Background: Overexpressionof B-cell lymphoma 2 (BCL-2)-related pro-survival proteins allows cancer cells to evade apoptosis, and targeting these proteins has become important in anticancer therapy. BCL-2 inhibition by venetoclax (VEN) is beneficial in many patients (pts) with acute myeloid leukemia (AML), but resistance is common due to upregulation of other pro-survival proteins such as BCL-extra-large (BCL-xL) and myeloid cell leukemia-1. Dual inhibition of BCL-2/xL has potential for broader activity than agents such as VEN. However, BCL-xL is critical for platelet survival and inhibition can cause dose-limiting thrombocytopenia (Konopleva and Letai. Blood 2018). To broaden therapeutic activity, we developed AZD0466, a drug-dendrimer conjugate in which the BCL-2/xL dual inhibitor AZD4320 is covalently conjugated to a pegylated poly-L-lysine dendrimer and gradually released by hydrolysis. Preclinically, AZD4320 showed greater inhibition of tumor growth than VEN and navitoclax in VEN-resistant xenograft models (Balachander et al. Clin Cancer Res 2020). A first-in-human study (NCT04214093) in pts with advanced solid tumors indicated that AZD0466 is well tolerated with no reported dose-limiting toxicities (DLTs). We present preliminary data from NIMBLE, a Phase I/II trial of AZD0466 in pts with advanced hematologic malignancies (NCT04865419).

Methods: Module 1, Part A of NIMBLE is a dose-escalation study of AZD0466 monotherapy investigating its preliminary safety and tolerability, pharmacokinetics (PK), and preliminary efficacy. Dose escalation and de-escalation of AZD0466 follow a modified toxicity probability interval (mTPI-2) design. Eligible pts are ≥18 years old with relapsed/refractory (R/R) AML, acute lymphoblastic leukemia (ALL), or high-risk myelodysplastic syndrome. AZD0466 is administered IV with a dose ramp-up on Days (D) 1, 4, and 8, reaching the target dose on D8 of Cycle 1, with weekly administrations thereafter. Cycle duration is 35 days for Cycle 1 and 28 days for subsequent cycles. Pts remain on study until disease progression, unacceptable toxicity, or withdrawal of consent.

Resul ts: As of May 31, 2023, 31 pts (n=25 AML, n=6 ALL; median age 69 years) had received ≥1 dose of AZD0466 at target doses of 300 mg (n=4), 600 mg (n=4), 1200 mg (n=7), 2400 mg (n=5), 3600 mg (n=9), and 5400 mg (n=2). Median treatment duration was 4.1 weeks (range 0.1−29.6). Twenty-two pts (71%) had prior VEN and 11 (35%) had prior hematopoietic stem cell transplantation. Treatment-emergent adverse events (TEAEs) of any grade reported in >10% of pts are displayed in Table 1. One Grade 5 intracranial hemorrhage unrelated to AZD0466 was reported. Four pts experienced a serious adverse event (SAE) possibly related to AZD0466 (alanine aminotransferase [ALT] increase, pneumonia, troponin T increase, and uncoded SAE). Grade ≥3 TEAEs possibly related to AZD0466, reported in 12 pts (39%), included febrile neutropenia (n=3), platelet count decrease (n=2), diarrhea, thrombocytopenia, ALT increase, blood creatinine phosphokinase increase, pneumonia, gamma-glutamyltransferase increase, lipase increased, and troponin T increase (n=1, each). DLTs of asymptomatic troponin increase were observed in two pts (3600 mg [n=1], 5400 mg [n=1]). Evaluation of maximum concentration and area under the concentration-time curve revealed dose-proportional exposure to AZD4320. Released AZD4320 represented 1-5% of total AZD4320 and had a longer half-life than total AZD4320. Preclinical modeling and PK data predicted that 5400 mg may be required to drive efficacy. As a surrogate of BCL-xL on-target activity, transient aggravation of thrombocytopenia post-dosing was observed across all dose cohorts followed by platelet recovery prior to the next dose. Platelet reduction was in line with preclinical models showing a substantial reduction at lower doses with a ceiling effect at higher doses. As of July 6, 2023, no complete responses have been observed. However, preliminary bone marrow (BM) blast reductions of >50% were observed in four pts (1200 mg [n=1], 2400 mg [n=2], 3600 mg [n=1]), indicating antileukemia activity of AZD0466.

