS; P < 0.001) vs AZA only [DiNardo 2020]. VEN, in combination with an HMA or LDAC, is approved in the US for Tx of pts with ND AML ≥ 75 years (y) of age or who cannot undergo IC due to comorbidities. Oral-AZA (CC-486) is approved for Tx of pts with newly diagnosed (ND) AML in first CR or CRi after IC who cannot receive curative therapy (eg, HSCT). In the phase 3 QUAZAR AML-001 trial, maintenance Tx with Oral-AZA 300 mg QD for 14 days (d)/28-d Tx cycle improved OS and relapse-free survival vs placebo in older pts in CR/CRi after IC [Wei 2020]. Incorporation of AZA into DNA is S-phase-restricted; thus, extending AZA exposure over a longer duration by using an oral formulation increases the opportunity for cycling tumor cells to incorporate the drug to sustain therapeutic activity [Laille 2015]. Additionally, an all-oral combination regimen allows for outpatient administration to optimize pt convenience and reduce resource utilization. Methods: OMNIVERSE (NCT04887857) is an open-label, multicenter, 2-part phase 1b trial. The main goals are to evaluate safety and establish the maximum tolerated dose of Oral-AZA + VEN in pts ≥ 18 y of age with relapsed/refractory AML who are ineligible for further IC ( part 1), and subsequently, in pts with ND AML ≥ 75 y of age, or pts 18–74 y of age with comorbidities that prevent use of IC or HSCT ( part 2). Key eligibility criteria include ECOG performance status of 0–2 (ECOG 3 is allowed for pts 18–74 y of age with comorbidities) and unfavorable-risk cytogenetics for pts with ND AML. The Oral-AZA starting dose is 300 mg QD × 14 d/28-d cycle, which can be de-escalated to 200 mg QD × 14 d depending on dose-limiting toxicities; oral VEN 400 mg QD is taken continuously (or 21 d/cycle for dose level −2). A modified toxicity probability interval-2 design is used to evaluate dose levels. Sample size depends on the dose levels utilized (≤ 18 pts/part). Enrollment began in 2021. The trial is ongoing at clinical sites in the United States and Australia. Clinical trial information: NCT04887857.