Conclusions: Given the observed DLTs of asymptomatic increase in troponin levels, and the lack of significant clinical benefit, the study was terminated.

Fleming:Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Curti:Pfizer: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees. Dinner:Novartis: Research Funding; BMS: Research Funding; Pfizer: Research Funding; Rigel: Research Funding; Kite/Gilead: Research Funding. Blachly:Abbvie: Honoraria; Astellas: Honoraria; AstraZeneca: Honoraria; Kite: Honoraria. Della Porta:Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees. Bajel:Novartis: Honoraria; Astellas: Honoraria; Amgen: Honoraria, Speakers Bureau; Pfizer: Honoraria; Abbvie: Honoraria. Sauer:Stemline: Consultancy; Novartis: Consultancy; Ridgeline Discovery: Consultancy; BMS: Consultancy; Amgen: Consultancy; Astellas: Consultancy; Takeda: Consultancy; AbbVie: Consultancy, Other: Travel, Accommodation, Expenses; Jazz: Honoraria, Other: Travel, Accommodation, Expenses; Gilead: Honoraria; Pfizer: Honoraria. Crysandt:Pfizer: Other: Travel grant. Pigneux:Servier: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings, Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Support for attending meetings; Gilead: Honoraria; Roche: Research Funding; Astellas: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Jazz Pharmaceuticals: Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria; Pfizer: Membership on an entity's Board of Directors or advisory committees. Fransecky:Pfizer: Consultancy; Jazz: Consultancy; Gilead: Consultancy, Research Funding, Speakers Bureau; Servier: Consultancy; Amgen: Consultancy. Baldus:BMS: Consultancy; AstraZeneca: Consultancy; Amgen: Consultancy; Astellas: Consultancy; Jazz Pharmaceuticals: Consultancy; Gilead: Consultancy; Jannsen: Consultancy. Konopleva:AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Clinical Trials Support, Research Funding. Marmor:AstraZeneca: Current Employment, Current holder of stock options in a privately-held company. Sharma:AstraZeneca: Current Employment. Elgeioushi:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Cheung:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Rowe:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Jahn:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Yu:AstraZeneca: Current Employment, Current equity holder in publicly-traded company; JNJ: Current equity holder in publicly-traded company; AbbVie: Current equity holder in publicly-traded company; Abbott: Current equity holder in publicly-traded company. Saeh:AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Tibes:AstraZeneca: Current Employment. Cader:AstraZeneca: Current Employment. Jain:Aprea Therapeutics: Research Funding; Dialectic Therapeutics: Research Funding; Beigene: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; BMS: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Adaptive Biotechnologies: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Fate Therapeutics: Research Funding; Incyte: Research Funding; TransThera Sciences: Research Funding; Medisix: Research Funding; AstraZeneca: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Pfizer: Research Funding; CareDX: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Takeda: Research Funding; ADC Therapeutics: Research Funding; Servier: Research Funding; MEI Pharma: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Novalgen: Research Funding; Mingsight: Research Funding; Loxo Oncology: Research Funding; TG Therapeutics: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Ipsen: Consultancy, Honoraria, Other: TRAVEL, ACCOMMODATIONS, EXPENSES; Janssen: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses; Precision Biosciences: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Newave: Research Funding; AbbVie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Cellectis: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Kite/Gilead: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding; Genentech: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Research Funding.

AZD0466 is a drug-dendrimer conjugate containing a BCL-2/xL dual inhibitor that is in development for use in hematological and other malignancies, and not approved for use anywhere worldwide

Figure 1
Figure 1
View largeDownload slide
This content is only available as a PDF.
2023
Sign in via your Institution